Victorian Electricity Transmission Network - Australian … Services - AMS... · Victorian Electricity Transmission Network . Asset Management Strategy (PUBLIC VERSION) Document number

Victorian Electricity Transmission Network Asset Management Strategy (PUBLIC VERSION)

Document number AMS 10-01

Issue number 13

Status Draft

Approver J. Dyer

Date of approval 21/10/2015

AusNet Services AMS 10-01

Asset Management Strategy – Victorian Electricity Transmission Network

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UNCONTROLLED WHEN PRINTED

ISSUE/AMENDMENT STATUS Issue

Number Date Description Author Approved by

5 12/12/06 Editorial review following feedback from Regulatory & Business Strategy group.

G. Lukies

D. Postlethwaite

G. Towns

6 23/02/07 Editorial following external review.

Published to support TRR submission.

D. Postlethwaite

G. Lukies

G. Towns

7 13/03/07 Editorial update and format. D. Postlethwaite

G. Lukies

G. Towns

8 23/08/10 New AM Policy and formal approval by GGM NSD

D. Postlethwaite A. Parker

9 23/02/11 Integrate STEM into AMS Objectives P. Bryant D. Postlethwaite

10 08/02/13 Major review and update C. Rabbitte

J. Dyer

D. Meade

D. Postlethwaite

11 19/8/13 Annual review and update J. Dyer D. Postlethwaite

12 11/8/14 Align network strategies, review and update D. Meade Asset Management Committee

13 21/10/15 Review and update P. Seneviratne J. Dyer

Disclaimer

This document belongs to AusNet Services and may or may not contain all available information on the subject matter this document purports to address.

The information contained in this document is subject to review and AusNet Services may amend this document at any time. Amendments will be indicated in the Amendment Table, but AusNet Services does not undertake to keep this document up to date.

To the maximum extent permitted by law, AusNet Services makes no representation or warranty (express or implied) as to the accuracy, reliability, or completeness of the information contained in this document, or its suitability for any intended purpose. AusNet Services (which, for the purposes of this disclaimer, includes all of its related bodies corporate, its officers, employees, contractors, agents and consultants, and those of its related bodies corporate) shall have no liability for any loss or damage (be it direct or indirect, including liability by reason of negligence or negligent misstatement) for any statements, opinions, information or matter (expressed or implied) arising out of, contained in, or derived from, or for any omissions from, the information in this document.



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Contact

This document is the responsibility of Asset Management Division, AusNet Services. Please contact the indicated owner of the document with any inquiries.

John Dyer

AusNet Services

Level 31, 2 Southbank Boulevard

Melbourne Victoria 3006

Ph: (03) 9695 6000



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Foreword

AusNet Services owns and operates the Victorian electricity transmission network, directly serving the energy needs of Australia’s second largest economy. AusNet Services also supports the National Electricity Market (NEM) via the national transmission grid.

This network transfers bulk power from NEM generators to the electricity distributors who service in excess of 2.5 million Victorian households and businesses. It interconnects high voltage customers such as the Portland Aluminium Smelter and the transmission networks of neighbouring New South Wales, South Australia and Tasmania. In total, this network transferred over 42,635 GW1 hours of energy in 2014/15 and serviced a peak demand of 8,626 MW1.

The Australian Energy Market Operator (AEMO) and Victoria’s electricity distributors jointly plan the augmentation of Victoria’s electricity transmission network. Forecast growth rates have reduced in recent years however some growth is expected and this will require continuing network augmentation to meet the 0.5% p.a. growth in Victorian electricity consumption and the 1.0% p.a. growth in maximum demand over the next decade.

AusNet Services exists to:

“Provide our customers with superior network and energy solutions”.

The provision of a superior network requires the management of network assets over their lifecycle. This will be achieved by sound risk management and the continuous improvement practices of our integrated safety, health, environment, quality and asset management systems.

This Asset Management Strategy (AMS) is a key tool in achieving the AusNet Services’ vision. This AMS facilitates delivery of agreed performance levels and optimised asset life cycles.

With a time horizon of ten years, this AMS and its supporting documentation provide the technical direction for responsible stewardship of Victoria’s electricity transmission assets on behalf of the NEM, energy generators, stakeholders, regulators, government and energy users.

1 National Electricity Forecasting Report (NEFR) 2015



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Table of Contents

1 Executive Summary ..................................................................................................................... 8

2 Document Overview ..................................................................................................................... 9

2.1 Purpose ....................................................................................................................................................... 9

2.2 Scope ........................................................................................................................................................... 9

2.3 Relationship to other Management Documents ...................................................................................... 10

3 Introduction ................................................................................................................................ 11

3.1 AusNet Services’ Overview ...................................................................................................................... 11

3.2 Strategic Business Context ...................................................................................................................... 12

4 Victorian Transmission Network Overview ............................................................................. 15

4.1 Network Summary .................................................................................................................................... 15

4.2 Victorian Planning Framework ................................................................................................................. 20

4.3 Regulatory Framework ............................................................................................................................. 21

5 Asset Management System ...................................................................................................... 23

5.1 Asset Management Methodology ............................................................................................................ 23

5.2 Asset Management Policy ........................................................................................................................ 24

5.3 Asset Management Objectives ................................................................................................................ 25

5.4 Planning to Achieve Objectives ................................................................................................................ 25

5.5 Asset Management Process .................................................................................................................... 25

5.6 Asset Management System Certification ................................................................................................. 26

6 Asset Management Drivers ....................................................................................................... 27

6.1 Network Safety .......................................................................................................................................... 27

6.2 Sustainability ............................................................................................................................................. 28

6.3 Network Risk ............................................................................................................................................. 29

6.4 Performance .............................................................................................................................................. 31

6.5 Augmentation ............................................................................................................................................ 32

6.6 Customer Connections ............................................................................................................................. 35



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6.7 Advances in Technology .......................................................................................................................... 36

6.8 Program delivery ....................................................................................................................................... 38

7 Network Vision ........................................................................................................................... 39

8 Network Objectives and Performance ..................................................................................... 40

8.1 Overview .................................................................................................................................................... 40

8.2 Network Objectives ................................................................................................................................... 40

8.3 Network Performance Summary .............................................................................................................. 40

8.4 Performance Benchmarks ........................................................................................................................ 43

9 Process and System Strategies ............................................................................................... 45

9.1 Risk Management ..................................................................................................................................... 45

9.2 Electrical Safety Management System .................................................................................................... 46

9.3 Health and Safety Management .............................................................................................................. 46

9.4 Environmental Management .................................................................................................................... 48

9.5 Condition Monitoring ................................................................................................................................. 49

9.6 Plant and Equipment Maintenance .......................................................................................................... 50

9.7 Asset Management Information Systems ................................................................................................ 51

9.8 Network Performance Monitoring ............................................................................................................ 52

9.9 Operations Management .......................................................................................................................... 53

9.10 Program delivery and optimisation ........................................................................................................... 53

9.11 Asset Replacement and Refurbishment .................................................................................................. 55

9.12 Process and Configuration Management ................................................................................................ 55

10 Plant Strategies .......................................................................................................................... 57

10.1 Auxiliary Systems ...................................................................................................................................... 57

10.2 Capacitor Banks ........................................................................................................................................ 60

10.3 Circuit Breakers ......................................................................................................................................... 60

10.4 Civil Infrastructure ..................................................................................................................................... 61

10.5 Communication Systems .......................................................................................................................... 62

10.6 Disconnectors and Earth Switches .......................................................................................................... 64

10.7 Earth Grids ................................................................................................................................................ 65



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10.8 Gas Insulated Switchgear ......................................................................................................................... 66

10.9 Infrastructure Security ............................................................................................................................... 66

10.10 Power Cables ............................................................................................................................................ 68

10.11 Secondary Systems .................................................................................................................................. 68

10.12 Static VAR Compensators ........................................................................................................................ 69

10.13 Surge Arresters ......................................................................................................................................... 70

10.14 Synchronous Condensers ........................................................................................................................ 71

10.15 Transformers ............................................................................................................................................. 71

10.16 Instrument Transformers .......................................................................................................................... 72

10.17 Transmission Lines ................................................................................................................................... 74



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1 Executive Summary

The Asset Management Strategy (AMS) is central to AusNet Services’ processes for managing Victoria’s electricity transmission assets, determining the delivery of quality services to customers and value to shareholders. It summarises the medium-term strategic actions for achieving regulatory and business performance targets, which are implemented via the programs of work listed in the five-year Asset Management Plan produced each year.

The AMS is underpinned by the regulatory and commercial imperatives of delivering efficient cost and service performance. It recognises that cost and service efficiency does not mean lowest possible cost, nor does it mean guaranteed reliability. Instead, efficiency requires the costs and benefits of all expenditure decisions to be weighed against one another. A key element in this cost benefit analysis is the consideration of risk in relation to asset performance and network reliability.

AusNet Services’ ongoing commitment to maintain compliance with the ISO 55001 standard ensures an auditable asset management system facilitating customer’s expectations to safely maintain the quality, reliability and security of supply in an economic manner.



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2 Document Overview

2.1 Purpose

The electricity transmission Asset Management Strategy (AMS) and its supporting documentation provide robust technical direction for the responsible stewardship of electricity transmission assets. AusNet Services is steward of these assets on behalf of Victoria’s energy users, generators, shareholders, regulators, government and the National Electricity Market (NEM) more broadly.

The AMS has the following key functions:

• It sets the framework for AusNet Services’ holistic approach to management of the network assets, and in so doing establishes the linkages with and between the underpinning detailed strategies, processes and plans;

• It provides important context for management strategies, by taking into account the demand for network services, the condition of network assets, and expected trends into the future. It therefore also has regard to the network augmentation planning process;

• As the output of a strategic assessment process, the AMS sets out the significant asset management focus areas, and associated management strategies, for each asset class.

• The AMS is central to AusNet Services’ processes for delivery of network services to customers safely and reliably in accordance with AusNet Services’ Asset Management Policy.

As the output of a strategic assessment process, the AMS sets out the significant asset management focus areas, and associated strategies, to manage each asset class.

The AMS provides authoritative guidance for the development of asset management works programs. Further, the AMS seeks to provide contextual information for the asset strategies that will enhance the skills, resources and knowledge employed at AusNet Services, and thereby facilitate efficient network development and asset management.

The information presented in the AMS also extends to longer term expectations for technological advancement of network assets, the functionality of the network and evolution of management approaches.

2.2 Scope

This AMS covers AusNet Services’ electricity transmission assets operating across Victoria, including:

• Transmission lines2, power cables and associated easements and access tracks; • Terminal stations, switching stations, communication stations and depots including associated electrical

plant3, buildings and civil infrastructure; • Protection, control, metering and communications equipment; • Related functions and facilities such as spares, maintenance and test equipment; and • Asset management processes and systems such as Supervisory Control And Data Acquisition

(SCADA) and asset management information systems (including SAP).

More specifically, the AMS relates to electricity transmission sites and facilities:

• Listed in the Network Agreement between AusNetServices (then PowerNet Victoria) and the Australian Energy Market Operator (AEMO) (then the Victorian Power Exchange) 1994;

• Listed in 1994 Connection Agreements between AusNet Services and connected parties, largely consisting of generators, direct connect customers and distributors; and

• Listed in various supplementary network and connection agreements, detailing AusNet Services’ unregulated transmission assets.

2 500 kV, 330 kV, 275 kV and 220 kV transmission lines and cables. 3 500 kV, 330 kV, 275 kV, 220 kV, 66 kV and 22 kV switchgear and transformers.



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This AMS excludes the assets and infrastructure owned by:

• Generators; • Exit customers; and • Other companies providing transmission services within Victoria.

This AMS also excludes AusNet Services’ corporate processes and associated information technology systems such as business communication, human resources and financial management systems. It does not include information on corporate offices or general business equipment such as computers and motor vehicles.

2.3 Relationship to other Management Documents

The electricity transmission AMS is one of a number of asset management related documents developed and published by AusNet Services in relation to its transmission network. The AMS presents an all-encompassing strategy for the transmission network, with this overarching strategy being supported by more detailed plant-specific strategies as depicted in Figure 1.

Figure 1 – AMS document interdependencies



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3 Introduction

AusNet Services’ electricity transmission network serves more than 2.5 million Victorian households and businesses with more than 6,500 circuit kilometres of transmission lines that transport electricity from ten power stations to five electricity distributors and one large industrial customer via 49 terminal stations. The network is centrally located among Australia’s five eastern states that form the NEM, providing key connections between South Australia, New South Wales and Tasmania’s electricity transmission networks. In total, the Victorian transmission network delivered over 42,635 GWh4 of energy in 2014/15 and serviced a peak demand of 8,626 MW.

AusNet Services is committed to providing safe and reliable network services by investing in the upgrade and maintenance of the network and achieving the objectives set for the provision of network services through pricing determinations and other regulatory instruments. The AMS documents AusNet Services’ holistic approach to management of the network assets, and establishes the linkages with and between the underpinning detailed strategies, processes and plans.

The approach seeks to deliver optimal electricity transmission network performance at efficient cost by ensuring that all decisions to replace or maintain network assets are economically justified. Decisions must appropriately consider all relevant criteria including:

a. safety, b. customer expectations, c. demand for network services, d. performance and condition of network assets, e. objective of maintaining quality, reliability and security of supply, f. desirability of improving quality, reliability and security of supply, g. technological advancements, h. the changing nature of generation and demand resulting from energy efficiency and climate

change drivers, i. the direct challenges of climate change impacts on network assets, j. the impact on the environment.

AusNet Services welcomes feedback from stakeholders on this document.

3.1 AusNet Services’ Overview

AusNet Services is a leading energy infrastructure company operating a diversified portfolio of both gas and electricity assets throughout Victoria, helping to meet the energy needs of more than 1.3 million5 residential and business consumers. AusNet Services’ core assets include:

− Gas Distribution Network Transportation of natural gas to approximately 647,000 customers across central and western Victoria. The network spans approximately 10,000km of buried pipelines.

− Electricity Distribution Network Consists of approximately 50,000km of powerlines and 50,000 pole transformers that carry electricity from the high voltage transmission grid to approximately 679,000 customers across eastern Victoria.

4 National Electricity Forecasting Report (NEFR) 2015. 5 Source: AusNet Services’ Business Review 2015, www.ausnetservices.com.au



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− Electricity Transmission Network Consist of approximately 13,000 transmission towers and 6,500km of transmission lines that carry high voltage electricity from power stations to electricity distributors across Victoria.

− Select Solutions AusNet Services’ commercial arm provides end-to-end commercial services to help customers manage their energy, water and environmental needs.

AusNet Services is a publically listed company listed on both the Australian Securities Exchange (ASX: AST) and the Singapore Exchange (SGX: ST:X04). AusNet Services’ securities are 31.1% owned by Singapore Power Limited (SPI) and 19.9% by State Grid International Development Limited (SGID); with the remaining owned by ASX and SCX investors.

AusNet Services’ purpose is to:

“Provide our customers with superior network and energy solutions”

This purpose acknowledges that the nature of the energy sector will alter fundamentally over the next decade, responding to community concerns about energy prices, shifting consumer behaviour and developments in the energy environment.

AusNet Services’ purpose statement headlines its Asset Management Policy provided in Section 5.2. The key outcome from achieving the purpose over the next five years will be to grow earnings to create and maintain sustainable value to security holders, customers, employees and the community.

3.2 Strategic Business Context

AusNet Services’ Corporate Business Plan (FY2015-FY2019) outlines how the business will respond to future challenges and uncertainties presented by a dynamic environment. The Corporate Strategy and Business Plan directs how divisional, team and individual plans contribute to our strategic objectives. To help with communication and assignment of accountabilities, the Corporate Plan is broken down into 5 key focus areas, each area with its objectives, initiatives and KPIs:

• Safety – our first priority is always safety – we believe in mission Zero; • People – we invest in people because they are our strength; • Customer – customers are the focus of our business and we put them at the forefront of what we do; • Financial – we use valuable funds and resources efficiently to deliver returns and grow our business;

and • Business and Asset – We operate our assets and business activities at the highest standards

achievable in our changing environment.



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AusNet Service’ purpose is underpinned by eight (8) Strategic Objectives that the business seeks to achieve by 2019, described in Figure 2 below:

Figure 2 – AusNet Services’ Purpose & Business Objectives



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3.2.1 AusNet Services’ Safety Vision

“Safety is our way of life. Everyone is responsible for leading safety. Together we seek out and correct all unsafe behaviours and situations and aim for zero injuries.”

Our safety vision is symbolised by the simple expression missionZero. When it comes to the safety of our people, contractors and visitors, zero injuries is the only acceptable target. We will not compromise on safety and we will not tolerate unsafe acts and behaviours. It is this mindset that drives us to ensure there are no negative impacts on our families and communities as a result of our business operations. To achieve our safety vision, our mission must be to work together to implement a common strategy with unified purpose and consistency of attitude. See also section 6.1



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4 Victorian Transmission Network Overview

This section provides a summary of the following areas:

• Network Summary; • Victorian Planning Framework; and • Regulatory Framework.

4.1 Network Summary

AusNet Services’ electricity transmission network serves more than 2.5 million Victorian households and businesses with more than 6,500 circuit kilometres of transmission lines that transport electricity from power stations to electricity distributors and large customers. The general electricity supply arrangement in Victoria is illustrated in Figure 3.

Figure 3 – Illustration of Victorian Electricity Supply Arrangements



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4.1.1 Locality and Geography

The Victorian electricity transmission network is depicted in Figure 4.

Figure 4 – Victorian Electricity Transmission Network

The network is centrally located among Australia’s five eastern states that form the NEM, providing key connections between South Australia, New South Wales and Tasmania’s electricity transmission networks. The NEM interconnections include:

• Two 330 kV lines from Dederang Terminal Station, to the Murray Switching Station (NSW); • One 330 kV line from Wodonga Terminal Station to Jindera (NSW); • One 220 kV line from Red Cliffs Terminal Station to Buronga (NSW); • Two 275 kV lines from Heywood Terminal Station to South East Substation (SA); • One 220 kV circuit from Red Cliffs Terminal Station to the 300 kV DC link to Berri (SA); and • One 500 kV circuit from Loy Yang to the 400 kV DC link to Bell Bay (TAS).



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The transmission network serving the metropolitan Melbourne area is depicted in Figure 5.

Figure 5 – Metropolitan Melbourne Electricity Transmission Network



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4.1.2 Asset Summary

Table 1 summarises the volumes, prevailing service age and expected service life of major assets in the network as reported to the AER:

Table 1 – Regulatory Information Data at March 20156

6 AusNet Services (transmission) 2008-15 - Category Analysis RIN - templates AER REPEX Model translation.

Asset calcs

WARL WAL WAAQuantity Unit RC prop total Rank prop cat RC / unit (Rep life) Rep life % Rep life

Cost $ millions % total % $ ('000)1 Overhead transmission assets 36258.1 8,269 56% 1 228.1 24.6 68.6 64%2 Underground transmission assets 11.2 21 0% 4 1883.8 38.9 60.0 35%3 Switchyard, substation and transformer assets 33745.0 6,397 43% 2 189.6 11.9 40.6 71%4 55 56 57 58 59 Other 4186.0 84 1% 3 20.1 6.2 39.8 84%

10 511 512 5

Total 14,771.5 19 56 67.0%

EDB categories

1 > 275 kV & < = 330 kV ; Single Circuit Overhead transmission ass 1,779.0 500 889,500 6% 3 11% 500 22 19,999,750 70 62,265,000 68%1 > 330 kV & < = 500 kV ; Single Circuit Overhead transmission ass 3,170.0 500 1,585,000 11% 2 19% 500 33 52,601,500 70 110,950,000 53%1 > 33 kV & < = 66 kV ; Multiple Circuit Overhead transmission ass 428.0 500 214,000 1% 16 3% 500 30 6,435,500 70 14,980,000 57%1 > 132 kV & < = 275 kV ; Multiple Circuit Overhead transmission ass 8,114.0 500 4,057,000 27% 1 49% 500 22 89,107,000 70 283,990,000 69%1 > 275 kV & < = 330 kV ; Single Circuit Overhead transmission ass 29.0 500 14,500 0% 58 0% 500 33 484,750 70 1,015,000 52%1 > 33 kV & < = 66 kV ; Multiple Circuit Overhead transmission ass 82.0 500 41,000 0% 42 0% 500 39 1,614,500 70 2,870,000 44%1 > 132 kV & < = 275 kV ; Multiple Circuit Overhead transmission ass 66.0 500 33,000 0% 46 0% 500 37 1,207,000 70 2,310,000 48%1 Other - GROUNDWIRE TOWER & MICROWAVE TOWER Overhead transmission ass 47.0 500 23,500 0% 54 0% 500 58 1,359,750 70 1,645,000 17%1 Other - COMMUNICATIONS, ELECTRIC FIELD SHIELD & LIGHTING POLE Overhead transmission ass 8,474.0 31 262,694 2% 13 3% 31 22 5,847,654 70 18,388,580 68%

1 > 33 kV & < = 66 kV ; < = 100 MVA Overhead transmission ass 176.0 73.5 12,935 0% 61 0% 74 28 356,346 60 776,101 54%1 > 132 kV & < = 275 kV ; > 200 MVA & < = 600 MVA Overhead transmission ass 4,159.6 94.3 392,247 3% 9 5% 94 17 6,524,035 60 23,534,807 72%1 > 275 kV & < = 330 kV ; > 800 MVA & < = 1200 MVA Overhead transmission ass 738.8 10.2 7,536 0% 65 0% 10 12 93,046 60 452,165 79%1 > 330 kV & < = 500 kV ; > 1500 MVA Overhead transmission ass 1,486.7 191.9 285,306 2% 12 3% 192 37 10,636,479 60 17,118,331 38%1 Other - Ground Wire Overhead transmission ass 7,508.0 60 450,481 3% 8 5% 60 16 7,234,858 60 27,028,859 73%2 > 132 kV & < = 275 kV ; Oil Filled Underground transmission 1.9 1884 3,487 0% 69 17% 1,884 45 158,304 60 209,237 24%2 > 132 kV & < = 275 kV ; XLPE Insulated Underground transmission 9.3 1884 17,614 0% 57 83% 1,884 38 661,779 60 1,056,811 37%3 < = 33 kV; Air Insulated circuit Breaker Switchyard, substation and 130.0 187 24,310 0% 53 0% 187 18 442,629 45 1,093,950 60%3 > 33 kV & < = 66 kV ; Air Insulated circuit Breaker Switchyard, substation and 367.0 247 90,649 1% 25 1% 247 31 2,814,442 45 4,079,205 31%3 > 132 kV & < = 275 kV ; Air Insulated circuit Breaker Switchyard, substation and 400.0 541 216,400 1% 15 3% 541 29 6,326,995 45 9,738,000 35%3 > 275 kV & < = 330 kV ; Air Insulated circuit Breaker Switchyard, substation and 186.0 853 158,658 1% 20 2% 853 2 324,140 45 7,139,610 95%3 > 330 kV & < = 500 kV ; Air Insulated circuit Breaker Switchyard, substation and 80.0 1066 85,280 1% 28 1% 1,066 23 1,934,790 45 3,837,600 50%3 < = 33 kV; Air Insulated Isolators / Earth Switch Switchyard, substation and 541.0 45.9 24,832 0% 52 0% 46 12 292,590 45 1,117,436 74%3 > 33 kV & < = 66 kV ; Air Insulated Isolators / Earth Switch Switchyard, substation and 1,157.0 52.4 60,627 0% 35 1% 52 15 926,720 45 2,728,206 66%3 > 132 kV & < = 275 kV ; Air Insulated Isolators / Earth Switch Switchyard, substation and 2,007.0 247 495,729 3% 7 8% 247 27 13,497,192 45 22,307,805 39%3 > 275 kV & < = 330 kV ; Air Insulated Isolators / Earth Switch Switchyard, substation and 121.0 312 37,752 0% 45 1% 312 11 401,076 45 1,698,840 76%3 > 330 kV & < = 500 kV ; Air Insulated Isolators / Earth Switch Switchyard, substation and 394.0 390 153,660 1% 21 2% 390 16 2,532,270 45 6,914,700 63%3 < = 33 kV; VT Switchyard, substation and 237.0 55.9 13,248 0% 60 0% 56 13 176,225 40 529,932 67%3 > 33 kV & < = 66 kV ; VT Switchyard, substation and 384.0 69 26,496 0% 50 0% 69 18 487,485 40 1,059,840 54%3 > 132 kV & < = 275 kV ; VT Switchyard, substation and 631.0 104.6 66,003 0% 31 1% 105 24 1,564,555 40 2,640,104 41%3 > 275 kV & < = 330 kV ; VT Switchyard, substation and 39.0 271.5 10,589 0% 63 0% 272 25 261,319 40 423,540 38%3 > 330 kV & < = 500 kV ; VT Switchyard, substation and 157.0 271.5 42,626 0% 41 1% 272 19 819,794 40 1,705,020 52%3 < = 33 kV; CT Switchyard, substation and 381.0 54.7 20,841 0% 55 0% 55 17 357,820 40 833,628 57%3 > 33 kV & < = 66 kV ; CT Switchyard, substation and 693.0 118.7 82,259 1% 29 1% 119 23 1,874,807 40 3,290,364 43%3 > 132 kV & < = 275 kV ; CT Switchyard, substation and 556.0 160.9 89,460 1% 26 1% 161 24 2,102,641 40 3,578,416 41%3 > 275 kV & < = 330 kV ; CT Switchyard, substation and 76.0 514.7 39,117 0% 44 1% 515 31 1,228,589 40 1,564,688 21%3 > 330 kV & < = 500 kV ; CT Switchyard, substation and 229.0 514.7 117,866 1% 23 2% 515 22 2,618,022 40 4,714,652 44%3 > 33 kV & < = 66 kV ; GIS Module Switchyard, substation and 2.0 2000 4,000 0% 68 0% 2,000 37 146,000 50 200,000 27%3 > 132 kV & < = 275 kV ; GIS Module Switchyard, substation and 9.0 3500 31,500 0% 48 0% 3,500 23 708,750 50 1,575,000 55%3 > 330 kV & < = 500 kV ; GIS Module Switchyard, substation and 7.0 7000 49,000 0% 38 1% 7,000 9 451,500 40 1,960,000 77%3 Other - RACK all voltages and OTHER Switchyard, substation and 1,774.0 500 887,000 6% 4 14% 500 -2 -1,900,500 40 35,480,000 105%3 < = 33 kV ; < = 10 MVA Switchyard, substation and 138.0 472 65,136 0% 33 1% 472 10 647,112 40 2,605,440 75%3 < = 33 kV ; > 30 MVA Switchyard, substation and 1.0 726 726 0% 74 0% 726 30 21,417 40 29,040 26%3 > 33 kV & < = 66 kV ; > 30 MVA Switchyard, substation and 9.0 726 6,534 0% 66 0% 726 11 70,785 40 261,360 73%3 > 132 kV & < = 220 kV ; < = 50 MVA Switchyard, substation and 27.0 21 196,142 1% 17 3% 7,265 -3 -533,941 40 7,845,660 107%3 > 132 kV & < = 220 kV ; > 50 MVA & < = 100 MVA Switchyard, substation and 24.0 7264.5 174,348 1% 19 3% 7,265 16 2,775,039 40 6,973,920 60%3 > 132 kV & < = 220 kV ; > 100 MVA Switchyard, substation and 87.0 7264.5 632,012 4% 5 10% 7,265 14 8,837,264 40 25,280,460 65%3 > 275 kV & < = 330 kV ; < = 100 MVA Switchyard, substation and 8.0 21 109,224 1% 24 2% 13,653 -8 -901,098 40 4,368,960 121%3 > 275 kV & < = 330 kV ; > 100 MVA & < = 250 MVA Switchyard, substation and 10.0 13653 136,530 1% 22 2% 13,653 -4 -559,773 40 5,461,200 110%3 > 275 kV & < = 330 kV ; > 250 MVA Switchyard, substation and 2.0 13653 27,306 0% 49 0% 13,653 -7 -191,142 40 1,092,240 118%3 > 330 kV & < = 500 kV ; < = 150 MVA Switchyard, substation and 1.0 13653 13,653 0% 59 0% 13,653 31 416,417 40 546,120 24%3 > 330 kV & < = 500 kV ; > 150 MVA & < = 300 MVA Switchyard, substation and 22.0 13653 300,366 2% 10 5% 13,653 1 177,489 40 12,014,640 99%3 > 330 kV & < = 500 kV ; > 300 MVA Switchyard, substation and 22.0 13653 300,366 2% 10 5% 13,653 15 4,628,367 40 12,014,640 61%3 > 500 kV ; < = 1000 MVA Switchyard, substation and 6.0 13653 81,918 1% 30 1% 13,653 3 232,101 40 3,276,720 93%3 Other - DIVERTER SWITCHES Switchyard, substation and 160.0 1 160 0% 78 0% 1 12 1,989 40 6,400 69%3 > 132 kV & < = 275 kV ; SVCS Switchyard, substation and 4.0 15000 60,000 0% 36 1% 15,000 10 600,000 40 2,400,000 75%3 < = 33 kV; Capacitors Switchyard, substation and 33.0 1414.5 46,679 0% 39 1% 1,415 12 563,678 40 1,867,140 70%3 > 33 kV & < = 66 kV ; Capacitors Switchyard, substation and 44.0 1414.5 62,238 0% 34 1% 1,415 23 1,403,184 40 2,489,520 44%3 > 132 kV & < = 275 kV ; Capacitors Switchyard, substation and 17.0 2722 46,274 0% 40 1% 2,722 25 1,160,933 40 1,850,960 37%3 > 275 kV & < = 330 kV ; Capacitors Switchyard, substation and 2.0 1697 3,394 0% 70 0% 1,697 24 79,759 40 135,760 41%3 < = 33 kV; Oil Filled Reactors Switchyard, substation and 130.0 201 26,130 0% 51 0% 201 13 332,454 40 1,045,200 68%3 > 33 kV & < = 66 kV ; Oil Filled Reactors Switchyard, substation and 162.0 1186 192,132 1% 18 3% 1,186 22 4,204,370 40 7,685,280 45%3 > 132 kV & < = 275 kV ; Oil Filled Reactors Switchyard, substation and 120.0 4850.7 582,084 4% 6 9% 4,851 16 9,255,136 40 23,283,360 60%3 > 275 kV & < = 330 kV ; Oil Filled Reactors Switchyard, substation and 4.0 13653 54,612 0% 37 1% 13,653 -6 -327,672 40 2,184,480 115%3 > 330 kV & < = 500 kV ; Oil Filled Reactors Switchyard, substation and 10.0 25953 259,529 2% 14 4% 25,953 8 1,998,373 40 10,381,160 81%3 Other < = 33 kV; SYNC CONDENSER Switchyard, substation and 5.0 1000 5,000 0% 67 0% 1,000 -13 -63,500 34 170,000 137%3 Communications Network Assets Switchyard, substation and 10,345.0 8.6 88,967 1% 27 1% 9 7 664,088 24 2,135,208 69%3 Control equipment / systems Switchyard, substation and 986.0 66.5 65,569 0% 32 1% 67 3 190,124 20 1,311,380 86%3 Infrastructure: protection and control Switchyard, substation and 10,808.0 3 32,424 0% 47 1% 3 7 217,449 20 648,480 66%9 OTHER: BUSHING < = 33 kV ; Other 131.0 1 131 0% 82 0% 1 7 941 20 2,620 64%9 OTHER: BUSHING > 132 kV & < = 275 kV ; Other 405.0 1 405 0% 75 0% 1 -1 -469 20 8,100 106%9 OTHER: BUSHING > 275 kV & < = 330 kV ; Other 28.0 1 28 0% 87 0% 1 23 630 60 1,680 63%9 OTHER: BUSHING > 33 kV & < = 66 kV ; Other 249.0 1 249 0% 77 0% 1 -2 -540 20 4,980 111%9 OTHER: BUSHING > 330 kV & < = 500 kV ; Other 43.0 1 43 0% 86 0% 1 -3 -113 20 860 113%9 OTHER: TAP CHANGING MECHANISMS Other 159.0 70 11,130 0% 62 13% 70 14 156,765 40 445,200 65%9 GENERATORS AND MOTORS Other 143.0 273.99 39,181 0% 43 46% 274 11 428,931 40 1,567,223 73%9 INFRASTRUCTURE : COMPRESSOR Other 29.0 100 2,900 0% 71 3% 100 -8 -23,450 40 116,000 120%9 INFRASTRUCTURE : Earth Grid Other 48.0 393 18,864 0% 56 22% 393 -3 -52,269 40 754,560 107%9 METERING Other 304.0 28.77 8,746 0% 64 10% 29 -5 -45,140 40 349,843 113%9 OTHER: NEUTRAL EARTH COMPENSATORS/RESISTORS Other 14.0 1 14 0% 89 0% 1 19 268 40 560 52%9 OTHER : SURGE DIVERTERS < = 33 kV ; Other 144.0 1 144 0% 79 0% 1 27 3,840 40 5,760 33%9 OTHER : SURGE DIVERTERS > 132 kV & < = 275 kV ; Other 727.0 1 727 0% 73 1% 1 28 20,692 40 29,080 29%9 OTHER : SURGE DIVERTERS > 275 kV & < = 330 kV ; Other 48.0 1 48 0% 85 0% 1 25 1,181 40 1,920 38%9 OTHER : SURGE DIVERTERS > 33 & < = 66 kV ; Other 825.0 1 825 0% 72 1% 1 22 17,785 40 33,000 46%9 OTHER : SURGE DIVERTERS > 33 kV & < = 66 kV ; Other 343.0 1 343 0% 76 0% 1 23 7,865 40 13,720 43%9 OTHER : SURGE DIVERTERS > 330 kV & < = 500 kV ; Other 139.0 1 139 0% 81 0% 1 29 3,968 40 5,560 29%9 OTHER: < = 33 kV ; BUS Other 143.0 1 143 0% 80 0% 1 7 1,047 40 5,720 82%9 OTHER: > 132 kV & < = 275 kV ; BUS Other 115.0 1 115 0% 84 0% 1 8 968 40 4,600 79%9 OTHER: > 275 kV & < = 330 kV ; BUS Other 6.0 1 6 0% 90 0% 1 -3 -15 40 240 106%9 OTHER: > 33 kV & < = 66 kV ; BUS Other 116.0 1 116 0% 83 0% 1 0 18 40 4,640 100%9 OTHER: > 330 kV & < = 500 kV ; BUS Other 27.0 1 27 0% 88 0% 1 18 497 40 1,080 54%



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4.1.3 Stakeholders

The following table summarises key stakeholders and their expectations of the service provided by AusNet Services’ energy delivery networks.

Stakeholder Expectation Summary

Connected Parties (energy consumers, electricity generators and gas producers, other network service providers)

• Responsive service • Efficient service costs • Network access • Capacity, reliability, quality, safety, environmental, compliance and

security performance within Code or Agreement

Community • Public safety • Environmental performance within Code

Employees and contractors • Safe work place • Reward and recognition • Skill development

Shareholders • Return on investment • Growth in investment value • Commensurate opportunities, liabilities and risks

Energy Retailers • Reliable information • Efficient service costs

Safety Regulator • Compliance with Acts, Regulations & Codes • Improving safety performance • Transparent processes • Reliable information

Economic Regulator • Compliance with Law, Rules & Codes • Efficient service costs • Transparent processes • Reliable information

State and Federal Government

• Compliance with Acts and Regulation • Support economic development • Improving safety performance • Efficient service costs

Local Government and VicRoads

• Coordinated infrastructure development • Coordination of works • Public land reinstatement

Table 2 – Energy Network Stakeholders and Expectations



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4.2 Victorian Planning Framework

Responsibility for planning of transmission network services in Victoria is shared by three different parties including the following:

• Australian Energy Market Operator (AEMO), which is the body solely responsible for planning the shared network7 and procuring network support and shared network augmentations;

• the asset owner, AusNet Services; and • the transmission customers (distribution companies, generation companies and directly-connected

industrial customers) which are responsible for planning and directing the augmentation of their respective transmission connection facilities.

In Victoria, the transmission network planning functions are separated from the functions of ownership and operation. This section summarises the planning roles of the various parties in Victoria. These arrangements differ from other states in Australia, where planning and responsibility for augmentation remains integrated with the incumbent transmission company (although independent planning oversight occurs in South Australia). The relationships between these parties and the Regulators are shown in Figure 6.

Figure 6 – Regulatory and commercial relationships

7 The shared transmission network is the main extra high voltage network that provides or potentially provides supply to more than a

single point. This network includes all lines rated above 66 kV and main system tie transformers that operate between two voltage levels above 66 kV.



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4.2.1 AEMO

The Australian Energy Market Operator (AEMO) is responsible for:

• procuring bulk shared network services from AusNet Services and other providers; • providing transmission use of system services to transmission customers (including administering

transmission pricing); and • planning and requisition of augmentation to the shared transmission network.

The responsibilities of the parties within the Victorian structure for electricity supply are set out in Victorian legislation, the licences, guidelines and codes administered by the Essential Services Commission and Victorian derogations in Chapter 9 of the National Electricity Rules (NER). Together these describe the Victorian model for procurement and provision of transmission services in Victoria.

4.2.2 Connected Parties

In Victoria, connected parties are responsible for the planning and augmentation of their connection assets. The five distribution businesses (DBs) have responsibility for planning and directing the augmentation of those facilities that connect their distribution systems to the shared transmission network. DBs plan and direct the augmentation in a way that minimises costs to customers, taking into account distribution losses and transmission losses that occur within the transmission connection facilities. Other connected parties (major consumers or generators) are responsible for their own connection planning. They can choose to delegate this task to a DB if they wish.

In the event that a new connection or augmentation of an existing connection is required the connected parties must consult with and meet the reasonable technical requirements of AEMO, AusNet Services and other effected parties.

Each year the DBs publish the Transmission Connection Planning Report (TCPR) that assesses network planning criteria, the risks of lost load and options for meeting forecast demand.

4.3 Regulatory Framework

The Victorian transmission network is subject to economic and technical regulation, which is the responsibility of the Australian Energy Regulator (AER) and Energy Safe Victoria (ESV) respectively.

4.3.1 Australian Energy Regulator (AER)

Economic regulation is subject to a national regulatory framework, which is governed by the National Electricity Law (NEL) and contained in the National Electricity Rules (Rules). The Australian Energy Markets Commission (AEMC) has responsibility for development of the Rules, and the AER is responsible for regulation of industry participants in accordance with the Rules. The AER's regulatory functions and powers are conferred upon it by the NEL and it must act in accordance with its obligations under the Rules (as must industry participants).

The AER’s key responsibilities include:

• regulating the revenues of transmission network service providers and distribution network service providers;

• monitoring the electricity wholesale market; • monitoring compliance with the national electricity law, national electricity rules and national electricity

regulations; • investigating breaches or possible breaches of provisions of the national electricity law, rules and

regulations and instituting and conducting enforcement proceedings against relevant market participants;

• establishing service standards for electricity transmission network service providers; • establishing ring-fencing guidelines for business operations with respect to regulated transmission

services; and • exempting network service providers from registration.



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Regulatory proposals (i.e. revenue applications) to the AER are assessed against, amongst other things, the operating expenditure objective and the capital expenditure objective (clauses 6A.6.6 (a) and 6A.6.7 (a) of the Rules). Accordingly network businesses are required to submit the total forecast operating expenditure and capital expenditure. The applicable criteria for the expenditure forecasts are:

• meet or manage the expected demand for standard control services over that period; • comply with all applicable regulatory obligations or requirements associated with the provision of

standard control services; • maintain the quality, reliability and security of supply of standard control services; and • maintain the reliability, safety and security of the distribution system through the supply of standard

control services.

4.3.2 Energy Safe Victoria (ESV)

ESV is an independent Victorian statutory authority. The objectives of ESV relevant to electricity networks are:

• ensure the electrical safety of electrical generation, transmission and distribution systems, electrical installations and electrical equipment;

• control the electrical safety standards of electrical work carried out by electrical workers; • promote awareness of energy efficiency through energy efficiency labelling of electrical equipment and

energy efficiency regulation of electrical equipment; • promote the prevention and mitigation of bushfire danger; • protect underground and underwater structures from corrosion caused by stray electrical currents; and • maintain public and industry awareness of electrical safety requirements.

The Council of Australian Governments has initiated the development of a regulatory framework for national safety regulation of energy networks.

The Electricity Safety Act (1998) requires AusNet Services to

“…design, construct, operate, maintain and decommission its supply network to minimise as far as practicable:

a) the hazards and risks to the safety of any person arising from the supply network; and

b) the hazards and risks of damage to the property of any person arising from the supply network; and

c) the bushfire danger arising from the supply network”.



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5 Asset Management System

This section provides an overview of AusNet Services’ Asset Management System including its underlying methodology, context, process, objectives, decision making criteria and certification.

Refer to AMS 01-01 Asset Management System Overview for additional details.

5.1 Asset Management Methodology

AusNet Services is focused on delivering optimal transmission network performance at efficient costs. Except in the case where outputs are mandated, this requires an explicit cost benefit analysis to be undertaken in order to assess whether the overall economic value of capital expenditure is positive.

In doing this, AusNet Services assesses the incremental costs of delivering an incremental change in network performance to customers, relative to the incremental benefits accruing to customers from the delivery of that enhanced network performance.

The asset strategy therefore ensures that all decisions to replace or maintain network assets are justified on economic grounds. The benefits are a function of the explicit customer value proposition, or proxy via the adoption of minimum performance standards which are stipulated in legislation or other statutory or regulatory instruments.

The various drivers that are brought to bear when undertaking AusNet Services’ Cost Benefit Analysis are summarised in Figure 7.

Figure 7 – Cost Benefit Analysis Drivers

An assessment of the above drivers – both individually and collectively – are fundamental to the cost benefit analysis that underpins AusNet Services' approach to managing its network.



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5.2 Asset Management Policy

AusNet Services’ Asset Management Policy acknowledges the company’s purpose and directs the content and implementation of asset management strategies, objectives and plans for the energy delivery networks.

The Asset Management Policy recognises that the provision of a superior network requires the management of network assets over their lifecycle. This will be achieved by sound risk management and the continuous improvement practices of our integrated safety, health, environment, quality and asset management systems.

AusNet Services has formally endorsed an Asset Management Policy as illustrated in Figure 8:

Figure 8 – Asset Management Policy



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This Policy is consistent across all three energy networks and sets the foundation for all asset management decisions. It is communicated throughout the business and copies of this policy are available in each workplace.

5.3 Asset Management Objectives

The Asset Management Policy summarises AusNet Services’ fundamental asset management objectives. AusNet Services’ asset management objectives have been developed to support the successful delivery of AusNet Services’ purpose. The asset management objectives for AusNet Services’ energy networks are8:

• Meet or manage demand for energy and connection services; • Enhance network and worker safety “so far as is practicable”; • Maintain network reliability and security commensurate with risk and cost; • Use smart network technologies and integrate ICT platforms to enhance service offerings; • Outperform cost and performance benchmarks; and • Comply with regulatory obligations.

The asset management objectives are supported by specific network objectives, which are detailed in Section 8.

5.4 Planning to Achieve Objectives

AusNet Services’ Asset Management System Overview outlines the methodology adopted for asset management decisions to achieve objectives.

Please refer to AMS 01-01 Asset Management System Overview Section 10.3 for further information.

5.5 Asset Management Process

AusNet Services’ Asset Management System is described in AMS 01-01 Asset Management System Overview. The asset management process is informed by an assessment of the external business environment and the corporate business and financial plans. The process, illustrated in Figure 9 below, includes the development of longer-term asset management strategies, five-year asset management plans, the management of projects and programs of change and the application of standards to the life cycle of network assets.

8 Section 1.5 2014/15 to 2018/19 Asset Management Plan.



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Asset Management Policy• Asset Management System content• Decision criteria

Environmental Analysis• Customer engagement• Law & Regulation• Regulatory decision• Technical vision

5-Year Business Plan• Values• Purpose• Objectives

5-Year Financial Plan• Revenue • Equity• Expenditure

Asset Management Strategy• Organisation & Industry• Stakeholders & Scope• Combine Asset status & condition• RCM & risk modelling• 20-year optimised strategy

5-Year Asset Management Plan• Objectives • Projects and Programs• Initiatives • CAPEX and OPEX

Customer Requests• Connect new consumers• Serve existing consumers• Connect generators & producers

Project Life Cycle (create assets)• IDEA – 10 year list of emerging constraints• PLAN – Business Cases• BUILD – Execute & Monitor• CLOSE – Post Implementation Review

Network Assets• Operate• Inspect & Test• Corrective maintenance• Confirm asset condition

Monitor Network Performance• Safety Capacity Reliability• Quality Environment Compliance• Security

Monitor Asset Performance• Monitor maintenance activity• Monitor maintenance costs

Standards & Procedures• Create & Acquire assets• Operate assets• Inspect & Maintain assets• Replace & Dispose assets

Figure 9 – Asset management process

AMS 01-01 and the top level Asset Management Strategies for each network; shaded blue in Figure 9, form a Strategic Asset Management Plan (SAMP) as defined in ISO55000:2014.

5.6 Asset Management System Certification

AusNet Services’ three energy networks demonstrate compliance with requirements of ISO 55001, the international standard for Asset Management. Adoption of this standard enables AusNet Services to achieve its objectives through effective and efficient management of its assets.

Complaince requires the demonstration of robust and transparent asset management policies, processes, procedures, practices and a sustainable performance framework. Compliance with the ISO 55001 is recognised as an indicator of best practice in asset management.



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6 Asset Management Drivers

This section highlights the significant drivers for future network investment to achieve customer, regulatory and shareholder expectations. AusNet Services is accountable for responding to these drivers in accordance with legislative and other regulatory instruments. The key asset management drivers include the following:

• Network safety; • Sustainability; • Network risk; • Performance; • Augmentation; • Advances in technology; and • Skills and resources.

6.1 Network Safety

AusNet Services’ safety vision is symbolised by the simple expression "missionZero". When it comes to the safety of people, contractors and visitors, the only acceptable target is:

AusNet Services meets its requirements under the Occupational Health and Safety Act (2004) through its Mission Zero program which is designed to improve safety of all employees and contractors.

In addition, the Victorian Safety Legislation requires network businesses to lodge an Electricity Safety Management Scheme (ESMS) with Energy Safe Victoria (ESV). The safety initiatives included in the transmission ESMS programs have been driven by increasing community expectations and a shift in Victoria’s energy safety regime that places greater emphasis on individual company accountability for safety and targeted risk management. This presents a challenge to ensure that safety programs are delivered as agreed with ESV. Failing to deliver has become more transparent and will result in compliance directives.

The specific risks that have been identified in the formal safety assessment for the electricity transmission network and the relevant mitigating management strategies are detailed in Table 3.



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Table 3 – Transmission Network Formal Safety Assessment – Identified Level II Risks9

Further information is provided in Section 9.2.

6.2 Sustainability

6.2.1 Emissions Management

Climate change (both in terms of the physical effects and government policies) and funding pressures are likely to continue to influence energy sector direction over the next five years, although the precise impacts remain uncertain, with ongoing global research and debate about near-term climate effects, and evolving national and international climate policy.

The Government has retained the Clean Energy Regulator and the National Greenhouse and Energy Reporting Scheme (NGERS) as part of the administration of the Emissions Reduction Fund.

There is also a possibility of an introduced carbon buyback via an Emissions Reduction Fund.

6.2.2 Environmental Management

AusNetServices focuses on protection of the immediate environment in which it operates through the AS/NZS ISO 14001 certified environmental management system. The environmental management system is the principal tool through which AusNet Services identifies environmental risks, develops and implements solutions and monitors success in controlling such risks. Key programs in the environmental management system include the management of vegetation, SF6 gas leaks, oil discharges, Poly chlorinated biphenyls (PCB) management, electromagnetic fields and noise abatement.

Further information on AusNet Services’ environmental management system is provided in Section 9.4 and in QMS 10-01 HSEQl Management System Manual.

9 Refer to ESMS 20-02 for further details.



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6.2.3 Community

The need to better understand customer behaviour in order to respond with service offerings that create value is identified in AusNet Services’ corporate business plan. Consultation with stakeholders has been undertaken as part of preparation of the forthcoming Transmission Revenue submission and plans are being developed to increase the scope and range of customer consultation related to regulated networks so that a better understanding of customer needs and future choices is formed. AusNet Services continuously works toward building meaningful relationships and dialogue with community groups through the social investment strategy which include initiatives such as partnering with community organisations such as the Country Fire Authority (CFA). AusNet Services’ commitment to community engagement is demonstrated through the collaborative approach taken whilst establishing designs for the RTS, BTS and WMTS station rebuilds.

6.2.4 People and Culture

The nature of the energy sector will change fundamentally over the next decade, responding to community expectations of safety and reliability, climatic change and emerging technologies. The systems, processes, tools and the appropriate employee skills set used to deliver transmission services will need to adapt to the changing operating environment as it continually evolves. More immediately, the industry faces skill shortages through retirement of an aging workforce. The retirement profile, together with an increase in network expenditures, has driven the increasing demand for knowledge-management, skills-transfer, training and recruitment. Retaining and developing AusNet Services’ people will be critical to the successful implementation of the wide range of asset management initiatives. Programs must be designed to promote behaviours and activities consistent with AusNet Services’ values, which are summarised in Figure 10.

Figure 10 – AusNet Services’ Corporate Values

6.3 Network Risk

This section summarises the risks associated with the transmission network, including corporate and asset-related risks. Further information is provided in Section 9.1 Risk Management.

6.3.1 Corporate Risks

AusNet operates a corporate Risk Management Framework10 based on ISO 31000:2009 “Risk management – Guidelines on principles and implementation of risk management” to assess a range of business risks. Corporate risks and control measures are registered using AusNet Services’ risk management information

10 RM 001-2006 Risk Management Framework, 2010, AusNet Services.



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systems, which includes Cura. These risks are regularly reviewed and the actions required to manage them are implemented in specified timeframes. Cura provides the monitoring and reporting capability to ensure these risks are managed in accordance with their priority level. The registered risks that relate to the transmission network are summarised in Table 4:

Risk Name Residual Risk Rating

Target Risk Rating

Major transmission network failure / failure to provide adequate capacity Level II Level II

AusNet Services’ assets cause a bushfire Level II Level II

Failure to achieve a satisfactory regulatory revenue determination Level II Level II

Changes in network regulations impacts on business value Level II Level II

Electric or magnetic fields being found to be harmful Level II Level II

BTS Project Z709 fails to meet business objectives or unplanned impacts result Level II Level III

RTS Project XA09 fails to meet business objectives or unplanned impacts result Level II Level III

WMTS Project XA14 fails to meet business objectives or unplanned impacts result Level II Level III

Physical effects of climate change on capacity and performance of network Level II Level III

Failure to meet network performance Level II Level III

Easements become encroached Level III Level III

Workplace exposure to Asbestos Containing Materials (ACM) Level III Level III

Failure to adequately manage greenhouse gas output Level III Level III

Failure to effectively manage changes to technical regulations Level III Level III

Reduction in CBD supply security Level III Level III

Failure to implement the recommendations from the Victorian Bushfire Royal Commission Level III Level IV

Table 4 – Transmission Network Risks Registered in Cura (as at October 2015)

6.3.2 Asset Risk

The risks associated with network assets are quantified through the application of Reliability Centred Maintenance (RCM) techniques. RCM requires the assignment of functions and functional failures to individual network assets. Failure Mode Effect Analysis (FMEA) of historical asset failure data determines typical root causes of functional failures and the effects these causes have on key performance measures including network safety, reliability and availability. Asset condition data collected during scheduled maintenance tasks is used to determine dynamic time based probability of failures and percentage of remaining service potential (RSP) of the asset in that lifecycle phase. RCM models output risk profiles for each asset category which are used to establish optimised maintenance and asset replacement plans.



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6.4 Performance

Network performance is recognised as a key driver for asset investment decisions. The performance of the transmission network is monitored against four inter-related elements, including reliability, plant availability, supply security and supply quality. AusNet Services participates in the performance incentive schemes, including:

• Availability Incentive Scheme (AIS) – AEMO; and • Service Target Performance Incentive Scheme (STPIS).

Further details are provided in AMS 10-17 Network Performance Monitoring.

6.4.1 Availability Incentive Scheme (AIS)

The Network Agreement between AusNet Services and AEMO includes an Availability Incentive Scheme (AIS) that provides an incentive to improve the availability of transmission network elements. The objective of the AIS scheme is to encourage asset management practices by AusNet Services that deliver high network reliability, and to seek outages at times when the expected cost of the outage to network users in minimal. AusNet Services and AEMO have agreed to cease the Availability Incentive Scheme (AIS) from 1 April 2017 with the possibility of an earlier closure by 1 April 2016 as it has been recognised that the operation of the AIS is not achieving its original objectives, and the performance incentives it provides are superfluous to those provided by the AER’s STPIS.

6.4.2 Service Target Performance Incentive Scheme (STPIS)

The service target performance incentive scheme (STPIS) administered by the AER aims to balance the incentive for TNSPs to minimise expenditure with the need to maintain and improve reliability for customers. The scheme provides TNSPs with a financial incentive to maintain or improve service levels. The scheme comprises three components; a Service Component, a Market Impact Component (MIC), and a Network Capability Component (NCC).

6.4.3 Service Component

The Service Component of the STPIS consists of four parameters which measure different aspects of service performance. These parameters measure network reliability by focusing on unplanned outages (the ability to minimise the number of events and to quickly rectify them when they occur) and by providing an incentive for TNSPs to improve their performance. The parameters are:

• Average Circuit Outage Rate – measures the frequency of unplanned (forced and fault) outages on lines, transformers and reactive plant.

• Loss Of Supply Event Frequency – measures the frequency of outages which cause a loss of supply to customers.

• Average Outage Duration – measures the duration of unplanned outages with a loss of supply. • Proper Operation Of Equipment – requires TNSPs to report on ‘near miss’ events such as failures of

protection systems, material failure of the Supervisory Control and Data Acquisition (SCADA) system and incorrect operational isolation of primary and secondary equipment. No financial incentive is associated with this parameter.

Weightings are applied to each parameter and sub-parameter to calculate the total incentive of the Service Component.



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6.4.4 Market Impact Component (MIC)

The MIC provides an incentive to TNSPs to minimise planned transmission outages that can affect the NEM spot price. It measures the number of dispatch intervals where an outage on the TNSP’s network results in a network outage constraint with a marginal value greater than $10/MWh.

The MIC that will apply from 2017 is a penalty-reward scheme which provides a TNSP with financial incentive value of ±1% of its MAR in each calendar year. Targets will be set based on the median five years of the last seven years of performance, with caps and collars set at zero and twice the target, respectively.

6.4.5 Network Capability Incentive Parameter Action Plan (NCIPAP)

The Network Capability Component was introduced in the December 2012 version of the STPIS, and, as such, AusNet Services is the first TNSP to participate in this parameter. This component applies to AusNet Services in the regulatory period which commenced on 1 April 2014.

The Network Capability Component was introduced to encourage improvements in the capability of transmission assets, particularly those that are most important to determining spot prices and at times when network users place greatest value on the reliability of the transmission system.

Participation in this component requires TNSPs to submit a Network Capability Incentive Parameter Action Plan (NCIPAP) which contains:

• A list of every transmission circuit and injection point on the network, and the reason for the limit for each; and

• A list of priority projects to be undertaken during the forthcoming regulatory control period to improve the limit of the transmission circuits and injection points listed above.

AEMO plans the transmission network in Victoria. Therefore the NCIPAP has been prepared jointly with AEMO. AusNet Services is delivering 14 approved NCIPAP projects in the 2014-17 regulatory period. A list of three priority projects has been agreed with AEMO and will be submitted to the AER as part of AusNet Services’ 2015 Revenue Proposal.

6.5 Augmentation

Network augmentation investments are driven by growth in electricity consumption and demand, and rising fault levels. AEMO is responsible for the planning and justification of transmission network augmentation projects. AusNet Services works closely with AEMO and Distribution Businesses in planning future asset replacement programs ensuring that alignment with planned augmentation works is optimised.

6.5.1 Energy and demand forecasts

During last five years, energy consumption in Victoria has declined. Residential and commercial sector consumption has decreased due to rising electricity prices and uptake of rooftop PV and energy efficiency, while the decline in the manufacturing sector and major industrial closures have affected industrial consumption.

AEMO’s forecast is to recover the operational consumption in the short term by 1% (from 42,635 GWh in 2014/15 to 43,963 GWh in 2017/18), in the long term by 0.5% (reaching 45,680 GWh by 2024/25) and long term by 1% (reaching 50,315 GWh by 2034/35). This forecast would lead to Victoria reaching its historical high of 47,935 GWh (in 2007/08) by 2030/31. The recovery is driven by the residential and commercial consumption with population growth being the major driver for recovery. Despite the recovery, the per capita consumtion is forecast to continue to decline.



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Figure 11 below, presents AEMO’s operational energy forecast to 2034/35.11

Figure 11 – 2015 NEFR annual operational energy forecast

The maximum demand for Summer 2014/15 was 8,626 MW on 22 January 2015 which is 1687 MW below the 2013/14 maximum demand (approximately 16.4% reduction). This was 149MW below the 2014 National Electricity Forecasting Report (NEFR) 50% probability of exceedence (POE) forecast. Victorian maximum demand is driven by demand from the residential and commercial sector. The industrial loads remains relatively flat during high temperature days.

AEMO’s 10% POE demand forecast as published in the 2015 NEFR is for demand to decrease at an average annual rate of 0.1% over the short term (2014/15 to 2017/18). The medium term (2017/18 to 2024/25)10% POE demand forecast is to increase the maximum demand with an average annual growth rate of 1.0% as a result of increasing population and GSP (Gross State Product).

11 Source: National Electricity Forecasting Report (NEFR) 2015 – AEMO.



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Figure 12 below, shows a comparison of the summer 10%, 50% and 90% POE maximum demand forecasts.

Figure 12 – Summer Maximum Demand Forecast for Victoria (MW)12

6.5.2 Fault Levels

AEMO is responsible for ensuring that fault levels at all terminal stations in the electricity declared shared network (DSN) are operated within their fault current interrupt and fault withstand capabilities. The fault current interrupt capability is determined either from terminal station equipment limits (rating of the lowest rated circuit breaker), or those set out in the National Electricity Rules (NER) or connection agreements.

AEMO’s analysis of terminal station fault levels concludes that fault levels are within asset capabilities at all Victorian terminal stations, but that fault levels are forecast to exceed limits at the following terminal stations within the next five years:

• West Melbourne Terminal Station 220 kV bus; • Moorabool Terminal Station 220 kV bus; • Hazelwood Terminal Station 220 kV bus; • Richmond Terminal Station 220 kV bus.

Further details of fault level calculations for terminal stations are available in the 2015 Victorian Annual Planning Report published by AEMO.

6.5.3 Connection Station Supply Risk

A key driver for augmentation of the transmission network is supply risk and augmentation proceeds when the network benefits exceed the annual cost. The ten connection stations with the highest supply risk are shown in Figure 13 below.

12 Source: National Electricity Forecasting Report (NEFR) 2015 – AEMO.



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Figure 13 – Transmission Connection Station Supply Risk for Summer 2015/16

Keilor, West Melbourne, Terang, Altona, Heatherton, Cranbourne and Morwell terminal stations are forecast to have the highest supply risk of all Victorian transmission connection stations over summer 2015/16 as shown in Figure 1313.

The monetised supply risk shown in Figure 13 is the probability weighted economic cost of an unplanned outage to electricity consumers. It is calculated by multiplying the energy at risk with the probability of the unplanned outage and weighing it with the value of customer reliability (VCR).

6.6 Customer Connections

There are four types of customer connections to the transmission network including generators, interstate connections, industrial customers and distribution business connections. AusNet Services charges customers for the use of connection assets. Connection assets are those assets that are dedicated to the connection of the generators, interstate networks, industrial customers and distributors to the transmission network. In some cases the connection assets are owned by the customer, in this case AusNet Services is not responsible for the management of the connection assets.

The number of generator connections is growing due to an increasing number of generation sources, mainly wind farm connections. Two wind farms; Ararat Wind Farm & Mount Gellibrand Wind Farm are to connect in July 2016 & March 2017 respectively. AEMO is assessing applications and enquiries to connect seven more wind farms during next 10 years14. These additional connections significantly increase the complexity of the necessary protection, communications and control schemes.

13 2014 Transmission Connection Planning Report (TCPR). The expected supply risk in Figure 13 takes into account the contingency

plan for WMTS, which allows for the hot spare 220/66 kV transformer to be put into operation prior to high demand days. The expected supply risk for WMTS is at a high level due to the condition of three of the four 220/66 kV transformer, with two transformers at condition C4 and one transformer at condition C5.

14 2015 Victorin Annual Planning Report – AEMO.



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Figure 14 displays the volume and type of customer connections existing on the transmission network.

Figure 14 – Transmission network customer connections

6.7 Advances in Technology

The nature of the energy sector will change fundamentally over the next decade, responding to community expectations of safety and reliability, climatic change and emerging technologies. Advances in technology are facilitating new electricity generation techniques and more efficient small-scale embedded generation solutions, and in the future, the introduction of electric vehicles. Integration of these new sources of generation presents new challenges the transmission network.

6.7.1 Innovation

Innovation is required to modernise the electricity transmission network and develop the most effective solutions for network challenges. It will explore the most economical way of maintaining reliability and safety of the network in the future. AusNet Services aims to keep innovation research focussed on resolving most urgent and important network problems and involve Victorian educational and research institutions.

It is intended to commercialise, wherever possible, the key technologies developed in order to ensure a cost effective supply of the new product or services for the benefit of AusNet Services and other TNSPs. AusNet Services’ innovation and research program can be classified into three main categories including Advanced condition monitoring, Network intelligence using smart analytics and Investigating emerging technologies. A number of innovative solutions from these key areas are currently being researched or trialled on the network.



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6.7.2 New Technology Adoption

Initiatives included in AusNet Services’ innovation and research program are currently at different stages of development. The maturity of the technology determines the timeframes for expected adoption to the transmission network. A number of technologies, following extensive research, have been deemed to present considerable benefits and so are currently being trialled for use on the network. These technologies include the following:

• Portable radio frequency scanning; • Online monitoring of partial discharge at terminal stations; • Aerial surveying image processing; • Smart analytics for asset data; • Radio frequency based line fault detection; and • Portable x-ray.

Additional innovative technologies are considered to be at an evolutionary stage and still require considerable levels of investment and development. Additional research is required to determine the cost effectiveness and suitability of these technologies before adoption to the transmission network. Developing technologies which are currently being monitored by AusNet Services are listed below:

• HVDC lines and converters; • EHV cable technology; • High temperature conductors; • Inexpensive modular station builds; • FACTS devices and power electronics; • Wireless Sensor Network (WSN) system for Substations; • Line Fault Detection System; and • Polymer Insulator Diagnostics.

Innovation Strategies:

• Monitor progress of new technologies

• Develop innovation and research program focussed on producing innovative solutions to the critical and urgent network problems

• Keep innovation program targeted and outcome focussed

• Collaborate with educational and research organisations to leverage investment into Research and Development (R&D)

• Provide right culture for innovation i.e., flexibility but delivery focus

• Commercialise innovation to enable wide spread deployment at the least cost

• Step change in the innovation program to deliver meaningful outcome in a timely manner

Further information can be found in AMS 10-20 Process and Configuration Management.

6.7.3 Secondary systems

The dominant trend in secondary systems is toward the application of digital technology devices and systems with in-built intelligence and integrated functionality. These digital technology platforms add value by:

• Increasing functionality, reliability and availability through the use of microprocessors, solid-state devices, digital technology and optic fibre-based communication systems;

• Lowering per function costs whilst increasing performance capability;



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• Embedding intelligent diagnostic software that optimises operation and improves asset management; • Rationalising equipment via functional integration and multiple signal processing capability; and • Providing remote management facilities for network elements based on real-time data communications.

IEC61850 is an electrical substation design standard which is widely seen as an enabler for the modernisation of high speed protection and control systems by integrating a number of functions into a smaller number of intelligent electronic devices. The standard is a potential driver for the replacement of secondary cabling with serial communications over optic fibre. IEC61850 capability is becoming readily available in relays and will enable the selective introduction of an IEC61850 “Station Bus” at terminal stations within the next few years.

Protection systems designed using IEC61850 are more likely to become economic firstly at Greenfield sites and where major Brownfield rebuilds are being implemented. The IEC61850 “Process Bus” is expected to become feasible for newly designed stations and for station upgrades in the medium term. The longer term goal is to develop and implement a complete modular design standard package for transmission station intelligence based on IEC61850.

6.8 Program delivery

The asset management strategies included in this document will require the continuation of capital expenditure similar to historical levels to maintain network performance.

In order to maximise the efficiency of program delivery AusNet Services has refined the program lifecycle process improving alignment with business processes and ensuring that program delivery objectives are achieved. The program lifecycle process is summarised in Figure 19. The program lifecycle model is supported by detailed work instruction documentation and an internal resourcing model. Program delivery is further supported by the formation of strategic alliances with external companies that provide design services, installation services and maintenance services.

Program delivery is discussed further in Section 9.10.



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7 Network Vision

AusNet Services conducted a visioning process and environmental scan during 2012. The visioning process involved analysis of three possible future scenarios in a day long workshop by more than 25 network specialists. The environmental scan identified emerging strategic issues through a series of targeted workshops. The processes took into account a range of significant factors, including community attitudes toward climate change and renewable energy sourcing, government policy, customer growth and energy needs, and future technology advances and applications. For the purposes of the AMS, the conclusions from the processes provide an important reference for prudent strategy. This is particularly so as the visioning process forecast a number of significant challenges for the electricity transmission network over the next 25 years.

Key influences identified are:

• demand may continue to grow, leading to continuing expansion of transmission network infrastructure however, this is not certain;

• future transmission networks may be constructed quite differently to existing networks due to the nature and location of generators, the maturity of technologies such as DC transmission and the uncertain need for networks that will last more than 50 years;

• the continuing development of information technologies (IT) and tools (robotics) along with the proliferation of network information from sensors, meters and analysis tools; and

• ongoing technical skills shortages.

In response to these influences, AusNet Services will need to continue to evolve and change in a number of areas including:

• the development of tools and systems that make available information readily available to users. This will include users in the field, network operators and customers, asset managers and technical specialists;

• improving understanding of new technologies and approaches such as HVDC transmission, robotic network inspections, modular stations and new materials;

• continuing to broaden skills that supplement traditional electricity network engineering skills and better enable activities such as environmental management, stakeholder engagement, robotics, and data analysis; and

• increasing the use of network modelling, predictive modelling, and integrated asset management tools. Use of more advanced tools will better enable management of risk from an ageing network, improve economic decision making and reduce the cost of network services.

Additionally, in July 2014 AusNet Services successfully completed another Visioning exercise designed to help technical subject matter experts explore a range of future energy supply scenarios. The primary focus was exploring issues directly influencing the Distribution network with limited focus on the transmission network . For more information refer to Section 8.4 of AMS 01-01.



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8 Network Objectives and Performance

8.1 Overview

The AMS identifies a number of network objectives to guide the development of the asset management strategy. In large part these reflect regulatory obligations and in some cases prudent and responsible decisions, justified on economic grounds. Actual capital and operational expenditure investment and process change arising from the AMS must nevertheless be subject to detailed cost-benefit analysis to ascertain the extent and the timing of the investment from an economic perspective.

8.2 Network Objectives

The AMS is focused on delivering optimal transmission network performance at efficient costs. The AMS ensures that all decisions to replace or maintain network assets are justified on an economic basis. The transmission network objectives have been developed to enable the successful delivery of the asset management vision and mission.

Two primary objectives have been developed for Ausnet Services’ electricity transmission network to enable the successful delivery of the asset management vision and mission and to govern how the network is operated and maintained.

A summary of the key objectives included in the AMS is provided in Table 5. AusNet Services’ ongoing commitment to maintain compliance with ISO 55001 ensures an auditable asset management system facilitating customer’s expectations to safely maintain the quality, reliability and security of supply in an economic manner.

Network Objective Drivers Targets

Value for money • Regulatory Reform • Technology Development

• STPIS – Service component: Not <-$1m (CY2015 and after) • STPIS – Market Impact Parameter Scheme: <1,035 Dispatch

Intervals (CY2015) and <828 Dispatch intervals (CY2016) • STPIS – NCIPAP < approved expenditure for each project. Complete

by 30 March 2017 • AEMO Availability Incentive Scheme: > -$0.3m (CY2015) and > -0.2m

(CY2016)

Table 5 – Electricity Transmission Network Objectives

8.3 Network Performance Summary

This section provides a summary of the performance of the transmission network in terms of STPIS and system incidents.



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8.3.1 STPIS performance

AusNet Services’ performance on the AER’s STPIS scheme is detailed in Table 6 and Table 7.

Parameter Sub-parameter Target (2010-13) 2010 2011 2012 2013 Target

(2014) 2014 Weigh

t (2014)

Unplanned outage

circuit event rate

Lines event rate – fault n/a 16.81% 24.37% 32.50% 20.66% 25.90% 30.58% 0.20

Transformer event rate – fault n/a 7.26% 11.90% 21.26% 31.25% 16.10% 22.83% 0.20

Reactive plant event rate – fault n/a 27.14% 34.29% 45.71% 47.14% 35.10% 25.71% 0.10

Lines event rate – forced n/a 14.29% 16.81% 14.17% 12.40% 14.90% 15.70% 0.00

Transformer event rate – forced n/a 13.71% 4.76% 13.39% 10.94% 12.00% 11.81% 0.00

Reactive plant event rate – forced n/a 14.29% 22.86% 22.86% 35.71% 15.40% 38.57% 0.00

Loss of supply event

frequency

Number of events greater than 0.05 system minutes per annum

6 1 0 2 5 2 3 0.15

Number of events greater than 0.30 system minutes per annum

1 0 0 1 1 1 0 0.15

Average outage

duration Average outage duration n/a 92.5 4 230 19.9 98 24 0.20

Proper operation of equipment

Failure of protection system n/a 12 16 32 37 n/a 32 0.00

Material failure of SCADA n/a 0 0 1 6 1 2 0.00

Incorrect operational isolation of primary or secondary equipment

n/a 7 5 8 4 n/a 6 0.00

Table 6 – STIPS Performance History – Frequency and Duration



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Parameter Performance

2009 2010 2011 2012 2013 2014

Market Impact Parameter

Dispatch Intervals (>$10/MWh Marginal change) 1417 2134 2687 909 745 851.5

Table 7 – STIPS Performance History – Market Impact Parameter

8.3.2 System incidents

AusNet Services records major incidents associated with the transmission system. Figure 15 provides a history of incidents from 2003. The frequency of major incidents has generally decreased since 2006.

Figure 15 – Transmission System Major Incident History



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8.4 Performance Benchmarks

AusNet Services participated in the 2013 International Transmission Operations and Maintenance Study (ITOMS) performance benchmarking, which enables AusNet Services to compare its performance relative to other transmission utilities based on service and cost levels.

8.4.1 Overall performance

The 2013 ITOMS results show that AusNet Services (SPA) compares favourably with the overall benchmarked average performance of other transmission companies in terms of transmission network service level and equivalent operating costs, with above average service levels and just below average cost levels.

Figure 16 – ITOMS Overall Composite Performance Benchmark – 2013

8.4.2 Transmission lines performance

The 2013 ITOMS results show that AusNet Services’ benchmarked performance for transmission lines maintenance has deteriorated compared with the 2009 survey, both in terms of cost and performance measures. AusNet Services’ benchmarked performance for transmission lines maintenance is depicted in Figure 17.



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Figure 17 – ITOMS Overhead Transmission Line Maintenance Performance Benchmark – 2013

8.4.3 Substations performance

The 2013 ITOMS results show that AusNet Services’ benchmark performance for substations maintenance has deteriorated compared with the 2009 survey, particularly as measured by service levels. AusNet Services’ benchmarked performance for substations maintenance is depicted in Figure 18 below, showing good performance with regard to cost measures compared with the other transmission network service providers:

Figure 18 – ITOMS Substations Maintenance Performance Benchmark – 2013



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9 Process and System Strategies

This section of the AMS provides a summary of the processes and systems and related strategies used to manage the transmission assets. These processes and systems are documented in full in the foundation level of resource documents. Each of the following sub-sections details issues and provides a summary of key strategies for their management.

Until April 2014, AusNet Services’ asset management system conformed to the requirements of the British Standards Institute’s Publicly Available Specification PAS 55-1:2008. This asset management system now conforms to the requirements of ISO 55001. Conformity with this standard means that AusNet Services’ asset management system meets contemporary asset management standards, comprehensively covers all aspects of asset management, and incorporates formal processes for continuous improvement.

9.1 Risk Management

AusNet Services operates a corporate Risk Management Framework15 based on ISO 31000:2009 “Risk management – Guidelines on principles and implementation of risk management”. The framework is a blue print to manage risk consistently across AusNet Services.

Risks are rated and prioritised under the following categories:

• Health, Safety & People; • Environment & Community; • Reputation; • Customers; and • Regulation, Legal & Compliance.

By adopting common metrics across the broad range of business risks and investment portfolios, AusNet Services can more effectively manage business risks and optimise network outcomes and objectives.

The risks associated with network assets are quantified through the application of Reliability Centred Maintenance (RCM) techniques. RCM requires the assignment of functions and functional failures to individual network assets. Failure Mode Effect Analysis (FMEA) of historical asset failure data determines typical root causes of functional failures and the effects these causes have on key performance measures including network safety, reliability and availability. Asset condition data collected during scheduled maintenance tasks is used to determine dynamic time based probability of failures and percentage of remaining service potential (RSP) of the asset in that lifecycle phase. RCM models output risk profiles for each asset category which are used to establish optimised maintenance and asset replacement plans.

More specific information can be found in the individual plant strategies referenced in section 10.

Key strategies for the management of business and asset risks include:

• Integration of the risk management process into all the processes used to make significant decisions and to deal with changes.

• Key controls will be identified and allocated to nominated control owners for periodic verification that they are adequate, effective and cannot be cost effectively improved.

• Conduct analysis after any significant incident, event, change or decision to learn from both successes and failures. This will include the use of root cause analysis.

15 RM 001-2006 Risk Management Policy & Framework, 2013, AusNet Services.



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• Maintenance of Emergency Operations Management Plans, the Mutual Aid Plan and Disaster Recovery Plans through AusNet Services’ Integrated Response and Contingency System, SPIRACS16;

• Maintain standardised asset design, installation, operation and maintenance procedures; • Establish contingency and risk mitigation plans where network risks have been identified as

unacceptable; • Utilise economic net benefit modelling and program prioritisation techniques; and • Manage risks ‘So far as is practicable’ (SFAIP)

9.2 Electrical Safety Management System

AusNet Services maintains an accepted Electricity Safety Management Scheme (ESMS) as required under the Electricity Safety Act 1998 and in compliance with the Electricity Safety (Management) Regulations 2010. The ESMS forms an outcome based regulatory framework against which ESV maintain regular audits to monitor AusNet Services’ compliance.

In summary the scheme contains information on:

• Executive officers responsible for the network; • A description of the location, extent and scope of the scheme; • A formal safety assessment including methodology, hazards identified and measures to reduce those

hazards; • A description of the management scheme including content, responsibilities, formal policy, technical

standards applied and an asset management plan detailing the change management process; • A system authorising access to the network and preventing access by unauthorised persons; • Emergency preparedness plans; • Monitoring, auditing and reviewing processes; • Key Performance Indicators; • Incident reporting and investigation processes; • Competence and training; • Record keeping; and • Reporting procedures for serious incidents.

Further information can be found in ESMS 10-03 Safety Management System.

9.3 Health and Safety Management

The AusNet Services safety vision is:

“Safety is our way of life. Protect and respect our people and community. Together we must achieve missionZero”

The AusNet Services’ health and safety management system complies with the Occupational Health and Safety Act (2004) and fulfils the requirements of AS/NZS 4801 Occupational Health and Safety Management Systems by enabling a framework to manage health and safety across our business. The primary aim of the health and safety management system is to establish an integrated, sustained and systematic approach to safety management in all areas of our activities. The strategy for managing health and safety over the next five years is:

16 30-4006 AusNet Services’ Integrated Response and Contingency System



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Through the setting of objectives and targets, and the incorporation of continuous improvement processes the Health and Safety Management System will be reviewed, and shaped for the future.

Safety is a core value at AusNet Services. Our missionZERO strategy will be achieved through strong safety leadership, safe behaviour, commitment to creating safe workplace environments and continuous improvements in safety systems and measurement. These missionZERO strategic elements illustrate our goals and objectives.

The AusNet Services’ missionZERO strategic elements provide the framework with which AusNet Services will achieve missionZERO. We rely on our leaders to set clear behavioural expectations and reinforce the reasons why it is important to work safely. In turn, our people must always have safety “front of mind” and apply safe behavioural decision making guided by our HSEQ management systems (policy, procedures, guidance materials, training and audit program).

The AusNet Services’ missionZERO HSEQ strategy aims to achieve the following objectives:

• ZERO injuries to our people, contractors and visitors; • ZERO tolerance of unsafe behaviour and acts; • ZERO compromise on safety; and • ZERO impacts to our families and communities.

Continuous improvement in HSEQ performance requires a commitment to improving line management accountability for safety and environment. Our leaders do take responsibility for the safety of our people.

The AusNet Services’ HSEQ plan has been developed in consultation with the executive and forms the basis of the AusNet Services’ vision and applies to all AusNet Services’ operations. Further information can be found in the Health, Safety, Environment and Quality (HSEQ) plan 2015-201617.

For further information please refer to AMS 10-15 Health and Safety Management.

17 HSEQ 01-01.



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9.4 Environmental Management

AusNet Services maintains a certified HSEQ Management System that applies to its electricity transmission assets. The HSEQ Management System drives the integration of policies, procedures and objectives pertinent to vegetation management, bushfire mitigation and environmental management to the AusNet Services’ HESQ policy and environmental objectives.

AusNet Services’ primary environmental objective is to protect the environment by responsibly managing the effects of our activities, while taking into account community concerns and threats to the functionality of the transmission network. On environmental matters, AusNet Services will:

• Conduct all operations in accordance with legislation; • Responsibly minimise adverse environmental effects and maximise favourable effects where possible;

and • Inform and consult with the community on significant environmental matters and respond effectively to

environmental concerns raised by the community.

Due to the importance of responsible environmental management, AusNet Services has embraced an environmental strategy that:

• Is designed to achieve effective compliance with regulation; • Minimises environmental risk to the business;and • Will be regularly audited (internally and externally) to assess compliance with the ISO 14001 standard,

regulatory requirements and good environmental practices.

Strategies include:

• Complete the final stage of the program of oil containment, treatment and drainage improvement works by December 2016.

• Continue to carry out soil testing in bunded and adjacent areas when replacing plant items containing large quantities of oil.

• Ensure any identified contaminated soil is disposed of appropriately and affected sites are remediated. • Continue to support revegetation of transmission line easements with appropriate vegetation. • Encourage the policy of sustainable vegetation on line easements. • Control pest plants and animals that may be harboured in terminal station sites and on line easements. • In consultation with neighbours, planning authorities and other stakeholders minimise the visual impact

of existing and new transmission assets, where practicable, as required to secure permission for the economic development of necessary infrastructure.

• Continue to monitor noise levels at terminal station sites and undertake abatement measures where noise exceeds legal limits.

• Address noise complaints to alleviate community concerns. • Continue to monitor SF6 leaks and trends from transmission assets • Locate and carry out repairs to SF6 leaks from transmission assets. • Ensure that any SF6 losses are minimised during gas processing for maintenance.

• Continue to work with the Department of Environment, Water, Land and Planning (DEWLP) to resolve outstanding issues relating to easements on Crown Land.

• Continue to identify and repair / replace damaged bridges that provide AusNet Services with minimum time access to line assets, subject to agreement with the DEWLP.

• Continue to reinstate access tracks that have been affected by heavy rains and flood events to acceptable conditions.

• Ensure Aboriginal cultural heritage is protected18.

18 For further information refer EMS 21-60: Protection of Aboriginal Cultural Heritage.



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• Conserve aesthetic, architectural or historical interests in maintaining buildings with historical importance19.

• Pay special consideration20 when pruning or removal of “significant vegetation”21

For further information please refer to AMS 10-14 Environmental Management.

9.5 Condition Monitoring

AusNet Services utilises online and off-line condition monitoring (CM) techniques to continuously improve levels of network reliability and safety. The asset condition information is critical for the optimisation of maintenance plans and prioritisation of asset replacement programs.

Existing CM programs for the Victorian electricity transmission network comprise visual inspections, off-line diagnostic tests, on-line or real time monitoring and routine non-invasive scanning. Although AusNet Services manages a large CM program, the application of contemporary condition monitoring techniques to all network assets has not yet been fully implemented. Limited application of new technologies has taken place due to high costs of particular monitoring systems, resource constraints and the developing nature of certain condition monitoring techniques.

AusNet Services is committed to further development of condition monitoring techniques including the enhancement of recently adopted technologies and through close monitoring of emerging technologies.

Key Strategies:

• Continue CAMS (CVT asset monitoring system, real-time monitoring of CVTS using SCADA).

• Continue Oil and SF6 sampling for analysis (CBs, GIS, Transformers, oil filled regulators, OLTCs, CTs).

• Climbing inspections every 3 years of transmission line structures to assess conductor, fittings insulators, attachment points, steel work and foundation condition.

• CM of power transformers using 6 yearly testing of bushings, windings, insulation and surge arresters.

• UHF partial discharge (PD) monitoring for GIS.

• Diagnostic testing of CBs and motorised disconnectors(contact resistance, mechanism and pole timing, etc.)

• Aerial survey and automated image processing (SAIP) to detect ACSR conductor defects involving a full coverage over a 3 year period followed by a reduced ongoing program to cover 50% in each following 3 year period.

• Commercialise and deploy 24/7 PD monitoring system in terminal stations where major augmentation works are proposed.

• Using LiDAR for vegetation & easement management, calibration of dynamic line rating system and network safety information on ground clearances

• Formalise economic CM methods for surge arrestors, SVCs, synchronous condensers22, polymer insulators and underground cables.

• Develop end of life condition modelling based on autopsies of removed assets.

19 Section 4(1) of the Planning & Environment Act 1987. 20 For further information refer BFM 10-06: Vegetation Management Plan (Transmission) 21 The term “significant vegetation” is defined in BFM 10-06 as the location of areas containing trees that are native or listed in a planning

scheme to be historical, aesthetic or ecological significance or trees of cultural or environmental significance, or contain threatened fauna that may need to be pruned or removed to ensure compliance with the Code of Practice.

22 Development will only occur if an ongoing need to maintain the existing synchronous condensers is established.



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• Investigate condition monitoring of polymer insulators.

• Research techniques for condition assessment of transmission tower foundations.

• Perform further research on introducing additional early warning methods for the transmission line conductor corrosion.

• Develop a power line fault detection system.

• Continue to support commercial innovation and participate in R&D Collaborations

For further information please refer to AMS 10-13 Condition Monitoring.

9.6 Plant and Equipment Maintenance

AusNet Services’ asset maintenance strategies ensure the safe and reliable operation of the transmission network assets. The asset maintenance strategies are developed using engineering best practice, incorporating manufacturer recommendations, and are in accordance with ESV guidelines. AusNet Services’ maintenance strategies are reflected in the Electrical Safety Management System which has been accepted by ESV.

AusNet Services’ maintenance programs are primarily managed via SAP, a computerised maintenance management systems (CMMS). Predominantly, the asset maintenance plan is enacted based on a recurrent nature, and is categorised into scheduled maintenance, corrective unscheduled maintenance and emergency maintenance tasks.

The highest volume of tasks completed as part of asset maintenance plan are scheduled maintenance tasks which involve time based inspection, or overhauls of network assets. During these tasks condition based data is collected to allow for predictive corrective maintenance to be carried out. Issues or defects identified through asset inspection, or overhaul process are rectified as corrective maintenance tasks within predefined timeframes, depending on the level of risk associated with the defect. Corrective maintenance can also involve investigation and resolution of equipment monitoring alarms received via the SCADA system. Emergency maintenance tasks require urgent attention and are usually triggered by fault events which adversely affect the overall availability of the transmission network.

AusNet Services also manages a program of Non-recurrent maintenance works. These works include tasks that do not meet the financial criteria for capitalisation, and have work scopes that are too large or specialised to be included in the normal maintenance plan (for recurrent works). They are not time or operation based and are generally non-repetitive, one-off projects or programs put in place to address specific problems. Examples include tower-corrosion mitigation works.

Reliability Centred Maintenance (RCM) techniques have been used to develop plant asset replacement models. Scheduled maintenance intervals and work instruction steps can be optimised through the application of RCM methodologies. The effectiveness of RCM based maintenance plans depends upon the quality of asset failure data and condition data collected during inspection tasks. This requirement has identified the need for improvements in order to progress the efficiency and effectiveness of current plant and equipment maintenance strategies. AusNet Services has introduced the initial stages of predictive based maintenance through the use of condition monitoring techniques.

Key Strategies:

• Maintain certification of asset management practices to an acknowledged standard such as PAS 55 or ISO 55000

• Adopt AS IEC 60300 Dependability Management to clarify the asset management framework and standardise practices in the Enterprise Asset Management (EAM) system.

• Enhance life cycle management of assets during: Concept & definition, design & development, manufacturing, installation, operational & maintenance, and disposal (IEC60300-2 Annex C)



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• Further development of plant and equipment performance analytics using contemporary techniques to underpin business decision making.

• Progressively refine the use of electronic data collection devices to enable field personnel to more easily collate asset failure and condition data.

• Ensure that data captured during maintenance tasks supports the implementation of RCM and regulatory data collection obligations

• Quantify and validate condition indices and implement algorithmic condition assessments to further enhance the objective condition assessment process.

• Where economic, specify built-in condition monitoring and self-testing facilities for new assets.

For further information please refer to AMS 10-19 Plant and Equipment Maintenance.

9.7 Asset Management Information Systems

AusNet Services’ main asset management information systems are SAP for asset and work management, TRESIS for relay settings, Ratings Database Repository (RADAR) for plant and equipment ratings and Field Mobile Inspection (FMI) for recording asset inspections.

The progressive development of asset management information systems is coordinated by the Enterprise Asset Management (EAM) program within the Business Systems Asset Management Strategy.

The key drivers of improvement in information systems are:

• Improving data quality for informed operation and strategic decision making; • Increasing costs of supporting disparate, customised, non-interfaced systems; • High risks associated with reliance on the ‘local knowledge’ of a mature-aged workforce; • Repeatable, transparent and auditable processes to assure compliance to regulatory and safety

obligations; and • Replacement of obsolete legacy systems.

Key development strategies include:

• Extend the electronic collection of data via mobile computing devices and automatic links between the EAM/ERP system and SCADA.

• Progressively implement the Enterprise Asset Management program to form a single authoritative asset and inventory register incorporating works management, and logistics management which includes:

• Consolidation of asset data from disparate systems within EAM/ERP system

• De-commission disparate systems

• Have common processes across the business for the same functions across the asset life cycle.

• As necessary, establish links from EAM/ERP system to other systems to facilitate automatic updates

• Establish web browser architecture to facilitate remote access by authorised stakeholders to view information and reports.

• Implement a flexible reporting capability that caters for routine and ad hoc requests from stakeholders.

• Ensure that there are appropriate data security and data recovery plans in place.

• Develop the presentation of EAM/ERP data in a GIS view so geography, topology and environmental factors can be combined with but not limited to asset or condition data and details of work completed or planned.



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For further information please refer to AMS 10-10 Asset Management Information Systems.

9.8 Network Performance Monitoring

The effectiveness of AusNet Services’ asset management practices is measured directly by the performance of extra high voltage network elements and their impact on the availability and reliability of the Victorian electricity transmission network in which they operate. The development of these practices requires the reliable capture of accurate information and data, effective analysis and trending and robust decision support tools.

The vision for network performance management is to improve the information and data collection and analysis process to a level that will facilitate enhanced network performance and maximise the return on investment during the ten-year planning period.

Key Strategies:

• Develop the ability to monitor and report on more KPIs which are additional to the STPIS.

• Recording of outage impacts for AER reports.

• Building an in-house information server to reliably analyse and monitor market information.

• Investigate the possibility of using the SAP system to improve operational efficiencies and provide greater immediate market transparency of AusNet Services’ operations.

• Develop incorporated modules for analysing System Incidents.

• Using SAP to generate System Incident reports automatically in predetermined format.

• Investigate system improvement possibilities of IMS system and implement. • Develop integrated modules to enable data analysis. • Incorporate systems that can prepare reports in predetermined formats for various benchmarking

requirements.

• Review the benefit and adequacy of current benchmarking activities.

• Target Improvements in completion and the accuracy of coding corrective maintenance Problem Cause Remedy (PCR) coding. Target 100% to be coded, and less than 10% of corrective maintenance to be coded ‘Other’.

• Automate PCR analysis of all equipment types for benchmarking.

For further information please refer to AMS 10-17 Network Performance Monitoring.



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9.9 Operations Management

The operation of the overall system and of individual assets is a key part of asset management to ensure that system performance targets are achieved, the integrity of the assets is not compromised, and safety and environmental requirements are met.

Current sites have different information sent back and in differing formats together with overlap in responsibilities for systems and processes that add to the complexity of managing the transmission network.

An over-riding principle is to ensure that operational staff have access to systems that can provide them with relevant information in a format that assists them to make timely and accurate decisions.

The following strategies will provide improved operation of the network:

• Maximise asset utilisation with the support of control schemes and support systems such as System Overload Control Scheme (SOCS), RADAR and Overload Shedding Scheme for Connection Assets (OSSCA).

• Optimise the timing of planned asset outages with the support of systems such as POMS and SAP.

• Utilise proactive and real-time condition monitoring of assets.

• Provide rapid fault response with the assistance of SCADA and real-time fault analysis.

• Record and analyse fault events using the SIR and Defective Apparatus Report (DAR) processes.

• Audit the short circuit ratings of primary plant in stations that are operating at or close to the designed rating.

For further information please refer to AMS 10-18 Operations Management.

9.10 Program delivery and optimisation

AusNet Services has an overarching Portfolio Framework which sets out the high level processes for the governance and management of capital programs and projects from conception (IDEA), through planning, business case approval, detailed design (PLAN), delivery (BUILD) and close out (CLOSE) phases as demonstrated in Figure 19.

The Enterprise Program Management Office (EPMO) ensures that capital projects (discrete projects) across each of the company networks (Electricity Transmission & Distribution, Gas Distribution, and ICT) adhere to the portfolio framework and enterprise-wide governance processes. As shown in Figure 19, stage gate checks are performed by the EPMO across lifecycle phases to ensure projects comply with set requirements prior to proceeding to the next phase. The EPMO also centrally facilitates the business case approval & change control request process.

The EPMO is also responsible for providing monthly reporting to senior management on the overall capital expenditure (capex) program. This provides for a centralised & transparent view of the monthly and EOY forecast capex position, so appropriate action can be taken by the relevant portfolios to meet the EOY target position.



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Figure 19 – AusNet Services Portfolio Framework

The Program Delivery group provides management and resources to deliver the AusNet Services’ maintenance and capital works programs relating to network assets. The project lifecycle is supported by the SAP system and work instructions.

The resource model includes the use of internal and external resources in the delivery of maintenance and capital works programs.

AusNet Services has formed Strategic Alliances with companies that provide design services, installation services and maintenance services. Contract arrangements are performance-based with benchmarking of costs and standards to ensure that quality and value is maintained throughout the contract.

Strategies for program delivery and optimisation are:

• Maintain key internal resources within the Program Delivery area to ensure that strategic works and program control services can be sustained;

• Assess the synergies between the transmission and electricity distribution businesses with respect to resource planning by considering the common and similar skill areas;

• Plan maintenance and capital works to ensure the efficient use of resources, the maximisation of network availability and the reduction of risks to supply security;

• Provide program management resources on a functional basis, covering project control, estimation, engineering standards and field technical services;

• Use unified systems which link the core project activities of planning, estimation and costing.

• Use the Constructability, Operability and Maintainability review process to test and confirm the appropriateness of technical decision making at key stages in the development and execution of major network augmentation, refurbishment and replacement projects;



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• Conduct internal Post Implementation Reviews or lessons learned of all projects, with key projects undergoing these reviews by independent teams such as the EPMO and where necessary, external consultants;

• Use the zone substation design guide and the pre-qualified design service providers to ensure that engineering and quality standards are maintained;

• Maintain construction resources within AusNet Services to ensure that key strategic projects can be delivered to the required schedule; and

• Control and supervise all site works through the field service areas to ensure safety, network security and quality of workmanship.

9.11 Asset Replacement and Refurbishment

In deciding between the replacement and refurbishment of assets, a range of asset management options are identified and evaluated, utility practices analysed and supporting arguments developed. Primary requirements for any replacement or refurbishment decision are a well-defined asset management strategy, a sound knowledge of asset condition and related factors affecting performance and expected technical life. AusNet Services’ plant maintenance strategies and their supporting asset risk models provide guidance on optimal asset management approaches for different asset classes operating on the transmission network.

Key Strategies:

• Broaden and enhance the use of on-line-condition-monitoring tools and techniques to uniformly gather, analyse and rank condition assessment data for major assets including power transformers, transmission lines and circuit breakers;

• Broaden and enhance the use of asset risk models to optimise the volume and timing of asset renewal programs;

• Use asset risk models to determine the optimal asset management strategies for different asset classes, specifically supporting decisions around the adoption of “replace on failure” or “risk based replacement” strategies;

• Refine the process used to manage ongoing changes to the selected portfolio to ensure that the the optimal set of capital projects is resourced; and

• Quantify the economics of each technically feasible remedial option and select the most economic option subject to pragmatic decisions on project risk (likelihood that selected option can be delivered as specified).

For further information please refer to AMS 10-11 Asset Replacement and Refurbishment.

9.12 Process and Configuration Management

The focus of Process and Configuration Management is Station Intelligence (SI) which embraces protection, control and monitoring functions within terminal stations, operated partly automatically and partly by manual control, which is predominantly remotely accessed but may also be locally accessed.

The protection, control and monitoring functions covered by the term ‘SI’ have been going through a fundamental change of technology, philosophy, capability and worldwide uniformity for more than 10 years but the pace of the change seems to be ever increasing. The main changes are related to increases of data processing power of digital Intelligent Electronic Devices, developments in digital communication and new configuration schemes being developed.



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Key SI strategies include:

• Develop new standards and refine existing standards in the areas of protection and automation philosophy, design solutions, practices and technology with a focus on economically efficiency.

• Progress the definition and standardization of the modular composition and interfaces of the Station Intelligence.

• For future systems, re-builds and extensions introduce the international standard IEC61850, new communication architecture, improved functionality of intelligent modules at several levels, and introduce new interface technology between the primary network and the substation intelligence systems where traditional instrument transformers will be replaced with digital sensors providing measured data via optical fibre links.

• Explore new opportunities emerging with the progress in digital technology, smart network methods and international cooperation. Economic innovations will be introduced at various modular levels.

For further information please refer to AMS 10-20 Process and Configuration Management.



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10 Plant Strategies

The following sections discuss in more detail the assets, issues and strategies selected to meet future network performance targets and to maintain a sustainable risk profile.

10.1 Auxiliary Systems

Station auxiliaries include diesel generators, compressed air systems, fire detection and suppression systems, secondary cables, and Direct Current (DC) power supplies and earth grids.

10.1.1 DC Systems

Terminal Station DC Supplies are critical to providing power to all protection, control, metering and SCADA systems. AusNet Services’ transmission network includes 255 individual Direct Current (DC) power supplies comprising batteries, battery chargers, DC power distribution switch boards, isolation, wiring and monitoring and alarm equipment. Failure of DC Supplies at a Terminal Station would have serious consequences, rendering a station uncontrollable and without protection The Australian Energy Market Operator’s (AEMO’s) Protection and Control Requirements specify duplicated and physically segregated “X” and “Y” DC batteries and chargers are provided with sufficient capacity to run identified station DC services for up to 10 hours.

In addition clause 5.1 (f) of the Electricity Network Agreement states that:

‘each terminal station must be provided with duplicated secondary Equipment such that no single electrical or mechanical failure or malfunction within the Secondary Equipment prevents that Terminal Station supplying electrical energy from the Transmission Network to Connected Parties up to relevant Ratings’23.

Most stations now have 250 V X and 250 V Y Control batteries and no longer have a 48 V Control battery, but provide the 48 V control supply via duplicated DC-DC converters from the 250 V batteries. Older station designs had separate dedicated single 250 V Control battery and 50 V Control batteries. Almost all stations have now been upgraded to have duplicated 250 V batteries. Separate control and communications batteries are provided to allow for the different rating times between control and protection functions and communication functions, but also segregate communications equipment from transients imposed by the switchyard wiring and equipment.

Batteries are subject to regular maintenance and planned replacement of cells after the expected life. Chargers are replaced on failure or as required by station augmentation. Older distribution and monitoring boards contain asbestos and so present health and safety risks.

DC systems strategies include:

10.1.1.1. Batteries

• Where economic replace batteries in conjunction with future terminal station rebuild projects. • As required replace selected batteries as part of DC Supply Upgrade Stage 3 project (XC84). • Station design is to continue to ensure that battery capacity is sufficient to meet the station load for the

required period. • Regularly inspect batteries for terminal corrosion, post growth, electrolyte level, electrolyte leakage,

voltage level, connection lead conditions and cleanliness. • Periodically review innovations in battery technology for more reliable and economic energy storage

options. • Establish spare portable 250 V and 50 V batteries for emergency use.

23 Network Agreement between Power Net Victoria and Victorian Power Exchange 1997.



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10.1.1.2. Battery Chargers

• Where economic replace chargers in conjunction with battery replacements during future terminal station rebuild projects.

• As required replace selected chargers as part of DC Supply Upgrade Stage 3 project (XC84). • Progressively augment charger functionality with temperature compensation and boost charging

facilities as recommended by battery manufacturers.

10.1.1.3. Battery Rooms & Distribution Boards

• Battery rooms are to be progressively upgraded to Australian Standards in respect of ventilation, lighting, floor sealing, eyewash facilities and manual handling requirements.

• DC power distribution boards manufactured from or containing asbestos reinforced panels shall be replaced before 2025.

10.1.1.4. DC Power Supply Alarms and Monitoring

• Continue to monitor DC-DC converters.

For further information refer to the detailed plant strategy, AMS 10-52 Auxiliary Power Supplies.

10.1.2 Diesel Generators

Diesel generators provide emergency, auxiliary 415 V AC supply at critical locations (terminal stations and communications sites) in the event of total loss of normal auxiliary supplies.

The majority of diesel generators located at terminal stations are provided for black start capability and those at remote communication sites are required to reduce the risks associated with the loss of critical network communication systems.

There are currently no major issues associated with the management of diesel generators.

Key asset management strategies include:

• Continue with current maintenance and operational practices. • Validate accuracy of diesel generator information as part of SAP migration close out activities. • Develop and apply a quantitative condition assessment methodology. • Economically replace diesel generators based on condition. • Ensure adequate spare holding levels.

For further information refer to the AMS 10-58 Diesel Generators detailed plant strategy.



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10.1.3 Fire Detection and Suppression Systems

Fire detection and suppression systems are required to minimise asset damage in case of fire. All the terminal stations in AusNet Services’ transmission network are provided with fire detection and suppression systems.

Terminal station buildings and switchyards are equipped with a combination of FPSs and FSSs such as:

• Very Early Smoke Detection and Alarm (VESDA) Fire Detection Systems (FDTS); • Multi zoned Smoke detectors and Fire Indicator Board (FIB); • Portable Fire Extinguisher (PFE); • Fire rated doors and walls between zones; • Fire pillows; • Fire walls; • Water Deluge System (WDS); • Fire Hydrant System (FHS).

The FPS and FSS assets are in place to mitigate the effects of potentially destructive fires. A fire in a terminal station can cause extensive damage to critical assets in the electricity supply chain which can take time to replace thereby causing long supply disruptions resulting in huge disruption to the community. Fire at terminal stations also has potential to spread, which poses a high risk for properties, etc, in surrounding areas. Hence detection of fire and initiation of fire suppression as early as possible is the key to minimising fire related risks in terminal stations.

Condition assessments at terminal stations indicate that 53% of FHS assets and 60% of WDS assets are in poor or very poor condition and are likely to require replacement / refurbishment within the next ten years. Upgrade programs and replacement projects have been initiated for the affected terminal stations and are expected to be complete by 2022.

The strategies to address risks imposed by the fire detection and suppression systems on Victorian transmission terminal stations include:

• Continue regular inspection and tests for all FPSs in accordance with the relevant Australian Standards (AS1851).

• Ensure completion of the fire risk study proposed to assess the effectiveness of [C.I.C]. • Progressively replace all the remaining FHSs in C4 and C5 conditions with systems complying with

relevant Australian Standards by the end of 2022. • Refurbish / replace WDSs that are in C4 and C5 conditions. • Retrofit adequate fire protection measures for spare transformers at HWTS and SMTS.

• Replace failing smoke detectors and FIPs in Control Buildings.

For further information refer to the detailed plant strategy, AMS 10-61 Fire Detection and Suppression.



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10.2 Capacitor Banks

The Victorian electricity transmission network includes 71 capacitor banks in service at 29 terminal stations. Capacitor banks range in size from 5.4 MVAr to 220 MVAr and are connected at voltages ranging from 22 kV up to and including 330 kV.

The primary purpose of a capacitor bank is to stabilise the network operating voltage particularly during heavy demand periods. Capacitor banks can also minimise electrical power losses, optimise the utilisation of transformers and lines augmentations and act as harmonic filters in Static VAR Compensators.

Prior to 2003, many capacitor cans containing Polychlorinated Biphenyls (PCB) were replaced and thus the capacitor fleet is relatively young with a mean service age of 18 years. Consistent with the service age profile, the majority of capacitor banks are in very good and good condition, with zero assets in very poor condition.

Between 2003 and 2013, the volume of Defective Asset Reports (DARs) or system incidents for capacitor banks has exhibited year to year variation equating to approximately eight DARs annually. In 2014 there was an increase in DARs that caused the increase in capacitor bank issues operating at 66 kV and 220 kV.

Key strategies for the continuing management of capacitor banks are to:

• Continue to monitor the performance of capacitor banks. • Continue to hold sufficient spares for capacitor cans to cover in service failures. • Maintain adequate spares for capacitor bank reactors. • Continue with the annual program of thermo-vision testing of capacitor banks. • Implement the measurement and recording of individual capacitor can capacitance measurements

together with their serial numbers and unique location. • Continue to monitor the reactors with paint flaking off for any rapid deterioration.

For further information refer to the detailed plant strategy AMS 10-53 Capacitor Banks.

10.3 Circuit Breakers

The Victorian electricity transmission network’s population of over 1,000 circuit breakers maintain the safety, reliability, quality and security of supply from the transmission network. Circuit breakers are electrical switches that, in conjunction with protection systems, operate automatically to protect the public and workers from electrical hazards and protect the electricity network from damage caused by overload and short-circuit faults. Circuit breakers are also used in day to day network operations to switch capacitor banks and to isolate parts of the network to enable maintenance or augmentation works.

Approximately 34% of circuit breakers in the fleet are in “poor” condition (C4) while another 7% are in “very poor” condition (C5). The overall strategic approach involves addressing those circuit breakers with high failure risks by virtue of their poor condition, modes of failure or location in critical circuits through specialised maintenance or refurbishment and selective replacement programs.

The circuit breaker risk assessment using the Availability Workbench software demonstrated a significant overall cost saving through planned replacement of 344 circuit breakers in C4 and C5 conditions over the next ten-year period.

Planned station rebuild projects integrating the network augmentation needs of the Australian Energy Market Operator (AEMO) and distribution network service providers (DNSP) with asset replacement needs will include the economic replacement of 53 circuit breakers over the period 2015 to 2022.



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Key strategies for the circuit breakers include:

• Replace [C.I.C ] bulk oil circuit breakers by 2022. • Replace high risk 220 kV minimum oil [C.I.C ] circuit breakers by 2022. • Prioritise replacement of 220kV minimum oil CBs in poor condition; [C.I.C ] types

by 2022. • Replace 66 kV [C.I.C ] circuit breakers by 2022. • Prioritise replacement of [C.I.C ] CBs in poor condition within next seven years. • Refurbish [C.I.C ] circuit breakers within next seven years. • Continue to repair SF6 leaks in a timely manner. • Review the performance of older SF6 CBs and develop refurbishment programs as required. • Replace poor performing SF6 Capacitor Bank CBs such as [C.I.C ] type before second wear out

refurbishment. • Monitor developments of vacuum technology at 66kV and introduce SF6 free CBs into the network,

where economic.

For further information refer to the plant strategy AMS 10-54 Circuit Breakers.

10.4 Civil Infrastructure

Assets within the classification of civil infrastructure include buildings, roads, footpaths, surfaced areas, foundations, support structures, signage, fences, cable ducting and trenching, water pipes, sewerage pipes and drains.

The strategies are aimed at ensuring the effective, economic and consistent management of civil infrastructure assets in all terminal stations.

Condition assessments for civil infrastructure assets at 49 terminal stations indicate that approximately 30 per cent of these assets require refurbishment / replacement within the next 10 years. This can be achieved through targeted civil infrastructure work programs or inclusions in planned station rebuild projects.

The principle asset management strategies are:

• Perform civil infrastructure condition assessments at the remaining 26 terminal stations by 2017 and record results in the Asset Management System.

• Following completion of the civil infrastructure condition assessments, determine the optimum frequency for future inspections at each station and incorporate this into the existing civil infrastructure maintenance program.

• Include recurring condition assessments of civil infrastructure assets in the scheduled maintenance program for terminal stations.

• Complete the asbestos containing material (ACM) removal program by 2025. • Supplement renewal, replacement or augmentation of condition C4 & C5 civil infrastructure in the

scopes of major augmentation and station re-build projects as and when economic. • Initiate targeted civil infrastructure (in condition C4 & C5) upgrade projects for sites with no major

projects/rebuild planned in next 10 years. • Where economic use relocatable buildings for new or major building refurbishments. • Investigate the use of pre-fabricated concrete slab foundations for selected primary plant such as

power transformers and capacitor banks. • Complete final stage of oil containment and water treatment works by March 2016. • Continue to upgrade security systems including CCTV camera surveillance systems and fences in

compliance with AMS 10-63: Infrastructure Security.



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• Continue to upgrade fire protection systems assets in compliance with AMS 10-61: Fire Detection and Suppression.

Please refer to the following documents for further information:

• AMS 10-14 Environmental Management; • AMS 10-15 Health and Safety Management; • AMS 10-55 Civil Infrastructure; • AMS 10-63 Infrastructure Security.

10.5 Communication Systems

AusNet Services maintains and operates communication infrastructure and equipment at more than 110 sites primarily to provide:

• Electrical protection signalling between generating stations and terminal stations. • Electrical protection signalling between terminal stations and other terminal stations. • Monitoring and control signalling between AusNet Services’ Customer and Energy Operations Team

(CEOT), generators, terminal stations, and AEMO. • Operational voice and business communication between NOC, offices, depots, terminal stations,

generating stations, distribution zone substations, connected interstate transmission and generating stations and AEMO.

These services are enabled through various telecommunications technologies, including:

• Bearers (optical, copper, power line and microwave radio) interconnecting sites. • Wireline technologies (SDH, PDH, WDM, routing, switching, etc.). • Telephony systems (OTN, CEOT console systems, mobile radio, etc.). • Gateways (interconnections to external/3rd parties). • Supporting Facilities(e.g. battery systems, radio towers).

10.5.1 Investment Drivers

Some of the key investment drivers governing the communication systems are:

• Compliance with regulatory and performance requirements outline in the National Electricity Rules (NER), the Electricity Safety Act (section 98(a)) and ISO27001 framework;

• Availability of spares, technical support from the vendors and manufacturers to achive high level of availability requirements;

• Rapidly changing technologies and ompatibility issues with legacy systems;

• End-to-end timing performance of mission critical protection and control signals such that operational schemes effectively operate within constraints of plant and electricity system requirements;

• Supportability of equipment to enable effective communications network augmentation, maintenance and cyber security features.



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10.5.2 Strategies

In consideration of the investment drivers mentioned above, key strategies include:

• Ensure a minimum of 2 independent communications bearers to each EHV Terminal Station site, in line with EHV plant protection scheme and NER regulatory requirements.

• Where applicable, establish and/or maintain a 3rd (independent) communications bearer to select transmission sites where excessive operational risk and repair/restoration times justify.

• Where justified , install OPGW in conjunction with planned EHV ground wire replacement programs.

• Maintain and/or replace existing ADSS based on end-of-life and/or physical/optical condition degradation when economic.

• Migrate existing 2G (GPRS) services to equivalent wireless service (3G/4G) prior to service termination date (end of 2016).

• Migrate 3G wireless technology to equivalent (wireless) service when required.

• Identify opportunities for Wireline Networks consolidation where feasible and justified.

• Develop a centralised network management system capability for both the OMN and ODN network devices.

• Reduce the number of network layers and devices through consolidation where economic.

• At time of asset replacement, identify opportunities (where feasible) to consolidate separate network gateways (that access 3rd party services).

• Consolidate multiple Inter-Data Centre link (Richmond and Rowville) gateways.

• At time of telephony system replacement, identify opportunities for system consolidation to minimise total cost of ownership, system complexity and feature inconsistency. Identify alignment of business wide requirements/features in line with telephony system capability.

• Replace batteries at risk of failure within the next five years.

• Enable extended back-up power capability through use of external diesel generator capability (or alternative technologies) to ensure uptime during extended (mains) power outages.

• Replace end-of-life network management systems hardware and software, including DR capability, in line with enterprise server architecture principles.

• Existing supporting applications to be kept current in line with vendor software version upgrades and associated vendor support framework.

• Align ICT initiatives with the NIST Cybersecurity Framework.

• Implement Network Security Monitoring (NSM) and allow for remote forensic investigation and reporting by SOC and InfoSec teams.

• Implement anti-tamper alerts on all cabinets or rooms that house ICS equipment, Satellite, 3G/4G or radio gear used for ICS.

• Implement Passive Vulnerability Assessment toolsets specifically for the ICS environment.

• Implement authentication proxy to enforce authentication, and automated revocation / continuous audit of access to any new or legacy ICS device, incorporating lockout policies to reduce risk of brute force attempts.

• Integrate auth-proxy to SIEM with audit tools to govern operational practices to remove, disable or rename default system accounts, enforce account lockout policies, and use of strong passwords and alert to SIEM.

For further information please refer to AMS 10-56 Communication Systems.



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10.6 Disconnectors and Earth Switches

AusNet Services has approximately 2,526 air-insulated disconnectors and 1,463 earth switches installed on the Victorian electricity transmission network.

After a circuit breaker has interrupted the relevant electrical current, a disconnector is used to create a physical separation between selected equipment and each source of electrical energy. A disconnector is an off-load switching device that electrically isolates selected equipment to permit safe inspection or maintenance.

Earth switches are closed (or portable earth leads are attached) to electrically connect selected isolated equipment to the general mass of earth via the station earth grid. The combined use of disconnectors and earth switches creates a safe working environment for inspection or maintenance, by preventing the formation of an electrical potential on the selected equipment.

Forty per cent of disconnectors and 18% of earth switches on the Victorian electricity transmission network have provided over 40 years of service. Three percent of earth switches are in C5 (very poor) condition while 57% are either in C1 (very good) or C2 (good) conditions.

As significant proportions of each fleet of disconnectors (29% of ≤ 66 kV, 8% of 220 kV, 24% of 330 kV and 26% of 500 kV) have been assessed as in C5 (very poor condition), disconnector replacement will continue to be a significant component of the scope of circuit breaker and station refurbishment projects through the planning period. With fewer station refurbishment projects forecasted in future, standalone switch replacement projects will be required to replace assets in “very poor” condition which pose a significant safety risk to workers.

Key asset management strategies for Disconnectors and Earth Switches include:

10.6.1 New installations

• Install 22 kV and 66 kV rotating double-break design isolators in new installations. • Review station service transformer supply design to minimise future use of fused isolators. • Install earth switches instead of earth receptacles at 220 kV and above for future earthing installations. • Install motorised rotary double break disconnectors to 220 kV and above new disconnector

installations.

10.6.2 Inspection

• Develop an inspection regime for disconnectors and earth switches by 2018. • Continue annual non-invasive inspection of disconnectors with particular attention paid to heavily

loaded circuits.

10.6.3 Maintenance

• Review maintenance regime with a focus on the selection of lubricants for disconnectors and earth switches

• Review and update specifications for disconnectors and earth switches to extend the maintenance intervals to better match that of new SF6 switchgear.

10.6.4 Refurbishment

• Continue to implement design modifications of the 220 kV [C.I.C ] earth switches • Where economic refurbish or replace 22 kV and 66 kV high-risk fused isolators and underslung

isolators in C5 condition. • Where economic refurbish or replace 220 kV and above high-risk disconnectors and earth switches

which are in C5 condition.



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10.6.5 Replacement

• Replace disconnectors and earth switches if their thermal or short circuit rating is exceeded.

• Where economic, include disconnector replacement in the scope of circuit breaker replacement and station refurbishment projects.

For further information please refer to the detailed plant strategy, AMS 10-59 Disconectors and Earth Switches.

10.7 Earth Grids

Earth grids are installed to ensure safety of personnel, to provide a low impedance path for fault currents to protect electrical equipment and to ensure correct operation of the electrical protection schemes.

Earthing systems consist of buried main earth grid electrodes and earthing conductors that are connected to equipment or other infrastructure from main earth grid electrodes within terminal stations. The earth grids were installed when the terminal station switchyards and communication sites were originally established. They have been progressively augmented as additional plant was installed. The condition of the earth grids can generally be regarded as good.

The condition of some station overhead earth wires is showing a level of deterioration due to surface corrosion, and is monitored during inspection.

For transmission lines, overhead earth wires were also installed at the same time that the transmission lines were constructed. Some original overhead earth wires have been replaced by optical fibre ground wire as part of augmentation of protection and communication system. Overhead earth wires for transmission lines are covered in AMS 10-79 – Transmission Line Conductors.

Key asset management strategies include:

• Complete the earthing system condition monitoring program for station earth grids

• Undertake analysis of historical results to establish an understanding of the capability of each earth grid

• Ensure earth grid step and touch voltage hazard limits for operational and maintenance requirements are consistent with international limits24, national limits25 and are specified in the AusNet Services Station Design Manual.

• Continue monitoring program for terminal stations main earth grid electrodes and earthing conductors, continue the ongoing monitoring programs.

• For terminal station overhead earth wires, continue to carry out visual inspections at a maximum interval of 2 years and replace deteriorated earth wires and connectors when appropriate.

• Continue the practice of visual inspection and earth continuity tests on representative critical earthing joints/connectors and sample main earth grid conductors during major terminal station projects.

• Continue to test earthing performance, and to analyse results to determine if augmentation and/or enhancement works are required based on risk assessment.

For further information please refer to the detailed plant strategy, AMS 10-60 Earth Grids.

24 International limits include IEC 61936-1, IEC 60479.1 and IEEE 80. 25 National limits include AS 2067, AS 7000 and AS60479.



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10.8 Gas Insulated Switchgear

AusNet Services has a total of 56 GIS equipment installed in the Victorian electricity transmission network.

The service age of GIS assets vary from one to 34 years with approximately 40% of the GIS equipment population in C1 (Very good) condition. Approximately 27% of the population is in condition C4 (Poor) and 11% is in condition C5 (Very Poor).

New GIS installations are planned for Brunswick and Richmond terminal stations by the end of 2016 and 2022 respectively. Additionally, one 66 kV GIS bus at WMTS is planned to be replaced with a GIS bus.

The current condition of GIS equipment indicates replacements at RTS and WMTS, and refurbishment activities at SYTS are expected before 2020. The remaining risks presented by the GIS equipment fleet will be addressed by closely monitoring the performance of individual assets and through planned maintenance and refurbishment works.

Key strategies to address the issues outlined above are:

• Continue monitoring the performance of all GIS to determine the need for refurbishment or replacement;

• Complete refurbishment of SYTS GIS – including reducing SF6 gas leakage;

• Audit SMTS GIS equipment and investigate if mid-life refurbishment is required; and

• Review long lead time spares holdings and contingency planning.

For further information please refer to the detailed plant strategy AMS 10-62 Gas Insulated Switchgear.

10.9 Infrastructure Security

The Commonwealth and state governments have imposed legal responsibility on the owners and operators of critical infrastructure, such as electricity transmission network installations, to take all necessary preventative security measures to ensure the continuity of supply. AusNet Services maintains more than 100 electricity transmission network installations that are subject to security provisions, including terminal stations, communication sites, depots and offices.

Credible security threats, having potential impacts on members of the public, the broader community and on the commercial viability of AusNet Services can be broadly classified as:

• Safety – of untrained persons in the vicinity of energy containing equipment; • Malicious – motivated by revenge, fame, association or challenge; • Criminal – profit driven and includes theft, fraud, sabotage or extortion; • Terrorism – use or threat of force or violence to influence the government or public through fear or

intimidation.

AusNet Services’ Infrastructure Security Risk Assessment Tool (ISRAT) is used on a site-specific basis for critical infrastructure and for major sites. ISRAT is based on the principles established in:

• National Guidelines for Unauthorised Entry Prevention, Energy Networks Australia, and • ISO 31000:2009, “Risk management – Guidelines on principles and implementation of risk

management”.



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The application of physical security control measures will be based on:

• Consistent risk identification and quantification;

• Defence in depth;

• Deterrence;

• Delay;

• Detection;

• Response;

• Contingency planning.

Commensurate with the assessed risk of unauthorised access and physical security policy, key strategies for the implementation of infrastructure security management are dependent on the risk at each site. Strategies include:

10.9.1 High Risk

In conjunction with network augmentation and asset replacement projects at existing higher-risk terminal stations over the next decade:

10.9.2 Medium Risk

• Install footing plinths under existing security fences.

• Install risers and flat looped barbed tape anti-climb measures on existing security fences.

• Install SCADA monitored microphonic or vibration detectors on existing security fences.

• Harden the exterior of control / relay buildings with projectile-resistant walls, security and fire-rated doors and window grills.

• Review / install SCADA monitoring of motion detectors within relay and switch rooms.

• Install SCADA controls for switchyard and building lighting.

[C.I.C]



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10.9.3 Low Risk

• Install footing plinths under existing security fences.

• Install risers and flat looped barbed tape anti-climb measures on existing security fences.

• Harden the exterior of control/relay buildings with projectile-resistant walls, security and fire-rated doors and window grills.

• Review / install SCADA monitoring of motion detectors in relay and switch rooms.

• Install SCADA controls for switchyard and building lighting.

For further information please refer to AMS 10-63 Infrastructure Security.

10.10 Power Cables

There are two main categories of power cables within the transmission network, namely Interconnecting and Station cables. Interconnecting cables are utilised to connect one station to another station, for example Brunswick terminal station (BTS) to Richmond terminal station (RTS), while Station cables connect items of plant within a particular station.

Within the Victorian electricity transmission network, AusNet Services owns and maintains two 220 kV interconnecting cables between Brunswick terminal station (BTS) – Richmond terminal station (RTS) and Eildon Power Station (EPS) – Thomastown terminal station (TTS) and one 66 kV interconnecting cable between Loy Yang Sub-station and Loy Yang South sub-station.

There are approximately 172 Station cables installed within various terminal stations throughout Victoria operating at each voltage level of the transmission network depending on the plant to which the cable is connected.

The majority of the power cable population has been in service for 20 to 40 years and is mainly in average to poor condition, with no cables in very poor condition. The strategic factors affecting the management of power cables are the change from oil filled cables to XLPE cables and the spares management for obsolete cables.

AusNet Services’ key asset management strategies for Power Cables include:

• Combine cable replacement, where possible, with other capital works. Otherwise, repair or replace based on condition;

• Develop and implement an oil filled cable contingency plan to help manage the impact of a fault on an oil filled cable;

• Update cable asset records and fault response plans; • Undertake a full review of cable spares to address the risks associated with cable failure; and

• Enhance Commission and Condition Assessment test techniques including the introduction of DTS.

For further information refer to the AMS 10-66 Power Cables detailed plant strategy.

10.11 Secondary Systems

Protection assets are combined in systems to detect electrical faults on the transmission network and, via the operation of circuit breakers, rapidly disconnect faulted circuits from sound circuits. Protection systems are designed to protect operators and the public from hazardous electrical conditions, limit damage to network equipment and maintain the network’s electrical operating parameters within selected limits to ensure reliable energy supplies to consumers.



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Secondary assets include devices to measure the network’s electrical operating parameters and monitor the function and condition of selected primary network assets. This data is essential for the effective tactical operation of the network,fulfilling commercial agreements between connected parties and the strategic management of primary assets. Examples include revenue metering, power quality monitoring, transformer loading and temperature measurement, circuit breaker operation, and monitoring insulating oil degradation and prevailing weather.

Control assets are arranged in systems to provide automatic or remote manual control of the function of primary assets. These systems are essential for the effective and efficient control of power flows within the network and include functions such as transformer voltage regulation and cooling system control, reactive voltage control, load shedding and runback schemes.

Secondary assets become obsolete within a typical timeframe of 15 years when they are no longer supported by manufacturers, are technically incompatible with interfacing equipment or are no longer able to provide the functionality established in industry standards or regulation.

An overarching strategy is to integrate secondary asset modernisation projects within Terminal Station rebuild projects or major primary asset replacement projects wherever economic. This approach ensures good technical and economic outcomes with efficient design, coordinated delivery and fewer circuit outages during implementation. Stand-alone secondary projects are initiated only where no suitable Terminal Station rebuild project or primary asset replacement project is planned in an appropriate timeframe and asset condition warrants replacement or augmentation.

Key secondary system asset management strategies include:

• Develop standard schemes and procure new assets with the capability for simultaneous operation of IEC61850 and DNP3 communication protocols ensuring compatibility with existing systems on brownfield sites and appropriate communication speeds for modern IP-based equipment.

• Continue asset inspection and maintenance in accordance with PGI 02-01-02. • Review and update PGI 02-01-02 by 2018. • Integrate secondary asset modernisation projects within terminal station rebuild projects or major asset

replacement projects wherever economic. • Ensure stand-alone secondary projects are initiated only where no suitable major projects is planned in

an appropriate timeframe. • Review the secondary assets condition and update the asset management systems by 2019. • In conjunction with the annual review of network contingency plans review spares requirement for

critical relays and maintain stock levels.

For further information refer to AMS 10-68 Secondary Systems.

10.12 Static VAR Compensators

AusNet Services has four Static VAR Compensators (SVCs) installed; two units at Rowville (ROTS) and single units at Horsham (HOTS) and Kerang (KGTS) terminal stations. SVCs are required for dynamic voltage control at critical locations on the transmission network.

The SVC serves to regulate system voltages by using the Thyristor Controlled Reactor (TCR) to consume VARs from the network under capacitive loading conditions. Conversely, under inductive loading conditions the SVC uses the Thyristor Switched Capacitor (TSC) to add VARs to the network. The use of the SVC facilitates continuous voltage stability enabling the network to withstand unplanned outage events such as the loss of a line following lightning strike.

The control systems (including thyristors) on two of the four SVCs date back to initial construction and consist of obsolete technology which is unsupported by the manufacturer ([C.I.C]). Obsolescence of these control systems increases existing risks associated with failure as fault rectification works are slow and difficult resulting in extended unplanned outages.



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Unplanned outages of SVCs constrain the network’s energy transfer capability, increasing the cost of electricity which negatively impacts the energy market. Furthermore, failure of the SVC control system at KGTS in 2008 resulted in poor performance against the availability component of STPIS. Risk assessments reveal that replacement of the two remaining [C.I.C] control systems would be prudent.

AusNet Services’ key asset management strategies for SVCs include:

• Continue with scheduled maintenance and existing inspection procedures. • Introduce regular PD testing on the thyristors and their controls at KGTS and HOTS SVCs for the years

leading to their upgrades. • Replace the reactive plant controls of the KGTS SVC with new Alstom controls and thyristors. • Replace the reactive plant controls of the HOTS SVC with new Alstom controls and thyristors. • Hold adequate air core reactor spares for the deteriorated TCR reactors at ROTS 2 SVC.

• Replace the deteriorating 10.4 kV wall bushings at ROTS.

For further information refer to the detailed plant strategy AMS 10-71 Static VAR Compensators.

10.13 Surge Arresters

Surge arresters protect expensive plant from over voltages caused by lightning strikes or transient switching voltages.

The population of 2,139 surge arresters in AusNet Services’ Victorian electricity transmission network is predominantly gapless metal oxide (approximately 97%) and the remainder are gapped silicon carbide (approximately 3%), and based on housing the population of surge arresters are 27 per cent of porcelain housed units and 73% of polymer housed units respectively.

The primary focus is on the replacement of silicon carbide surge arresters that have porcelain housings (currently in poor condition) with the metal oxide type with polymer housing.

In comparison to the more modern polymer housed units, failures of ageing surge arresters with porcelain housings pose a significantly higher safety risk that has an accompanying risk of collateral damage.

Currently, 3% of the surge arrester population are in “poor” and “very poor” conditions and should be replaced over the next 10 years.

The following summarises the key surge arrester asset management strategies:

• Complete replacement of 90% of the silicon carbide surge arresters (this constitutes 100% of surge arresters carrying risk of high impact failure will be replaced) by 2020.

• Complete replacement of surge arresters in conditions C4 (poor) and C5 (very poor) by the end of 2022.

• Where possible, coordinate the replacement of silicon carbide, C4 and C5 surge arresters with major station or plant replacement works.

• Commence investigation on the first generation porcelain housed metal oxide surge arresters for condition deterioration.

• Investigate the economic viability of implementing an online condition assessment program to benchmark the condition of metal oxide surge arresters.

Further information can be found in AMS 10-73 Surge Arresters.



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10.14 Synchronous Condensers

AusNet Services currently has two synchronous condensers in service in electricity transmission network. The synchronous condenser installed at Brooklyn Terminal Station (BLTS) in 1971, was refurbished in 2005/2006 and is currently providing an adequate level of service. The synchronous condenser installed at Templestowe Terminal Station (TSTS) in 1967 is becoming unreliable and presents safety hazards to workers.

The Australian Energy Market Operator (AEMO) determined that the services of the synchronous condensers installed at Fisherman’s Bend terminal station (FBTS) is no longer required26 and AusNet Services switched this machine off. Both synchronous condensers at BLTS and TSTS need to remain in service until April 2017 at least. AusNet Services expects to incur the minimum expenditure requied to keep these machines safe and in service.

10.15 Transformers

Power transformers and oil filled reactors are an essential component of the Victorian electricity transmission network. These specialised assets are required to transfer power between circuits to maintain quality and security of supply in a safe manner. AusNet Services’ power transformer and oil filled reactor fleet includes a total of 142 transformer banks with ratings from 35 MVA to 1000 MVA. These transformer banks include 45 single-phase and 127 three-phase transformers, operating at 22 kV, 66 kV, 220 kV, 330 kV and 500 kV. Energy losses in the Victorian electricity transmission network have been reduced by progressively replacing single-phase 220 kV transformers with more efficient three-phase units. Importantly, replacement of deteriorated transformers with units incorporating modern technology extends maintenance cycles and rationalisation reduces the probability of transformer failures.

Transformers in Victoria are operated at high utilisation levels as a result of the probabilistic planning criteria that are used to plan the transmission network in Victoria. Cyclic ratings rather than continuous ratings are also used in the economic assessment, which results in higher load levels. The high ambient temperatures, during the extended 2002 – 2009 drought, coupled with high utilisation and poor cooling designs of the [C.I.C] transformer have negatively impacted the maintenance, reliability and the condition of power transformers.

The long term targeted replacement and component refurbishment programs are demonstrating positive outcomes in effective management of the fleet’s reliability as shown in the volume of unplanned maintenance on power transformers over the period 2000 to 2014 peaking in the 2006-10 period. Also in the similar period the major failure rates peaked with six major failures of power transformers, driving the Victorian failure rate above the CIGRE Australia average of 0.4% per annum. As the current condition of the overall fleet indicates above-average deterioration for 32 % of the power transformer fleet with 25% of the above average deteriorated units in the ‘extremely advance’ condition that should be addressed by the appropriately identified economical solution of either asset replacement or refurbishment.

Reliability centred maintenance models show that a reactive management approach; such as “Do Nothing” or “Replace on Failure” is neither prudent nor economic with an associated increase in failure risk over the next ten years. Continuing investment in power transformer refurbishment and replacement is necessary to economically manage failure risks which are being driven by the value of unserved energy, declining reliability and measurable deterioration.

Key strategies for the Power Transformers and Oil Filled Reactors include:

10.15.1 New Assets

• Continue to improve the tender specification for power transformers by making use of experience gained by maintenance, refurbishment and emerging and tested new technologies.

• Continue to evaluate suppliers for their ability to provide transformers that meet the requirements of the AusNet Services transformer tender specification.

26 AEMO letter to Manager Regulation and Network Strategy dated 7/08/15: Synchronous condensers at Brooklyn, Fisherman’s Bend

and Templestowe terminal stations.



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• Continue to conduct Design reviews to ensure that suppliers understand the requirements contained in the AusNet Services transformer tender specification.

• Continue to inspect and monitor transformers during each stage of manufacture to ensure compliance with the requirements of the transformer contract.

• Perform transformer tests to confirm that the transformer meets design expectations and operational performance before the end of manufacturer’s warranty period.

10.15.2 Monitoring, Maintenance and Refurbishment

• Continue to carry out routine monitoring and testing of transformer on a periodic basis to detect incipient failure behaviour and assess general condition.

• Undertake mid-life refurbishment of selected transformers to extend asset life where economic. • Monitor closely transformers with deteriorating individual components i.e. core and winding, bushings,

oil condition, OLTC or external components, which typically being assessed at C4 or C5 condition. Implement necessary repair or refurbishment to manage the risk of unexpected transformer outage.

• Continue replacement program for SRBP and Oil impregnated paper bushings identified as being in poor condition.

• Continue the program to repair significant oil leaks and oil damaged wiring on transformers. • Continue to paint and treat corrosion on transformers which exhibit poor external condition. • Continue to hold appropriate contingency spare transformers and components in order to provide a

satisfactory network contingency response.

10.15.3 Replacement

• Replace 15 power transformers recommended by the reliability modelling and the remaining five Condition 5 power transformers that are approaching end of life within next 10 years.

• Where economic replace high risk power transformers as part of major station rebuild projects.

For further information refer to AMS 10-67 Power Transformers and Oil-Filled Reactors.

10.16 Instrument Transformers

Instrument transformers provide accurate measurements of the operating voltages and currents necessary for the safe, reliable and economic protection and control of the Victorian electricity transmission network and its interconnections with the National Electricity Market (NEM). AusNet Services’ instrument transformer fleet consists of 3380 units including current transformers (CTs), inductive voltage transformers (VTs) and capacitive voltage transformers (CVTs).

The majority of units in service are still of oil-insulated porcelain-housed construction, but since 2005 there has been a transition to polymer housings. By 2007 all CTs were purchased with polymer housings and from 2012 CVTs and MVTs have also been procured with polymer housings.

A small number of instrument transformers are SF6 gas insulated units, and this number was expected to increase in coming years, but with the exception of 330 kV and above, the trend has reversed. The latest instrument transfomers have reverted to a paper-fluid insulation, with mineral oil in the bottom tank (where applicable). The volume of instrument transformers in service continues to increase with expansion of the network. However, this increase has been moderated over the last decade by replacement of deteriorated post-type CTs with toroidal CTs located within the bushings of new dead tank 220 kV and 66 kV circuit breakers.



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Over the last decade there have been significant replacements of both current transformers and voltage transformers as part of major asset replacement projects and in smaller projects focussed on managing specific supply risks to consumers, safety risks to workers and collateral plant damage risks within terminal stations. This replacement program has forestalled explosive failures and reduced the average service age of current transformers to 18 years and voltage transformers to 20 years. However, there are 482 instrument transformers with service ages greater than 40 years; which suggests they will approach the end of their useful lives by 2020.

Condition assessments based on dissolved gas analysis (DGA) confirm deterioration in over 36 single-phase extra high voltage CTs and over 33 high voltage CTs. Reliability centred maintenance (RCM) models clearly demonstrate that a reactive management approach; such as “Do Nothing” or “Replace on Failure” is neither prudent nor an economic strategy for the management of these deteriorated units. A smaller but continuing investment in instrument transformer replacement is necessary to economically manage failure risks which are being driven by worker health & safety, environment risks and collateral damage risks associated with explosive failure modes.

Following key strategies are aimed at meeting the obligations of the Electricity Safety Act and the National Electricity Rules:

10.16.1 New Assets

• Review and finalise the specification for purchasing instrument transformers by 2016.

10.16.2 Inspection, Monitoring & Testing

• Continue regular SF6 gas purity analysis on 500 kV SF6 filled CTs. • Continue to keep up-to-date with analysis and ranking techniques to assist the maintenance of a CT

condition priority list. • Continue and expand condition monitoring of CVTs by a comparison of their output voltages using the

CAMS system. • Continue to monitor the failure or replacement programs of other utilities to identify risk areas, and then

perform condition monitoring accordingly. • Continue DGA analysis of nominated CTs and inductive VTs by sampling the insulating medium during

scheduled maintenance. • Continue annual oil-sampling of Tyree CTs. • Develop an enhanced condition-monitoring program, including off-line electrical tests, as an alternative

to oil sampling/ DGA for specific higher risk CTs.

10.16.3 Maintenance

• Continue implementation of auto-isolation policy requirements for loss of SF6 pressure on 500 kV SF6 filled CTs.

• Finalise long term requirements for management of 166 [C.I.C] CTs (66 kV and 220 kV) supplied from 2005 to 2007.

• Optimise the spares inventory of CTs and CVTs to match the increasing need for condition based replacements.

• Continue the condition testing of the older instrument transformers in the spares inventory. • Perform autopsy strip downs of specific types of instrument transformers to verify physical condition

and to provide feedback to condition assessment and risk models. • Investigate the potential benefits of fibre optic current sensor (FOCS) technology as a potential

replacement for existing instrument transformer technologies.



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10.16.4 Refurbishment

• Reburbish instrument transformers where economic. AusNet Services’ experience is that replacement is more likely to be economic than refurbishment of instrument transformers which have experienced more than 50% of their expected service life.

10.16.5 Replacement

• Complete the replacement of 39 remaining 220 kV [C.I.C] CTs by 2022. • Replace remaining fleet of six 220 kV [C.I.C] CTs by 2022. • Replace 29 [C.I.C ] 220 kV CVTs over the next 5 years. • Replace three poor condition 220 kV Oil Filled post type magnetic VTs of type [C.I.C ]

by 2022. • Replace remaining 16 very poor and poor condition 66 kV [C.I.C ] VTs by 2022. • Complete replacement of 55 outstanding [C.I.C ] 500 kV CT units by 2022.

For further information refer to AMS 10-64 Instrument Transformers.

10.17 Transmission Lines

Asset management strategies for transmission line assets are separated into four logical asset classes; structures, structure footings, conductor and insulators.

10.17.1 Line Easements

The Victorian transmission line easements are approximately 3,600 kilometres in length and cover a total area of approximately 21,600 hectares.

Transmission line easements are generally held through allocation statements under the Electricity Industry Act and secure access rights for all transmission lines to ensure security of supply and so that maintenance activities can be performed.

The volume of transmission line easements has increased marginally in recent years mainly to accommodate connections of new generators and the extension of the transmission network to the desalination plant at Wonthaggi.

The key issues associated with transmission line easements include:

• Some line easements share usage with other infrastructure such as roads, railways, pipelines and fences posing increased health and safety risks;

• Non-compliant developments have been identified on transmission line easements which compromise the levels of safety and reliability of the overhead line;

• Additional non-compliant developments may exist on line easements which have not yet been assessed using aerial photography;

• Forced outages of transmission lines can be caused by bushfire on or in close proximity to easements; • Easement tracks can be adversely affected by heavy rainfall and require remedial works so that

adequate access is maintained; • Flashovers caused by the operation of equipment with no permission granted; and • Erosion due to land owner activity near towers placing tower integrity at risk.



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Key Asset Management Strategies include:

• Implement risk management plans which outline steps required to address identified non-compliant developments on easements.

• Extend inspections using aerial photography to all other transmission line easements situated within Melbourne Metropolitan boundary. Store all identified non-compliant developments in the asset management system against the relevant line easement segment numbers including detailed descriptions and associated levels of risk.

• Continue the regular patrols of the BTS – RTS and CBTS – WGI 220 kV cable easements.

• Quantify the feasibility of aerial laser vegetation-clearance scanning of transmission lines.

• Work in conjunction with DEWLP and CFA to develop fire risk assessments for the critical transmission corridors that consider vegetation near the transmission line or easement to quantify the fire risk to the corridors.

• Create a register of fuel loading and transmission corridors based on the fire risk assessments.

For further information refer to AMS 10-65 Line Easements.

10.17.2 Structures

There are approximately 13,000 transmission lines structures in service on the transmission network, 96 per cent of these structures are steel lattice towers situated along transmission line easements.

There have been 38 structure functional failures associated with ten extreme wind events affecting this transmission network since 1959. All failed structures were built to historical design standards with inadequate strength to withstand convective downdraft winds occurring during extreme storm events. Modern design standards produced in 2010 ensure sufficient structural capacity to withstand extreme wind events; however, structures designed to old standards still exist on the network.

The mean time between failures (MTBF) of transmission line structures has declined since 1992 due to failures of low-strength towers in extreme winds. Eleven structures along the Bendigo to Kerang line were replaced in January 2013. AusNet Services is undertaking the reinforcement of 108 towers from the Dederang to South Morang 330 kV lines. Risk assessments reveal that 48 structures on the Murray switching station to Dederang 330 kV lines present health and safety risks due to their proximity to road ways and will be upgraded before 2022.

The average age of structures is 45 years as the majority of the fleet were erected prior to 1965. Primary inspection techniques indicate that the structures are generally in good condition. The structure corrosion management program is extending the life of targeted structures where replacements are impracticable due to high cost and prolonged circuit outages. Typical corrosion mitigation works include structure painting and replacement of bolts and members.

The continuing installation of Fall Arrest Systems (FAS) will ensure the Occupational Health and Safety Regulations are met.

The key asset management strategies for transmission line structures include:



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10.17.2.1. New Assets:

• All new structures are designed and constructed in accordance with current industry guidelines and standards27.

10.17.2.2. Inspection:

• Continue to assess the condition of transmission line structures during structure routine inspections which are conducted at a maximum interval of every 37 months.

• Implement the use of Field Mobile Inspection (FMI) technologies for the collation of condition assessment data which facilitate automatic updates of Asset Management databases.

10.17.2.3. Maintenance:

• Continue to replace corroded or damaged steel members and bolts as part of corrective and scheduled maintenance programs.

• Continue to perform corrosion mitigation works on damaged or corroded towers. • Perform fleet wide risk assessment to identify corrosion mitigation works based on the structural

strength, corrositivity zone and failure effects. • Use the emergency restoration structures (ERS) to temporarily reinstate a line impacted by high

intensity winds.

10.17.2.4. Refurbishment:

• Continue to install Fall Arrest Systems (FAS) on remaining structures; approximately 78 per cent of the tower fleet will be retrofitted with FAS by 2022.

• Complete the installation of FAS on all rack structures and ground wire masts in terminal stations by 2022.

• Perform structural modelling of existing structures as part of tower upgrades and other lines projects, e.g. conductor and ground wire replacement projects.

• Approved project (XC78) to upgrade the strength and serviceability of 108 towers for the Dederang to South Morang 330 kV No.1 and No.2 circuits to the current design standard for overhead lines28 will be completed in 2016.

• Upgrade the physical strength of an additional 48 structures demonstrating high risk of functional failure due to inadequate design on the Murray switching station to Dederang No.1 and No. 2 circuits by 2022.

For further information refer to the detailed plant strategies, AMS 10-77 Transmission Lines Structures and AMS 10-65 Line Easements.

10.17.3 Structure Foundations

Transmission line structures are anchored and supported by structure footings. There are approximately 13,000 transmission line structures in service in the transmission network. There are six different types of structure foundations which comprise all components which are located below a point 300mm above the ground line. Different types of structure foundations in service include pier and slab, grillage, pyramid, tripod, bored (augured) and piled. Structure footings are generally in good condition.

27 AS/NZS 7000:2010 Overhead Line Design – Detailed Procedures. 28 AS/NZS 7000:2010 Overhead Line Design – Detailed Procedures.



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Generally steelwork exposed to soil corrodes more quickly than steelwork encased by concrete. Corrosion has been observed to be most severe in the top 100mm of soil where oxygen penetrates most freely. In order to prevent the deterioration of footings protective coatings called SOX are applied to the exposed areas.

The key issues associated with structures footings include:

• Structure footings corrode at ground line due to a mix of air and moisture.

• Structure foundations can be compromised by flooding due to wet weather events.

• Corrosion of direct buried steel footings is accelerated by electrical currents circulating between structure earths and a nearby terminal station earth grid or from stray currents from DC traction supplies. Cathodic protection systems are necessary to mitigate this effect in selected locations.

• Electrical fault currents may discharge through the tower foundations and create earth potential rise (EPR) at the tower legs and in soil surrounding the structure foundations and drive increased line trip events.

• Structure footing legs can be damaged by vehicles or farming machinery.

• Data records for structure foundations in the asset information system lack sufficient technical detail for future targeting of economic remedial works.

The key asset management strategies associated with transmission line structure footings include:

• Continue to perform visual inspection of structure footings as part of the routine inspection cycle. • Continue to monitor the status of the tower site and foundation for flooding, vegetation and erosion to

assure the safe performance of all structures. • Continue to perform life extension works on damaged or corroded footings identified as part of the

SOXS program. • Continue the program of inspections for cathodic protection systems. The effectiveness of cathodic

protection systems is maintained by inspecting and replenishing anodes. • Implement the use of Field Mobile Inspection (FMI) technologies to automatically update the asset

information system with condition assessment data.

For further information refer to the detailed plant strategies, AMS 10-78 Transmission Lines Structure Foundations and AMS 10-65 Line Easements.

10.17.4 Conductors

The total route length of EHV phase conductor on the transmission network exceeds 6,500 circuit kilometres. The phase conductors operate at four standard voltages including 500kV, 330kV, 220kV and 66kV. EHV conductors are protected from lightning strike by over 7,470 kilometres of ground-wire and optical fibre ground wire (OPGW). There are three different types of phase conductors in use on the transmission network including aluminium conductor steel reinforced (ACSR), all aluminium conductor (AAC) and all aluminium alloy conductor (AAAC). There are three different types of ground-wire in use on the transmission network including steel, ACSR and OPGW.

The fleet of transmission line conductors and ground wires are ageing. Approximately 24 per cent of the population has been in service for more than 50 years, this figure will increase to 58 per cent by 2022. A significant proportion of the ground wire population is now reaching its original design life and much of the conductor population will reach its design life in the next 10-20 years. Although conductor and ground wire assets are ageing, primary inspection techniques indicate that they are generally in good condition, however

http://ecm/pandp/Transmission%20Strategies/Plant%20Strategy/AMS%2010-78.pdf





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some assets are showing signs of corrosion based deterioration. Corrosion is most prevalent in areas exposed to coastal or industrial pollution.

Visual inspection of ACSR presents challenges in assessing the condition of the inner steel strands. Visual inspection techniques are limited in their ability to support the development of optimised conductor and ground wire replacement programs. Smart Aerial Image Processing (SAIP) inspection of conductor is being adopted as the standard inspection technique. This advanced condition monitoring technique is additional to the existing business as usual patrols and tower climbing practices.

There is an approved project (XC77) to replace approximately 79 km of ground wires by 2017. An additional 226 km ground wires are forecast for replacement before 2022. No conductor is forecast for replacement before 2022.

The key issues associated with conductor and ground-wire are as follows:

• Approximately 24 per cent of the conductor and ground wire fleet have been in service for more than 50 years29, this figure is forecast to be to approximately 58 per cent by 2022.

• Steel ground wires are approximately 44 percent of the ground wire fleet; most of them are in service for more than 50 years and are approaching the end of life.

• Corrosion of transmission line conductor and ground wire is accelerated in some areas due to exposure to harsh environmental conditions which can reduce expected service life by more than 50 per cent.

• Four per cent of transmission line conductor and ground-wire spans are displaying established signs of corrosion and require remedial action within ten years.

• Functional failure of conductors and ground wire on spans crossing road or rail corridors present significant public health and safety risks.

• Current condition assessment techniques for ACSR may not accurately assess the true condition of the internal steel strands. More advanced technologies offer more objective alternative such as the application of the SAIP system which can improve the accuracy of condition data collected.

• Accurately assessing the condition of mid span sections of conductor and ground wire during tower climbing inspections is very difficult. More advanced technologies such as the application of the SAIP system can improve the accuracy of condition data collected.

• Transmission line conductor and ground wire condition data is collected via a paper based system and subsequently converted to electronic format. This process is labour intensive and out dated. Field Mobile Inspection (FMI) systems offer a more advanced and efficient approach to collation of a wide range of asset data including condition grades.

The key asset management strategies associated with transmission line conductor include:


• All newly installed conductors are designed and constructed in accordance with current industry guidelines and standards30.

• Replace ground wires with OPGW where required for communication purposes. • AAAC is more corrosion resistant than ACSR and is suitable to be used in area subjected to extreme

corrosivity to ensure maximum life.

29 The expected asset lives of conductors and ground wires at low, moderate, severe and very severe corrosivity environment are 80, 70,

40 and 30 years respectively. 30 AS/NZS 7000:2010 Overhead Line Design – Detailed Procedures.



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• Adapt the use of Smart Aerial Image Processing (SAIP) technology to assess the condition of conductor and ground wire. A program of inspection involving a full coverage over a 3 year period followed by a reduced ongoing program to cover 50% in each following 3 year period is recommended.

• Complete Aerial Laser Surveys (ALS) using LIDAR laser technology on the remaining three per cent of transmission lines by 2022.

• Implement the use of the Field Mobile Inspection (FMI) system as the primary means of capturing condition assessment data. The FMI system must be designed to update the transmission asset management system as part of automated process.


• Replace or repair defective conductor and ground wire assets as part of corrective maintenance tasks. • Develop and implement a risk management plan for all transmission line spans identified as not

meeting current design standard by 2022.

10.17.4.4. Replacement:

• There is an approved project (XC77) to replace approximately 79 km of ground wires on the KTS-WMTS and KTS-GTS No.2 220 kV lines by 2017.

• Replace additional 226 km of ground wire (three per cent of the ground wire fleet) which have been deemed economically justified for replacement by April 2022. Ground wire replacements will address the highest risk spans as a priority.

For further information refer to AMS 10-79 Transmission Lines Conductors and AMS 10-65 Line Easements.

10.17.5 Insulators

Approximately 89,000 transmission line insulator strings are in service on the transmission, the majority of insulator strings are comprised of a number of linked discs made from either porcelain or glass with steel pins to form a continuous string. There are a growing number of polymeric insulators in operation which consist of composite polymer material that has a fibreglass core with a sheath made from silicone rubber or ethylene propylene diene monomer (EPDM).

AusNet Services has undertaken a large program of targeted insulator replacements which began in 2006. This program responded to increasing trends in insulator functional failures in the period between 2000 and 2007. Approximately 23,800 porcelain insulator strings comprising 27% of the total insulator fleet have been replaced with polymeric insulators since 2006. As a result of this replacement program there have been no insulator functional failures since 2009.

In order to maintain the performance and reliability improvements attained in recent years further selective insulator replacements are required.

AusNet Services has developed risk based models to assist with the application of formal risk assessments31 as required by the Electrical Safety (Management) Regulations 2009. Approximately 2,900 insulator strings (3.3% of the insulator fleet) are forecast for replacement before 202232 due to combinations of deteriorated condition, and high failure consequence locations.33

31 Electrical Safety (Management) Regulations 2009 – Clause 11. 32 From 2015 to 2022, approximately seven years. 33 There is an approved project (XC76) to replace 2040 insulator strings on various transmission lines over five financial years from

2015/16 to 2019/20.



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Implementation of this selective replacement strategy, addressing both failure frequency and consequences is necessary to maintain public safety and assist in meeting the safety objectives set out in AusNet Services’ MissionZero34 strategy.

This key issues associated with the transmission line insulator fleet are as follows:

• Approximately nine per cent of transmission line insulators are displaying established signs of corrosion or worse. This includes insulators exhibiting condition grades C4 and C5.

• Corrosion of transmission line insulators is accelerated in some areas due to exposure to harsh environmental conditions.

• Some transmission line insulators have become aged which means that the probability of failure is increasing due to the adverse effects of thermal cycling and cement growth.

• Limited research literature is available on the negative affect that age based phenomenon such as thermal cycling and cement growth have on the probability of the major electrical failure mode occurring in glass or porcelain insulators.

• Functional failure of insulators on structures adjacent to road or rail crossings presents health and safety risks.

• Volumes of polymer composite insulators on the transmission line network are increasing due to insulator replacement program. Research to develop techniques for accessing the condition and the remaining expected service life of these insulators is ongoing.

The key asset management strategies associated with transmission line insulators include:


• Current policy is to install polymeric insulators as part of insulator replacement programs. Polymeric insulators have an expected service life of 40 years which is considerably less than the porcelain, glass and mixed type (porcelain and glass) insulators.

• Polymeric insulators have been known to be attacked by birds if strung under dead line conditions. Provision will be made to prevent bird attack during project implementation planning.

• Fail-safe design concepts to be applied for insulation systems on new replacement of transmission line structures adjacent to high risk roadways and railways or proof test all insulator fittings prior to installation on towers across roads and railways.


• Continue to assess the condition of transmission line insulators during structure climbing inspections which are conducted at a maximum interval of every 37 months.

• Develop policies for inspection, maintenance and ultimate replacement of polymeric insulators considering expected service life. These policies must include a condition assessment methodology.

• Import all relevant technical asset data including condition assessment grades into SAP.

34 Mission zero is a company health and safety objective which aims at achieving zero injuries, zero tolerance, zero compromise and zero

impacts.



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• Replace defective insulator strings as part of corrective maintenance tasks. Complete string replacement is preferred as it is more economic and safer than replacement of an insulator from within a string of insulators.

10.17.5.4. Replacement:

• Selectively replace high failure risk insulator strings representing up to 3.3% of line insulator fleet before 202235. There is an approved project (XC76) to replace 2,040 insulator strings on various transmission lines over five financial years from 2015/16 to 2019/20.

For further information refer to the detailed plant strategies, AMS 10-75 Insulators and AMS 10-65 Line Easements.

35 From 2015 to 2022, approximately seven years.