ENERGEX Standard 00233 Inverters _30kW to 1000kW

Energex Limited Standard Standard 00233 22 April 2014 (V5) Energex Limited Standard No: 04240 24 Apr 2013 (V3 draft) No: 04240 15 Mar 2013 (V2)

Energex Limited 2014 Page 1 of 35 Page 1 of 35

Page 1 of 34

(Uncontrolled document when printed)

Customer Standard for Parallel Embedded Generation

Via Inverters - >30kW to 1000kW

This manual is to be read in conjunction with any current Standards Alerts. Standards Alerts may supersede information contained within this manual.

Approved by: C Lee



Page 2 of 34


Foreword

This Standard has been prepared by Energex to provide owners and proponents of embedded generation

installations via inverters information about their rights and obligations for the connection to and interfacing with the Energex Distribution Network.

Energex as the Distribution Network Service Provider, has an inherent obligation to ensure that such inverter energy system (IES) do not cause a material degradation in the quality of supply to other network users and do not adversely affect operation of the distribution network.



Page 3 of 34


Contents

Foreword .............................................................................................................................................. 2

Contents ............................................................................................................................................... 3

Section 1 - General .............................................................................................................................. 4 1.1 Scope ......................................................................................................................................... 4 1.2 Application.................................................................................................................................. 4 1.3 Object ......................................................................................................................................... 4 1.4 Referenced Documents .............................................................................................................. 5 1.5 Definitions For This Document ................................................................................................... 5 1.6 Changes from Previous Version ................................................................................................. 6

Section 2 - Network Connection Agreement ..................................................................................... 7 2.1 Network Connection Assets ....................................................................................................... 7 2.2 General Requirements For Connection Of Generators ............................................................... 8 2.3 Connection Enquiry .................................................................................................................... 8 2.4 Connection Enquiry Response ................................................................................................... 8 2.5 Connection Application ............................................................................................................... 8 2.6 Financial Requirements, Fees and Charges ............................................................................. 11

Section 3 - Technical Considerations .............................................................................................. 12 3.1 Stage 1 Initial Tests .................................................................................................................. 12 3.2 Technical Considerations Stage 2 Assessment & Mitigation Options .................................... 13 3.3 Types Of Embedded Generators .............................................................................................. 13

Section 4 - Technical Requirements And Performance Standards ................................................ 16 4.1 Scope ....................................................................................................................................... 16 4.2 Connection ............................................................................................................................... 16 4.3 Network Supply Arrangements ................................................................................................. 16 4.4 Supply Network Environment ................................................................................................... 16 4.5 Three Phase Balanced Inverters .............................................................................................. 17 4.6 Battery Energy Storage Systems (BESS) ................................................................................. 17 4.7 Strata-Title Developments with Bulk Metering .......................................................................... 17 4.8 IES Design and Construction.................................................................................................... 19 4.9 IES Operations ......................................................................................................................... 19 4.10 Protection of the IES ................................................................................................................ 20 4.11 Protection of the Distribution Network ....................................................................................... 21 4.12 Interruption and withstand capacity .......................................................................................... 23 4.13 Earth grid ................................................................................................................................. 23 4.14 System neutral earthing............................................................................................................ 23 4.15 Power factor ............................................................................................................................. 23 4.16 Steady State Voltage ................................................................................................................ 24 4.17 Disturbance issues ................................................................................................................... 24 4.18 Metering ................................................................................................................................... 26 4.19 Testing and commissioning ...................................................................................................... 27

Appendix A Backup Protection Requirements ............................................................................. 28

Appendix B Compliance Assessment Report .............................................................................. 29 Covering Letter (sample only) .............................................................................................................. 29 Attachment 1 Compliance Checklist ................................................................................................. 30 Attachment 2 PV/Inverter Checklist (Form 1552) .............................................................................. 31 Attachment 3 Circuit/Block Diagrams (samples only) ........................................................................ 32 Attachment 4 Compliance Assessment Report - Commissioning ...................................................... 34



Page 4 of 34


Section 1 - General

1.1 Scope

This Standard outlines the requirements for small to medium scale photo-voltaic (PV) three phase balanced type inverter Generating Systems with a total nameplate rating from >30kW up to but not exceeding 1000 kW at a single connection point; that are intended to be connected to and operate in parallel with, any part of Energexs distribution network under normal operating conditions.

1.2 Application

This Standard does not apply to:

Micro scale parallel customer generation via single phase unbalanced Inverters in the range up to 30 kVA (refer to Energexs Network Connection Agreement for Inverter Energy Systems (IES) Photovoltaic Systems and Microgenerators)

Embedded synchronous Generating Systems.

Non-parallel operating back-up generation

This document does not cover issues associated with the sale of electricity exported into the Energex distribution network. This is a matter between the proponent and their selected electricity retailer.

1.3 Object

The object of this Standard is to provide owners and Proponents of Inverter Energy Systems (IESs) information about their rights and obligations for connection to and interfacing with the Energex Network. Under National Electricity Rules (NER) 5.3 Energex has an obligation to review and process applications to connect or modify a connection which are submitted to it and must enter into a connection agreement with the applicant. This requirement covers both customer load and embedded generation plant.

Inverter energy systems (IESs), when connected to the Energex network, can impact the operating conditions, voltage profile and feeder load.

Energex has obligations to ensure safety and security of its network for ALL customers connected to

the Energex network. Energexs prime directives, in order of importance, are:

Safety of people (staff and general public)

Safety and security of plant and equipment

Minimise disruption (quality and reliability) of supply to network customers.

It is Energexs responsibility to ensure all proposed IES connections comply with these directives.



Page 5 of 34


1.4 Referenced Documents

1.4.1 Energex Standards

Copies of Energex Standards may be obtained from the following website

http://apps.energex.com.au/service_providers/technical_docs/asp/technical_documents.asp

1.4.2 Referenced Standards

Additional Australian Standards are listed in Energexs standard design documents.

AS 4777 Grid Connection of Energy Systems via Inverters, Parts 1, 2 and 3;

AS/NZS 3000 Electrical installations (known as the Australian/New Zealand Wiring Rules)

AS/NZS 3008 Electrical installationsSelection of cables

AS/NZS 5033 Installation of Photovoltaic (PV) Arrays

ENA ENA Guideline for the preparation for connection of Embedded Generation within Distribution Networks May 2011

1.5 Definitions For This Document

Anti-islanding protection

A protection system to detect islanded conditions and disconnect the PV inverter(s) from the network. Backup protection may be required where multiple inverters are installed together.

Connection Point: The agreed point of supply established between Network Service Provider(s) and another Registered Participant, Non-Registered Connection Applicant or franchise Connection Applicant.

Customer: A person who: (a) engages in the activity of purchasing electricity supplied through a transmission or distribution system to a connection point; and

(b) is registered by AEMO as a Customer under Chapter 2. (of the NER).

Distribution System: A distribution network, together with the connection assets associated with the distribution network which is another transmission or distribution system.

Electricity Distributor:

Energex is the owner, lessor and operator of the South East Queensland electricity distribution network.

Generating System:

The actual generator of electricity and all related equipment essential to its function as a single entity.

HV: High Voltage nominally above 1kV.

Interconnection Synchronous parallel operation of a generating system to the electricity network

Inverter Energy System (IES)

Performs the conversion of the variable DC output of the photovoltaic (PV) modules into a utility frequency AC power that can be fed into the Supply Network.

Islanding Occurs when the Supply Network is isolated and one or more PV generators remain connected to the isolated network and continues to supply load in this part of the network.

Low Voltage Connection Point:

This can range from the point of entry on a residence, to a low voltage fuse on a pole or pillar to the low voltage terminals of a distribution transformer.

Micro-embedded generating system via inverters

For the purpose of this Standard an embedded generating system via inverters that has a nameplate rating up to 10kW (one phase) or 30kW (three phase)



Page 6 of 34


Small to medium scale generating system via inverters

For the purpose of this Standard an embedded generating system via inverters that has an aggregated nameplate from >30 kW and up to 1000 kW three phase.

National Metering Identifier (NMI)

A National Metering Identifier as described in NER clause 7.3.1(d).

Supply Network: The apparatus, equipment, plant and buildings used to convey, and control the conveyance of, electricity to customers (whether wholesale or retail) excluding any connection assets. In relation to a Network Service Provider, a network owned, operated or controlled by that Network Service Provider.

Network Coupling Point

The point at which connection assets join a distribution network, used to identify the distribution service price payable by a Connection Applicant.

Network Augmentation Works:

Augmentation works required on network assets to enable a new project to be supplied or the increase in supply for an existing Connection Applicant.

Network Islanded Operation:

Generation is allowed to back feed into a portion of the distribution network that is isolated from the rest of the electricity supply network, typically as a result from a protection operation on the transmission or distribution network.

Proponent:

Means the Generator, Customer or developer or their agent (i.e. Consulting Engineers);

Retailer: Means the holder of an electricity retail licence granted under the Electricity Act, 1994, who is contracted to sell electricity to the Customer at the Supply Address.

Service Provider (SP): A person or organisation authorised by the DNSP to carry out design and/or construction of certain electrical works.

Compliance Assessment Report (CAR)

A report compiled by a Registered Professional Engineer of Queensland detailing the technical components of the Generating System, including single line and protection diagrams, protection settings and details of commissioning tests undertaken.

Three Phase Balanced Inverters

Means a three phase inverter configured to ensure balanced output to all phases at all times whilst connected to the Network and all three phases simultaneously disconnect from, or connect to the Network in response to protection or automatic controls (e.g. anti-islanding and subsequent reconnection).

Negotiated Customer Connection Contract (NCCC)

A commercial contract between the proponent and Energex which acts as the Network Connection Agreement and details the specifics of the IES

Wayside Loading The additional load off a shared network (either low voltage or 11kV depending on the situation) to provide a sink for excess power generated by the IES.

1.6 Changes from Previous Version

Removed reference to TUoS Sect 2.6. Sect 3.2 modified to give options where individual tests fail. Table 2 removed option for power export on shared LV circuits. Sect 4.11 Removed requirement for UPS to backup relay Sect 4.16 Added requirement for internal voltage rise calculation Appendix A NVD setting added, and reference added to internet site for approved relays.



Page 7 of 34


Section 2 - Network Connection Agreement

The Proponent of any IES installation must enter into a Connection Agreement with Energex. These connection agreements are subject to commercial negotiations between the parties. The Connection Agreement (Negotiated Customer Connection Contract or NCCC) encompasses both the technical and commercial aspects of the connection, addresses the Standards and Minimum Technical requirements and specifies the terms and conditions including the connection charge, use of system charges and quality of supply.

The Proponent shall indemnify Energex and accept liability for safety and supply quality issues that occur when the generator is operating. Energex will provide supply to local customer loads on a no-risk basis. This requirement shall apply to all loads that are connected on the customer side of the network Boundary and which can be supplied from the generator.

2.1 Network Connection Assets

Connection assets are those assets which are dedicated to providing connection services to a customer or generator. These asset boundary principles are summarised in Figure 1. The Network Coupling Point defines the boundary between Network and Connection Assets. The Connection Point identifies the ownership responsibility between Energex and the embedded generator. Revenue metering is normally installed as close as practicable to the Connection Point.

Where Connection Assets include transformers, the Network Coupling Point and low voltage metering will normally be on the low voltage side of the transformer. HV metering will be installed in situations where the customer owns and operates the HV assets.

Network

(HV)

Customer Facility or Development Site

Customers

Electrical Installation

Legend

NCP Network Coupling Point

CP Connection Point

MP Metering Point

NCP

MP

CP

Connection Assets HV

Customer Facility or

Development Site

Customers Electrical

Installation

MPCP

NCP

Connection Assets HV & LV

Customer Facility or Development Site

Customers

Electrical Installation

MP

CP

Customer Owned Connection Assets

HV

Customer 1

Customer 2

Customer 3

NCP

Figure 1: Asset Boundary Principles



Page 8 of 34


Energex may need to upgrade or augment the network to provide adequate capacity for connection of the IES. In addition, the Customer may require a separate low voltage circuit or supply transformer to mitigate possible voltage supply fluctuations to other customers. When determining whether a required section of network is Shared Network or Connection Asset, Energex will consider a planning horizon giving consideration to the potential for other developments in the area. Energexs Capital Contribution Policy and Network Pricing Principles Statement will apply with respect to augmentation of Shared Network associated with the new connection.

2.2 General Requirements For Connection Of Generators

The process for connection of an embedded generation system with an aggregated nameplate capacity in excess of 30kW is defined in the Energex Large Customer Connection Manual (BMS 03544).

Generators cannot be connected to the Energex Network without the approval of Energex (Qld Electricity Regulation Section 28). Energex approval to connect and commission an EG installation is only granted after entering into a Network Connection Agreement (proponent has returned a signed NCCC). Energex approval to connect will be revoked if the proponent fails to return an RPEQ certified Compliance Assessment Report (CAR) in a satisfactory timeframe.

Generators that are intending to export energy to the network must enter into a power purchase arrangement with an Energy Retailer and have export and import metering installed.

Connection Applicants facilities shall comply with technical and performance standards as defined in Section 4 of this document.

2.3 Connection Enquiry

A formal connection enquiry shall be made by the Proponent / Connection Applicant.

The enquiry must be submitted on the Energex LCC Connection Enquiry form.

It is recommended that the Connection Applicant makes early contact with an Electricity Retailer. The installation cannot be connected unless there is an electricity supply contract between the Connection Applicant and an Electricity Retailer.

Additional information may be required by Energex and this will be advised as necessary.

2.4 Connection Enquiry Response

A response will be provided which will detail the available connection options applicable to the Proponents proposed IES. Generally a response shall be made within 20 business days.

2.5 Connection Application

After considering the information provided by Energex in the enquiry response, the Connection Applicant may make a Connection Application, pay the application fee and include the information specified in the Connection Application Form.

It will be necessary for the Connection Applicant and Energex to formalise the works program. This program may be amended on the agreement of both Energex and the Connection Applicant.



Page 9 of 34


The Proponent may be required to submit the following technical information as part of their Connection Application.

(a) Detailed description of the IES facility; including, but not limited to:

I. Number of inverters and technical details

II. Proposed operating mode(s) - ie peak load lopping, continuous operation, seasonal operation etc.

III. Proposed interaction with Energexs distribution network under both normal network conditions and abnormal network conditions.

IV. Proposed local customer loads to be supplied from the IES facility.

V. Requirement for Customer Islanded operation. Note Network Islanded Operation is not permitted.

VI. Power export intentions refer also items (b) and (c) below.

VII. Known future staging / development of the IES facility and/or local customer loads.

(b) Anticipated 24 hour local customer load profiles (both summer and winter) for the local customer loads that are to be normally supplied from the IES facility. The profiles shall include apparent power (S), active power (P) and reactive power (Q) for both lightly loaded and maximum demand scenarios.

(c) Anticipated 24 hour power (import from network) / (export to network) profiles (both summer and winter) at the network connection point. The profiles shall include apparent power (S), active power (P) and reactive power (Q) for both lightly loaded and maximum demand scenarios.

(d) Site Plan showing the precise physical location of the embedded generator, the location of customer main switchboards and other relevant switchboards and the location of Energex substations and associated infrastructure.

(e) Detailed electrical single line diagram(s) showing the configuration of all IES facility / customer equipment and circuits between the IES(s) and the network connection point; including as a minimum:

All primary circuit equipment such as main switchboards, intermediate switchboards, circuit breakers and isolators/load break switches. In particular, all points where the customer embedded generation facility and the Energex distribution network can be connected / disconnected must be clearly identified.

All secondary protection and control equipment associated with the generators connection and parallel operation with the Energex distribution network including:

- current transformers, voltage transformers, protection and control elements and sensing points.

Local customer load connections including any interconnections with other parts of the customers installation. In particular, where interconnection with other parts of the customers installation are proposed the means to prevent paralleling of Energex substations / transformers and/or unsynchronised connection to the Energex distribution network shall be clearly identified.

All metering equipment associated with the generator and the import and export of power from/to the Energex distribution network.



Page 10 of 34


All proposed power factor correction equipment that will be installed within the part of the customers installation that is supplied directly from the embedded generator.

(f) Detailed functional block / schematic diagram of the protection and control systems relevant to the generators connection to the Energex distribution network showing the philosophy of the protection and control systems including all relevant relay current circuits, relay potential circuits, alarm and monitoring circuits, back-up systems, auxiliary power supply systems and proposed parameters / settings of all protection and control system elements.

(g) Detailed schematic diagram of the proposed earthing system arrangements for the

embedded generation facility and associated customer electrical installation including all proposed earth connections, MEN connections and relevant switchboard earthing arrangements.

(i) Proposed operating procedures, auto/manual reclose arrangements, bus interlocks. A detailed Operating procedures manual and communications plan may be required for Category 2 EG installations >150kW and/or HV connection points.

Sufficient detail must be provided to enable Energex to assess compliance with the minimum requirements outlined in this document, and conduct protection and load flow studies to assess the impact on plant fault ratings, protection scheme requirements and power export limits of existing infrastructure; and assess generator power factor and voltage limit requirements.



Page 11 of 34


2.6 Financial Requirements, Fees and Charges

The following fees in Table 1 apply for services provided by Energex to facilitate the connection works. Energex reserves the right to recover any project fees levied by a third party.

Table 1: Fees and Charges

Fee / Charge Type Purpose

Assessment Fee

Quoted fixed fee Where a proponent requires Energex to undertake a feasibility studies to consider generator connection options prior to making a formal application, the proponent and Energex may agree to undertake the study on a fee for service basis.

Application Fee Actual Costs apply Payable on lodgement of an Application to Connect. Covers the reasonable costs of all work anticipated to arise from assessment of the proposal and preparing the associated Offer to Connect.

Design and Construction of Connection Assets (Actual Costs Apply)

Actual costs apply as an up-front payment or progressive payments over construction period.

Where new connection assets must be designed and constructed to facilitate connection of an embedded generator, the connection application will generally be responsible for the cost of these assets as an up-front payment. New connection assets may include:

HV or LV power-lines

Associated switchgear

Protection equipment

Protection signalling telecommunications link

SCADA

The design and construction of large connection assets is contestable service. For full details of these arrangements refer to the LCC Manual (BMS 03544).

Design and Estimation Fee

Actual costs apply Covers the reasonable costs of preparing a cost estimate and design for the Connection Assets.

Property & Easements

Actual Costs apply Costs associated with property transactions including easements if undertaken by Energex.

Switching Quoted fixed fee HV or LV switching required for the Connection Applicant e.g., to isolate customers installation for works or testing.

Distribution use of Network Charges

On-going charges by Energex, included in Energy Retailers Power purchase and/or billing arrangements

Network charges reflect a customer or generators allocation or use of network capacity and are aimed at recovering the cost of investment in the shared network allocated to that party.

The NER requires Energex to calculate avoided NUoS (transmission use of system) charges.

For more details refer to Energexs Annual Pricing Principles Statement at http://www.energex.com.au

In addition to the above fees and charges, Energex may require other prudential requirements to be satisfied as part of a negotiated connection agreement. These arrangements may require lodgement of a bond or security that address financial risks.

Energex Limited Standard Standard 00233 22 April 2014 (V5)

Energex Limited 2014 Page 12 of 34


Section 3 - Technical Considerations

3.1 Stage 1 Initial Tests

Energex will assess all proposals for connection of inverter energy systems based on the following five criteria:

3.1.1 Test 1 - 11kV Feeder Penetration Test for HV Voltage Regulation

That the addition of the proposed inverter system will not cause the total installed PV capacity on the 11kV feeder to exceed 15% of the 50%POE load (50% of the assumed minimum daytime load), such that the feeder does not enter export mode back to the 11kV zone substation bus.

3.1.2 Test 2 - Transformer Penetration Test for LV Voltage Regulation

That the addition of the proposed inverter system will not cause the total installed PV capacity off a shared transformer to exceed 25% of the transformer nameplate rating, reducing the probability of the transformer entering net export mode back onto the 11kV feeder.

3.1.3 Test 3 - Maximum Single Phase Inverter Test (Unbalance) Not Applicable

That the maximum single phase inverter size does not exceed 10% of the transformer nameplate rating (single phase transformers), or 8% of the nameplate rating (three phase transformers). This test is not applicable to three phase balanced inverters.

3.1.4 Test 4 - 11kV Feeder Voltage Fluctuation & Distortion Test

Ratio Si / Sschv 0.1% Where: Si Three phase inverter rating (kVA) Sschv Three phase fault level at point of common coupling 11kV (kVA) To minimise voltage disturbance to customers on same 11kV network.

3.1.5 Test 5 - LV Feeder Voltage Regulation, Fluctuation & Distortion Test

Ratio Si / Ssclv 1.0% Where: Si Three phase inverter rating (kVA) Ssclv Three phase fault level at point of common coupling low voltage (kVA) To minimise voltage disturbance to customers on same low voltage network.

.




3.2 Technical Considerations Stage 2 Assessment & Mitigation Options

3.2.1 Options Where Proposed IES Fails Stage 1 Tests

Where the proposed system fails to meet the five criteria, the Proponent may have the following options:

Fails Test 1 and 2 (Over supply of IES on either 11kV or LV network) 3.2.1.1

Reduce size of proposed system

Install an approved power limiting device that prevents generation export to the network, or alternatively use advanced inverters with the capability to adjust Maximum Power Point Tracking (MPPT) to reduce generation and ensure zero net export to the network.

Install a dedicated transformer (where Test 2 fails only)

Fails Test 4 and 5 (Voltage rise on 11kV or LV network) 3.2.1.2

Reduce size of proposed system

Installing a dedicated low voltage circuit from the transformer (where Test 5 fails only)

Installing a dedicated transformer (where Test 5 fails only)

Install a four quadrant inverter with variable power factor setting and modify the power factor setting to reduce voltage rise to acceptable limits.

Having additional reactive compensation to reduce voltage rise on combination with inverter shedding

The Electricity Distributor will require information to perform the detailed analysis study and fees may apply. Network solutions such as a dedicated transformer or low voltage circuit shall be fully funded by the Proponent.

3.3 Types of Embedded Generators

Each IES connection can be classified according to a number of factors:

Size of system (total installed peak inverter capacity in kW and number of phases connected)

Connection point (HV or LV, and if LV is it from a dedicated transformer or shared LV network)

Export capability (is it expected that generation output may exceed customer load and cause power export back through either the LV or HV network).

Inverter connection (are all inverters connected through a common, independent power circuit, or are inverters distributed over a number of circuits providing additional services).

These parameters define the allowable connection arrangements and the rules for assessment of suitability, and are summarised in Tables 2 & 3. Further technical details are included in Section 4.




Table 2 Connection Arrangements / Customer Requirements

Customer Requirements

Connection Arrangement

>30 150kW IES

(3 phase)

151 1000kW IES

(3 phase)

Shared Transformer

Dedicated Transformer

Dedicated Transformer or HV Shared LV Circuit Dedicated LV Circuit

Load Offset Power Export Load Offset Power Export

Load Offset Power

Export Load Offset Power Export

Level 1 Backup protection1 Yes

NO

T A

LLO

WE

D

Yes

NO

T A

LLO

WE

D

Yes Yes Yes Yes

Level 2 Backup protection2 No No No NVD

4 NVD

4 NVD

4 and/or

intertrip

(on case by case)

Reverse power flow protection Yes Yes Yes Yes6 Yes Yes6

AS4777 inverters required Optional see

4.11

Optional see 4.11

Optional see 4.11 Optional see 4.11

Power Quality disturbances within limits specified

3 (see 4.17.2)

Yes Yes May be waived3 May be waived

3

Additional RPEQ design & certification Yes Yes

Yes Yes

Restrictions on total installed PV capacity (Sect 3.1)

Tests 1, 2, 4 &

5,or

Reverse power

relay set to nil

export + Sect

4.17

Tests 1, 2, &

4,or

Reverse power relay

set to nil export + Sect

4.17

1.Tests 1 and 4, or

Reverse power relay set to nil export + Sect 4.17

2. 100% of transformer nameplate rating

5

1.Tests 1 and 4,


5

1.Tests 1 and 4, or

Reverse power relay set to nil export + Sect 4.17


5

1.Tests 1 and 4,


5

TABLE 2 - NOTES

1. Level 1 backup protection over and under voltage, over and under frequency, voltage vector shift and rate of change of frequency (ROCOF for mixed synchronous/inverter networks only).

2. Level2 backup protection neutral voltage detection/unbalance, and/or direct intertrip to inverter (for systems 150kW and above).




3. Low voltage disturbance limits are set for Voltage fluctuation, Unbalance and Harmonics to ensure there is no adverse impact on the network at the point of common coupling with other customers. Where the PCC is at 11kV, these requirements may be waived by Energex.

4. Requirement for NVD protection may be waived when sufficient wayside load (customer or 11kV network) can be guaranteed to isolate the EG installation through UV/OV and prevent a network island. (0.5 x 11kV load > IES capacity < 0.5x min cust load).

5. Limiting total installed PV capacity to less than 100% nameplate rating ensures transformer is not overloaded for complete loss of customer load.

6. Reverse power relays are required even where full export is allowed to prevent islanding of the IES as well as restricting maximum export power.

Table 3 Connection Arrangements (Note Single line diagrams for some typical arrangements are given in Attachment 3)

APPLICATION GENERATION CAPACITY (kV.A)

PHASES CONNECTION TYPE METER TYPE

PROPERTY TITLE

EXPORT POTENTIAL

MAIN ISLANDING RISK

ADDITIONAL PROTECTION

EXAMPLE

>30 to 150

Category 1b

3 Dedicated or shared LV circuit

Single Strata LV Local LV network Anti-islanding to protect other LV customers

1

Retirement village

Strata titled C&I customers

>30 to 150

Category 1a

3 Dedicated or shared LV circuit

Single Individual LV Local LV network Anti-islanding to protect other LV customers

C& I customer

>30 to 150

Category 1

3 Dedicated transformer Single Any HV Local LV & HV network

Anti-islanding to protect other customers via HV

C&I customer with or without load or

Rural generator

151 to 1000

Category 2

3 Dedicated transformer Single Any HV Local LV & HV network

Anti-islanding to protect other customers via HV

Large C& I customer Solar farm

TABLE 3 - NOTES

1. For a retirement village or strata title application, where the combined PV inverter capacity is less than 25% of the transformer nameplate rating (reducing the risk of islanding on loss of mains), the requirement for additional anti-islanding protection may be waived subject to agreement from Energex (see Section 4.7).




Section 4 - Technical Requirements And Performance Standards

4.1 Scope

The technical conditions hereafter refer to the mandatory requirements for the Inverter Energy System (IES) configured as 3 phase installation and installed with multiple AS 4777 compliant inverters, or single inverter systems that meet the technical requirements of AS4777 and AS3100.

These Technical Requirements are applicable to the Proponents proposed IES and the Premises where the IES connection point resides.

If there is any inconsistency between these Technical Requirements and provisions in the Laws referred to in these Technical Requirements, the more stringent standards will be applicable (be they from the Laws or the Technical Requirements).

The Technical Requirements have been developed for the safety of Energex's and the Proponents operators and assets under normal operating conditions. These requirements ensure operation of the IES in parallel with Energex's Supply Network without interference to the continuity and quality of supply to Energex's other customers (refer to Energex Supply and Planning Manual BMS 01607).

4.2 Connection

These Technical Requirements provide for the connection of the Customers Premises (including the IES) to the Supply Network at the Connection Point. Unless otherwise agreed between the parties, the Connection Point is the only point at which the Premises may be connected to the Supply Network.

The Customer must not add additional inverters, or make modifications, to the IES which impact on the Supply Network or the ability to perform obligations, without prior written agreement from Energex. Additional solar panels are acceptable provided they match existing inverters capacity.

4.3 Network Supply Arrangements

For aggregate inverter ratings greater than 30kW, the network supply arrangements can be either:

Shared low voltage (LV) circuit connection to overhead or underground low voltage network shared with other customers.

Dedicated low voltage (LV) circuit from a distribution transformer for example a dedicated circuit supplied from the low voltage board of a shared transformer, or a dedicated overhead line or underground cable, feeding the Proponent only, directly from the terminals of a shared pole transformer. In this instance voltage rise and disturbance from the PV generation has less impact to other customers fed from this transformer.

Dedicated high voltage (HV) supply for the largest connections only, and generally detailed studies required and augmentation costs required from the Proponent for a HV connection.

4.4 Supply Network Environment

The Customer must ensure that the IES and other systems and facilities at the Premises operate satisfactorily:

for the full range of variation of system parameters and characteristics; and




with-in the distortions and disturbances specified in these technical requirements.

4.5 Three Phase Balanced Inverters

Three phase Inverters must be configured to ensure reasonably balanced output to all phases at all times whilst connected to the Network. All three phases of the Inverter must simultaneously disconnect from, or connect to the Network in response to protection or automatic controls (e.g. anti islanding and subsequent reconnection).

4.6 Battery Energy Storage Systems (BESS)

A battery energy storage system (BESS) provides an independent source of power from the Supply Network. Being able to supply energy needs from a battery storage system increases customers flexibility for when energy is taken from the Supply Network, or as a backup supply in the event of a loss of supply from the Supply Network. It is anticipated that energy storage, whether it be a stand-alone battery system, an electric vehicle, or some other arrangement, will enable customers to maximise their internal use of electricity generated by micro-embedded generators such as solar PV.

It is a requirement that:

All BESS systems with export to grid functionality will need to connect via a grid connect inverter compliant with AS 4777

Special studies will need to be done to confirm the impact on the Energex network the costs of which will be additional to the fixed Assessment Fee.

Reverse power flow protection installed to ensure BESS systems do not export energy when PV panels are not generating.

4.7 Strata-Title Developments with Bulk Metering

Where a strata-titled development (such as townhouses or a retirement village) is bulk metered, there are three supply options available to the Proponent:

Option 1 Aggregated IES off a separate circuit from the main switchboard that is not separately metered by the Proponent.

Option 2 Separate reticulation circuit for IES, individually metering of each inverter system by the Proponent.

Option 3 Aggregated IES and customer load off mixed circuits.

Options 1 and 2 require additional anti-islanding protection in accordance with Section 4.12. Option 3 may have the requirement for additional anti-islanding protection waived provided the total installed capacity is less than 25% of the transformer nameplate rating (as per Table 2 - Note 1) or Stage 2 Power Quality assessment of 2yr historical minimum load.




Figure 2 Supply Arrangements for Strata-Titled Bulk Metered Developments




4.8 IES Design and Construction

The Customer must ensure that:

o All IESs and associated equipment, including earth grid and earthing connections, are designed and constructed to conform to the requirements of this Standard, all relevant Laws, AS/NZS 3000, and Australian, International or British Standards relevant to the installed equipment and good electricity industry practice.

o Each inverter unit must be capable of safe and satisfactory operation in parallel with the Supply Network and be capable of effective and swift automatic disconnection from the Supply Network upon the occurrence of an inverter unit fault or a Supply Network fault.

o Line commutated inverters (interfaced between a DC source and an AC supply) have the advantage of not requiring special synchronising equipment, and of ceasing to generate in the event of a failure of the supply. Self-commutated inverters (interfaced between a DC source and an AC supply) are required to incorporate automatic synchronising equipment by means of electronic controls. The inverter must disconnect from the Energex Supply Network upon any irregularity in system voltage and frequency and/or failure of supply. In addition, the equipment must ensure that after a disconnection there is no chance of re-closing the IES to the Energex Supply Network before synchronisation is completed. Care must be taken to limit the generation of harmonic distortion, particularly with the larger inverter sizes.

o The line inverters connected to the Energex Supply Network must be tested by an authorised testing laboratory and certified as being in compliance with AS 4777. If non-compliant inverters are proposed to be used, a separate Primary Protection scheme shall be installed (in addition to the Backup Protection scheme) to satisfy Energex requirements. Inverter settings shall be in accordance with Clause 4.11

4.9 IES Operations

4.9.1 General Standard

The Customer must ensure that the IES is maintained and operated in accordance with good electricity industry practice and relevant Laws, in consideration of the IES supplier's recommendations and in accordance with the operational limits imposed by Energex in this Schedule.

4.9.2 Operating Procedures

If operation of the IES would materially impact on the Energex Supply Network, taking into account good electricity industry practice, then the parties must develop further Operating Procedures. In the event that the parties do not agree, then the Operating Procedures will be those reasonably determined by Energex.

The onus of ensuring that these Operating Procedures are adhered to and the training of staff rests with the Customer. Any changes to the operating procedures in the Operating Procedures Schedule must be agreed to by both parties and documented.




4.9.3 Operation During and Following Supply Network Outages

An island external to the Customers Connection Point supplied from the Customer must not be created during any outage on the Supply Network.

For the situation where the IES has disconnected from the connection point and shut down and the supply from the network is or becomes available at the connection point then the procedure for IES reconnection will be as follows. The Customer must wait for a period of at least five minutes following restoration of supply following a Supply Network outage before attempting to synchronise with and re-connect to the Supply Network. An automatic interlock must be provided to ensure this delay occurs.

Where it is practical to isolate the IES from the Supply Network to test the anti-islanding features of all connected inverters and the operation of backup protection relays, such tests shall be done and submitted with the Compliance Assessment Report.

4.10 Protection of the IES

The Customer must implement measures to safeguard against potential damage to the IES and associated equipment or operational difficulties due to Supply Network-related events, which include, but are not limited to, the following:

o transient voltage sags during Supply Network faults;

o transient voltage sags during Supply Network faults followed by fault isolation and then successful unsynchronised auto re-closing onto the IES;

o Supply Network instability and loss of synchronism;

o interruption of the supply from Energex (including auto-reclose the Customer should check with Energex for auto-reclose settings for the particular location as these are subject to change. At the Premises, the present settings are one reclose at 20 seconds);

o high or low frequency;

o high or low voltage;

o load reduction (instantaneous loss of complete load) due to operation of Supply Network switches;

o lightning and switching surges;

o step change in voltage due to upstream switching; and

o phase unbalance or single phasing due to loss of one supply phase.




4.11 Protection of the Distribution Network

Inverter systems connected to the supply network shall be compliant to AS 4777.3 Grid Protection Requirements. The inverter settings shall be set to the values given in Table 4:

Table 4 Energex Prescribed Inverter Settings

Parameter Setting

Vmax

Vmin

Fmax

Fmin

Disconnect time

Reconnect time

257V

225V

52Hz

48Hz

2 secs

60 - 90 seconds

In addition to the protection systems installed for the generator itself, the Proponent shall install protection systems that:

Prevent the IES connecting with the supply network unless all phases of the network are energised, there is correct phase rotation and no unbalance at the network connection point.

Prevent the IES from connecting to the supply network unless the IES supply is synchronised to the supply network.

Disconnect the IES from the supply network in the event that one or more phases of the supply network at the network connection point are lost.

Disconnect the IES from the supply network in the event that a network abnormality causes unacceptable voltage and/or frequency deviations at the network connection point.

Disconnect the IES from the supply network in the event that the IES output becomes unstable causing unacceptable voltage and/or frequency deviations at the network connection point.

Prevent the IES connecting with, or disconnecting the IES from, the supply network in the event of failure of electrical supplies to the protection and/or control system equipment.

Prevent the generator connecting with, or disconnect the generator from, the supply network in the event of a failure of the intertrip (if installed) and/or SCADA communication link.

Prevent the export of power if not approved, or if approved, limit the export of power where Energex has specified a power export limit.

The Proponent shall also allow for automatic reclosing of the 11kV network after faults. The typical reclose time is 5 seconds, and reclaim time can be 20 seconds. The number of reclose attempts can vary from 1 - 3. Reconnect times for inverters should take this into account after islanding due to loss of mains.




In accordance with Table 2, for systems larger than 30kW the Customer is required to install an additional (back-up) anti-islanding protection relay to isolate the IES from the Supply Network in the event of a Supply Network fault or failure. Approved protection schemes and settings shall be provided to ensure this occurs. These schemes may include:

o A direct inter-trip protection scheme;

o Voltage vector shift (VVS);

o Rate of Change of Frequency (ROCOF) protection (for combined synchronous/inverter systems only);

o Neutral voltage displacement;

o Negative sequence voltage or current;

o Overcurrent and earth fault protection;

o Directional overcurrent and earth fault protection;

o Under/Over Voltage protection;

o Under/Over Frequency protection;

o Reverse power flow protection, with a manual reset

o Relay fail scheme

An approved list of relays for use are available from Energex Protection Department. Alternative relays can be used that satisfy protection requirements in consultation with Energex.

Recommended initial settings for undervoltage, overvoltage, underfrequency and overfrequency are given in Appendix A. The Customer shall ensure all instrument transformer ratios and relay settings are included in the Compliance Assessment Report as per Clause 4.19.1

The back-up protection relay settings must be submitted to and agreed by Energex prior to the connection of the IES to the Energex Supply Network. Where the backup protection isolates both customer load and PV generation (eg strata title developments that are bulk supplied), the backup relay may be blocked by a PE Cell or night timer circuit to reduce the potential for spurious trips.

In addition, the Customer must install adequate protection systems to isolate the IES from the Supply Network in the event of a generating system fault. If there is a loss of supply to the backup protection relay, the protection system shall failsafe by tripping the inverter circuit breaker until supply is restored to the relay.

The backup relay shall be housed in a steel cubicle with a lockable hinged door. The cubicle shall be weatherproof to IP65 and have an internally mounted GPO. All components in the cubicle shall be clearly labelled to identify their purpose. The cubicle shall be wall or floor mounted with the protection relay situated such that the display is at a readable height for a person standing.

The Customer must be responsible for the design, installation, testing, operation and maintenance of the IES protection and control systems.

The Customer must ensure that its IES protection systems are installed and commissioned and maintained and tested in accordance with this Standard and good electricity industry practice.




The Customer must ensure that the IES protection systems will provide complete automatic separation from the Supply Network, or shutdown, in the event of any irregularity or failure on any phase of the supply, or for a fault on the Customers plant or its associated circuits.

Failure of the IES to disconnect from the Supply Network upon loss of synchronism, or in the event of any irregularity or failure on any phase of the supply, or for a fault on the Customers plant or its associated circuits will be deemed to be unreasonable interference and a breach of the requirements of this Standard.

The Customer must ensure that all of its protection settings are coordinated with Energex's protection systems.

The Customer must submit a single line diagram and information on proposed protection systems at each site to Energex. Energex shall review and accept these proposals for inclusion in the Negotiated Customer Connection Contract, prior to installation.

4.12 Interruption and withstand capacity

o The Customer must ensure that the Customers switchgear has the appropriate minimum short time interrupting and withstand capabilities for the combined fault current from Energex's Supply Network and the Customers IES. The Supply Network fault level at the Connection Point is documented and advised.

o Generating units connected to the Supply Network may not raise fault levels beyond the capacity of Energex's interruption devices. The Customer will be required to pay upon demand any costs incurred by Energex with respect to fault level control measures attributable to connection of the IES.

4.13 Earth grid

The Customer must establish an earth grid for the Premises and provide satisfactory earthing independent of Energex's Supply Network in accordance with regulatory requirements. Any subsequent connection to Energex's earth grid will be by mutual agreement in writing.

4.14 System neutral earthing

Energex's design approval and agreement is required for all earth connections applied to any Multiple Earth Neutral (MEN) point or supply neutral provided within the Premises for use by Energex.

4.15 Power factor

For low voltage customers, pursuant to clause 36(2)(d) of the Electricity Regulation, Energex requires the Customer to ensure that the power factor of the IES is for low voltage supply to the Customer, between at least 0.80 lagging to 0.80 leading at all times whilst generating electricity.

For high voltage customers, the power factor shall range from 0.90 lagging to 0.90% leading.




4.16 Steady State Voltage

The Proponent shall ensure that the proposed installation will not cause the steady state voltage at the Network Coupling Point to rise/fall outside the following range:

Low voltage Proponent - Vph-n = 240V 6% High voltage Proponent - Vph-ph = 11 000V 5%

In addition, the Proponent shall show that the proposed IES installation will not cause more than:

2% voltage rise total from inverter to point of common coupling on shared LV networks, or

2% voltage rise from inverter to transformer terminals for dedicated transformer customers. As part of the commissioning procedure, the voltage shall be monitored at the network coupling point (or as close as practical) over a one week window to ascertain existing supply voltage levels, and then for a further week after the IES is installed to verify the IES will not nuisance trip as a result of temporary overvoltage, and that the supply voltage stays within statutory limits.

Where the IES installation design or power export requirements would exceed the above limits, voltage control through reactive compensation and inverter shedding may be used in consultation with Energex. The results of these tests/models shall be included in the Compliance Assessment Report.

4.17 Disturbance issues

4.17.1 General

The distortion, fluctuation and unbalance limits specified in clause 4.17.2 below are specified for Supply Network intact operating conditions and must be assessed at the Connection Point. The Customer should refer to the standards as follows:

o AS/NZS 61000.3.6:2001 Electromagnetic compatibility (EMC) Assessment of emission limits for distorting loads in MV and HV power systems (IEC 61000-3-6:1996, MOD).

o AS/NZS 61000.3.7:2001 Electromagnetic compatibility (EMC) Limits Assessment of emission limits for fluctuating loads in MV and HV power systems (IEC 61000-3-7:1996, MOD).

o BS EN61000-3-14 Electromagnetic compatibility (EMC) Part 3-14 Assessment of emission limits for connection of disturbing installations to LV Power Systems. Measurement of voltage disturbances shall be as described in AS/NZS 61000.4.30:2007 using Class A instruments.

Energex may undertake, or may reasonably require, a program of tests be performed at the Customers cost, to ensure compliance with these disturbance limits.

If such tests determine that the limits specified in this clause are exceeded and the non-compliance is due to the IES, then the Customer must take remedial action at its own expense to reduce any disturbance caused by the IES to less than the levels specified in this clause.

If the tests demonstrate compliance, or that the non-compliance is not caused by the operation of the IES, then Energex must reimburse the Customer for the reasonable expenses incurred by the Customer as a result of conducting the tests.




4.17.2 Limits

Voltage Fluctuations 4.17.2.1

The Customer must ensure that voltage fluctuations caused by the switching or operation of the IES are less than the emission limits specified by Energex in Table 5, in accordance with the Australian Standard AS/NZS 61000.3.7:2001 when all of the IES is in service. Where multiple inverters are installed on a shared low voltage network, the summated effect can be calculated as per Clause 7 of IEC 61000.3.14.

Table 5 - Short and long term flicker emission limits

Individual Short Term Emission Limit

EPsti

Individual Long Term Emission Limit

EPlti

0.25 0.20

Rapid Voltage Changes Emission Limits (Starting Condition) are given in the following Table 6:

The maximum voltage change U/UN for normal operating conditions is expressed in percent of the actual voltage in the table below. A customer may cause voltage changes, depending on the repetition frequency of these changes. Where U is steady state voltage change and UN is steady state voltage.

Table 6 - Emission Limits for voltage changes in function

of the number of changes per hour, r

r

(hour-1)

U/UN (%)

240/415V (LV)

r 1 5

1 < r 10 4

10 < r 100 2.5

100 < r 1000 1.5

Unbalance 4.17.2.2

The Customer must balance the current injected in each phase at each of its Connection Points so as to achieve average levels of negative sequence voltage at its Connection Points that are less than or equal to the values set out in Table 7 below:

Table 7 Unbalance Levels

Nominal supply voltage

(kV)

Maximum negative sequence voltage (% of nominal voltage)

no contingency

event

Credible contingency

event

General once per hour

30 minute average

30 minute average

10 minute average

1 minute average

10 or less 2.0 2.0 2.5 3.0




Harmonics 4.17.2.3

The harmonic current distortion level of the IES should be less than the emission limits specified by Energex in accordance with the Table 8 below when all of the IES is in service.

The following principles apply to the use of the shared network:

o the sharing between Network Users of the capability of connection assets to absorb or mitigate harmonic voltage distortion is to be managed by Energex in accordance with the provisions of clause S5.1.5 of schedule 5.1 of the National Electricity Rules; and

o to the extent practicable, the costs of managing or abating the impact of harmonic distortion in excess of the costs which would result from the application of an automatic access standard are to be borne by those Network Users whose facilities cause the harmonic voltage distortion.

o Where multiple inverters are installed on a shared low voltage network, the summated effect can be calculated as per Clause 7 of IEC 61000.3.14.

o Harmonic emission levels to be assessed in accordance with Clause 8 of IEC 61000.3.14.

Table 8 - Current Distortion Limits for distribution system

Maximum Harmonic Current Distortion in Percent of IL

Individual Harmonic Order (Odd Harmonics)

ISC/IL




4.19 Testing and commissioning

4.19.1 Inspection, Testing and Commissioning of IES

The Customer must ensure that the IES and any subsequent significant modification to the IES is inspected and tested to demonstrate compliance with this Standard.

Commissioning tests shall include a test for anti-islanding in accordance with Clause 4.9.3 in addition to UV & OV tests to prove settings for both inverters and backup relay.

Energex will be entitled to witness such inspections and tests.

For inverter systems greater than 30kW, the Customer must ensure that commissioning is certified by a registered professional engineer under the Professional Engineers Act 2002 (Qld)

who is registered in the area of electrical engineering, and that the engineer provides to Energex, as soon as practicable after commissioning, a Compliance Assessment Report that the IES complies with the technical requirements set out in this Standard.

The Compliance Assessment Report shall contain a covering letter, completed schedules, as constructed SLDs & relay settings, test results and supporting documentation as laid out in Appendix B.

Energex may waive the above requirement for a registered professional engineers report at its absolute discretion.

4.19.2 Control and Protection Changes

No alterations to the protection and control equipment which impact on Energex's Supply Network are to be performed without the written consent of Energex, which must not be unreasonably withheld. If any changes other than relay settings are approved to be made, then the whole of the affected scheme must be tested to demonstrate compliance with this Standard.




Appendix A Backup Protection Requirements

Table A1 Protection Scheme Types

Item Protection Functional Description ANSI/IEEE Standard C37.2 Code EC 60617

1 Neutral Voltage Displacement (NVD) 59N U0>

2 Undervoltage (UV) 27P U<

3 Overvoltage (OV) 59P U>

4 Underfrequency (UF) 81U f<

5 Overfrequency (OF) 81O f>

6 Rate of Change of Frequency (ROCOF) Loss of Mains 81R

7 Voltage Vector Shift Loss of Mains (VVS)

8 Auxiliary supply scheme or relay fail

9 Directional Power (for inverter shedding) 32

Initial settings for the backup protection shall be: OV: 445V phase-to-phase (257V phase-to-neutral) 5 second definite time delay UV: 346V phase-to phase (200V phase-to-neutral) 5 second definite time delay OF: 52.5Hz 5 second definite time delay UF: 47.5Hz 5 second definite time delay VVS: 8o in a half cycle (may be de-sensitised up to 12o if spurious tripping occurs) ROCOF: 0.4 Hz/second (only set for combined synchronous/inverter generation on network) Neutral Voltage Displacement: : 48V (20% phase-to-ground voltage) 5 second definite time delay (240V

network) Reverse Power Flow

Non Export Export

Stage 1 (anti-islanding) 5% of inverter rating or 1% of transformer rating (whichever is

largest)

1.3 x Power Export Limit

Definite time delay 5 sec 5 sec

Stage 2 (export limit) 1.1 x Export Power Limit

Definite time delay 60 sec

These may need to be adjusted based on site measurements and advice from Energex. A list of approved relays are available from Energex Protection Department, and on Energex web site http://apps.energex.com.au/upload/technical_documents/20140408_141032_4083826.pdf. Alternative relays can be used that satisfy protection requirements in consultation with Energex.




Appendix B Compliance Assessment Report

Covering Letter (sample only)

Energex GPO Box 1461 BRISBANE QLD 4001 Your Ref: XXXXXX Our Ref: YYYYYY (if applicable) DD/MM/YY Dear Sir/Madam Subject: xxkW PV IES Embedded Generator Connection Project Name, Location Please find attached our submission for the abovementioned project. This letter is to certify that as a Registered Professional Engineer of Queensland and by virtue of my training and experience, the submission documentation issued together with this letter complies with the requirements the latest revisions of the following:

Energex Technical Requirements for Inverter Energy Systems (>30kW to 1000kW)

AS/NZS 3000

AS 3100

AS 4777

AS 5033

Qld Electricity Connection & Metering Manual V7 In addition, the following attachments have been submitted as part of the application:

Attachment 1 Compliance Checklist Attachment 2 PV/Inverter Checklist or NCCC Schedule 8 Attachment 3 As Construction SLD & Relay Settings Attachment 4 Commissioning Test Results

Should you have any queries, please contact the undersigned. RPEQ Engineer Name and Registration Number Professional Title Company Name Company Address Contact Details




Attachment 1 Compliance Checklist

Description Clause Complies Comments

Supply Network Environment 4.4

Battery Energy Storage System 4.6

IES Design & Construction 4.8

IES Operations 4.9

Backup Protection 4.11

Inverter Anti-islanding Protection Settings

4.11

Protection Line Diagram 4.11

Backup Protection Settings 4.11, App A

Interruption & Withstand Capacity 4.12

Earthing 4.13,4.14

Power Factor 4.15

Steady state voltage 4.16

Voltage fluctuations 4.17.2.1

Unbalance 4.17.2.2

Harmonics 4.17.2.3

Testing and Commissioning 4.19

Inverter Information Att 2

Single line Diagram Att 3

Commissioning test results Att 4




Attachment 2 PV/Inverter Checklist (Form 1552)

Note: NCCC Schedule 8 may be used to substitute this Form.




Attachment 3 Circuit/Block Diagrams (samples only)




Attachment 4 Compliance Assessment Report - Commissioning

Compliance Assessment Report Commissioning shall include:

INVERTERS

Passive anti-islanding protective settings for fmin, fmax, Vmin and Vmax.

Tests to prove anti-islanding operation during network outage

DC Input voltage to inverter on commissioning

AC Output voltage from inverter on commissioning

Input and output power from inverter on commissioning

Warning signs fitted as per AS 4777 and AS 5033

PROTECTION

Protection line diagram

Tripping and control scheme logic

Instrument transformer ratios

Backup relay details (make, model, serial no.)

Relay settings

Relay pickup test results.

POWER QUALITY (Results can be either calculated from inverter and network data or measured values)

Steady state voltage rise/fall at network coupling point

Flicker

Harmonics

Voltage unbalance

Power factor