Report Technology Title: NORTHERN ALIGNMENT Unique ... · PDF fileto ensure it is in line with the ... Extract of the Perseus Station Electric Diagram illustrating ... It comprises

PCM Reference: 240-53459042

SCOT Study Committee Number/Name: Substations

Report Technology

Title: NORTHERN ALIGNMENT PROJECT ASSESSMENT OF SUBSTATION BOUNDARY AREA AND LAYOUT FOR THE ABILITY TO ENABLE THE INTEGRATION OF 765KV

Unique Identifier: 240-106271056

Alternative Reference Number: N/A

Area of Applicability: Engineering

Documentation Type: Report

Revision: 1

Total Pages: 22

Next Review Date: N/A

Disclosure Classification: Controlled Disclosure

Compiled by Functional Responsibility Authorized by

Braam Groenewald

Corporate Specialist - Substations

Rukesh Ramnarain

Chief Engineer – Substation Engineering

Phineas Tlhatlhetji

Senior Manager – Substation Engineering

Date: Date: Date:

Document Classification: Controlled Disclosure

NORTHERN ALIGNMENT PROJECT ASSESSMENT OF SUBSTATION BOUNDARY AREA AND LAYOUT FOR THE ABILITY TO ENABLE THE INTEGRATION OF 765KV


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Content

Page

1. Introduction .................................................................................................................................................. 4

2. Supporting clauses ...................................................................................................................................... 5 2.1 Scope ................................................................................................................................................. 5

2.1.1 Purpose .................................................................................................................................. 5 2.1.2 Applicability ............................................................................................................................ 5

2.2 Normative/informative references ...................................................................................................... 5 2.2.1 Normative ............................................................................................................................... 5 2.2.2 Informative ............................................................................................................................. 5

2.3 Definitions ........................................................................................................................................... 5 2.3.1 General .................................................................................................................................. 5 2.3.2 Disclosure classification ......................................................................................................... 5

2.4 Abbreviations ...................................................................................................................................... 5 2.5 Roles and responsibilities .................................................................................................................. 6 2.6 Process for monitoring ....................................................................................................................... 6 2.7 Related/supporting documents .......................................................................................................... 6

3. Document content ....................................................................................................................................... 6 3.1 Perseus substation ............................................................................................................................. 7 3.2 Kronos ................................................................................................................................................ 8 3.3 Aries ................................................................................................................................................. 10 3.4 Helios ............................................................................................................................................... 12 3.5 Juno .................................................................................................................................................. 15 3.6 Aurora ............................................................................................................................................... 16 3.7 Sterrekus .......................................................................................................................................... 18

4. Authorization .............................................................................................................................................. 21

5. Revisions ................................................................................................................................................... 21

6. Development team .................................................................................................................................... 22

7. Acknowledgements ................................................................................................................................... 22

Figures

Figure 1: Map illustrating the proposed 765kV expansion along the west coast MTS substations ................... 4

Figure 2: Extract of the Perseus Station Electric Diagram illustrating proposed extension to the 765kV yard for the Kronos line ........................................................................................................................ 7

Figure 3: Extract of the Perseus Key Plan illustrating proposed extension to the 765kV yard for the Kronos line ........................................................................................................................................... 8

Figure 4: Kronos locality map ............................................................................................................................. 9

Figure 5: Extract of the Kronos Station Electric Diagram illustrating proposed 400kV extensions 765kV yard integration ..................................................................................................................................... 9

Figure 6: Extract of the Kronos Key Plan illustrating proposed 400kV extensions 765kV yard integration ..... 10

Figure 7: Aries locality map .............................................................................................................................. 11

Figure 8: Extract of the Aries Station Electric Diagram illustrating proposed 400kV extensions 765kV yard integration ................................................................................................................................... 11

Figure 9: Extract of the Aries Key Plan illustrating proposed 400kV extensions 765kV yard integration ........ 12




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Figure 10: Helios locality map .......................................................................................................................... 13

Figure 11: Extract of the Helios Station Electric Diagram illustrating proposed 400kV extensions 765kV yard integration ................................................................................................................................... 14

Figure 12: Extract of the Helios Key Plan illustrating proposed 400kV extensions 765kV yard integration .... 14

Figure 13: Juno locality map ............................................................................................................................. 15

Figure 14: Extract of the Juno Station Electric Diagram illustrating proposed 400kV extensions 765kV yard integration ................................................................................................................................... 16

Figure 15: Extract of the Juno Key Plan illustrating proposed 400kV extensions 765kV yard integration ....... 16

Figure 16: Aurora locality map .......................................................................................................................... 17

Figure 17: Extract of the Aurora Station Electric Diagram illustrating proposed 400kV extensions 765kV yard integration ................................................................................................................................... 17

Figure 18: Extract of the Aurora Key Plan illustrating proposed 400kV extensions 765kV yard integration .... 18

Figure 19: Sterrekus locality map ..................................................................................................................... 19

Figure 20: Extract of the Sterrekus Station Electric Diagram illustrating proposed 400kV extensions 765kV yard integration ....................................................................................................................... 20

Figure 21: Extract of the Sterrekus Key Plan illustrating proposed 400kV extensions 765kV yard integration ........................................................................................................................................... 21




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1. Introduction

This document reports on the feasibility of integrating 765kV into the existing West Coast MTS substations, the required expansions necessary at 400kV and 765kV, and the extent to which these expansions can be accommodated within the existing substation boundary lines and to determine the amount of additional land to accommodate the new 765kV yards. Figure 1 shows the existing 400kV and 765kV networks feeding down towards the Eastern and Western Cape regions. This report looks at the following substations: Perseus, Kronos, Aries, Helios, Juno, Aurora and Sterrekus in that order.

Figure 1: Map illustrating the proposed 765kV expansion along the west coast MTS substations




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2. Supporting clauses

2.1 Scope

This document reports on the findings of a desktop assessment carried out on existing substations in terms of their capability of accommodating, where they do not exist, new 765kV yards, and where they do exist, expanding on the existing 765kV yards in order to realise a West Coast 765kV ring down to the Western Cape.

2.1.1 Purpose

The purpose of this document is to report on the feasibility of integrating 765kV to the West Coast MTS substations, the required expansions necessary at 400kV, and the extent to which these expansions can be accommodated within the existing substation boundary lines.

2.1.2 Applicability

This document shall apply throughout Eskom Holdings Limited, its divisions, subsidiaries and entities wherein Eskom has a controlling interest.

2.2 Normative/informative references

Parties using this document shall apply the most recent edition of the documents listed in the following paragraphs.

2.2.1 Normative

[1] ISO 9001 Quality Management Systems.

[2] Substation Layout Design Guide.

[3] The Design Philosophy for 765kV Tubular Conductor Busbar Yards, 240-85660414, March 2015

2.2.2 Informative

None

2.3 Definitions

2.3.1 General

Definition Description

Diameter A term used to describe the three circuit breakers and associated equipment in the diagram below. A number of such “diameters” in parallel are applied to the two busbars

2.3.2 Disclosure classification

Controlled disclosure: controlled disclosure to external parties (either enforced by law, or discretionary).

2.4 Abbreviations

Abbreviation Description

D/C Double circuit

Dx Distribution




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Abbreviation Description

IPP Independent power producer

kV Kilo-volt

MVA Mega-volt amperes

SLDG Substation Layout Design Guide

SVC Static var compensator

URS User requirement specification

2.5 Roles and responsibilities

The document is intended for the guidance of both Substation Engineering and Transmission Grid Planning. Substation engineering shall utilise and implement the finding within this document only once the appropriate URS from the Transmission Grid Planning Department.

2.6 Process for monitoring

1) Substation Design Review Team.

2) Power Delivery Engineering Design Review Team.

2.7 Related/supporting documents

Not applicable.

3. Document content

An important observation from Figure 1 is that the 765kV ring is to lie on the inside of the 400kV ring. It is necessary to know this as it dictates on which side of the 400kV system at each substation one needs to locate the 765kV yard in order to perform the integration. The following high level scope of work was received from Grid Planning:

Extending the existing substations to include 765 kV at Kronos, Aries, Helios, Juno and Aurora:

765 kV yard

765 kV busbar

765 kV feeder bays with line reactors: 2 equipped, 2 x future

765 kV busbar reactor (with transfer to any line)

Extend 400 kV yard

Extend 400 kV busbar

765 / 400 kV 2000 MVA transformers and bays: 1 equipped, 1 future

In all of the above cases, a three diameter system is required. The only differences between the stations is the manner in which the connections to the 400kV systems are made and the orientation of the 765kV diameters.

Additional Grid Planning requirements are:

Perseus Substation:

765 kV feeder bay with line reactor: 1 equipped

Sterrekus Substation:

765 kV feeder bay with line reactor: 1 equipped, 1 future




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3.1 Perseus substation

Perseus is currently a 765/400/275/22kV substation which forms part of the main 400kV and 765kV feeds to the Eastern and Western Cape. There is a small amount of transformation to 22kV in order to feed the towns of Dealsville and Tshwanraganang, and a repeater station. It has 4 x 765kV lines, 8 x 400kV lines and 5 x 275kV lines.

Figure 2 is an extract from the Perseus Station Electric Diagram showing the existing 765kV yard. The 765kV busbar system philosophy followed is breaker-and-a-half. It also has a reactor transfer busbar to facilitate the connection of a busbar reactor as a line reactor. All further extensions will therefore follow this philosophy. It comprises a single 2000MVA, 765/400kV transformer and bay, a busbar reactor and bay, and four line bays, all excepting one with line reactors.

Figure 2: Extract of the Perseus Station Electric Diagram illustrating proposed extension to the 765kV yard for the Kronos line

The original planning of Perseus made provision for further 765kV line bays and a second transformer. The Kronos 1 feeder can therefore be accommodated by merely extending the 765kV yard to the west by another diameter, thus providing for the feeder and the second transformer. This is shown in Figures 2 and 3. An additional 150m of terracing is required to the west to accommodate this diameter.




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Figure 3: Extract of the Perseus Key Plan illustrating proposed extension to the 765kV yard for the Kronos line

3.2 Kronos

Kronos is currently a 400kV switching station which is connected to Hydra and Aries via single lines. There is currently an approved project to integrate 132kV into the station to feed Cuprum via a firm 2 feeder supply and to connect 2 x IPPs. Included in this phase is 2 x unequipped 132kV feeders. The design is such that it will be able to accommodate a total of 3 x 500MVA, 400/132kV transformers. An additional 6 x 132kV feeders is possible with an extension to the north-east. Two of these feeders are to be used for the 132kV supplies to the SKA project near the Karoo town of Canarvon hence a total of 6 x additional IPP connections into Kronos is possible.

Figure 4 shows the locality plan and orientation of Kronos. With the 765kV lines running on the inside of the 400kV network, the most optimal position for the 765kV yard is on the southern side of the existing 400kV yard. Additional land beyond the existing Eskom boundary is required to accommodate the 765kV yard.

The 400kV yard will have to be extended by three bays to provide connection points for the 765/400kV transformers as well as for two future 400kV lines. Figure 5 is a SLD for the proposed integration while Figure 6 is an extract of the Key Plan illustrating the area required by the 400kV extension and 765kV yard. An area of 400m by 650m required for the 765kV yard which partly lies within the existing boundary and partly outside of it.

The new 400kV busbar extension must be stung with 3xBull conductor to handle the full current rating of the 2000MVA transformers. In addition, the existing 2xBull conductor for the 400kV busbar is required to be uprated to 3xBull.




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Figure 4: Kronos locality map

Figure 5: Extract of the Kronos Station Electric Diagram illustrating proposed 400kV extensions 765kV yard integration




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Figure 6: Extract of the Kronos Key Plan illustrating proposed 400kV extensions 765kV yard integration

3.3 Aries

Aries is currently a 400/50/22kV substation which feeds the 50kV Sishen-Saldhana traction loads as well as a small amount of transformation to 22kV in order to feed the town of Kenhart. It has 4 x 400kV line connections, viz. Kronos, Helios, Aggeneis and Kokerboom (Namibia), with a 5th connection to Nieuwehoop to be energised shortly. Sixth and seventh 400kV connections to Upington Solar Park are also planned.

The 22kV system is supplied from a recently installed 45MVA, 400/22kV transformer, and has a backup connection from the tertiary connection from Busbar Reactor 1.

Planned extensions at Aries include the installation of a 300MVAr SVC, a second line from Kronos and a second line to Aggeneis and the integration of 132kV at Aries to provide a connection point for IPPs that are proposed for the area by constructing a 132kV yard on the northern side of the 400kV busbar as illustrated in Figure 8.

Figure 7 shows the locality plan and orientation of Aries. As before, with the 765kV lines running on the inside of the 400kV network, the most optimal position for the 765kV yard is on the south-western side of the existing 400kV yard. Additional land 480m beyond the existing Eskom boundary is required to accommodate the 765kV yard. The 765kV yard itself occupies an area of 400m x 650m. Additional land is required for the line servitudes.




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The 400kV yard will have to be extended by five bays in order to get beyond the control building and 50kV traction supplies, as well as passing over the access road (this at 20m). In addition, four 400kV bays are required, orientated at right angles to the existing 400kV busbar to provide connection points for the 765/400kV transformers as illustrated in Figures 8 and 9.


Figure 7: Aries locality map

Figure 8: Extract of the Aries Station Electric Diagram illustrating proposed 400kV extensions 765kV yard integration




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Figure 9: Extract of the Aries Key Plan illustrating proposed 400kV extensions 765kV yard integration

3.4 Helios

3.4.1.1 Helios is an existing 400/132/50/22kV substation that also forms part of the western 400kV corridor down to Cape Town. These stations, along the western part of the country mainly supply the railway traction loads of the Sishen-Saldhana iron ore rail link operated at 50kV AC, but in recent times are forming connection points for IPPs. Helios is currently connected at 400kV to Aries and Juno via single lines.

There is currently an approved project for the integration of 132kV at the station for the connection of two IPPs. There is enough space for several more line bays, and at least another 8 feeders, together with a second 500MVA transformer. Any further expansion to the north-east would require the purchase of additional land however the 132kV busbar can be expanded on the other side of the proposed new installation into the stores area. Most of the lines will however have to exit using D/C towers due to space constraints. It is possible to install a 3

rd 500MVA unit by replacing the 45MVA, 400/22kV transformer with a

500MVA, 400/132kV unit. The 22kV supplies can in turn be supplied via a 132/22kV unit. The 45MVA transformer unit can be used as a spare for those units used at power stations to feed power station supplies.

The additional requirements for 132kV and 400kV can be accommodated within the existing boundary lines of the substation however the integration of 765kV into the 400kV system at Helios requires a fairly large parcel of land, 520m x 650m as shown in Figures 10 and 12. The 400kV busbar needs to be extended by 5 bays to accommodate the future installation of 400/132kV transformers as well as the two 765/400kV transformers. The new 400kV busbar extension must be stung with 3xBull conductor to handle the full current rating of the 2000MVA transformers. In addition, the existing 2xBull conductor for the 400kV busbar is required to be uprated to 3xBull.

The most optimal position of the 765kV yard is on the southern end of Helios as illustrated in Figure 10.




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Figure 10: Helios locality map




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Figure 11: Extract of the Helios Station Electric Diagram illustrating proposed 400kV extensions 765kV yard integration

Figure 12: Extract of the Helios Key Plan illustrating proposed 400kV extensions 765kV yard integration




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3.5 Juno

Juno 400/132/66kV substation forms part of the western corridor down to Cape Town that feeds the Sishen-Saldhana iron-ore 50kV railway traction loads. It is connected to Helios and Aurora at 400kV via single lines. Transformation at Juno comprises 2 x 120MVA, 400/132kV and 2 x 40MVA, 132/66kV transformer units. There is sufficient space for another 8 x 132kV feeder bays. Most of the lines will however have to exit using D/C towers due to space constraints. The expansion required for more 132kV bays to connect IPPs, and the added requirements of 400kV bays can be comfortably accommodated within the existing substation boundaries as shown in Figure 13.

Figure 13 shows the locality plan and orientation of Juno. As before, with the 765kV lines running on the inside of the 400kV network, the most optimal position for the 765kV yard is on the south-western side of the existing 400kV yard. Additional land 480m beyond the existing Eskom boundary is required to accommodate the 765kV yard. The 765kV yard itself occupies an area of 400m x 650m. Additional land is required for the line servitudes.

The 400kV yard will have to be extended by three bays in line with the busbar, as well as by four 400kV bays orientated at right angles to the existing 400kV busbar to provide connection points for the 765/400kV transformers as illustrated in Figures 8 and 9.


Figure 13: Juno locality map




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Figure 14: Extract of the Juno Station Electric Diagram illustrating proposed 400kV extensions 765kV yard integration

Figure 15: Extract of the Juno Key Plan illustrating proposed 400kV extensions 765kV yard integration

3.6 Aurora

Aurora is currently a 400/132/66kV substation which is connected to Juno and Ankerlig via single line and Ankerlig via two lines. Aurora feeds Saldanha Steel and surrounding Distribution substations.

Figure 16 shows the locality plan and orientation of Aurora. As before, with the 765kV lines running on the inside of the 400kV network, the most optimal position for the 765kV yard is on the north-eastern side of the existing 400kV yard. Additional land, 550m beyond the existing Eskom boundary, is required to accommodate the 765kV yard. The 765kV yard itself occupies an area of 400m x 650m. Additional land is required for the line servitudes.




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The 400kV yard will have to be extended by five bays in line with the busbar to provide connection points for the 765/400kV transformers as illustrated in Figures 17 and 18.


Figure 16: Aurora locality map

Figure 17: Extract of the Aurora Station Electric Diagram illustrating proposed 400kV extensions 765kV yard integration




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Figure 18: Extract of the Aurora Key Plan illustrating proposed 400kV extensions 765kV yard integration

3.7 Sterrekus

Sterrekus is a newly constructed 765/400kV substation which is due for commissioning in April 2016. It is the last of the 765kV stations along the north-south corridor feeding the Western Cape region and is located about 5 kilometres north-east of Koeberg. The site that was bought by Eskom is home to a number of historical buildings that were to remain untouched by construction activities. They are located on the same side as that to which the 400kV lines exit the 400kV yard. This makes terminating the 3 x 400kV lines into the station quite challenging, but a means to do this was found. In addition to the 6 x lines to enter the station, a further 2 lines from Ankerlig Gas Fired Power Station will also be brought into Sterrekus on the southern end. This essentially negates building the 132kV yard on the southern end. Figure 19 shows that 11 x 132kV feeders with 3 x transformers can be accommodated on the northern end.

A further 3-4 x 400kV lines need to be accommodated if Nuclear 1 is to be placed on the Koeberg site. Two of these have been allowed for on the northern end of the 400kV busbar. The remaining one or two lines can be accommodated on the southern end by expanding by another diameter and rearranging the lines.

Figure 19 shows that provision has been made for further expansion of the 765kV towards the south-west. This space can easily accommodate an additional two diameters to provide for the second 2000MVA, 765kV transformer and the 765kV feeder from Aurora and well as the second 765kV feeder from Kappa. Figures 20 and 21 are extracts of the Station Electric Diagram and Key Plan respectively.




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Figure 19: Sterrekus locality map




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Figure 20: Extract of the Sterrekus Station Electric Diagram illustrating proposed 400kV extensions 765kV yard integration




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Figure 21: Extract of the Sterrekus Key Plan illustrating proposed 400kV extensions 765kV yard integration

4. Authorization

This document has been seen and accepted by:

Name and surname Designation

NP Tlhatlhetji Senior Manager – Substation Engineering

MP Peffer Chief Engineer – Substation Engineering

R Ramnarain Chief Engineer (Northern Cape) – Substation Engineering

SA Zulu Chief Engineer (North East) – Substation Engineering

I Hill Senior Advisor (Western) – Substation Engineering

E Naicker Chief Engineer (East) – Substation Engineering

D Delly Chief Engineer (North West) – Substation Engineering

5. Revisions

Date Rev Compiler Remarks

Feb 2016 1 AJS Groenewald First Issue.




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6. Development team

The following people were involved in the development of this document:

Braam Groenewald

7. Acknowledgements

Not applicable.

Documents

Report Technology Title: NORTHERN ALIGNMENT Unique ... · PDF fileto ensure it is in line with the ... Extract of the Perseus Station Electric Diagram illustrating ... It comprises