optimised energy solutions report

7/31/2019 Optimised Energy Solutions Report

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Optimised Energy Solutions Ltd

This document shall not be modified or copied to a third party under any circumstances, except with prior approval in writing from OptimisedEnergy Solutions Ltd.

Copyright Optimised Energy Solutions Ltd. 2011. All rights reserved.

DOCUMENT NO:

DOCUMENT TITLE: Power System Studies For New Arc Furnace Installation

PROJECT REFERENCE:

- Client Project No:

- Project Location: ROTHERHAM, UK

- Project Title: NEW ARC FURNACE INSTALLATION

- Client: TATA STEEL


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Table of Contents

1.0 SCOPE OF WORK ........................................................................................................................ 3

2.0 EXECUTIVE SUMMARY................................................................................................................. 4

33 kV Bustube Sizing ........................................................................................................................... 4

Minimum 33 kV Bustube Clearances ................................................................................................... 4

33 kV Bustube Supports ....................................................................................................................... 4

Existing 33 kV CTs ............................................................................................................................... 4

Fault Level Study Results ..................................................................................................................... 5

Power Flow Study Results .................................................................................................................... 5

Protection .............................................................................................................................................. 5

Power Quality Issues ............................................................................................................................. 5

3.0 POWER SYSTEM MODELLING ..................................................................................................... 6

4.0 POWER SYSTEM STUDIES DESIGN CRITERIA ......................................................................... 6

4.1 Power System Data Documents ...................................................................................................... 6

4.2 Engineering Assumptions ............................................................................................................... 6

5 0 DESCRIPTION OF POWER SYSTEM STUDIES 7


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1.0 SCOPE OF WORK

This scope of work is for the power system design work for the arc furnace transformer upgrade and system atthe Tata Steel plant in Rotherham.

The scope of work will consist of the following two areas:

Computer based analysis of new system and the interconnection to the grid as previously supplied.

The following studies will be carried out:

o Load Flow - steady state (continuous) thermal rating of electrical equipment and voltage levels

o Fault rating for short time withstand, make and break duty

o Busbar connector sizing and specification

Report / specification to enable client to order equipment

Section 2.0 of this report is the executive summary where the main conclusions of the report are highlighted.

Section 3.0 of this report describes the software used for power system modelling.

Section 4.0 of this report describes the design criteria for these studies

Section 5.0 of this report describes the studies carried out in this report.

Section 6.0 of this report describes the results of the studies.

A di O f hi d h i d f h di d l l i


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2.0 EXECUTIVE SUMMARY

33 kV Bustube Sizing

The bustube sizing calculations were carried out based on the following data and standards:

UK Copper Development Associationo Publication 22: Copper For Busbars

BS 7354: 1990: Code of practice for design of high voltage open terminal stations

The selected high conductivity copper bustube is 75mm diameter with 10.2mm wall thickness

Minimum 33 kV Bustube Clearances

The clearances between the phases and phase to earth should be as follows as a minimum:

Phase to earth minimum clearance = 500mm

Phase to phase minimum clearance = 430 mm

33 kV Bustube Supports


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Fault Level Study Results

The maximum 33 kV fault levels are:Peak asymmetrical current = 58 kARms symmetrical current = 21.33 kA

The proposed 33 kV bustube will be adequately fault rated.

Although not part of this scope of work, OES recommend that a full audit is carried out on the Tata Steel 33 kVsystem in order to verify that all electrical equipment is adequately fault rated in order that the requirements ofthe following UK statutory legislation is realised:

Electricity At work Regulations 1989

It should also be verified that the arc furnace transformer secondary circuits are complaint with these regulations

with respect to fault level.

Power Flow Study Results

The power flow studies show there are various transformer overloads for various network operating conditions.The client should confirm the number of arc furnaces in operation per network operation configuration. Seesection 6.6 of this report.

Although not part of this scope of work OES recommend that a full audit is carried out on the Tata Steel 33 kV


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3.0 POWER SYSTEM MODELLING

The power system studies were carried out using ETAP. This is a computer based power system simulationpackage based on the application of the rms phasor based approach to solve the load flow and fault levelalgebraic equations. Fault level calculations are based on the use of IEC 60909, which is considered the mostconservative method of fault level calculation as, due to its assumptions, produces the highest fault level results.This will be used as the basis of design.

Bustube sizing will be based on the results from ETAP and supporting hand calculations.

4.0 POWER SYSTEM STUDIES DESIGN CRITERIA

4.1 Power System Data Documents

The power system data is based on the following documents provided by the client:

Tata Steel to OES email dated 21/10/11.

o Transformer, VCB and cable data


o N Furnace transformer Electrical study

o RC Study


ARC Furnace Tripping Scheme


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c. Bustube maximum temperature rise during maximum load conditions = 35C

d. Bustube emissitivity factor = 0.1 (ability for copper to dissipate generated heat energy byradiation effect)

3. All fault level calculations have been carried out in accordance with IEC 60909 Short Circuit Currents InThree Phase AC Systems 2001.

a. All fault impedance was considered zero, i.e. solid short circuit.

4. Presently, no data has been provided by the client for the earthing study.

5.0 DESCRIPTION OF POWER SYSTEM STUDIES

5.1 Power System Study Scenarios

The power system studies were carried out for the scenarios as the Tata Steel ARC Furnace Tripping Scheme:Rotherham Works Electrical Loading and Supply Capacities, 33 kV furnace board. Based on data from Tat Steelthe following operating configurations were considered:

Tata Steel The furnace board and the works board are completely independent, this is because of theperformance of a furnace means that we would have a lot of flicker on the works board therefore wehave to have them completely independent.


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6.0 POWER SYSTEM STUDIES SUMMARY OF RESULTS

6.1 Bustube SizingThe bustube sizing calculations were carried out based on the following data and standards:

UK Copper Development Associationo Publication 22: Copper For Busbars

BS 7354: 1990: Code of practice for design of high voltage open terminal stations

BS EN 13600: 2002 Copper and copper alloys Seamless copper tubes for electrical purposes

The bustube size was selected based on the following parameters: Maximum continuous current based on 132 MVA transformer on full load (2309 A on 33 kV system)

33 kV substation ambient temperature = 40C (this is on the high side but after the site inspection it wasfound that the 33 kV substation was very warm)

Bustube maximum temperature rise during maximum load conditions = 35C

Bustube emissitivity factor = 0.1 (ability for copper to dissipate generated heat energy by radiationeffect)

Impact of skin effect on bustube rating (skin effect denotes the tendency of AC current to flow awayfrom the centre of a conductor).

Short circuit withstand current

Appendix Four shows the standard copper bustube ratings obtained from the UK Copper DevelopmentAssociation.

OES calculations based on the UK Copper Development Association calculation methods have found that theexisting copper bustube of 50mm diameter with 10mm wall thickness is inadequately rated for the 33 kVcontinuous current of 2309 A for the new 132 MVA transformer.

It as fo nd that the minim m b s t be si e as 70mm diameter ith a 10 2 mm all This ga e a ma im m


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6.2 Minimum Bustube Clearances

The clearances between the phases and phase to earth should be as follows as a minimum:

Phase to earth minimum clearance = 500mm

Phase to phase minimum clearance = 430 mm

It is recommended that these clearances are exceeded at all times throughout the installation. It is assumed that

specific vendor equipment purchased for the project is already compatible with the correct clearances based onthe standards governing its design.

6.3 33 kV Bustube Supports

The existing supports are based on the use of 33 kV post insulators for indoor substations. The supports willneed to be able to meet the following criteria in order to support the new bustube:

Be of adequate mechanical strength to support the bustube

Provide adequate creepage to maintain safe distance between the bustube and earthed steelworksupporting the post insulators.

Appendix Five shows the proposed new 33 kV post insulators as provided by Connectors and Switchgear in theUK. After discussions with Connectors and Switchgear it is advisable that this 33 kV post insulator is used. Dueto the thickness of the new bustube, the bustube will be adequately supported as long as the distance betweenbrackets is less than 5m. Connectors and Switchgear can provide this information if an order is placed uponthem in the future. Based on the close proximity of the existing supports, the existing support spacings areconsidered adequate to support the new bustube.


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CTs need to be rated for the maximum continuous current that can flow on the 33 kV system (2309 A). Basedon this the CTs are inadequately rated for the new transformer. The CT short circuit withstand time could not beobtained from the CT rating plate. It is unknown whether the CT is adequately rated for the short circuit currentscalculated in this report. The client has two options with regard to the CTs:

Replace CTs for those of an adequate rating for the new transformer

Carry out detailed testing of the CTs to establish the CT characteristics, this is also important to theprotection study. If the new transformer is energised using these CTs then the client must realise thatthe thermal withstand of the existing CTs could be exceeded, causing CT insulation breakdown and apossible system fault.

6.5 Fault Study Results

Tables 1 7 show the fault level results. Full detailed reports are given in Appendix Three of this document.It can be seen that the following Tata Steel electrical network operating configurations give the maximum faultconditions on the network.

Table 1: Base Case: SGT1B, SGT3, SGT4 in ParallelTable 7: Case 6: SGT3, SGT4, SGT1A in Parallel

It can be seen that the maximum fault levels on the 33 kV system are:Peak asymmetrical current = 58 kARms symmetrical current = 21.33 kA

It can be seen that the maximum fault levels on the arc furnace transformer secondary are:Peak asymmetrical current = 647 kA

R t i l t 240 kA


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6.6 Power Flow Study Results

Tables 8 14 show the power flow results. Full detailed reports are given in Appendix Two of this document.Voltage profiles and equipment power flows are given for the network configurations as described in section 5.1of this report. The 33 kV switchboard voltage is assumed to be at 1 pu based on the grid transformer automaticvoltage control. The power flow results are described below:

Table 8/8.1: Base Case: SGT1B, SGT3, SGT4 in ParallelFrom Table 8.1, it can be seen that the transformer SGT1B is overloaded at 126 %. This is assumed to be due

to the operation of the transformer tap changer control scheme. If there is a circulating current automatic voltagecontrol scheme, then any circulating current should be eliminated. It is understood that this is an NGC issue.

Table 9/9.1: Case 1: SGT1B, SGT3 in ParallelFrom Table 9.1, it can be seen that the transformer SGT1B and SGT3 are overloaded. This isbased on all arc furnaces running. The client should confirm the loading scenario for this case.

Table 10/10.1: Case 2: SGT1B, SGT3, SGT1A in Parallel

From Table 10.1, it can be seen that the transformer SGT1B and SGT 1A are overloaded. This is assumed tobe due to the operation of the transformer tap changer control scheme. If there is a circulating current automaticvoltage control scheme, then any circulating current should be eliminated. It is understood that this is an NGCissue.

Table 11/11.1: Case 3: SGT1B, SGT4 in ParallelFrom Table 11.1, it can be seen that the transformer SGT1B and SGT4 are overloaded. This is based on all arcfurnaces running. The client should confirm the loading scenario for this case.

T bl 12/21 1 C 4 SGT1B SGT4 SGT1A i P ll l


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Vanguard House, Daresbury SIC, Keckwick Lane, Daresbury, Cheshire WA4 4AB United KingdomTelephone: 0151 606 422 email: [email protected]

Registered in England, Company No: 3593777 Registered Office: Vanguard House, Daresbury SIC, Keckwick Lane, Daresbury, Cheshire WA4 4AB

FAULT STUDY RESULTS FOR DIFFERENT SCENARIOS

Table 1: Base Case (red coloured font shows worse case fault level)

S.No

3P Fault - IEC60909 Methods at the Following Times

SWBD

Voltage

Level(kV)

Rating Calculated Results

Make(kA)

Break(kA)

Ip (t=10ms) I

k(t=0ms)

Ibsym(t=60ms)

Idc(t=60ms)

Ibasym(t=60ms)

I k sym

1 1.2kV SWBD 1.2 647.066 239.743 239.743 183.42 301.86 239.743

2 33kV - 1 33 57.2 21.334 21.334 14.895 26.019 21.334

3 33kV-2 33 57.2 21.334 21.334 14.895 26.019 21.334

4 33kV-3 33 55.409 20.884 20.884 12.681 24.433 20.884

5 33kV-SGT1B 33 56.394 21.1 21.1 14.134 25.396 21.1

6 33kV-SGT3 33 56.501 21.116 21.116 14.362 25.537 21.116

7 33kV-SGT4 33 56.388 21.08 21.08 14.276 25.459 21.08

8 275kV 275 47.505 16.796 16.796 3.606 17.178 16.796


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Vanguard House, Daresbury SIC, Keckwick Lane, Daresbury, Cheshire WA4 4AB United KingdomTelephone: 0151 606 422 email: [email protected]

Registered in England, Company No: 3593777 Registered Office: Vanguard House, Daresbury SIC, Keckwick Lane, Daresbury, Cheshire WA4 4AB

Table 2: Case 1

S.No


SWBD Voltage

Level(kV)


Make(kA)

Break(kA)

Ip (t=10ms) I

k(t=0ms)

Ibsym(t=60ms)

Idc(t=60ms)

Ibasym(t=60ms)

I k sym

1 1.2kV SWBD 1.2 539.499 203.216 203.216 124.124 238.125 203.216

2 33kV - 1 33 39.923 14.819 14.819 11.043 18.481 14.819

3 33kV-2 33 39.923 14.819 14.819 11.043 18.481 14.819

4 33kV-3 33 39.043 14.601 14.601 17.618 9.859 14.601

5 33kV-SGT1B 33 39.851 14.798 14.798 10.978 18.425 14.798

6 33kV-SGT3 33 40.027 14.85 14.85 11.145 18.567 14.85

7 275kV 275kV 41.472 16.796 16.796 3.606 17.178 16.796


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Table 3: Case 2

S.No


SWBD VoltageLevel(kV)


Make(kA)

Break(kA)

Ip (t=10ms) I

k(t=0ms)

Ibsym(t=60ms)

Idc(t=60ms)

Ibasym(t=60ms)

I k sym

1 1.2kV SWBD 1.2 625.2 236.486 236.486 136.367 272.987 236.486

2 33kV - 1 33 55.371 20.644 20.644 14.489 25.221 20.644

3 33kV-2 33 55.371 20.644 20.644 14.489 25.221 20.644

4 33kV-3 33 53.691 20.222 20.222 12.398 23.72 20.222

5 275kV 275 41.472 16.796 16.796 3.606 17.178 16.796

6 33kV-SGT 1A 33 54.505 20.392 20.392 13.673 24.552 20.392

7 33kV-SGT 1B 33 54.662 20.438 20.438 13.817 24.67 20.438

8 33kV-SGT3 33 54.78 20.459 20.459 14.039 24.813 20.459


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Table 4: Case 3

S.No


SWBD Voltage

Level (kV)


Make(kA)

Break(kA)

Ip (t=10ms) I

k(t=0ms)

Ibsym(t=60ms)

Idc (t=60ms) Ibasym(t=60ms)

I k sym

1 1.2kV SWBD 1.2 534.871 201.433 201.433 123.37 236.21 201.433

2 33kV - 1 33 39.232 14.56 14.56 10.871 18.171 14.56

3 33kV-2 33 39.232 14.56 14.56 10.871 18.171 14.56

4 33kV-3 33 38.382 14.35 14.35 9.725 17.335 14.35

5 33kV-SGT1B 33 39.181 14.545 14.545 10.828 18.133 14.545

6 33kV-SGT4 33 39.316 14.586 14.586 10.956 18.242 14.586

7 275kV 275 41.472 16.796 16.796 3.606 17.178 16.796


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Table 5: Case 4

S.No


SWBD Voltage

Level (kV)


Make(kA)

Break(kA)

Ip (t=10ms) I

k(t=0ms)

Ibsym(t=60ms)


I k sym

1 1.2kV SWBD 1.2 622.293 235.357 235.357 135.951 271.801 235.357

2 33kV - 1 33 54.748 20.409 20.409 14.351 24.95 20.408

3 33kV-2 33 54.748 20.409 20.409 14.351 24.95 20.408

4 33kV-3 33 53.105 19.997 19.997 12.301 23.477 19.997

5 275kV 275 41.472 16.796 16.796 3.606 17.178 16.796

6 33kV-SGT1A 33 53.921 20.168 20.168 13.57 24.309 20.168

7 33kV-SGT1B 33 54.071 20.212 20.212 13.709 24.422 20.212

8 33kV-SGT4 275 54.091 20.204 20.204 13.849 24.495 20.204


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Table 6: Case 5

S.No


SWBD Voltage

Level (kV)


Make(kA)

Break(kA)

Ip (t=10ms) I

k(t=0ms)Ibsym(t=60ms)


I k sym

1 1.2kV SWBD 1.2 552.316 208.184 208.184 125.988 243.338 208.184

2 33kV - 1 33 41.902 15.564 15.564 11.494 19.348 15.564

3 33kV-2 33 41.902 15.564 15.564 11.494 19.348 15.564

4 33kV-3 33 40.934 15.323 15.323 10.206 18.411 15.323

5 33kV-SGT3 33 41.939 15.574 15.574 11.539 19.384 15.574

6 33kV-SGT4 33 41.889 15.559 15.559 11.497 19.346 15.559

7 275kV 275 47.505 16.796 16.796 3.606 17.178 16.796


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Table 7: Case 6 (red coloured font shows worse case fault level)

S.No


SWBD Voltage

Level (kV)


Make(kA)

Break(kA)

Ip (t=10ms) I

k(t=0ms)

Ibsym(t=60ms)


I k sym

1 1.2kV SWBD 1.2 633.319 239.658 239.658 137.399 276.251 239.658

2 33kV - 1 33 57.155 21.321 21.321 14.85 25.983 21.321

3 33kV-2 33 57.155 21.321 21.321 14.85 25.983 21.321

4 33kV-3 33 55.368 20.872 20.872 12.645 24.403 20.872

5 275kV 275 41.472 16.796 16.796 3.606 17.178 16.796

6 33kV-SGT1A 33 56.175 21.036 21.036 13.934 25.232 21.036

7 33kV-SGT3 33 56.459 21.103 21.103 14.323 25.505 21.103

8 33kV-SGT4 33 56.346 21.068 21.068 14.237 25.428 21.068


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LOAD FLOW STUDY RESULTS FOR DIFFERENT SCENARIOS WITH TAP SETTINGS (33 kV System Voltage Control)

Table 8: Base Case: Load Flow Bus Voltage Profile

Bus ID Nominal (kV) Actual Voltage (kV) Actual Voltage (%)

1.2 kV SWBD 1.2 1.082 90.17

33kV - 1 33 32.521 98.55

33kV - 2 33 32.521 98.55

33kV - 3 33 32.449 98.33

33kV - SGT 1B 33 32.575 98.71

33kV- SGT 3 33 32.591 98.76

33kV - SGT4 33 32.592 98.76

Grid 275 275 100.00


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Table 8.1: Base Case: Load Flow Branch Power Flow

ID Type Rating

Power Flow

(MVA)

Real Power

(P)

Reactive

Power (Q) % Loading

Cable(275kV) Cable 302.81 236.881 188.623

Cable (SGT4) Cable 120MVA 89.79 78.979 42.717


Cable (SGT 1B) Cable 75MVA 84.08 73.988 39.946

C (33kV-1 - 33kV-2) Cable 117.29 98.24 64.07

C1(33kV-2 - 33kV-3) Cable 37.39 32.271 18.885

C2(33kV-2 - 33kV-3) Cable 37.39 32.271 18.885

C3(33kV-2 - 33kV-3) Cable 42.75 33.699 26.302

SGT 1B Transf. 2W 75MVA/ 275kV 95.17 74.449 59.289 126.90

SGT 3 Transf. 2W 120MVA / 275kV 106.05 82.964 66.063 88.4


T (132MVA) Transf. 2W 132MVA /33kV 117.03 98.109 63.8 88.7


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Table 9: Case 1: Load Flow Bus Voltage Profile

Bus ID Nominal (kV) Actual Voltage(kV) Actual Voltage (%)

1.2 kV SWBD 1.2 1.081 90.08

33kV - 1 33 32.607 98.81

33kV - 2 33 32.607 98.81

33kV - 3 33 32.535 98.59

33kV - SGT 1B 33 32.688 99.05

33kV- SGT 3 33 32.712 99.13

Grid 275 275 100.00


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Table 9.1: Case 1: Load Flow Branch Power Flow

ID Type Rating

Power Flow

(MVA) Real Power (P)

Reactive Power

(Q)

%

Loading

Cable(275kV) Cable 324.95 238.771 220.41



C (33kV-1 - 33kV-2) Cable 117.49 98.573 63.94

C1(33kV-2 - 33kV-3) Cable 37.46 32.375 18.838

C2(33kV-2 - 33kV-3) Cable 37.46 32.375 18.838

C3(33kV-2 - 33kV-3) Cable 42.82 33.824 26.264





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Table10: Case 2: Load Flow Bus Voltage Profile


1.2 kV SWBD 1.2 1.094 91.17

33kV - 1 33 32.99 99.97

33kV - 2 33 32.99 99.97

33kV - 3 33 32.99 99.97

33kV - SGT 1B 33 33.05 100.14

33kV- SGT 3 33 33.062 100.19

33kV - SGT 1A 33 33.058 100.18

Grid 275 275 100.00


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Table10.1: Case 2: Load Flow Branch Power Flow

ID Type Rating

Power Flow

(MVA)

Real Power

(P)

Reactive

Power (Q) % Loading

Cable(275kV) Cable 311.96 243.611 194.859



Cable (SGT1A) Cable 75MVA 88.17 77.64 41.793

C (33kV-1 - 33kV-2) Cable 120.27 100.903 65.451

C1(33kV-2 - 33kV-3) Cable 38.34 33.14 19.283

C2(33kV-2 - 33kV-3) Cable 38.34 33.14 19.283

C3(33kV-2 - 33kV-3) Cable 43.84 34.623 26.885

Cable (Furnace Board) Cable 87.99 77.565 41.548


SGT 1A Transf. 2W 75MVA/ 275kV 100.02 78.132 62.446 133.4




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1.2 kV SWBD 1.2 1.096 91.33

33kV - 1 33 33.052 100.16

33kV - 2 33 33.052 100.16

33kV - 3 33 32.979 99.94

33kV - SGT 1B 33 33.136 100.41

33kV - SGT4 33 33.163 100.49

Grid 275 275 100.00


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ID Type Rating PowerFlow

(MVA) Real Power (P)Reactive Power

(Q) % Loading

Cable(275kV)Cable

335.41 245.388 228.651

Cable (SGT4)Cable 120MVA

142.69 125.502 67.902

Cable (SGT 1B)Cable 75MVA

133.59 117.569 63.425

C (33kV-1 - 33kV-2)

Cable

120.72 101.279 65.695

C1(33kV-2 - 33kV-3)Cable

38.48 33.263 19.355


38.48 33.263 19.355


44.00 34.752 26.986

SGT 1BTransf. 2W 75MVA/ 275kV

162.24 118.692 110.61 216.3

SGT 4Transf. 2W 120MVA / 275kV

173.16 126.696 118.042 144.3



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Table12: Case 4 : Load Flow Bus Voltage Profile

Bus ID Nominal (kV) Actual Voltage (kV) Actual voltage (%)

1.2 kV SWBD 1.2 1.091 90.92

33kV - 1 33 32.922 99.76

33kV - 2 33 32.922 99.76

33kV - 3 33 32.85 99.55

33kV - SGT 1B 33 32.978 99.93

Furnace board 33 32.922 99.76

33kV - SGT4 33 32.996 99.99

33kV - SGT 1A 33 32.991 99.97

Grid 275 275 100.00


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ID Type RatingPowerFlow

(MVA)

Real Power

(P)

Reactive

Power (Q)

%

Loading

Cable(275kV) Cable 311.31 242.632 195.048



Cable (SGT1A) Cable 75MVA 89.16 78.505 42.264

C (33kV-1 - 33kV-2) Cable 119.77 100.485 65.181

C1(33kV-2 - 33kV-3) Cable 38.19 33.003 19.208

C2(33kV-2 - 33kV-3) Cable 38.19 33.003 19.208

C3(33kV-2 - 33kV-3) Cable 43.66 34.488 26.78




SGT 4 Transf. 2W 120MVA /275kV 108.40 84.479 67.928 90.3



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1.2 kV SWBD 1.2 1.088 90.67

33kV - 1 33 32.81 99.42

33kV - 2 33 32.81 99.42

33kV - 3 33 32.738 99.21

33kV- SGT 3 33 32.912 99.73

33kV - SGT4 33 32.914 99.74

Grid 275 275 100.00


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ID Type Rating

Power Flow

(MVA) Real Power (P) Reactive Power (Q) % Loading

Cable(275kV) Cable 326.97 241.676 220.231



C (33kV-1 - 33kV-2) Cable 118.96 99.802 64.737

C1(33kV-2 - 33kV-3) Cable 37.92 32.778 19.073

C2(33kV-2 - 33kV-3) Cable 37.92 32.778 19.073

C3(33kV-2 - 33kV-3) Cable 43.36 34.245 26.592





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Table 14: Case 6: Load Flow Bus Voltage Profile

Bus ID Nominal kV Actual Voltage (kV) Actual Voltage (%)

1.2 kV SWBD 1.2 1.078 89.83

33kV - 1 33 32.53 98.58

33kV - 2 33 32.53 98.58

33kV - 3 33 32.458 98.36

33kV- SGT 3 33 32.599 98.78

33kV - SGT4 33 32.601 98.79

33kV - SGT 1A 33 32.596 98.78

Grid 275 275 100.00


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Table 14.1: Case 6: Load Flow Branch Power Flow

ID Type Rating Power Flow (MVA) Real Power (P)Reactive Power

(Q)% Loading

Cable(275kV) Cable 302.45 236.826 188.116



Cable (SGT1A) Cable 75 MVA 83.91 73.887 39.772

C (33kV-1 - 33kV-2) Cable 116.94 98.106 63.637

C1(33kV-2 - 33kV-3) Cable 37.28 32.221 18.749

C2(33kV-2 - 33kV-3) Cable 37.28 32.221 18.749

C3(33kV-2 - 33kV-3) Cable 42.62 33.664 26.14







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APPENDIX ONE: POWER SYSTEM STUDIES INPUT DATA

APPENDIX TWO: LOAD FLOW RESULTS

APPENDIX THREE: FAULT LEVEL RESULTS

APPENDIX FOUR: STANDARD COPPER BUSTUBE RATINGS

APPENDIX FIVE: 33 kV POST INSULATOR DATA