Dc Short Circuit Calculations Of Al Dhahiyah 380/115kv Bsp: Saudi Electricity Company

‫الشركـة السعوديـة للكـهرباء‬

Saudi Electricity Company

‫فرع المنطقة الشرقـية‬

CERT'D

Eastern Region Branch APPR'D DESCRIPTION

OF AL DHAHIYAH 380/115kV BSP

BY

1

DATE

0

NO.

REVISIONS DRAWN BY:DATE:- 13-03-2007

CHECKED BY:DATE:-

OPRG. DEPT BY DATE:-

ENG'G. DEPT. BY:DATE:-

CERTIFIED. BY:DATE:THIS DRAWING IS NOT TO BE USED FOR CONSTRUCTION OF FOR ORDERING MATERIALS UNTIL CERTIFIED AND DATED

DRAWING TITLE

INDEX

AL DHAHIYAH 380/115kV BSP DC SHORT CIRCUIT CALCULATIONS AL DHAHIYAH

A

PLANT

DA409

SAUDI ARABIA JOB ORDER NO. –

DRAWING NO.

EE-026322

SHEET NO.

1 OF 4

THI S DR AW ING AN D TH E INF OR MA TIO N CO NT AIN ED HE REI N AR E TH E SO LE PR OP ER TY OF SA UDI EL EC TRI CIT Y CO. NO RE PR OD UC TIO N IN FU LL OR IN PA RT SH ALL BE OB TAI NE D FR OM THI S DO CU ME NT WI TH OU T TH E WR ITT EN CO NS EN T OF ITS OW NE R.

ISSUED FOR BASE DESIGN SUBMITTAL

CHK'D

DC SHORT CIRCUIT CALCULATIONS

REV NO.

A

DWG. CONT. SHT.

SEC-ERB CAD-E WORD

‫الشركـة السعوديـة للكـهرباء‬

Saudi Electricity Company

‫فرع المنطقة الشرقـية‬

CERT'D

Eastern Region Branch APPR'D

ISSUED FOR BASE DESIGN SUBMITTAL

CHK'D

INDEX DESCRIPTIONS

PAGE NO.

1.0

INTRODUCTION

3

2.0

SYSTEM DESCRIPTION

3

3.0

CONSIDERATIONS FOR STUDY

3

4.0

STUDY METHOD AND PROCEDURE

3

5.0

STUDY CASE

3

6.0

INPUT DATA

3-4

7.0

STUDY RESULTS & CONCLUSION

4

DESCRIPTION BY

1

DATE

0

NO.

REVISIONS

ATTACHMENTS

:

DRAWN BY:DATE:- 13-03-2007

CHECKED BY:-

SKETCH –1

: 3 Phase Short Circuit : ETAP software generated drawing

ANNEXURE-1 : 3 Phase Symmetric Short Circuit Study, ETAP software generated report

DATE:-

OPRG. DEPT BY DATE:-

ENG'G. DEPT. BY:DATE:-

CERTIFIED. BY:DATE:THIS DRAWING IS NOT TO BE USED FOR CONSTRUCTION OF FOR ORDERING MATERIALS UNTIL CERTIFIED AND DATED

DRAWING TITLE

INDEX

AL DHAHIYAH 380/115kV BSP DC SHORT CIRCUIT CALCULATIONS AL DHAHIYAH

A

PLANT

DA409

SAUDI ARABIA JOB ORDER NO. –

DRAWING NO.

EE-026322

SHEET NO.

2 OF 4

THI S DR AW ING AN D TH E INF OR MA TIO N CO NT AIN ED HE REI N AR E TH E SO LE PR OP ER TY OF SA UDI EL EC TRI CIT Y CO. NO RE PR OD UC TIO N IN FU LL OR IN PA RT SH ALL BE OB TAI NE D FR OM THI S DO CU ME NT WI TH OU T TH E WR ITT EN CO NS EN T OF ITS OW NE R.

CLAUSE NO.

REV NO.

A

DWG. CONT. SHT.

SEC-ERB CAD-E WORD

‫الشركـة السعوديـة للكـهرباء‬

Saudi Electricity Company

‫فرع المنطقة الشرقـية‬

CERT'D

Eastern Region Branch APPR'D CHK'D

1.0 INTRODUCTION: This report provides the DC Short Circuit study to determine the short circuit current flow in Main DCDB and DC Panels’ buses at 125V during DC Short Circuit and to check the suitability and adequacy of the MCCBs/ Fuses and Buses Rating to work satisfactorily.

ISSUED FOR BASE DESIGN SUBMITTAL

2.0

SYSTEM DESCRIPTION: 125V DC Distribution of the Substation is as per attached Single Line Diagram for DC Distribution.

DESCRIPTION

4.0

CONSIDERATIONS FOR STUDY: 

Total fault level at 125V Main DCDB Bus has been considered as 20 kA.



Standby Charger is left open for DC short circuit calculations.



Internal Resistance of Batteries has been neglected.



All loads fed from 125V DC Panels are neglected. STUDY METHOD AND PROCEDURE: The DC short circuit study is based on ANSI method and has been carried out with the help of TAP 5.5.5 version.

5.0

STUDY CASE:

BY

DC short circuit current flows in all buses.

1

DATE

0

NO.

REVISIONS DRAWN

6.0

INPUT DATA: A) Interrupting Fault Level at 125V MCCBs and Fuse = 20 kA B) Detail of Cables

BY:DATE:- 13-03-2007

CHECKED

a)

Cable from battery to main DCDB - Cable Size :  1/C x 630 sq mm Cu - Max. operating temp : 90 Deg. C - No.of Cables : 2 Nos. per phase - DC Resistance at 20 Deg. C : 0.0283 Ohm / Km - Approx. length = 50 m

b)

Cable from battery charger to main DCDB - Cable Size :  1/C x 630 sq mm Cu - Max. operating temp : 90 Deg. C - No.of Cables : 2 Nos. per phase - DC Resistance at 20 Deg. C : 0.0283 Ohm / Km - Approx. length = 25 m

BY:DATE:-

OPRG. DEPT BY DATE:-

ENG'G. DEPT. BY:DATE:-

CERTIFIED. BY:DATE:THIS DRAWING IS NOT TO BE USED FOR CONSTRUCTION OF FOR ORDERING MATERIALS UNTIL CERTIFIED AND DATED

DRAWING TITLE

INDEX

AL DHAHIYAH 380/115kV BSP DC SHORT CIRCUIT CALCULATIONS AL DHAHIYAH

A

PLANT

DA409

SAUDI ARABIA JOB ORDER NO. –

DRAWING NO.

EE-026322

SHEET NO.

3 OF 4

THI S DR AW ING AN D TH E INF OR MA TIO N CO NT AIN ED HE REI N AR E TH E SO LE PR OP ER TY OF SA UDI EL EC TRI CIT Y CO. NO RE PR OD UC TIO N IN FU LL OR IN PA RT SH ALL BE OB TAI NE D FR OM THI S DO CU ME NT WI TH OU T TH E WR ITT EN CO NS EN T OF ITS OW NE R.

3.0

REV NO.

A

DWG. CONT. SHT.

SEC-ERB CAD-E WORD

‫الشركـة السعوديـة للكـهرباء‬

Saudi Electricity Company

‫فرع المنطقة الشرقـية‬

CERT'D

Eastern Region Branch APPR'D

Cable from main DCDB to DCP1 - Cable Size :  1/C x 630 sq mm Cu - Max. operating temp : 90 Deg. C - No. of Cables : 1 No. per phase - DC Resistance at 20 Deg. C: 0.0283 Ohm / Km - Approx. length = 140 m

d)

Cable from main DCDB to DCP2 - Cable Size :  1/C x 630 sq mm Cu - Max. operating temp : 90 Deg. C - No. of Cables : 1 No. per phase - DC Resistance at 20 Deg. C : 0.0283 Ohm / Km - Approx. length = 140 m

e)

Cable from main DCDB to DCP3 - Cable Size :  1/C x 630 sq mm Cu - Max. operating temp : 90 Deg. C - No. of Cables : 1 No. per phase - DC Resistance at 20 Deg. C : 0.0283 Ohm / Km - Approx. length = 20 m

ISSUED FOR BASE DESIGN SUBMITTAL

CHK'D DESCRIPTION

C) Battery / Battery Charger - Full load current =300 A - Nominal Voltage=125V - No. of Cells =58 - Nominal Cell Voltage =2V - No. of Cells =58 BY

7.0 STUDY Results & CONCLUSION: DATE

1

The detailed result of the short circuit study generated by ETAP software is shown in ANNEXURE-I with this report. Single Line Diagrams indicating short circuit current values are shown in Sketch-1. Annexure-1 and Sketch-1 show DC short circuit study report.

0

NO.

REVISIONS DRAWN

A) Calculated short circuit current contributions from various sources to specific fault locations

BY:DATE:- 13-03-2007

Please refer to Annexure-I – from page no. 8 to page no. 19.

CHECKED BY:-

B) Calculated short circuit currents for sizing of busbars

DATE:-

OPRG. DEPT

Bus Fault Current at all Buses =12.393kA

BY

C) Calculated short circuit currents for selection of MCCBs and Fuses

DATE:-

ENG'G. DEPT. BY:DATE:-

CERTIFIED. BY:-

Sl. No. 1

Nominal Voltage in V 125

MCCB/ and Fuses

Maximum Fault Current in kA

Selected Device Rating in kA

12.393

All

Remarks

20

DATE:THIS DRAWING IS NOT TO BE USED FOR CONSTRUCTION OF FOR ORDERING MATERIALS UNTIL CERTIFIED AND DATED

DRAWING TITLE

INDEX

AL DHAHIYAH 380/115kV BSP DC SHORT CIRCUIT CALCULATIONS AL DHAHIYAH

A

PLANT

DA409

SAUDI ARABIA JOB ORDER NO. –

DRAWING NO.

EE-026322

SHEET NO.

4 OF 4

THI S DR AW ING AN D TH E INF OR MA TIO N CO NT AIN ED HE REI N AR E TH E SO LE PR OP ER TY OF SA UDI EL EC TRI CIT Y CO. NO RE PR OD UC TIO N IN FU LL OR IN PA RT SH ALL BE OB TAI NE D FR OM THI S DO CU ME NT WI TH OU T TH E WR ITT EN CO NS EN T OF ITS OW NE R.

c)

REV NO.

A

DWG. CONT. SHT.

SEC-ERB CAD-E WORD