cover sheeetTCE CONSULTING ENGINEERS LIMITED30421007-3CL-00016-P0ASHEET i OF i125V DC STATION BATEERY AND BATTERY CHARGERSIZING REPORTSAUDI ELECTRICITY COMPANYEASTERN OPERATING AREADammam, Saudi ArabiaGENERATION EXPANSION OF ARAR POWER PLANT(CONTRACT NO : 30421007/00)DESIGN BASISFOR125V DC STATION BATTERY & BATTERY CHARGER SIZINGDOCUMENT NO : 30421007-3CL-00016-P0AOCTOBER 2004ENGINEERING CONSULTANTTCE CONSULTING ENGINEERS LIMITED73/1, ST.MARK'S ROADBANGALORE 560001INDIACONTRACTOR:AL-TOUKHI COMPANY FOR INDUSTRY & TRADINGP.O.BOX 497, RIYADH 11411, KINGDOM OF SAUDI ARABIATEL.00966-1-14633660 : FAX.00966-1-4631150P0A 26.10.2004MPSRREV NO. DATEPREPARED BYCHECKED BYCLEARED BYAPPROVED BY

IndexCALCULATION DOCUMENTDOCUMENT NO. 30421007-3CL-00016-P0A.SIZING CALCULATION FOR STATION 125V DC SYSTEMCONTENTSSECTIONDESCRIPTION1.0PURPOSE2.0STANDARDS & REFERENCES3.0SIZING CRITERIA4.0BATTERY LOAD CYCLE.5.0CONSIDERATIONS6.0DETERMINATION OF NO. OF CELLS7.0CORRECTION FACTOR S FOR BATTERY SIZING8.0DUTY CYCLE( LOAD PROFILE)9.0BATTERY AND CHARGER SIZING CALCULATIONS.10.0DC LOAD ESTIMATION11.0CONCLUSION

WriteupCALCULATION DOCUMENTDOCUMENT NO. 30421007-3CL-00016-P0A1.0PURPOSE:The purpose of this calculation is to determine the sizes of the 125V DC battery and battery charger for the Station DC System of GTG#7 and GTG#8 of ARAR Central Power Station.2.0STANDARDS & REFERENCES2.1SCECO Engineering Standard SES-P-103.02 - Revision 3 Storage Battery Selection and Capacity determination2.2SCECO Engineering Standard SES-P-103.03 - Revision 3 Battery Charger sizing.2.3IEEE-485 - IEEE Recommended Practice for Sizing of Large Lead Acid Storage Batteries for Generating stations and Sub Stations.2.4Key One Line Diagram for Arar Plant Drawing No:KA-667481, Rev-P0D SHEET 1 OF 13.0SIZING CRITERIA3.1The battery has been sized to meet the Station DC loads, namely the switchgear control supplies and the Lighting load in the event of black out, for a period twelve (12) hours.The DC Loads pertaining to Gas turbine and Generator Auxiliaries are not considered as part of these calculation.since these loads would be catered to unit DC system.3.2The Type of battery selected is Vented Type Lead Acid Battery as per cl no 3.03-19(a), page 40 of 336 of PTS-10223.3The tripping/closing coil/spring charging motor loads for MV breakers are based on Schneider Electric switchgear catalogues.3.4The End cell voltage is considered as 1.75V as per SES-P-103.02.3.5Design marigin factor of 1.1 has been considered as per cl.no.4.4.2 of SES-P-103.023.6Ageing factor of 1.25 has been considered as per cl.no. 4.4.3 of SES-P-103.023.7The Battery room temperature is considered as 25 deg C and the temperature correction factor of 1.19 based on inside room temperature of 10 Deg C in case of power failure is considered as per cl.no 2.2 of SES-P-103.02. Page 17 of 353.8Capacity correction factors and Temperature correction factors are based on SCECO engineeringstandard SES-P-103.02.

Notes for SizingCALCULATION DOCUMENTDOCUMENT NO. 30421007-3CL-00016-P0A.4.0BATTERY LOAD CYCLE4.0.1Prior to blackout the following plant configurations are considered:As a worst case, Incomer & Feeder Breakers of 4.16kV Switchgear, Unit LV Switchgear and Station LV Switchgear are considered as closed. On loss of power in the plant, all the above referred circuit breakers will trip.This load is considered as 1 minute load at starting of duty cycle.4.0.2On return of normal power supply, simutaneous closing of one incomer & one outgoing feeder, tripping of one breaker if fault persists, starting of one spring charging motor and running of one spring charging motor are considered as per c.l.no.2.3(b) of SES-P-103.02. page no 18 of 35. This load is considered as 1 minute load prior to end of duty cycle.4.0.3Starting current of spring charging motor is taken as 5 times the normal current as per cl.no 2.4 SES-P-103.02.4.0.4Continuous loads corresponding to remote control/annunciation panels, OLTC panels of Generator Transformer, LV Aux Transformers,indications on switchgear for a period of 12 hours.4.0.5DC Emergency lighting load for 3 hours which will be switched on within 3 hours of power failure in accordance with cl.no. 2.6 of SES-P-103.035.0CONSIDERATIONS5.1.1Maximum of 2000Watts of lighting loads has been considered.5.1.2The following type of indication lamps and transducers have been condsidered for the MV breakers(a)Indication Lamps for(b)Transducers fori) Breaker -ONi) Voltage(V) Transducerii) R phase -ONii) Ammeter(A) Transduceriii)Y phase -ONiii) Watt (W) Transduceriv) B phase -ONiv) Power Factor(PF) Transducerv) Trip circuit healthy -ONv) VAR Transducer5.1.3The following type of Indication Lamps & Annunciation have been condsidered for Remote control/annunciation Panel.(a)Indication Lamps for(b)Annunciations fori) Breaker -ONi) Transformer Winding Temperature highii) R phase -ONii) Transformer Winding Temperature very high.iii)Y phase -ONiii)Transformer oil temperarue highiv) B phase -ONiv) Transformer oil temperature very highv) Trip circuit healthy -ONv) Buchholz relay for transformer and OLTCvi) Pressure relief valvevii) DC supply supervision relayviii) Trip circuit supervision relayix) O/C & E/F protectionx) REF protectionxi) Differntial protectionxii) Overall Differntial protectionxiii) Lockout relayxiv) Under Voltage Relayxv) AC trip coil healthyxvi) Motor Protection Relay

Cell NumberCALCULATION DOCUMENTDOCUMENT NO.30421007-3CL-00016-P0A6.0DETERMINATION OF NUMBER OF CELLSNominal cell voltage:2voltsNominal battery voltage:125voltsas per cl.no 2.0 of SES-P-103.02Float voltage:2.2voltsas per cl.no 2.0 of SES-P-103.02End cell voltage:1.75voltsas per cl.no 4.1.2(d) of SES-P-103.02Minimum permitted Voltage:101.5voltsas per cl.no 2.0 of SES-P-103.02Maximum Permitted Voltage:136.3voltsas per cl.no 2.0 of SES-P-103.02Number of cells required considering the minimum system voltage and end cell voltage =101.5/1.75=58.00..(i)Number of cells required considering the maximum system voltage and float voltage =136.3/2.2=61.95..(ii)Number of cells chosen is lower of the above 2 values =58.00Maximum system voltage considering 58cells and float voltage of 2.2 volts is 58 * 2.2=127.6volts