3582282242

Elcctrical & Computer Enginccring: An International Journal t ECU) Volumc 3. Numbcr 2. Junc 2014

This CCT is thcn used to opcrate the circuit breakers near thc faullcd bus and hence thc corrcsponding generator* arc iemosed front thc system. This crcates the generałion - load imbalancc and hence the system frecjuency is aiTected.

When the frcquency of lite system cross es the permissible limit after thc fauli has occurred. thc frequency protection scheme is activated. The frequency stability of the system isenhaneed using Load Shedding.

Tablc.l Load Flow Report

Bus No.	Bus KV	Voltagc Mag.(%)	Voltagc Anglc	Gen. (MW)	Gen. (Mvar)	Load (MW)	Load (Mvar)
I	I6.5	100.0	UO	73.83I	9.738	0	0
2	I8.0	ioao	OJ	155.00	9209!	0	0
3	I3.8	KKt.O	-0.2	85.(Kl	41.951	0	0
4	230	98.940	-4.3	0	0	0	0
5	230	98.827	-4.3	0	0	I23.947	49.550
6	230	98.834	-4.3	0	0	89247	29.726
7	230	99.132	-4.3	0	0	0	0
8	230	98.884	-4.3	0	0	99.2*4	34.790
9	230	99.005	-4.3	0	0	0	0

Tablc.2CCT for diITcrcnt generotion - loading conditioiu

Cases	Fault Bus	CCTłsec)
I	Bu s I	0J6l 109
2	Bu s 2	OJ 1693
3	Bu s 3	OJ 17587

For the above mentioned generation - loading condilions. load shedding was performed liii the system frcquency stability is regained. The bas frcquency and bas vollagc ploLs for thc thrce cases arc shown in Fig. 3- Fig 8.

FigJ Bus vohagc when thc fault hasoccunrcd at bus l

Al t= l.O sec 3pha.se faultoccurred al bus l. the circuit breaker l and 4 arc operated before the CCT calculated for the case i.c. at 1.36 sec. As a resull generator l is rcmovcd front the system

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