Research On Generators Safe Operation Of Fengzhen Power Plant

Fengzhen Power Plant has a special main wiring structure.There are four units connected to 220kV bus, two units connected to 500kV bus of the plant's booster station. 220 kV bus has three outlet lines connected to Fengquan substation while 500kV bus has one. There are interconnecting transformers between Fengquan substation and Fengzhen Power Plant's 500kV bus and 200kV bus. We need to analyse the stability of 200kV system and units under the conditon that the unit 5# parallel switchs or the 500kV line gets out of order.After analysis, we conclude that switching over station power of the unit 5# should be avoided when the interconnecting transformer in Fengquan substation is out of operation, otherwise there will be serious overloads in HV transformer. When the 500kV Fengfeng line is out of operation while all generating units of Fengzhen Power Plant are in, the 5# and 6# unit will supply to the 220kV system through the plant's interconnecting transformer, which will result in a serious overload in the interconnecting transformer; When three typical failure occurs on the 500kV Fengwan line, all the units of Fengzhen Power Plant can maintain stability. During the fault transient period, all units' voltage can return to near normal level(standard unitary values between 0.96 ~ 1.05), while the frequency deviation kept within -0.2 ~ 0.085Hz. When three-phase short circuit fault occurs on Fengwan line, the foult current of some 220kV lines will be large, which may lead to the maloperation of protections on I or II section. The conclusion can be a valuable reference for other plants.