Operation Analysis Of 500kV Protection For Transformer In Hangzhou Area

Power transformer is one of the most important electrical equipments in power system, especially the 500kV large power transformer, its running state directly affects the safe and stable operation of the whole electric power backbone network. When the transformer faults of transformer protection, need timely and accurately cut the fault, to ensure safe and stable operation of power supply reliability and power system.Currently, there are five 500kV substations in Hangzhou area,14 sets of existing 500kV transformer, transformer protection a total of 28 sets of (according to the entire screen Statistics), due to the production period is different, the configuration of each substation main transformer protection of different types, both at home and abroad, the transformer protection principle and latching logic also each are not identical, now operating switching operation, especially current loop operation requirements also each are not identical, if there is a problem may caused by the mal operation of the transformer tripping, lead to serious consequences.This paper briefly introduced the structure of 500kV transformer, analyzes features of 500kV transformer, transformer protection are considering how to configure, brief introduction of basic principle of 500kV transformer protection, transformer protection 500kV substation and then Classification of transformer protection 500kV substation to the jurisdiction of Hangzhou area, analysis of protection principle, secondary loop and operational considerations. Finally, through the recent 500kV Fuyang substation RET521 analysis of misoperation of protection tripping device, find out problems and put forward RET521 main transformer protection emergency overhaul and localization of alternative design scheme.