Analysis Of The Influence Of Transient Over Voltage To The Secondary Circuit When Isolating Switch Operating In500kV Substation

With more and more high transmission voltage of power system, and the systemof each component in the increasingly high degree of automation, in substation500kV,when the500kV bus isolating switch operation, the isolating switch occurs to the arc.The total power air switch which below the bus terminal box or other air switch willtrip. After tripping, some substation can manually close air switch(such as Die lingstation), some can not overlap(such as the Zhao qing500kV station). When manualclosing operation, operation staffs who directly stand below the bus have a certainsafe hidden trouble, when manual operation is not successful, long time will cause theswitched shunt capacitors explosive accident.The current response is guidance on how to operate when the terminal box airswitch tripping of looting the arc, not radically solve and avoid the problems.This article presents two500kV substation in Guangdong both occur within theswitch is not successful fault conditions were introduced, followed by the staff on thedescription of failure, a preliminary analysis of the causes of failure, that the cause ofunsuccessful closing switch is switch operation is coupled to the two circuit transientover voltage power circuit short circuit control switch division. Through the analysisof the field measurement data, it verifies that the hight frequency signal whenisolating switch is switching can interconnect to the secondly side, and estimates theamplitude of voltage in secondly side. Then we put forward a measure that we canparalleling Install the Surge protective device (overvoltage suppression device) in thesecondary thermal system. The measure can make The instantaneous over a sidecoupling overvoltage limiting voltage range can bear the equipment or system.