顺北油田二区变电站35kV电压互感器烧毁故障分析

Analysis on the burning fault of 35kV voltage transformer in the second district of Shunbei oilfield

油田电网运行中,35kV系统和10kV系统为中性点经消弧线圈接地系统或不接地系统,在电网发展时期,系统参数可能处于谐振区,电磁式电压互感器易发生铁磁谐振现象,产生过电压或过电流,严重时会烧毁电压互感器。本文对顺北油田二区变电站35kV系统发生的3次电压互感器烧毁故障开展研究,得出电力系统处于谐振区,电压互感器铁磁谐振是造成电压互感器烧毁的原因。通过采取投入消弧线圈、应用饱和特性好的电压互感器和4PT改造等措施,有效治理了铁磁谐振。

During the operation of power grid in the oilfield,the 35kV and 10kV systems are neutral grounded or ungrounded systems through arc suppression coils.During the development period of the power grid,the system parameters may be in the resonance zone,and electromagnetic voltage transformers are prone to ferromagnetic resonance,generating overvoltage or overcurrent.In severe cases,the voltage transformers may be burned out.In this paper,three voltage transformer burn-out faults occurred in Shunbei No.2 substation are studied.The conclusion is drawn that the power system is in the resonant region,and the ferromagnetic resonance of voltage transformer is the cause of voltage transformer burn-out.By adopting measures such as investing arc suppression coils,applying voltage transformers with good saturation characteristics,and renovating 4PT,ferromagnetic resonance is effectively controlled.