500kV北郊变电站断路器雷击过电压仿真计算

Simulation Calculation of Circuit-breaker Lightning Overvoltage of 500 kV Beijiao Substation

利用ATP-EMTP电磁仿真计算程序对广州供电局500kV北郊变电站北石乙线因雷击造成线路电流互感器(current transformer,CT)U相闪络、断路器U相爆炸过程中可能产生的过电压进行了仿真计算,分别计算了切空线过电压和二次雷击过电压。计算结果表明二次雷击产生的小幅值雷电侵入波在线路上传递过程的反射和叠加导致北郊变电站侧断路器重击穿、CT闪络,并最终导致断路器爆炸。

Simulation calculation is made of the possible overvoltage in Phase U flashover of current transformer （CT） and Phase U explosion of circuit breaker caused by lightning strikes on Beishi Line B of 500 kV Beijiao Substation under Guangzhou Power Supply Bureau by use of ATP-EMTP electromagnetic simulation calculation program. The unloaded line tripping overvoltage and the secondary lightning-strike overvoltage are computed respectively. Computational results show that the reflection and superposition of small-amplitude lightning intruding waves caused by secondary lightning strike and transferred on lines led to circuit breaker restrike and CT flashover on Beijiao Substation side and eventual explosion of circuit breaker.