10kV消弧线圈补偿系统线路耦合谐振分析

Analysis of Coupling-resonance in Petersen-coil Compensated 10 kV Networks

通过对城市某110kV站10kV母线设备两次闪络事故分析,得出如果两个非有效接地10kV系统之间通过线路有较强的耦合联系,当一个系统发生单相接地故障时,所产生的零序电压就会通过线路耦合电压,对另一个有自动跟踪补偿消弧线圈的系统产生作用,其作用结果因消弧线圈的补偿方式不同而各异,其中采用过补偿方式就有可能形成串联谐振,产生危险的过电压,是造成设备闪络事故的原因之一。针对形成该类串联谐振的条件,提出采用欠补偿方式避免闪络事故的发生。

In this paper, through analysis of two flashover faults on 10 kV bus equipment in certain 110 kV urban substation, the fault reason is found. If there are stronger coupling connections through circuit between two ineffective grounding system, when the single phase to ground fault takes place in a system, the produced zero-sequence voltage will cause a couple voltage, this voltage will influence another system which has an autotracking Petersen-coil compensated. The results of the influence are different because the modes of Petersen-coil compensated are different. Adopting the mode of excessive compensation can cause series resonance. And the measures to avoid the dangerous reso- nance over-voltage also presented in this paper.