Influence of interphase interference on resistive leakage current of MOA

The latent faults of the metal oxide surge arrester (MOA) can be found by on-line resistive leakage current monitoring. However, because of the influence of location and distributing mode of the MOA, the voltage of two other phases affect a single MOA by interphase interference, and this influences the monitoring accuracy of the MOA´s resistive leakage current. A software analysis method for every phase influential factor is advanced. And we analyze the double CT method to eliminate this influence. Based on the double CT method, a bus-module on-line leakage current monitoring system for the MOA is developed.