Influence of Power System´s Harmonic Voltage and Interphase Interference to On-line Resistive Leakage Current monitoring of MOA

Surge arrester is an important over voltage protection equipment in substation, and the latent faults of MOA can be found by on-line resistive leakage current monitoring. However, the existence of harmonic voltages in the power system will influence the monitoring accuracy. At the same time, because of influence of location and distributing mode of MOA, the voltage of two other phases affect single MOA by interphase interference, and this will surely influence the monitoring accuracy of MOA´s resistive leakage current too. In this paper, the influence is analyzed and the method to separate the resistive leakage current under the existence of harmonic voltage is analyzed