Method for on-line detection of leakage current of power supply SPD

On-line detection of leakage current of Zinc oxide power supply SPD can be affected by many factors, such as harmonic voltage, inter-phase interference, etc. These factors mutually affect each other, making the problem quite complicated. How to eliminate the influence of inter-phase interference and voltage harmonic wave of system on MOV leakage current detection and thus improve the accuracy of results has always been the focus of attention. In this paper, we detected the phase difference between working voltage and total leakage current instead of detecting resistive leakage current. In addition, data fusion method that combined arithmetic mean and batch estimate was used to process on-line detection data of MOV. By using this method, the results can more accurately reflect the degradation of MOV.