The online detection of faulty insulator using fast Fourier transformation

In high voltage line, faulty insulator, especial zero value insulator, may greatly reduce the insulation level of highvoltage transmission line, thus can threat to the safe operation of power system directly. In order to detect the faulty insulator on the ground, in this paper, the current sensor is slipped into the grounding wire of pylon, and then we can collect the tiny leakage current pulse signal. After that, there are two kinds of method to analyze the signal in this article. The two methods are the analysis of fast Fourier transformation spectrum of leakage current pulse and the corona pulse phase comparison method. Based on the analysis of laboratory and field data, the detector can clearly see the existence of faulty insulator.