In order to study the characteristics of leakage current of catenary insulator during the pollution flash-over

in this paper

the catenary composite insulator FQX-25 is selected to do artificial contamination test. First ofall

study on the partition of experimental data by using the variation of the leakage current can re-determine the par-tition threshold of the safe zone

forecast area and danger zone which are 10 mA and 30 mA. Secondly

the RMS andthe pulse time-domain entropy are obtained and the relationship between them and contamination degree is pro-cessed by MATLAB. Then

by doing the FFT analysis in each section

the amplitude ratio of 3rd harmonic

5th har-monic and fundamental wave are extracted as K3/1、K5/1. Finally

the total harmonic distortion of the leakage current inthe whole process of the contamination flashover of the 3 section is built and the approximate range of waveform har-monic distortion of each section is established. The research shows that the RMS of the leakage current and the pulsetime domain entropy and the equivalent salt density ρESDDhave very good exponential fitting relation and the total har-monic distortion and the of the K3/1waveform in the leakage current prediction area could describe the leakage cur-rent characteristics more accurately. The results of this study can provide a new way to evaluate the contamination status of insulators.