Application of sequential hierarchical signal method in online monitoring of partial discharge in GIS

After analyzing the various interferences when monitoring the Gas Insulated Substation (GIS) partial discharge, this paper puts forward a hierarchical sequential model, which can reduce the disturbance of partial discharge signal. The hierarchical sequential method, based on the Fourier series and wavelet transform method, can effectively and accurately suppress the white noise and periodic narrowband interference, so as to extract the useful partial discharge signal from the strong interference background. The method is simple, flexible and easy to apply to the other occasions. In the meanwhile, the subsequent data and simulation both verify the accuracy of the method, which will have wide range of application.