Analysis of Partial Discharge in GIS under Impulse Voltage by Using Quadratic Short-time Fourier Transform
Wenrong Si · Electric Power · 2013
In order to analyze the characteristics of signals of partial discharge(PD) in GIS under the impulse voltage,a kind of timefrequency transform theory called the quadratic short-time Fourier transform was applied in analysis of the PD pulse sequence to get the distribution of energy and variation law of signals in the time-frequency plane.In this research,the time-frequency transform of a kind of typical PD pulse sequence containing noise was simulated,which showed that PD pulse could be extracted efficiently.Besides,a kind of spikes defect model was installed in the bus segment of 220 kV GIS and the PD of GIS under impulse voltage was detected.By timefrequency analysis of experiment data,it can be found that the theory of quadratic short-time Fourier transform can be applied in analysis of PD signals efficiently and the variation law of time-frequency spectrogram was affected by the length of window function.