Time-frequency Analysis of Partial Discharge Signal by Gabor Transform

In order to understand more details on the time-frequency characteristics of the partial discharge signal,the time-frequency distribution is an efficient tool.The Gabor transform is a time-frequency transform,in which signals are expressed as the sum of wavelets of sinusoidal form and Gaussian amplitude variation,it is very suitable for analyzing non-stationary time-varying signals.The Gabor transform was applied to time-frequency analysis of partial discharge signal in this paper,because different window functions in regard to their mean square time and frequency widths used in the Gabor transform would produce different results,so the Gaussian window function which can improve joint time-frequency localization of the results was selected by using the Heisenberg inequality.Experimental results show that the time-frequency analysis of partial discharge signal based on the Gabor transform can describe the change of the signal details on the time-frequency plane,and it also can reflect the characteristics of time and frequency accurately of the partial discharge signal.The results can effectively meet the requirements of choosing suitable parameters,it can be used in characteristic extraction of signals,and it also offers a kind of new method for pattern recognition of PD signals.