Based on short-time fourier transform impulse frequency response analysis in the application of the transformer winding deformation

In order to improve the accuracy of on-line application and winding condition assessment of pulse frequency response method, this paper proposes a short time Fourier transform (STFT) algorithm to construct the pulse frequency response curve of the transformer windings, trying to solve the problem of the fast Fourier transform, (FFT) algorithm is not suitable for dealing with transient signal. PSPICE software is used to establish the equivalent circuit model of the single winding and the transient time domain simulation. The MATLAB software is used to analyze the effect of the sampling time. The correctness of the proposed method is verified by simulation analysis. Processing and analysis of the frequency response test data of the winding pulse frequency in the 110kV health transformer, and the correlation coefficient index of the sub critical evaluation, experimental results also shows that the after treatment of short time Fourier algorithm, the frequency response curve of high definition, noise is small, the frequency response curve closer to the actual situation, is better than fast Fourier transform algorithm.