Wavelet Transform as an Alternative to the Short-Time Fourier Transform for the Study of Conducted Noise in Power Electronics

This paper compares the characteristics of the classic and short time Fourier transform with the continuous wavelet transform. The wavelet transform perfectly suits the considered application, the study of the time evolution of frequency spectra in switched mode power supplies, which operate with significant transients. The analysis made with wavelets offers a means to better understand the generation and propagation of conducted noise from the noise source, the switching devices, to the point where the noise is actually measured, the line impedance stabilization network.