Visual analysis of electrical signals

Abstract

The sinusoidal spectrum of electrical signals is analyzed by using The Fourier series method and the Fast Fourier change method. Amplitude-frequency characteristic diagram and phase-frequency characteristic diagram are obtained respectively. The amplitude-frequency characteristic and the phase-frequency characteristic are superimposed in time domain and compared with the original signal. The analysis uses fast Fourier transform to analyze the minimum sampling frequency of electrical signals. The GUI module in MATLAB is used for programming, which makes the experimental parameters easy to modify. A more general conclusion can be drawn. Through experiments, we find that when the sampling frequency is more than twice the cut-off frequency of the original periodic signal, the fast Fourier transform method can better restore the original signal. When the sampling frequency is small, the signal will be seriously distorted. The amplitude-frequency and phase-frequency characteristics obtained by Fourier series can better restore the original signal when the harmonic frequency is large, but it is different from the original signal to some extent.