Frequency domain interpolation wavelet transform based algorithm for harmonic analysis of power system

A power system harmonic detection technique based on frequency domain interpolation wavelet transform is proposed in this paper. Aiming at harmonic detection, Fast Fourier transform (FFT) can only detect integer harmonics; Short Time Fourier transform (STFT) can detect non-integer harmonics with low resolution; wavelet transform can detect non-integer harmonics, but it have spectral aliasing and spectral leakage phenomenon, which result in low resolution. So this paper use frequency domain interpolation algorithm to detect harmonic signal by choosing Shannon wavelet. Simulation and comparative results obtained by three algorithms reveal that the proposed method can effectively eliminate spectral aliasing, spectral leakage and Gibbs phenomenon, can precisely detect harmonic signal, so it provide an effective means for power system harmonic analysis and detection.