A New Method to Detect Harmonics and Inter-Harmonics Based on Hilbert Marginal Spectrum
Aiming at the problem that harmonic pollution is becoming more and more serious in power system, a new method to detect harmonics and inter-harmonics based on Hilbert marginal spectrum is proposed in this paper. Firstly, the original signal is decomposed into several Intrinsic Mode Functions through Empirical Mode Decomposition. Then Hilbert marginal spectrum is obtained through Hilbert Huang Transform. It contains the information of signal’s harmonics frequency and those amplitudes. Finally, both harmonics and inter-harmonics are detected by this method. Fourier transform lacks the ability of time-frequency analysis. Wavelet transform is affected by the selection of wavelet base. This method overcomes these shortages and can detect the component of each harmonic quickly and accurately. Simulation result verifies that this method can meet the requirement of voltage and current distortion detection in power system.