Harmonic Detection in Electric Power System Based on Wavelet Multi-resolution Analysis

Because of widespread uses of nonlinear load, electric power system network is injected with much harmonic current, which does great harm to consumer equipment. In order to prevent harmonic current from influencing safety of system¿s operation, we should know well how much distorted harmonic wave contained and take corresponding measurement to control or compensate it. Inthis paper, based on a kind of multi-resolution wavelet method, we use seven levels of restructuring through using Daubechies wavelet (db24) to decompose the electric current signal into fundamental wave and higher harmonic. By experiment analysis of simulation software MATLAB, separated fundamental wave error is less than 1%, which realizes harmonic effective tracking and gives accuracy compensation by making use of total distorted component.