Detecting Methods of Harmonic in Power System Based on Wavelet Transform

It is very important to measure the harmonic accurately and then restrain it effectively. Wavelet Transform is a analytical method of time-scale (time-frequency) of processing signals. It can figure out frequency distribution at a particular time, and also can decompose the frequency spectrum which composed of different frequency´s signals into the different frequency´s signal block. Finally this paper gives one simulation example to decomposes and analyzes the sampled signal i(t) by using Daubechies (dbN) wavelet. The result of the simulation indicates that this method can effectively separate the fundamental wave and the harmonic from the current.