An improved harmonic detection algorithm

Accurate and fast detection of harmonics is the basis for active filters to work regularly. Propose an improved generalized IP-IQ harmonic detection algorithm. Analyzed generalized IP-IQ harmonic detection algorithm, pointed out two advantages of this algorithm: It can separate any order of harmonic and detect harmonic correctly even if the voltage of grid is distorted. But the generalized IP-IQ algorithm has disadvantage of delay from low pass filter(LPF). Using moving average to replace LPF, shorten the delay and the design of LPF is avoided, the amount of calculation become smaller and the algorithm is easy for programing. By establish Matlab/Simulink simulation platform to simulate the algorithm, the result shows that the algorithm has characteristics of high accuracy and small delay.