Application of Moving Average Algorithm for Shunt Active Power Filter

In the design of the shunt active power filter, the Low Pass Filter is very important if we detect the harmonic current in dq synchronous rotating frame. This paper introduced the principle of harmonic current detection in dq synchronous rotating frame and the Low Pass Filter based on the moving average algorithm. Then we compared the moving average algorithm with the Butterworth LPF in the simulation, it proved this algorithm is advanced in the dynamic response speed (within 15ms) and the steady state compensation precision. Finally, the experimentation results proved that the dynamic response time is 15ms and the THD of the compensation current is about 2%. So we can reach a conclusion that the LPF based on the moving average algorithm have the excellent the dynamic response speed and the steady state compensation precision.