Simulation of APF digital low-pass filter with FPGA

The harmonic detection of active power filter in the low-pass filter design directly affects the detection accuracy of the system and the compensation effect. The digital low-pass filter type,order,cut-off frequency,sampling frequency in the active power filter harmonic detection are analyzed. The second-order Butterworth digital low-pass filter is selected. FPGA is used to process the harmonic detection,by using the Ip-Iqdetection method in reactive power theory and suitable configuration of low-pass filter,the unbalance of loads in power network is solved. The simulation indicates that the delay of this method is only 200 ns,which has no influence on fundamental wave.