Implement on APF using the optimal design of digital low pass filter

Optimized design is presented with adding lead-lag correction to improve low-pass filter character according to the harmonic detection of APF. Second-order ellipse filter is chose as the core of the harmonic detection after compared with kinds of filters. Relationship of parameters which affects system performance is worked out by analyzing distribution of system zero-pole point, then lead-lag correction is added to optimize low-pass filter. Simulation result shows that optimized design raised in this paper fits the detection of power harmonic and fundamental reactive current better, nice accuracy and dynamic response are obtained in the detection system, it has a strong engineering practicality to improve compensation performance of APF.