Optimal Design of Active Power Filter Phase-Locked Loop Circuit

Phase-locked loop circuit is an important part of active power filter. In view of the parameters difficult to be determined, an optimal design method is proposed. Based on the studying the basic principle of phase-locked loop circuit, the characteristics of phase detector, filter, voltage controlled oscillator and summary counter are also studied. A mathematical model of phase-locked loop circuit is established, and an experimental prototype is built. Simulation and experimental results show that phase-locked loop circuit designed by the proposed method can provide active power filter with stable and accurate trigger signal, and make active power filter work fast and stably. The proposed method can reduce difficulty of the design and decrease the design error, and has better engineering practicability.