Research on Fuzzy Control of PWM Rectifier Voltage

Abstract

PWM rectifier has the advantages of high power factor and low harmonic pollution, and usually adopts double closed loop control method of voltage outer loop and current inner loop in synchronous coordinate system. Since it is difficult to reflect the nonlinear nature of the voltage equation by using only linear PI control, this paper introduces nonlinear fuzzy control, combines fuzzy control with PI control, and combines the advantages of both. Using the fast adjusting ability of fuzzy control and the steady-state precision of PI control, the fuzzy-PI control method is adopted. The fuzzy adaptive PI control is adopted to adjust the parameters online to overcome the shortage that the PI adjustment parameters are fixed and cannot be adjusted. Simulation results show that both fuzzy control methods improve the dynamic and static performance of the system.