Design of PWM Rectifier Control System Based on Unit Power Factor

Due to the presence of nonlinear power devices in rectifiers, a large amount of harmonic pollution will be generated during system operation. Harmonic pollution has a significant impact on the stability and efficiency of the system, and may also lead to more serious accidents.In response to the nonlinearity in the rectifier, this article adopts sliding mode control as the design method. During the research process, a mathematical model of the PWM rectifier system is first established, and then the control rate in the sliding mode controller is calculated based on the obtained mathematical model. The Fcn module in MATLAB is used to edit the formula based on the obtained system control rate to achieve sliding mode control.Through simulation verification, it can be seen that the rectifier control with sliding mode control has faster response speed, anti-interference ability, and robustness; When facing changes in a given voltage, sliding mode control quickly adjusts without static error. Therefore, the performance of sliding mode control is superior to that of PI control when controlling nonlinear systems.