Design of Single-phase PWM Rectifier Based on PI Double-loop Control

Abstract

: In this paper, the mathematical model of PWM rectifier is analyzed first, and the rotating coordinate system transformation is used to convert the mathematical model to frequency domain, and the control model is established through the frequency domain model. Since the d -axis and q -axis currents are coupled with each other, this paper adopts the current feedforward processing to decouple the current loop, and introduces the PI regulator as the main control link between the current loop and the voltage loop to obtain the control models of the current inner loop and the voltage outer loop. In this paper, the current inner loop control model and the voltage outer loop control model are simulated in Simulink, and root locus analysis and Bode diagram analysis are used to first determine the parameters of the current inner loop within the expected range of the relevant parameters, and then determine the parameters of the voltage outer loop by the control model of the current inner loop. A double-loop control system with better performance is finally derived.