A three-phase voltage source PWM rectifier with strong DC immunity based on model predictive control

Abstract

A Pulse Width Modulation (PWM) rectifier with strong DC disturbance rejection is presented based on Model Predictive Control (MPC). The design of outer voltage square loop and inner current loop using model predictive control is presented, where voltage square loop indicates the square of output DC voltage calculated to be linear with active current. A discrete-time model of the rectifier is constructed to predict the future current for all voltage vectors. Then, one voltage vector minimizing the current errors is selected by solving the cost function. Two weighting matrices, which affect the performance of the rectifier greatly, are used in the cost function to weight prediction error and control actions. This paper indicates the function of the two different weighting coefficients and the way to choose proper weighting factors on a typical three phase PWM rectifier under different conditions. The static, dynamic, pre-charging performance and anti-disturbance ability are discussed upon the proposed rectifier model. The results are proved by simulation that the proposed method can achieve strong DC immunity and a fast dynamic performance with pre-charging strategy compared to the traditional method.