Model Predictive Control and Ripple Suppression Method for Three-phase PWM Rectifier Under Unbalanced Grid Condition
A ripple suppression method is studied in this paper for the DC voltage secondary ripple and grid-side cur-rent harmonics of voltage-based PWM rectifiers under three-phase unbalanced grid faults.Based on the traditional dual-closed-loop control structure,a reference current calculation method under unbalanced grid faults is proposed.The model predictive control replaces the current loop PI control,and the fixed switching frequency is realized by combin-ing the PWM modulation.According to the current prediction model and the principle of minimum current error,the proposed method can not only suppress the grid-side current harmonics and DC bus voltage ripple,but also reduce the average switching times and the losses of devices.Finally,an experimental platform of 0.7 kW output power with 110 V on AC side and 300 V on DC side was established,which had a good steady-state performance.Simulation and experi-mental results verified the effectiveness of the proposed control method and the correctness of theoretical analysis.
three-phase imbalancethree-phase PWM rectifiermodel predictive control
万方数据
维普
