Multimode Model Predictive Control for Three-phase PWM Rectifier

In this paper, a multimode model predictive control(MMPC) strategy is proposed for PWM rectifiers. The control strategy automatically switches between single vector control, two vector control and three vector control, three modes according to the demand of PWM rectifier performance under different operating conditions. Thus, the conflicts between the wasted computing power, total harmonic distortion (THD) values and switching frequency caused by fixed control modes are effectively solved. First, a multimode control system framework is constructed in this paper. This framework uses two cost functions for vector selection and vector operation time calculation, respectively. THD values and DC side voltage value are used as the condition for mode switching. The simulation results show that the control strategy proposed in this paper can effectively reduce the losses caused by the switching frequency under the condition of ensuring the control accuracy.