A Novel Dead-beat Predictive Direct Power Control of Three-phase PWM Rectifier

Conventional dead-beat predictive direct power control (DB-P-DPC) for three-phase PWM rectifier has numerous advantages such as low current harmonics, small power ripples and fixed switching frequency under ideal grid voltages conditions. However, in unbalanced network conditions, the conventional DB-P-DPC cannot work normally, which leads to high current harmonics and large power ripples. To this end, this paper adopts a new instantaneous power definition and presents a novel DB-P-DPC strategy. The aim of the novel DB-P-DPC is to eliminate twice frequency oscillations in instantaneous active power. Based on the power control model of PWM rectifier, the proposed control strategy can obtain the voltage vector reference in the next control period, which is synthesized by using space vector modulation (SVM). A feedback compensation link is introduced to modify predictive reference value of the novel instantaneous power in each control period. Both simulation and experiment results show that the proposed strategy can effectively reduce current harmonics and instantaneous power ripples without steady-state power errors. What's more, it can work normally under both balanced and unbalanced network conditions. © 2021, Power System Technology Press. All right reserved.