Research on Direct Power Control Strategy for PWM Rectifier

The traditional direct power control (DPC) strategy exits the problems that the switching frequency is not fixed, the sampling frequency is high and so on. To combat these problems, a control system of improved virtual-flux control strategy with DPC (VF-DPC) is proposed in the paper. In order to overcome the problem that switching frequency is not fixed, hysteretic controller and switching table are replaced by PWM modulation module in the DPC strategy, In order to improve the system anti-jamming capability and reduce system cost, it is use virtual flux to estimate the instantaneous power. The simulation results verify the system is accuracy and feasibility.