Unity Power Factor Operation of Three-Phase PWM Rectifier Based on Direct Power Control

In this paper, direct power control (DPC) of three-phase PWM rectifiers is presented, without line voltage sensors. The controller builds upon the ideas of the well known direct torque control (DTC) for induction motors. In our case, the active and reactive powers replace the torque and flux amplitude used as controlled output in DTC. The instantaneous active and reactive powers, directly controlled by selecting the optimum state of the converter, are used as the PWM control variables instead of the phase line currents being used. The controller ensures a good regulation of the output voltage, and guarantees the power factor close to one. The proposed controller was tested both in simulation and experimentally. The results show the excellent performance of the proposed system such as a good dynamic behavior, a good rejection of impact load disturbance.