Direct power decoupling control using optimal switching table combined with virtual flux estimator for PWM rectifier

This paper presents the design and implementation of a Direct Power Control (DPC) based on a virtual flux estimator and an optimal Switching Table (VF-ST-DPC) for a three-phase PWM rectifier. The proposed approach combines DPC principles, a virtual flux estimator concept, and an optimal switching table (ST) to select the optimal converter vector control. The objectives of this approach are to solve the cross-coupling between instantaneous active and reactive powers for each sector and to enhance harmonic line currents. Thus, the proposed method is carried out in a fixed coordinate frame. It therefore does not require a Park transformation or the synchronization of the grid voltage, which is achieved by a virtual flux estimation method. Experimental results, based on the dSpace DS1104 board, show that the VF-ST-DPC ensures smooth and decoupled control of instantaneous active and reactive power, as well as low harmonic levels (THD = 4.6%), verifying the expected performances of the proposed method under both steady-state and transient operations.