Direct Power Control Based on Natural Switching Surface for Three-Phase PWM Rectifiers

In this letter, the natural trajectories of the output voltage and the inductor currents for three-phase pulse width modulation rectifiers are presented. On this basis, a novel direct power control (DPC) using the natural switching surface is proposed by combining DPC with the boundary control. Compared to the conventional DPC, the proposed control considers the output voltage when selecting the switching states. Therefore, the proposed control does not need an outer voltage control loop and can highly improve the dynamic performance of the dc output voltage. The experimental results on a 1.5-kW prototype confirm the correctness of the theoretical analysis. They verify the feasibility and the validity of the proposed control and show the excellent dynamic performance.