Direct Power Control Strategy for Three-phase PWM Rectification Based on Sliding Mode Control

For traditional PWM rectifier controllers, it is necessary to add a capacitor on the DC side to stabilize the DC voltage. If the capacitor value is too high, it will increase the system volume and cost, and the system's dynamics will deteriorate and reliability will decrease. A smaller capacitance value leads to significant voltage fluctuations on the DC side, which will increase under sudden load. This article analyzes the relationship between voltage fluctuations and capacitance values, and proposes a PWM direct power control scheme with sliding mode control, which can achieve comparable performance to traditional control under small capacitance values. The simulation results also verify the feasibility of this scheme.