Unidirectional three-phase rectifier with high power factor

A three-phase three-level rectifier with less power switches is proposed. Four power switches with voltage stress of half DC bus voltage are used in the circuit. A carrier-based current control strategy is proposed to draw the sinusoidal line currents with nearly unity power factor. The switching signals for power switches are derived from the DC bus voltage controller and neutral point voltage compensator. The mathematical model of the rectifier is derived and the control scheme is provided. To verify the proposed operation scheme, performance characteristics are given by experimental results.