Experimental verification of a three-phase multilevel rectifier with reduced number of power switches

A three-phase multilevel rectifier with reduced number of power switches to achieve high-power factor, low harmonics and high-voltage capability is presented. In the conventional three-phase neutral point clamped rectifier, 12 power switches are used to draw the sinusoidal line currents with unity power factor. The main drawback of these systems is the large number of power switches used in the circuits. Only six power switches with voltage rating of half DC-link are adopted in the proposed multilevel rectifier. Based on the proposed control strategy, the input power factor is close to unity and line currents are controlled to be balanced and sinusoidal. Simulation and experimental results are provided to verify the effectiveness of the proposed control strategy based on a laboratory prototype.