Novel multilevel converter for power factor correction

An eight-switch three-phase neutral-point switch-clamped rectifier is presented to achieve the high input power factor and draw the sinusoidal currents from the AC mains. In the conventional three-phase neutral-point switch-clamped rectifier, the circuit configuration consists six power switches with voltage stress v_dc and three ac power switches with voltage stress V_dc/2. There are only four power switches with voltage stress of DC bus voltage and two AC power switches with a voltage stress of half the DC bus voltage in the proposed rectifier. The main functions of the proposed control scheme are to achieve unity input power factor, to draw the sinusoidal line currents from the AC source, and to keep the DC link voltage constant. The analysis and mathematical model of the proposed rectifier is derived. Some simulations and experimental results are provided to verify the effectiveness of the proposed control scheme.