High-power factor rectifier based on neutral point clamped scheme

A high power factor rectifier based on neutral point clamped scheme is proposed. The voltage stress of each power semiconductor of the adopted rectifier is equal to the half DC bus voltage instead of full DC link voltage in the conventional switching mode rectifier. The control signals of the rectifier switches are derived from the DC link voltage balance compensator, fine current controller and DC link voltage regulator. The carrier-based pulse-width modulation (PWM) scheme is employed to draw a clean sinusoidal line current, high input power factor, regulated DC link voltage and balance capacitor voltages. Three voltage levels are generated on the AC terminal of the adopted rectifier. To verify the proposed operation scheme, performance characteristics are given by the computer simulations.