Experimental verification of three-phase four-wire current-regulated PWM converter

A bidirectional power flow, three-phase AC/DC converter is presented to implement power factor correction, regulate the DC-bus voltage and draw balanced and sinusoidal line currents from AC source. Four switches are adopted in each converter leg to generate a three-level PWM waveform on the AC terminal to neutral-point voltages. Compared with conventional three-phase three-level converters, the proposed converter has a simpler circuit configuration and fewer power semiconductors. The classical proportional-integral voltage controller and carrier-based current controller are adopted in the outer loop and inner loop to implement DC-bus voltage regulation and current-command tracking, respectively. Simulation and experimental results verify the validity and effectiveness of the control scheme.