Single-phase/-stage PFC AC/DC converter based on the integration of interleaved DCM boost converter and three-level DC-DC topology composed by the series connection of two half-bridge converters

A single-phase single-stage high power factor AC/DC converter based on the integration of interleaved DCM boost converter and three-level DC-DC topology composed by the series connection of two isolated half-bridge converters is proposed in this paper. The DC-DC isolated converters operate in CCM with ZVS commutation in all switches and the three-level structure configuration allows the operation with reduced switch voltage and the use of lower voltage rating devices. The input interleaved boost converters operate in DCM and the input current follows the input voltage waveform without an input current control loop. The input current also presents low current ripple due to the interleaved operation. The control of the integrated converter is obtained using an asymmetrical PWM modulation and a balance capacitor is used in order to maintain the voltage balance in the primary bus capacitors. The performance of the isolated rectifier is tested with a prototype with 1 kW output power, 127 V input voltage, 200 V output voltage and 40 kHz switching frequency.