Single-stage bridgeless three-level AC/DC converter with current doubler rectifier

This paper proposes a new bridgeless single-stage three-level ac-dc converter. The proposed converter integrates the operation of the bridgeless power factor correction (PFC) boost rectifier and the zero-voltage switching (ZVS) three-level dc-dc converter. The proposed converter provides high power factor and direct power conversion from the line voltage to an isolated dc output voltage without using the full-bridge diode rectifier. Conduction losses are lowered with a simple circuit structure. Voltage stresses of the power switches are reduced by the use of three-level topology. Switching losses are also reduced by achieving ZVS of the power switches. The effectiveness of the proposed converter is verified on a 400 W (48 V/8.33 A) experimental prototype at 90 V_rms line voltage.