Flexible Mode Bridgeless Boost PFC Rectifier With High Efficiency Over a Wide Range of Input Voltage

Abstract

For the conventional PFC rectifiers, the high efficiency cannot be achieved over a wide input range, and the efficiency will be greatly decreased at low-input voltages. In order to overcome the efficiency bottleneck under low-line input, a flexible mode bridgeless boost power factor correction (PFC) rectifier is proposed in this paper. According to the input voltage, the proposed rectifier can be flexibly adapted to the suitable operating mode to obtain the maximum efficiency. Meanwhile, the circuit components can be reused by different operating modes, so the extra cost is low. In the proposed rectifier, a back-to-back bridgeless boost PFC topology is adopted at high-line conditions and a three-level bridgeless boost PFC topology is rebuilt to reduce the switching losses at low-line conditions. Compared with the traditional bridgeless boost PFC rectifier, an extra low-voltage bidirectional switch (usually composed of two switches) is added, so the increased cost is low. In addition, the low common-mode noise can be achieved at both high- and low-line conditions due to the direct connection between the input mains and the output electrolytic capacitor. The detailed principle analysis about the proposed rectifier is presented in this paper. Finally, an experimental prototype is built to verify the feasibility and the effectiveness of the proposed topology.