Abstract: There are several circuit topologies and control methods for traditional three-phase APFC(active power factor correction) converter. However, the rectifiers often use full-bridge, which results in low efficiency of the whole circuit, high input of current harmonics and complexity of the control methods. Based on single phase module, a novel one-cycle controlled three-phase bridgeless PFC circuit is established through paralleling two-phase bridgeless Boost PFC circuits by autotransformer. In order to reduce the coupling interference between two paralleling circuits, the discrete elements are added to achieve the independent control of the two paralleling circuits. Simulation and experiment have proved the correctness of the proposed system. The new circuit can achieve high power factor, and the bridgeless scheme is helpful to raise the total efficiency of the circuit. Simple in control, the one-cycle control strategy can simplify the circuit structure.

Key words: one cycle control strategy, active power factor correction, bridgeless Boost PFC, three-phase circuit, coupling interference