Novel Single-Stage High-Frequency-Isolated Four-Switch Bidirectional Single-Phase PFC Rectifier

Power Factor Correction (PFC) rectifiers supplying a dc bus common for several variable speed motor drives should provide galvanic isolation and bidirectional power flow capability. State-of-the-art topologies often suffer from two-stage power conversion and/or high active component count. Therefore, this paper investigates a novel single-phase single-stage high-frequency-isolated PFC rectifier with non-pulsating input current and low active component count, i.e., only four standard power transistors with well-defined blocking voltages. The paper systematically explains the operating principle, and derives the main power component voltage and current stresses resulting in design guidelines for the realization of a 2.5 kW prototype system interfacing the European 230 V (rms) single-phase ac grid and an isolated 400 V dc output, which achieves an estimated nominal efficiency close to 96%. Further, the paper details the closed-loop control strategy and proposes a start-up procedure, which are both verified by means of circuit simulations.