A Three-Phase Single-Stage Isolated Flyback-Based PFC Converter With Leakage Energy Recovery Clamping Circuit

This article presents a three-phase single-stage isolated flyback-based power factor correction (PFC) converter with a clamping circuit to recover the transformer leakage inductance energy for more electric aircraft application. With the proposed clamping circuit, the transformers' leakage inductance energy is successfully captured in clamping capacitor, and subsequently, a constant power 28-V secondary supply is derived by using a two-switch forward converter to improve the converter overall efficiency. The converter unity power factor (UPF) operation is obtained by using the inherent resistance property of discontinuous conduction mode (DCM). Hence, the input current shaping circuit is eliminated and resulted in a single-loop control system. Thus, the converter control circuit requires only one sensor, which decreases the system cost and increases the system reliability and robustness. In addition, the converter provides fault-tolerant operation for single-phase loss. The converter is analyzed and the design equations are explained in detail. The voltage and current stress equations for all power components are derived and validated with the simulation. The novelty and the operation of the converter are demonstrated with the experimental results from a 2-kW laboratory prototype.