Single-phase step-up/down rectifier with improved supply current waveform

The paper presents a novel single-phase rectifier with step-up/down characteristics. This is fundamentally based on the cascade combination of a diode bridge and a single-ended primary inductor power convertor. To sinusoidally waveshape the supply current with a near-unity power factor independent of the working conditions, a buffer capacitor is operated with voltage reversibility for the supply by arranging the auxiliary power switching device and diode. The circuit operation is macroscopically analysed by the state-space averaging method based on a DC equivalent circuit and such an operation is also simulated by a rigorous state-space method. Moreover, the tested setup, using two insulated-gate bipolar transistors and a 16-bit microcomputer, is implemented to experimentally investigate the steady-state and transient characteristics. The experimental and simulated results confirm the usefulness of the rectifier presented