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 convertor. To sinusoidally waveshape the supply current with a near-unity power factor independent of the working conditions, 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 state-space averaging method based on a DC equivalent circuit and such an operation is also simulated by 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.