A soft-switching inverter using a voltage clamp soft-switching step-up/down DC link

A soft-switching pulse-width-modulation single-phase inverter using a voltage clamp soft-switching step-up/down dc link is proposed in this paper. The proposed voltage clamp soft-switching step-up/down not only provides the switches in the section of conventional PWM buck inverter operate at zero-voltage-switching (ZVS), but it has a step-up/down input voltage function and the switches in itself also operate at ZVS. Thus, except for the switch in the section of ZVS-PWM auxiliary circuit, all power semiconductor devices in proposed inverter operate at ZVS turn on and turn off. The switch in the section of ZVS-PWM auxiliary circuit operates at zero-current-switching (ZCS) turn-on and turn-off. Besides operating at constant frequency, the proposed inverter has no voltage stress and current stress on the main switch compared to the hard switching inverter counterpart. Auxiliary components rated at very small current are used. The principle of operation, theoretical analysis, and experimental results of the proposed soft-switching inverter, rated 1 kW and operated at 40 kHz, are provided in this paper to verify the performance.