Zero-Voltage Transition Flyback Inverter for Small Scale Photovoltaic Power System

A zero-voltage transition (ZVT) flyback inverter is proposed. The current in the flyback transformer is controlled in the fixed frequency, and the pulse width is varied to make the inductor current sinusoid. In order to reduce switching losses and noises, a soft-switching technique is adopted. The soft-switching technique is called the switched snubber circuit or the primary current steering technique. It is suitable for the pulse-width modulation (PWM), because the time of the resonant transition is very short and the time is independent of the switching frequency. A laboratory prototype using a digital controller for the ZVT flyback inverter was built. From the simulation using the PSPICE and experimental results, the zero-voltage transition operation of the main switch is confirmed. The proposed inverter is suitable as a power conditioner for PV power systems