Energy regenerating snubber assisted sinewave soft switching pulse modulation inverter for renewable and sustainable energy applications

This paper presents a novel prototype of the utility-interfaced soft-switching sinewave pulse modulated inverter using the three-winding high-frequency flyback transformer for the small scale distributed solar photovoltaic power conditioner, which is defined as a cycloinverter. It is noted that the sinewave pulse modulated output current of this inverter with a high-frequency transformer link is synchronous to the AC main grid voltage. The proposed sinewave inverter type power conditioner circuit with a high-frequency link has a function of electrical isolation, which is cost-effective and reliable for small-scale distributed renewal and sustainable energy utilization system from a safety point of view. The discontinuous pulse current mode (DCM) in the secondary windings of the flyback transformer is introduced to implement a simple circuit configuration and control scheme. The auxiliary power regenerating snubber circuits with power generating snubber are mathematically analyzed for the purpose of the parameter settings. Then, the performance of the proposed cycloinverter is evaluated and discussed on the basis of the computer-aid simulation results.