A Bidirectional Snubber Less Soft-switched High Frequency Link DC/AC Converter

This paper presents two novel modulation schemes for a bidirectional single phase inverter with a high frequency link. The topology with the proposed modulation scheme can be used for the grid integration of renewable energy sources like photovoltaic and fuel cell, energy storage system, hybrid and electrical vehicle, vehicle to grid (V2G) integration, uninterruptible power supply (UPS) system. The use of high frequency transformer results in reduction of cost with improved power density. The proposed modulation strategies of the converter achieve soft-switching for both direction of power flow. During DC to AC power flow, modulation is done in the DC side with zero voltage switching (ZVS) of the DC side switches and the AC side switches are line frequency switched. For AC to DC power flow, zero current switching (ZCS) of AC side switches and zero voltage switching (ZVS) of DC side switches are achieved. A detailed analysis of operation of the proposed converter is presented in the paper. Key simulation results are shown to demonstrate the effectiveness of the proposed topology.