Single-phase common ground type 5L inverter with reduced capacitor voltage stress for photovoltaic applications

Abstract

In recent years, common ground (CG)-type transformerless (TL) inverters have been paid more attention. However, the existing topologies have more voltage stress on either switch or on capacitor voltage or in both. This article proposes a novel five-level TL inverter topology with a CG type and a voltage stress reduction on power components. The proposed topology offers less component count and a simple structure. Here, the quasi-soft charging (QSC) technique is proposed to minimize the high charging current during the capacitor charge. Since the proposed topology is the family of switched capacitors (SC), the determination of SC and QSC is presented. A detailed comparison of the proposed topology with other recent five-level topologies is presented, and the proposed topology's advantage is highlighted. Further, the performance of the proposed topology is verified in simulation software and verified in a scale-down hardware setup developed for 400 W. The various experimental results are presented to ensure the feasibility of the proposed topology.