A Nine-Level Common-Ground Type Boost Inverter for PV Applications

Abstract

Transformer-less multilevel inverters (TLMLIs) are widely used in solar photovoltaic (PV) applications because they are cheap, have higher power density, have a lower dv/dt, and are more efficient. However, the major concern of TLMLIs is the ground leakage current flow due to the presence of PV parasitic and the absence of galvanic isolation between grid neutral and PV. This paper proposes a nine-level double boost (9L2B) common ground type inverter topology with near zero leakage current using the concept of switched capacitors (SCs). The voltages across all the SCs are balanced using the series-parallel technique, and this eliminates the need for a complex control circuit and sensors. The SCs are self-balanced in every fundamental cycle. Furthermore, a detailed comparative analysis is performed to emphasise the remark's such as switch count, leakage current elimination, TSV, self-balancing, and boosting features of the proposed inverter with respect to others. Finally, the feasibility and operation of the proposed topology are validated by performing several simulations, and the results are presented.