A Novel Seven-Level Switched Capacitor Multilevel Inverter Topology with Common Ground Configuration

Transformer-less photovoltaic (PV)-based grid-connected converters are becoming progressively more common in renewable energy applications owing to their reduced size, lower cost, and enhanced efficiency. However, the lack of galvanic isolation causes the flow of leakage current in these systems, which compromises power quality and jeopardizes personal safety. This research proposes a single-phase common ground MLI topology with fewer components and less complexity for the complete mitigation of leakage current. The proposed topology employs a DC power source, 2 diodes, 3 capacitors and 12 switches to give 7 voltage levels across the load. Additionally, the proposed configuration, which is based on the switched/auxiliary capacitor principle, has the inherent capability to achieve three times voltage gain without the use of any magnetic components or boosting circuits. The Nearest Level Control Pulse Width Modulation (NLC-PWM) scheme is also used to provide gate pulses in order to obtain reduced harmonics in the output voltage and current waveforms. This paper presents a comprehensive study of the proposed topology. Additionally, the advantages of the suggested inverter topology in terms of voltage gain, elimination of leakage current, and reduced switch counts are then highlighted in a quantitative comparative analysis.