Common-Grounding Triple-Boost Seven-Level Compact Inverter for Transformerless PV System

This paper proposes a new common ground seven-level compact multilevel inverter with three times boosting gain for a single-phase transformer-less system. This proposed topology has significant benefits, for example, a low total standing voltage when compared to others with the same performance-boosting gain at a lower cost. Due to common ground, this topology eliminates the leakage current of the PV system. The proposed topology employs one source, three capacitors, and ten semiconductor switches employed to build the circuit. The capacitor voltages are self-balanced through regular charging and discharging of the capacitors, ensuring sensor-less operation. The circuit description and operations of different levels are described in detail. A comprehensive comparative analysis of the proposed topology is carried out in this paper. Finally, simulation results for the proposed topology are presented under steady-state and dynamic conditions in both open-loop and closed-loop configurations to validate its feasibility and operability.