Development and analysis of a seven-level common- ground switched-capacitor inverter topology

This paper presents a novel Seven-Level Common-Ground Switched-Capacitor Boost Inverter (7L-CG-SCBI) topology with high efficiency, voltage boosting feature, and reduced leakage current for renewable energy applications. The proposed inverter employs a single DC source, three switched capacitors, eleven unidirectional switches, and one bidirectional switch to generate a seven-level output voltage with a gain of three. The capacitors achieve self-balancing without additional sensors or complex control, ensuring stable operation and reduced design complexity. The common ground structure effectively eliminates leakage currents, enhancing system safety and grid compatibility. A comprehensive analysis covering operating principles, modulation strategy, loss evaluation, and reliability assessment using a Markov model is presented. The simulation results in MATLAB/Simulink and experimental validation confirm the inverter’s higher efficiency (96.13%), low total harmonic distortion, and reliable performance of the inverter under varying load and frequency conditions. The compact configuration, self-balancing feature, and high reliability make the proposed 7L-CG-SCBI a promising solution for photovoltaic and other renewable energy systems.