A Switched-Capacitor based 7-Level Inverter Capable of Voltage-Boosting and Natural Voltage Balancing of Capacitors, Suitable for Supplying Off-Grid AC Loads

The feeding of off-grid AC loads, like military loads or defense systems is of high importance. This paper proposes a novel structure for Switched-Capacitor based Multi-Level Inverter (SCMLI) that produces a high quality (low THD) 7-level output-voltage waveform for supplying off-grid AC loads. The proposed inverter requires only single DC-source and can boost the input voltage up to three times, at the output port. The boosting capability is very crucial at PV applications. The reduced device count, high quality (low THD) output voltage, and natural voltage balancing of capacitors are other main merits of suggested inverter. The proposed inverter can effectively supply any load type, including pure resistive, resistive-inductive and pure inductive loads. The short discharging interval of capacitors leads to reduced capacitors' voltage-ripple, high voltage quality, low voltage-ripple losses and better inverter efficiency. Comparison results approve the superiority of proposed converter over existed counterparts. Also, the correct operation of proposed inverter during different operational conditions, has been validated by simulation (performed in MATLAB-Simulink software) and experimental analysis.
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