Study and implementation of seven-level inverter using coupled inductor and switched-capacitor

This paper proposes a novel single-phase seven-level inverter. The topology of the proposed structure is composed of a DC source, a switched-capacitor circuit, and a coupled inductor. Compared to conventional seven-level inverter structure, numbers of switches and capacitors are reduced. The voltages of capacitors are self-balanced by using coupled inductor without complex control method. Therefore, the output voltage total harmonic distortion can be reduced. Finally, the simulation and experimental result show the 350-V input voltage, 380-V_ac output voltage, and 0.52% output total harmonic distortion under 3kW output power condition to verify the feasibility of the proposed multilevel inverter.