A Common Ground-type Single-Phase Dual Mode Five-Level Switched-Capacitor Transformerless Inverter

This paper presents a novel dual mode five-level common ground type (5L-DM-CGT) transformerless inverter topology with a wide input range (200 V – 400 V). It consists of eight switches, one diode, two capacitors, and an LC filter at the output. The topology eliminates common mode (CM) leakage current by connecting the negative terminal of the photovoltaic (PV) directly to the neutral point of the grid, which bypasses the PV array’s stray capacitance. Depending on the magnitude of the input voltage, the converter can operate in buck or boost mode to produce the same AC voltage output. The analysis shows the advantages of dual mode inverter for various industrial applications. MATLAB Simulink simulations and experimental results verify the concept of the proposed topology and control method.