A Five-Level Common-Ground Inverter with Dynamic Voltage Boost and Fewer Elements for Photovoltaic Applications

Abstract

Transformer-less multilevel inverters (TL-MLIs) are the subject of recent research due to their high-voltage or high-power capacity to convert low-voltage output from renewable energy sources into the desired output. They are also less expensive and smaller than traditional varieties. Nevertheless, leakage current is a common problem with these inverters. The proposed inverter aims to address this issue to the maximum extent possible. In the proposed inverter structure, there is a common ground for the input and output terminals. As a result, the overall common mode voltage (CMV) remains constant. This common ground feature short-circuits the Photovoltaic (PV) source to the grid parasitic capacitor, resulting in negligible leakage current. Furthermore, the proposed inverter boosts output voltage using the least amount of power devices and a single voltage source. The proposed inverter can be used modularly, increasing the number of output levels that can be achieved. The simulation results from MATLAB/Simulink and the conclusion of the mathematical analysis for the proposed inverter are shown. The results also demonstrate the output voltage boost capability, zero leakage current, and an appropriate total harmonic distortion for the output voltage and current waveforms.