A Filter-Based Topology and Modulation Strategy With Leakage Current Mitigation for Grid-Connected CHB Photovoltaic Inverters

The transformerless cascaded H-bridge (CHB) inverter is a potential topology for low-cost, high-efficiency photovoltaic (PV) systems. The leakage current problem caused by parasitic capacitors between the PV panels and the earth, on the other hand, remains a challenge in constructing a reliable PV system. The distinctive properties of the CHB inverter's leakage current paths are investigated in this research. A new multicarrier pulsewidth modulation method and topology are presented to suppress the leakage current. Simulations in the MATLAB/Simulink environment are used to verify the validity of the suggested solution. An experimental prototype with a power rating of 600 W is also produced and tested, with the experimental findings confirming the theoretical and simulation results.