A Comprehensive Analysis of AC-Decoupling Techniques for Common-Mode Leakage Current Reduction

Transformerless inverters have gained popularity in grid-tied photovoltaic (PV) systems due to their advantages such as reduced size, weight, and cost. However, the absence of galvanic isolation in these inverters creates a direct path between the PV modules and the grid, requiring careful design to meet safety requirements. Various research studies have focused on reducing the common-mode ground current (CMGC) while maintaining a constant common-mode voltage (CMV). In this paper, investigate the drawbacks of using transformers in photovoltaic inverters connected to the electrical grid and propose a solution in the form of transformerless grid-connected inverters. Further analyze traditional single-phase photovoltaic inverter topologies without a transformer and propose a novel neutral point clamped topology namely N-HERIC to overcome the challenges associated with galvanic isolation. The proposed topology is evaluated using simulation tools like MATLAB/SIMULINK to assess its performance in terms of efficiency, common-mode voltages, and leakage currents. By examining these topologies and proposing a new solution, contribute to the ongoing research and development of transformerless grid-connected photovoltaic inverters. The simulation results provide valuable insights into the feasibility and performance of these inverters, opening possibilities for further advancements in real-world applications.