Prediction of leakage current in transformerless photovoltaic inverter system by a more accurate method

In case of the grid connected transformerless photovoltaic (PV) inverter, the leakage current through the parasitic capacitance of the PV panel can cause very serious electromagnetic interference problems. In this paper, a more accurate high frequency PV array model is proposed. It includes the influence of PV frame, mounting rack, solar cell material and area. Based upon that model, the common mode leakage current is predicted through numerical analysis and calculation. The accuracy of the theoretical results is certified by MATLAB simulation and experimental test. This developed method can be easily incorporated into PV inverter system for further device/circuit design optimization with various panel parameters.