Study on leakage current suppression of photovoltaic inverters with filter circuits

The transformerless photovoltaic (PV) inverter systems can generate significant leakage current to the ground. Currently, the main methods to reduce leakage current are based on optimizing circuit topology and control methods. This paper, after analyzing the causes of ground leakage current, proposes a novel integrated common-mode and differential-mode filtering topology with a buffer circuit to reduce the leakage current in transformerless PV inverter systems. This solution can effectively reduce the system's ground leakage current. Through theoretical analysis and circuit simulation verification, it is shown that this topology can effectively reduce the leakage current of the transformerless PV inverters.