Integrated Common-Mode and Differential Mode Filter Circuit for Leakage Current Suppression in Transformerless Photovoltaic Inverter Systems

The transformerless photovoltaic inverter system will lead to a large leakage current between the photovoltaic inverter system and the ground, and the current reduction is mainly based on the optimization of circuit topology and control mode.This paper first analyzes the causes of ground leakage current, as well as several strategies and mechanisms to control the ground leakage current.On this basis, a novel integrated common-mode and differential mode filter circuit is proposed to reduce the leakage current of transformerless photovoltaic inverter system.Through theoretical analysis and circuit simulation, it is proved that the suppression technology can effectively reduce the leakage current of transformerless photovoltaic inverters.