A new three-level six-switch topology for transformerless photovoltaic systems

Leakage current suppression is one of the most important issues for transformerless photovoltaic systems, where the technical challenge is how to keep the system common-mode voltage constant to reduce the leakage currents. A new single-phase three-level topology for transformerless photovoltaic systems is presented in this paper. Compared with the conventional H-bridge topology, it only needs two additional asymmetrically distributed switches, and the system common-mode voltage can be kept constant with a simple modulation scheme. Test results verify the theoretical analysis and the feasibility of the presented topology.