A high efficiency hybrid 7-level inverter with single DC source

A high efficiency 3-phase hybrid 7-level inverter is presented in this paper. Compared with traditional hybrid 7-level converters, the proposed topology and its T-type cell have lower power loss and simple configuration. It can be easily implemented and applied in renewable energy areas. In the paper, power loss of proposed T-type cell is analyzed, by which conduction loss of T-type cell is proved to be lower than commonly used H-bridge. Therefore, it can be considered to replace H-bridge as a higher efficiency approach in many multi-level topologies. Due to single DC source proposed, DC voltage control scheme for auxiliary inverters is also discussed and presented. A comparison study is carried out by MATLAB + PLECS simulation platform in a grid-connected system.