Grid-Tie Multicell Inverter with High Safety and Ability to Obtain Maximum Power from Solar Cells

Nowadays multilevel converters have progressed in high power and renewable energy applications¡ because of their ability to generate multiple voltage levels. But the balancing of capacitor voltage¡ the existing of multiple DC sources and particularly protection issues in renewable energy application are the main problems of these multilevel converters. The proposed inverter in this paper¡ by modifying the structure of existing five-level multicell inverter with the new control method for this inverter¡ in addition to having the ability to maintain the capacitor voltage in the specified value¡ it also obviates the protection problems of them. Also the modified inverter has the ability of safety¡ connectivity of solar cells and obtaining maximum power. Finally¡ the operation of the proposed inverter and control method and mathematical analyzing is verified by simulation results with PSCAD/EMTDC software.