Design, Engineering and Optimization of a Grid-Tie Multicell Inverter for Energy Storage Applications

Abstract

Multilevel converters have found many applications within renewable energy systems thanks to their unique capability of generating multiple voltage levels. However, these converters need multiple DC sources and the voltage balancing over capacitors for these systems is cumbersome. In this work, a new grid-tie multicell inverter with high level of safety has been designed, engineered and optimized for integrating energy storage devices to the electric grid. The multilevel converter proposed in this work is capable of maintaining the flying capacitors voltage in the desired value. The solar cells are the primary energy sources for proposed inverter where the maximum power density is obtained. Finally, the performance of the inverter and its control method simulated using PSCAD/EMTDC software package and good agreement achieved with experimental data.