Modular Multilevel Converter Design for Grid Integration of Solar Photovoltaic Systems

In the paper, a novel MMC design is proposed, which simultaneously acts as the DC power optimizer to capture maximum power and as the DC/AC inverter to transfer solar power from DC link to AC power system. In order to make MMC fit for sources with inherent variability in DC side voltage (DC link), the full-bridge submodule based MMC (FBMMC) topology, modulation techniques, and required control systems are designed. The proposed control platform consists of two components to realize maximum power point tracking and AC power flow control. Model predictive control is employed to design the switching algorithms. Finally, effectiveness of designed MMC for grid integration application of a PV array with varying irradiance and temperature is validated.