Design and Control of 11-Level Modular Multilevel Converter with Dual Purpose Inverter for Grid Connected Photovoltaic System

An 11-level modular converter is designed to cater to the need of a single-phase system in accordance with IEEE standards in respect of total harmonic distortion (THD). The control technique is used for controlling the KW as well as KVAR by means of power angle and modulation index respectively. The objective of the inverter is to make operate in dual mode as an active power injector, as well as a reactive power injector into the grid irrespective of the active power supply from the solar photovoltaic (PV) arrays. The operation is accomplished with a grid-connected solar photovoltaic (PV) system. The modular multilevel converter (MMC) inverter is placed between the grid and the PV array along with an RL load. All the simulation and analysis work has been performed in MATLAB Simulink software. Further, THD is compared with two techniques such as level shifted Pulse Width Modulation (PWM) and phase shifted PWM.