Multilevel inverter based Grid Connected Solar Photovoltaic System with Power Flow Control

Abstract

In this paper a 3.25 $\mathrm{kW}_{\mathrm{P}}$ grid connected single stage solar photovoltaic system with multilevel inverter and real time weather conditions is simulated on the MATLAB SIMULINK platform. DC-DC converter is completely avoided, voltage stabilization, maximum power point tracking and DC to AC conversion are done through only multilevel inverter. Five level multilevel inverter with five switches is developed and further to increase each two levels in the output voltage waveform only one more additional switch is to be added. The $1-\Phi$ multilevel inverter output is integrated with the $1-\Phi$, 230V, 50 Hz supply from the grid. Shunt active current controller is designed to ensure that only real power flow exist in the system. The output voltage total harmonic distortion obtained is only 1.18% till $100^{\mathrm{t}\mathrm{h}}$ harmonic content, which is very less and multi carrier sinusoidal pulse width modulation control scheme is used to control inverter. The simulation results are validated with the practical per day energy generated through grid connected conventional inverter. Proposed work closely fits with practical data and better power quality is achieved.