Unipolar Single Reference Multicarrier Sinusoidal Pulse Width Modulation Based 7-level Inverter with Reduced Number of Semiconductor Switches for Renewable Energy Applications

Abstract

In the present scenario of increasing power demand and depletion of fossil fuel results in the research advancements in the field of renewable energy sources. Among various types of renewable energy sources, photovoltaic related applications are gaining importance. DC-AC converters play a very prominent role in photovoltaic system in efficient power delivering for various applications. This paper proposed a 7-level inverter with reduced number of switches for photovoltaic applications. Unipolar Single Reference Multicarrier Sinusoidal Pulse Width Modulation (U-SR-MC-SPWM) technique is used for the purpose of gate pulse generation for the proposed multilevel inverter. A comparative study of seven-level cascaded multilevel inverter and a proposed multilevel inverter is carried out. Simulation and power quality analyses of both multilevel inverters are performed in MATLAB/Simulink platform version 2016(a). It is noticed that the total harmonic distortion is slightly more of the proposed multilevel inverter when compared with cascaded h-bridge inverter. But, with the reduction in the number of power semiconductor switches in proposed multilevel inverter overall switching power losses, circuit complexity, gate driver requirements and cost of the system can be reduced. The simulation results always show a good agreement with the proposed approach.