A Single-Phase Multilevel Inverter with Reduced Switch Count for Solar PV Application

Abstract

The persistent energy problems facing developing nations can be addressed by investing in renewable energy sources and technologies as these RES, such as fuel cell, PV energy, wind energy, and biomass energy can provide the needed energy to overcome energy shortages in such nations. MLIs are commonly used for high power high/medium voltage applications as they are considered an advanced topology for power conversion. Studies are currently focusing on the design of “reduced switch MLI (RS MLI) topologies” to facilitate the production of high-quality output without using numerous numbers of switches. These RS MLI are currently emerging techniques for various reasons, such as cost reduction, optimal sizing, reduced volume, minimized losses, and high efficiency. This study presents the design and development of a Multilevel Inverter (MLI) structure with fewer switch count for PV application. The proposed inverter architecture comprises of an H-bridge unit that acts as the polarity generator and the level generating unit comprising independent voltage sources with switches and diodes. It combines the proposed inverter with a PV array through a DC-DC converter. The boost converter will improve the output voltage of the solar photovoltaic system to its maximum value using MPPT (P&O). The proposed inverter is designed and tested for structures of five, seven, and nine levels by using MATLAB/Simulink. Selected results are presented to verify the validation of the 5, 7, and 9 levels MLIs. As a result, the proposed system successfully managed to achieve 96 % efficiency.