Cascaded H-Bridge Multilevel Inverter Based Solar PV Power Conversion System

In recent years, renewable sources of energy have witnessed a steady rise in their integration into the electrical utility system due to the concept of microgrids. A dc microgrid connected with both types of loads, i.e., ac and dc loads are presented. In this paper, an isolated dc microgrid system is proposed, which consists of a 5-level cascaded H-bridge multilevel inverter (CHB-MLI) with LC filter for ac loads. This microgrid also consists of 48V and 72V dc buses for dc loads with different ratings. The total harmonic distortion (THD) of the inverter output is computed using the MATLAB/Simulink FFT analyzer and the losses in the system have been calculated. The complete performance of the CHB-MLI based dc microgrid is assessed and validated using the MATLAB/Simulink simulation software.

I. Introduction

Due to the rapid exhaustion of fossil fuels and the harmful consequences on the environment due to their consumption, the focus on renewable energy sources (RES) for electrical power generation has increased substantially in the recent years. Renewable energy sources are the best possible alternatives for production of clean energy and if they are harnessed efficiently, they can produce energy more than the required world energy demand [1]. In the available renewable energy sources, solar energy turns out to be the cleanest and most abundant in nature. In the last few years, there has been an emphasis on the integration of photovoltaic systems into the electrical grid.