Improved power rating of cascaded H-Bridge multilevel inverter

This paper presents a simulation of 5-level Cascaded Diode Clamped Half Bridge (CDCHB) Inverter using Hybrid Level-shifted and Phase-shifted (HLP) Sinusoidal Pulse Width Modulation (SPWM) technique. The output voltage, output current and voltage across each device, and the THD of the CDCHB inverter are obtained. Further, the paper aims to perform a comparison between 5-level CDCHB inverter with Cascaded H-Bridge (CHB) inverter. The comparison is done on the basis of the peak inverse voltage of each device, output power and the THD obtained with both the inverters. Simulations are done in MATLAB Simulink and results obtained are shown.

I. Introduction

The power conversion systems for large renewable energy stations are facing a great challenge today as Battery Energy Storage Systems (BESS), PV cells and all other renewable energy sources output approaches in MWs, which demand three phase multi-level inverters. Medium voltage applications include high power motor drives, high power uninterruptable power supplies (UPSs), flexible ac transmission systems (FACTs). Neutral (diode) clamped converters (NCCs), capacitor clamped converters (FCs), and cascaded H-Bridge converters (CHBs) are the typical multi-level converters [1]–[2].