Thirteen and Twenty-one level Hybrid H-Bridge Multilevel Inverter Topology for Grid Connected System

Abstract

The need for high power and high voltage converters with quality waveform and better spectrum of harmonics has been increasing rapidly for industrial applications. In this connection, the Multilevel Inverters (MLI) came into existence and became popular. Out of various MLIs, CHB type got its own identity because of its unique features. The voltage stress on devices and harmonics can also be minimized with an increase in levels.  But with an increase in levels count of switches required would also increase, further increases cost. This project proposes an innovative topology for Hybrid H-Bridge MLI. Using this proposed topology, required switches can be reduced when we compare with CHB inverter for same voltage stress. In this paper, simulation for 13 and 21 level H-bridge inverters is computed and performance is compared. This MLI configuration also minimizes bearing stress of motor and harmonics with low voltage stress. In major applications MLIs are considered to attain higher voltage levels. To raise the level, circuit needs to have more switches. But switch count and operations have to be optimized. The inverter power level is inadequate due to high load currents and stress.  The proposed topology is configured to enable switches at distinct voltage levels that can minimize switching losses, so that performance can be improved. These circuits are modeled in both Hardware and MATLAB/Simulink and results are analyzed for thirteen and twenty-one level configurations.