Harmonic Improvement of Multilevel Inverter with Asymmetric Switching Modes and Harmonic Search Optimization Method

Abstract

This paper deals with the harmonic analysis of multi-level converters and harmonic reduction methods. The proposed method for multilevel converter aims to provide a suitable model in an asymmetric switching mode and extract the analytical relationships for output harmonics. In the end, the harmony search optimization method is used to obtain the optimized output voltage harmonics in asymmetric switching mode. The proposed structure for the 5-level asymmetric inverter is presented using the results of the proposed model as well as the optimized harmony. Simulations are performed in Matlab 2018a software and the results show the total harmonic distortion (THD) reduction by about 17% and 28% for the proposed inverter.