## A Novel Approach for Harmonic Optimization of a Single Phase Multilevel Inverter

INTERNATIONAL REVIEW OF ELECTRICAL ENGINEERING-IREE, vol.4, no.4, pp.532-538, 2009 (Journal Indexed in SCI)  • Publication Type: Article / Article
• Volume: 4 Issue: 4
• Publication Date: 2009
• Journal Name: INTERNATIONAL REVIEW OF ELECTRICAL ENGINEERING-IREE
• Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
• Page Numbers: pp.532-538
• Kocaeli University Affiliated: Yes

#### Abstract

In this paper, a novel approach for harmonic optimization of a single-phase multilevel inverter is introduced Firstly, a novel single-phase multilevel inverter structure is proposed and structural parts of the inverter are described A simple Switching strategy that uses a formula to calculate switching angles for obtaining multilevel voltage form is improved Simulation and experimental results are given together for 7, 15, 31 and 63 levels. For harmonic optimization of proposed method, firstly general equation of Total Harmonic Distortion (THD) is obtained for n-level voltage wave. After obtaining the general equation of THD, four different analysis methods are used for THD optimization in multilevel voltage wave forms. The common point in all analyses is finding switching angles (alpha(j)) and level coefficients (k(j)) for obtaining multilevel output voltage that has minimal THD value. After finding optimum switching angles (alpha(j)) and level coefficients (k(j)), THD values are calculated and the results are given related to level number All analysis methods are realized by proposed inverter structure and THD values of output voltage waves are measured by a harmonic analyzer Proposed switching strategy is an analysis method which is simple and easily applicable compared to the other methods. It is seen that the method closely converges to the best solution that gives minimal THD value. Output voltage waves obtained by using proposed switching strategy are given up to 127-level, THD values are also measured and experimental results are given. Copyright (C) 2009 Praise Worthy Prize S. r. l. - All rights reserved.