Selective Harmonic Elimination Technique Based on Genetic Algorithm for Multilevel Inverters

Abstract

Multilevel inverters have been used in medium or high voltage levels of the power applications to get low total harmonic distortion (THD). Several techniques have been emerged to decrease the THD of the output voltage in multilevel inverter. One of these techniques is Selective Harmonic Elimination (SHE) that has an extensive research area in the field of power electronics. In addition, it is an alternative to usual PWM techniques and includes nonlinear equations of stepped voltage waveform. In this paper, conventional multilevel inverter structures have been analyzed and it is concluded that cascaded H-bridge topology needs lower device component. According to this implication a multilevel inverter topology with reduced number of switches which resembles the cascaded H-bridge topology and enables a reduction in the system cost has been proposed, and solution of SHE equations have been optimized using Genetic Algorithm (GA). The results of analysis and simulation obtained have evidently proved that proposed GA based SHE technique eliminates desired harmonic order.