Comparative Analysis of Different Switching Techniques for Cascaded H-Bridge Multilevel Inverter

U. B. Tayab; M. A. Roslan; F. N. Bhatti

Authors

U. B. Tayab School of Electrical Systems Engineering, Universiti Malaysia Perlis, Malaysia
M. A. Roslan School of Electrical Systems Engineering, Universiti Malaysia Perlis, Malaysia
F. N. Bhatti School of Electrical Systems Engineering, Universiti Malaysia Perlis, Malaysia

Keywords:

Multilevel Inverter, Total Harmonic Distortion, Selective Harmonics Elimination Pulse Width Modulation, Switching Angle

Abstract

Multilevel inverters have capability to producing AC staircase output waveform without bulky passive filter. Therefore, among different types of inverters the multilevel inverters are gaining popularity for photovoltaic applications. However, if the switching angle arrangement technique is not selected carefully then the total harmonic distortion (THD) of voltage output waveform may become unacceptable. In this paper, selective harmonics elimination pulse width modulation (SHEPWM) and Equal Phase (EP) switching angle arrangement techniques are applied to a cascaded H-Bridge multilevel inverter. PSIM software is used for evaluation and compare the performance of 9-level cascaded H-Bridge multilevel inverter with two switching angle arrangement techniques. Simulation results shown that SHEPWM technique can produce an output voltage waveform with the lowest THD. On the other hand, the output voltage waveform produced by EP technique had the highest fundamental voltage component.