THD Comparison of 5, 7, 9, 11, 13, 15 and 17 Level Cascaded H-Bridge Multilevel Inverters

Abstract

In this paper, we simply compare the total harmonic distortion (THD) of different levels of cascaded H-bridge multilevel inverter. The major drawback of any inverter is THD. In this paper, comparison of THD is carried out for 5, 7, 9, 11, 13, 15 and 17 level inverters using MATLAB Simulink. In this paper, we use level-shifted multicarrier modulation, and also we show how THD is reduced as we increase the level of the inverter. Fast Fourier transform analysis is provided for all-level inverters to calculate the THD. Keywords: cascaded H-bridge, FFT analysis, THD