Optimum control of total harmonic distortion in field programmable gate array-based cascaded multilevel inverter

Abstract

Nowadays high quality power is essential for medical, research and industrial applications to produce good quality results and analysis. In this work an attempt has been made to improve the power quality by minimizing the harmonic content in the output voltage of a cascaded multilevel inverter using the selective harmonic elimination pulse width modulation technique. Sinusoidal PWM technique is used to generate the switching signals. A single phase nine-level cascaded multilevel inverter with identical DC supply is designed to reduce the harmonic components of the output voltage. Particle swarm optimization technique is applied to determine the optimum switching angles, thereby reducing some higher-order harmonics while maintaining the required fundamental voltage. This generalized technique can be extended to multilevel inverters with any number of levels. The total harmonic distortion is measured accordingly for different modulation indices. A prototype model of a field programmable gate array-based nine-level inverter has been designed, fabricated and tested. The results are presented and analyzed and hence the hardware results are verified with the simulation results.