Title: Modified GSA for minimisation of THD of voltage source multilevel inverter

Authors: Varsha Singh; Shubhrata Gupta; Swapnajit Pattnaik

Addresses: Department of Electrical Engineering, NIT Raipur, G.E. Road, Chhatisgarh, 492010, India ' Department of Electrical Engineering, NIT Raipur, G.E. Road, Chhatisgarh, 492010, India ' Department of Electrical Engineering, NIT Raipur, G.E. Road, Chhatisgarh, 492010, India

Abstract: Optimisation techniques have always been a reliable friend while dealing with complex nonlinear problems. Among a wide gamut of available optimisation techniques, genetic algorithm (GA) has always stood out on account of its being flexible and adaptable. This paper is an attempt to find a worthy competitor to GA. In the process, a new heuristic algorithm, gravitational search algorithm (GSA) has been chosen for implementation. The new technique, GSA is based on the laws of gravity and mass interaction. In order to obtain an efficient solution and quick convergence to the problem of minimisation of THD of the 15 level MLI under study; the algorithm is further modified. In the modified GSA (MGSA), the initial gravitational constant (Go) and the updating constant (α) are suitably modified. In this paper, SHE equations are used to find the optimum switching angles in both GA and GSA to minimise the total harmonic distortion (THD) of the inverter output voltage. The simulation and hardware results rendered by sinusoidal pulse width modulation (SPWM), GA, GSA and MGSA are compared for validity with each other. It is found that hardware results are in concurrence with the simulation results.

Keywords: gravitational search algorithm; GSA; modified GSA; MGSA; GA; MLI; sinusoidal pulse width modulation; SPWM; total harmonic distortion; THD; power quality.

DOI: 10.1504/IJPELEC.2020.108841

International Journal of Power Electronics, 2020 Vol.12 No.2, pp.191 - 212

Received: 16 Sep 2017
Accepted: 21 Feb 2018

Published online: 05 Aug 2020 *

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