Grey Wolf Optimized Modified Selective Harmonic Elimination PWM in Multilevel Inverter with Lesser Number of Switches

Abstract

In this paper, a modified SHEPWM for multilevel inverter with lesser number of switches to minimize dominant lower order harmonics and switching losses is proposed. In SHE PWM, nonlinear transcendental equations with switching angles can be developed and these equations are calculated by using any numerical method or any optimization algorithm to find optimum value of these switching angles. Main drawback of selective harmonic elimination is while dealing with increased level of inverters optimization of switching angles is not available for some values of modulation index and this will increase undesired harmonics. A modified SHEPWM optimized by grey wolf optimization algorithm is proposed in this paper for reduced switch 17 and 53 level inverter. Fitness function in modified SHEPWM comprises of fundamental component of voltage and lower order harmonics to derive switching angles. Simulation results using MATLAB/SIMULINK are presented for 17 and 53 level inverter and switching losses and THD are compared with conventional selective harmonic elimination..