Exchange market algorithm for selective harmonic elimination in cascaded multilevel inverters

Abstract

Utilization of Exchange Market Algorithm (EMA) for selective harmonic elimination (SHE) in cascaded multilevel inverters (CMIs) is investigated in this paper. The nonlinear SHE equations are derived for a 7-level CMI based on the Fourier expansion of the output voltage waveform. A cost function is constructed according to the SHE equations and optimization is performed with EMA. In order to compare the results, the SHE equations are also solved with Genetic Algorithm (GA) with similar parameters as used for EMA. Optimization results prove that EMA is superior to GA in terms of convergence rate, and achieving exact global minima. For verifying the optimization results, simulations are performed on a 7-level CMI for different modulation indices.