Performance Analysis Of Harmonic Elimination In Cascaded H-Bridge Multilevel Inverters Using Constrained PSO Algorithm

Abstract

This paper focus on elimination of harmonics in a Cascaded H-bridge Multilevel Inverter by applying constrained Particle Swarm Optimization (PSO) algorithm. The expression for output voltage with fundamental equal to desired voltage and lower order harmonics equal to zero is considered as objective function. The proposed algorithm is utilized to obtain the optimized switching angles that reduce the effect of specific higher order non triplen harmonics from the output voltage of the multilevel inverter. In this paper, three phase 5 level Cascaded H-Bridge Inverter is considered to compare and analyze the level of harmonics with variation in modulation index. The simulation studies are extended to further 7-level, 9-level and 11-level to validate if same code can produce better results for obtaining more switching angles. The Simulation results indicate that constrained PSO based SHE effectively outperforms SPWM in terms of minimizing THD and provides high-quality output voltage waveform.