Evolutionary Algorithm based Optimal Angle strategy for a Cascade H-bridge Inverter

This paper presents an approach using Pigeon Inspired Optimization (PIO) for selective harmonic elimination in a cascaded H-bridge (CHB) multilevel inverter fed with unequal dc sources. The aim of this work is to find the optimal combination of switching angles, such that the lower order harmonics are eliminated and the output voltage is constant irrespective of voltage change in the input side. This paper the PIO has been used to find the optimal angles for a 7-level inverter and the method can be scaled to any number of levels. To show the effectiveness of PIO the results have been compared with the results obtained using genetic algorithm (GA). The results show that the PIO is the most accurate and fastest evolutionary algorithm for switching angle optimization for the case of un-equal dc voltages.