Intelligent optimization techniques for real-time harmonics reduction in multilevel inverters

The current paper proposes a methodology for calculating switching angles for a multilevel cascaded H-bridge converter connected to varying DC sources. Here desired voltage is synthesized from separate DC sources connected to each series-connected bridges of the cascaded multilevel inverter. This is obtained by generating the suitable switching angles and thereby achieving the required fundamental frequency and the lower harmonics can be minimized. Particle Swarm Optimization (PSO) algorithm is used to find the solution for the set of equations where the input voltages are the known variables and the switching angles are the unknown variables and the Artificial Neural Networks (ANN) is trained to store solutions without excessive memory storage requirements. Switching pulse logic is designed for H-bridge. The effectiveness of the proposed system is validated by simulation using MATLAB/Simulink.