Enhancing Selective Harmonics Elimination in Cascaded H-Bridge Multilevel Inverters Through Dragonfly Algorithm Optimization

In the past decade, the use of multilevel inverters (MIs) has increased in high-voltage and high-power applications because they can generate waveforms with a wider harmonic spectrum. In Cascaded H-bridge (CB) MIs, Selective Harmonics Elimination (SHE) is a crucial technique for enhancing output voltage quality by removing particular lower-order harmonics. Because SHE equations are nonlinear, that finds best switching angles to reduce Total Harmonic Distortion (THD) which is difficult. This proposes a optimisation method to improve SHE process in CBMIs, which is based on Dragonfly Algorithm (DFA). This helps in finding the exact switching angles that remove specified harmonics while conserving the fundamental voltage component by uniting DFA with the SHE strategy. In order to regulate the ideal switching angles, formulate the SHE problem as a nonlinear optimisation task and use DFA. Simulations are used to assess the performance of DFA-optimized SHE approach, and it is contrasted with conventional optimisation methods. The findings show that DFA significantly increases the accuracy of locating the best solutions for SHE. The combination of SHE and the DFA in CBMIs presents a feasible method to achieve high-quality power conversion with low harmonic distortion.