Optimization of Line voltage THD in Multilevel Inverter's with Alterable DC Links using TLBO

In this paper an efficient switching scheme is presented to minimize the multilevel inverters' line output voltage's Total Harmonic Distortion (THD). THD Minimization (THDM) is a proper switching scheme which is used in some applications such as: the electrical drives which have been using multilevel and the equipment with AC transmission systems like multilevel static which has been using for Reactive Power compensation, multilevel UPQC and multilevel UPFC, where the voltage of the DC link are altering. By using THDM the DC link values are set to the predefined values in order to optimize THD. In this paper the recently developed evolutionary optimization technique named Teaching-Learning-Based Optimization (TLBO) is applied to solve THDM problem. In this work, line voltage waveform’s THD is minimized directly and the provided comparison between obtained results with the results given in the recently published paper using GA, confirmed that TLBO is more effective in this regard. Simulation and Experimental results based on a 7-level multilevel inverter are shown to verify the performance of TLBO and its effective results in solving MTHD problem.

THD Minimization (THDM), Teaching-Learning-Based Optimization (TLBO), Line voltage