Implementation of ICMPPSO Algorithm to Minimize PVTHD of Three-Level Inverter

ABSTRACT:The three level inverters have been found wide application in industry from the prior for converting DC voltage to AC voltage. The main problem in these equipment’s is the existence of harmonic in output voltage. THD is a very important factor to determine losses in the equipment’s such as induction motor, transformers and etc. Loss plays an important role in determining the cross section in distribution network cables and overhead lines, hence the exact determination is important. In prior literature, to determine the amount of THD, approximate methods have been used. They have considered some limited low order harmonics. In this paper, to determine the exact amount of phase voltage THD (PVTHD), an exact method based on extracting formula is presented. The proposed methods consider all harmonic orders and can be utilized for each number of switching angles. Another feature of introducing methods is presented analytical formulas for phase voltage THD that eases finding those switching angles that globally minimize THD. Comparing with heuristic methods, which find local minimums, can clearly show the advantage of proposed methods for usage in some switching strategies like THD Minimization (THDM). In this paper, the new algorithm will have been employed to minimize phase voltage THD. The optimization angles are calculated by Intelligent Coefficient Multi Population Particle Swarm Optimization (ICMPPSO) algorithm. Finally, to show the effectiveness of the proposed methods, approximate and exact methods are compared. Simulation and programming are done in MATLAB software. Experimental results are presented to validate the theoretical results.