Reduction of total harmonics distortion thd in line to line voltage for multi level inverter using differential phase angle control strategies

Abstract

Multilevel inverter is a power electronics circuits used for newlineconverting DC voltage to AC voltage. Multilevel inverters are considered as newlinea source of high power and often used in the industrial applications. newlineGenerally, IGBT switches are used in the inverter. Multilevel inverter newlineconsists of series combination of individual power converters (usually two to newlinethree). Reduce of harmonics at the output signal to achieve reduced THD, newlineswitching angles of the converters to be considered. Different types of newlinealgorithms are utilised to reduce the THD level but the drawbacks are the newlinecost function which becomes more difficult to optimize and an increased newlinenumber of iterations is required. Hence, to reduce the number of iterations, newlinethree optimization methods such as Genetic Algorithm (GA), Nonlinear newlineVersatile Tolerant Control (NVTC) and Nonlinear Transformational newlineOptimization (NTO) are proposed. These algorithms are proposed to enhance newlinethe overall performance of the system. newlineIn the proposed work THD minimization algorithm is used to newlinemitigate the line to line voltage harmonics. In this, an 11-level inverter is newlineconsidered with swathing angle generation produces such as GA, NVTC and newlineNTO. The THD of an 11-level inverter is examined for various modulation newlineindices to reduce the line to line voltage harmonics. The simulation of MLI newlinewith optimization control algorithm to reduce THD is performed by utilizing newlineMATLAB/ Simulink software. The simulation results confirmed that the newlineproposed methods enhanced the power quality. The THD values of an 11 newlinelevel MLI with GA, NVTC and NTO are 5.03%, 3.08% and 2.83% newlinerespectively. newline