SHOWING THE THYRISTOR AND TRIAC HARMONICS IN 3D SPACE AND CURVE FITTING TO THD

Abstract

The switching equipment, like thyristors and triacs, are widely used power electronics. Also, they have nonlinear load characteristics and produce effective harmonics. In order to compensate harmonic currents of nonlinear loads, THD value and the amplitude of harmonics produced from loads at the working conditions should be known. Also, this process is only possible with harmonic analysis. Harmonic analysis is expensive process because of demanding special equipment. In this study, by expressing harmonics, produced thyristor and triac with different load and firing angle, in 3D space, a new viewing point to show harmonic analysis was presented; with curve fitting to the THD values at the each firing angle, polynomials were obtained; by doing so, THD values will be directly found without harmonic analysis.

Keywords

• Harmonik analizi, Eğri uydurma, THD