Evaluation of harmonic impedance presented by a thyristor controlled AC load

The growing use of thyristor controlled loads in AC distribution systems is a major cause of increased level of harmonics which have many other detrimental effects on power system operation. One aspect of interest to the electric utility is the harmonic impedance presented by the power converter/load to the distribution system. In this preliminary investigation, the harmonic impedance of a power converter/load as a function of the power converter delay angle is evaluated.