Harmonic Current Generation by Thyristor Rectifiers

By using thyristors in AC/DC conversion equipment, it is well known that high current harmonics are generated on the AC input of the rectifiers. This causes following two main problems: - distortion of commercial mains - unsuccessful operation of rectifiers, working on primary power sources with high internal impedance. It is the objective of the present paper to investigate this phenomenon and to come up with adequate solutions. The main point is, that means have to be found to keep the harmonic current generation by rectifiers sufficiently low. Following two main items will be handled - influence of source impedance on distortion level on input - 4 double star rectifier configuration as a suitable solution for reducing harmonic currents.