GTO by-Pass Thyristor Based Method for Improving Performance of Single-Phase AC/DC Bridge Converters

High power phase-controlled converters suffer from several fundamental disadvantages. They inject current harmonics into the input AC mains due to their non-linear characteristics, thereby distort the supply voltage waveform and demand reactive power from the associated AC power system at retarded firing angle. In this paper, a novel GTO by-pass Thyristor technique is suggested, which, when applied to the conventional AC-DC bridge converter, substantially overcomes these disadvantages. Experimental and theoretical results are given which show a good input power factor, a good waveform of the line current, and a wide adjustable range of the DC output voltage.