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 nonlinear 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.