Bridge leg snubbers for GTO thyristor inverters

This paper considers two common snubber circuits used in gate turn-off thyristor inverters. Both circuits incorporate an inductive turn-on snubber and capacitive turn-off snubbers. The first snubber circuit, which normally has resistive losses, is converted into an active recovery snubber circuit by the addition of a switch. The second snubber is a passive recovery lossless snubber, and an improvement to this circuit renders it viable. The comparative features and operation of the two improved recovery snubbers are considered and supported by PSPICE simulations and experimental results.