Snubber circuit design for GTO converters

The design of snubber circuits for GTO (gate turn-off thyristor) power converters used in electrical railways is considered. The amount of energy stored in the series and in the parallel snubbers is significant. For this reason designers are interested in limiting the losses connected with the trapped energy in the snubbers. Inverter and chopper circuits with improved snubbers which allow the reduction or the recovery of the trapped energy have thus been developed. These snubber networks are an evolution of the basic L-snubber and C-snubber. The proposed circuits are studied together with their drawbacks and limits