Common turn-off circuit for thyristor power converter (COMMON TURN-OFF CIRCUIT FOR A THIRD POWER CONVERTER)

摘要

A common turn-off circuit for the thyristor power converter was provided. This common turn-off circuit is particularly suitable for AC converters such as railway grid connections. The turn-off thyristor is directly connected to the second transformer winding. In addition, a predetermined freewheeling path may be provided to draw energy stored in the transformer inductor or other associated inductor. An advantage of the present invention is that all thyristors of the power converter can be easily turned off without any pre-prescription, since the common turn-off circuit is automatically turned off. In addition, overvoltage can be avoided by a predetermined freewheeling path.