Single or multi-phase electrical circuit for switching current produced via alternating current or three-phase power controller, has controller with valves designed as disconnectable valves, where device is connected parallel to valves

摘要

The circuit has an alternating current (AC) or three-phase power controller with a valve per phase, where the valves are designed as disconnectable valves. A parallel switched protection device is connected parallel to the valves via diodes. The device has a parallel connection of a resistor (R) and a capacitor (C) or a serial connection of the resistor and the capacitor or a varistor. The capacitor or the varistor is dimensioned with respect to a possible failure i.e. overload current. Switching-thyristors (T1, T2) e.g. gate-turn-off-thyristors (GTO), are provided as the disconnectable valve. An independent claim is also included for a method for switching current produced by a valve of alternating current or a three-phase power controller.