Multiphase electric circuit for shutting down a current conducted over respectively one AC power controller

A multiphase electric circuit for shutting down a current, the circuit comprising:

• an AC power controller, configured to conduct current, provided in each phase of the multiphase electric circuit, the phases of the multiphase electric circuit being connected to two voltage systems, each of the voltage systems having a neutral point and the neutral points of the two voltage systems are not connected to each other by way of a neutral connector, each AC power controller including two thyristors;
• a quenching arrangement including a single series connection of a capacitor and a parallel circuit having a number of parallel-connected quenching switches, the number of quenching switches corresponding to the number of phases,
• wherein the capacitor of the quenching arrangement is connected on one side to the number of parallel-connected quenching switches of the series connection and on the other side to a number of parallel-connected diodes, the number of parallel-connected diodes corresponds to the number of phases,
• wherein each of the parallel-connected diodes is connected to one phase of the multiphase electric circuit on one side of the thyristors of the AC power controllers, and
• wherein each of the parallel-connected quenching switches of the quenching arrangement is connected to one phase of the multiphase electric circuit on the other side of the thyristors of the AC power controllers;
• and
• a control configured such that, for charging of the capacitor, one of the quenching switches and one of the thyristors of one of the AC power controllers having the same direction, are simultaneously switchable into their conductive state.

A method for shutting down a current in a multiphase electric circuit having an AC power controller configured to conduct current provided in each phase of the multiphase electric circuit, the phases of the multiphase electric circuit being connected to two voltage systems, each of the voltage systems having a neutral point and the neutral points of the two voltage systems are not connected to each other by way of a neutral connector, each AC power controller including two thyristors;

• and a quenching arrangement including a single series connection of a capacitor and a parallel circuit having a number of parallel-connected quenching switches, the number of quenching switches corresponding to the number of phases, wherein the capacitor of the quenching arrangement is connected on one side to the number of parallel-connected quenching switches of the series connection and on the other side to a number of parallel-connected diodes, the number of parallel-connected diodes corresponds to the number of phases, wherein each of the parallel-connected diodes is connected to one phase of the multiphase electric circuit on one side of the thyristors of the AC power controllers, wherein each of the parallel-connected quenching switches of the quenching arrangement is connected to one phase of the multiphase electric circuit on the other side of the thyristors of the AC power controllers, and the capacitor is connected to a diode bridge, the method comprising:
• charging the capacitor via the diode bridge;
• switching one of the quenching switches into its conductive state;
• and
• driving a current over the quenching switch by the capacitor.

A method for shutting down a current in a multiphase electric circuit having an AC power controller configured to conduct current provided in each phase of the multiphase electric circuit, the phases of the multiphase electric circuit being connected to two voltage systems, each of the voltage systems having a neutral point and the neutral points of the two voltage systems are not connected to each other by way of a neutral connector, wherein each AC power controller includes two thyristors;

• and a quenching arrangement including a single series connection of a capacitor and a parallel circuit having a number of parallel-connected quenching switches, the number of quenching switches corresponding to the number of phases, wherein the capacitor of the quenching arrangement is connected on one side to the number of parallel-connected quenching switches of the series connection and on the other side to a number of parallel-connected diodes, the number of parallel-connected diodes corresponds to the number of phases, wherein each of the parallel-connected diodes is connected to one phase of the multiphase electric circuit on one side of the thyristors of the AC power controllers, wherein each of the parallel-connected quenching switches of the quenching arrangement is connected to one phase of the multiphase electric circuit on the other side of the thyristors of the AC power controllers, the method comprising:
• charging the capacitor by simultaneously switching one of the quenching switches and one of the thyristors of one of the AC power controllers having the same direction, into their conductive states;
• switching one of the quenching switches into its conductive state;
• and
• driving a current over the quenching switch by the capacitor.