Switching device for disconnecting a current path

1. A switching device for disconnecting a current path in a DC supply system, said current path comprising inductances at the source end and the load end, the switching device comprising:

two series-connected switching modules;

wherein each of the series-connected switching modules comprises two branches connected in parallel;

a first of the two branches consists of a controllable semiconductor switching element;

a second of the two branches consists of a resistor and a capacitor connected in series.

2. The switching device as claimed in claim 1 , wherein the parallel-connected arrangement of the controllable semiconductor switching element and the series-connected arrangement of the resistor and the capacitor is interconnected between a first switching module terminal and a second switching module terminal of the respective switching module.

3. The switching device as claimed in claim 1 , wherein:

the parallel-connected arrangement of the controllable semiconductor switching element and the series-connected arrangement of the resistor and the capacitor is interconnected between a first rectifier terminal and a second rectifier terminal of a rectifier bridge of the respective switching module;

the first rectifier terminal comprises a first node point of the rectifier bridge on which the cathode terminals of two rectifier components are mutually interconnected; and

the second rectifier terminal comprises a second node point of the rectifier bridge on which the anode terminals of two further rectifier components are mutually interconnected.

4. The switching device as claimed in claim 1 , wherein, in the operation of the switching device for disconnecting the current path, pending the clearance of the energy stored in the inductances, at a given time point, the controllable semiconductor switching element of at least one of the switching modules is switched to a blocking state.

5. The switching device as claimed in claim 1 , wherein, in the operation of the switching device for disconnecting the current path, pending the clearance of the energy stored in the inductances, at a given time point, the controllable semiconductor switching element of a first partial number of switching modules is switched to a blocking state, and a second partial number of switching modules is switched to a conducting state.

6. The switching device as claimed in claim 1 , wherein, in the operation of the switching device for disconnecting the current path, pending the clearance of the energy stored in the inductances, the controllable semiconductor switching element of that or those switching module(s) is switched to a conducting state, across the capacitor(s) of which the voltage achieves a predefined upper threshold value.

7. The switching device as claimed in claim 1 , wherein, in the operation of the switching device for disconnecting the current path, pending the clearance of the energy stored in the inductances, the controllable semiconductor switching element of that or those switching module(s) is switched to a blocking state, across the capacitor(s) of which the voltage achieves a predefined lower threshold value.

8. The switching device as claimed in claim 1 , wherein, in the operation of the switching device for disconnecting the current path, pending the clearance of the energy stored in the inductances, the controllable semiconductor switching element of that or those switching module(s) is permanently switched to a blocking state, if, via the capacitor(s) thereof, the voltage no longer achieves the predefined threshold value.

9. The switching device as claimed in claim 1 , wherein, in the operation of the switching device for disconnecting the current path, pending the clearance of the energy stored in the inductances, at a given time point, the controllable semiconductor switching element of the switching module is switched to a conducting state, on the capacitor of which the highest voltage is present, in comparison with the voltages on the capacitors of the remaining switching modules.

10. The switching device as claimed in claim 1 , wherein, in the operation of the switching device for disconnecting the current path, pending the clearance of the energy stored in the inductances, the semiconductor switching elements are respectively switched on and off in an alternating manner.

11. The switching device as claimed in claim 1 , wherein, in the operation of the switching device for disconnecting the current path, pending the clearance of the energy stored in the inductances, the semiconductor switching elements of different switching modules are switched on and off at different time points.

12. The switching device as claimed in claim 1 , wherein, in the path of the controllable semiconductor switching element of a respective switching module, a further controllable semiconductor switching element is interconnected in an anti-series arrangement with the controllable semiconductor switching element.

13. The switching device as claimed in claim 1 , wherein the controllable semiconductor switching element comprises at least one interruptible semiconductor switching element selected from the group consisting of: an IGBT, a MOSFET, an IGCT, and a thyristor having a cut-off device.

14. The switching device as claimed in claim 1 , wherein the latter is provided for use in a DC supply system having a voltage greater than 1,000 V.