Short-circuit limiting device in a low-voltage installation

1. A limiting device for limiting a short-circuit current in an alternating-current low-voltage installation, including one or more supply lines having power-supply points with power-supply aggregates protected by feeder switches, the supply lines being separable at an isolating point into a first and a second line sections in response to a short circuit fault, each of the line sections including at least one power supply aggregate, the limiting device comprising:

at least one polyphase high-speed short-circuiting device coupled to the isolating point, having a current carrying capacity sufficient for short-circuit current intensities occurring on the supply lines, the at least one high-speed short-circuiting device being configured to perform a short-circuit switching operation at the isolating point in response to a trip signal by contacting phases of the supply lines with each other;

a first and a second power circuit breaker, respectively connected in series between the first and second the line sections and the high-speed short-circuiting device, the first and second power circuit breakers having a break time that is shorter than that of the feeder switches; and

a respective current-sensing device coupled to each of the line sections, the current-sensing device being configured to detect a short circuit fault, and, in response thereto, transmit the trip signal to the at least one high-speed short-circuiting device so as to trigger the short-circuit switching operation.

2. The limiting device as recited in claim 1 ,

wherein the at least one high-speed short-circuiting device includes two high-speed short-circuiting devices coupled in parallel so as to provide a current carrying capacity sufficient for the current intensities generated by the short-circuit fault.

3. The limiting device as recited in claim 1 ,

wherein the supply lines include at least one of a cable and a busbar.

4. The limiting device as recited in claim 1 ,

wherein the power-supply aggregates include at least one of a generator and a transformer.

5. The limiting device as recited in claim 1 ,

wherein the supply lines are disposed in an isolated system.

6. The limiting device as recited in claim 5 ,

wherein the supply lines are disposed in an electrical system onboard a vessel.

7. The limiting device as recited in claim 5 ,

wherein the supply lines are disposed in an offshore platform system.

8. The limiting device as recited in one of claims 1 ,

wherein the supply lines form a ring.

9. The limiting device as recited in claim 1 ,

wherein the at least one high-speed short-circuiting device includes a one-time short-circuiting device.

10. The limiting device as recited in claim 9 ,

wherein the at least one high-speed short circuiting device includes a pyrotechnically-operated high-speed short-circuiting device.

11. The limiting device as recited in claim 1 ,

wherein the current-sensing device has an adjustable sensing threshold.

12. The limiting device as recited in claim 11 ,

wherein the sensing threshold is adjustable to a value of substantially from two to four times a rated current.

13. The limiting device as recited in claim 1 ,

wherein the power circuit breakers are electronically controllable and configured to lock in an open position when the at least one the high-speed short-circuiting device is actuated.

14. The limiting device as recited in claim 1 ,

wherein the current-sensing device includes a current transformer.