Hybrid direct-current circuit breaker

Patent metadata

Field	Value
Publication number	US-9654102-B2
Application number	US-201414510575-A
Country	US
Kind code	B2
Filing date	Oct 9, 2014
Priority date	Oct 9, 2014
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

A circuit breaking system includes a first branch including at least one solid-state snubber; a second branch coupled in parallel to the first branch and including a superconductor and a cryogenic contactor coupled in series; and a controller operatively coupled to the at least one solid-state snubber and the cryogenic contactor and programmed to, when a fault occurs in the load circuit, activate the at least one solid-state snubber for migrating flow of the electrical current from the second branch to the first branch, and, when the fault is cleared in the load circuit, activate the cryogenic contactor for migrating the flow of the electrical current from the first branch to the second branch.

First claim

The invention claimed is:

1. A method for operating a circuit breaker coupled between a power line circuit (PLC) and a load circuit and comprising a first branch comprising at least one solid-state snubber, a second branch coupled in parallel to the first branch and comprising a superconductor, and a cryogenic contactor coupled to the superconductor, the method comprising:
when an electrical current from the PLC is below a PLC threshold current value, supplying the electrical current from the PLC to the load circuit through the second branch;
when a fault in the load circuit occurs such that the electrical current from the PLC is above the PLC threshold current value, inhibiting flow of the electrical current in the second branch, supplying the electrical current from the PLC to the load circuit via the first branch, and then deactivating the at least one solid-state snubber; and
when the fault in the load circuit is cleared, activating the at least one solid-state snubber to supply the electrical current from the PLC to the load circuit via the first branch.

2. The method of claim 1 , further comprising, during the fault in the load circuit, deactivating the cryogenic contactor after the electrical current flowing through the second branch is reduced to a second threshold current value.

3. The method of claim 2 , wherein the deactivating of the at least one solid-state snubber occurs after the deactivating of the cryogenic contactor.

4. The method of claim 1 , further comprising, when the fault in the load circuit is cleared, reactivating the cryogenic contactor when the electrical current in the first branch is above the second threshold current value and below a nominal current value.

5. The method of claim 1 , wherein supplying the electrical current from the PLC to the load circuit via the first branch comprises activating the at least one solid-state snubber.

6. A circuit breaking system configured for being coupled between a power line circuit (PLC) and a load circuit, the circuit breaking system comprising:
a first branch comprising at least one solid-state snubber; and
a second branch coupled in parallel to the first branch and comprising a superconductor and a cryogenic contactor coupled in series; and
a controller operatively coupled to the at least one solid-state snubber and the cryogenic contactor and programmed to:
when a fault occurs in the load circuit, activate the at least one solid-state snubber for migrating flow of the electrical current from the second branch to the first branch; and
when the fault is cleared in the load circuit, reactivating the at least one solid-state snubber to supply the electrical current from the PLC to the load circuit via the first branch and then activating the cryogenic contactor for migrating the flow of the electrical current from the first branch to the second branch.

7. The circuit breaking system of claim 6 , further comprising a first sensor operatively coupled to the first branch for providing a first sensor signal representing the electrical current in the first branch.

8. The circuit breaking system of claim 7 , wherein the controller is programmed for activating the cryogenic contactor when the fault is cleared and the first sensor signal is above a second threshold current value and below a nominal current value.

9. The circuit breaking system of claim 6 , further comprising a second sensor operatively coupled to the second branch and configured to provide a second sensor signal representing the electrical current in the second branch.

10. The circuit breaking system of claim 9 , wherein the controller identifies the fault in the load circuit based on the second sensor signal.

11. The circuit breaking system of claim 10 , wherein the controller activates the at least one solid-state snubber when the fault occurs in the load circuit and the second sensor signal is increased above a PLC threshold current value.

12. The circuit breaking system of claim 9 , wherein the controller deactivates the cryogenic contactor when the second sensor signal is reduced below the second threshold current value.

13. The circuit breaking system of claim 6 , wherein the controller receives a signal from the load circuit when the fault is cleared in the load circuit.

14. A circuit breaker coupled between a power line circuit (PLC) and a load circuit, the circuit breaker comprising:
a first branch of the circuit breaker comprising at least one solid-state snubber;
a second branch of the circuit breaker coupled in parallel to the first branch and comprising a superconductor and a cryogenic contactor coupled in series; and
a control mechanism for:
maintaining the at least one solid-state snubber in a deactivated state to prevent current from flowing through the first branch when electrical current from the PLC is below a PLC threshold current value;
activating the at least one solid-state snubber when electrical current from the PLC is above the PLC threshold current value, and
deactivating the at least one solid-state snubber when the electrical current from the PLC transitions from flowing from the second branch to the first branch.

15. The circuit breaker of claim 14 wherein, when electrical current from the PLC is below a PLC threshold current value, an impedance of the at least one solid-state snubber is automatically higher than an impedance of the superconductor such that the electrical current from the PLC flows through the second branch, and
wherein, when the electrical current is above the PLC threshold current value, the impedance of the superconductor is automatically higher than the impedance of the at least one solid-state snubber such that the electrical current from the PLC flows through the first branch.

16. The circuit breaker of claim 15 , wherein the control mechanism is configured for deactivating the cryogenic contactor when the electrical current flowing through the second branch is reduced to a second threshold current value.

17. The circuit breaker of claim 16 , wherein, after a fault in the load circuit is cleared and the electrical current from the PLC is above the second threshold current value and below a nominal current value, the cryogenic contactor is configured for re-activating.

Assignees

• Gen Electric

Inventors

• Wang Ruxi
• Premerlani William James
• Caiafa Antonio
• Pan Yan

Classifications

• H01H9/541

  Contacts shunted by semiconductor devices · CPC title

• H03K17/92 Primary

  by the use, as active elements, of superconductive devices · CPC title

• H01H2009/543

  third parallel branch comprising an energy absorber, e.g. MOV, PTC, Zener · CPC title

• H01H9/542

  Contacts shunted by static switch means · CPC title