Fault current limiter providing symmetrical electrostatic shielding

Patent metadata

Field	Value
Publication number	US-10468876-B2
Application number	US-201715495149-A
Country	US
Kind code	B2
Filing date	Apr 24, 2017
Priority date	Apr 24, 2017
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

Embodiments of the disclosure include a fault current limiter (FCL) providing symmetrical electrostatic shielding. In some embodiments, a FCL includes a superconductor maintained at a first voltage greater than zero voltage, and an enclosure containing the superconductor, the enclosure maintained at a second voltage greater than zero voltage, wherein the second voltage is different from the first voltage. The FCL may include an electrical connection directly coupling the superconductor and the enclosure, wherein the electrical connection enables each of a plurality of current limiting modules of the superconductor to receive, during a fault condition, an equal or unequal sub-portion of a total voltage drop.

First claim

What is claimed is:

1. A fault current limiter system comprising:
a superconductor matrix within an enclosure, the superconductor matrix electrically connected to a set of terminals; and
an electrical connection electrically connected between the superconductor matrix and the enclosure, wherein the electrical connection permits a voltage across the superconductor matrix with respect to the enclosure to be less than a total voltage across the set of terminals.

2. The fault current limiter system of claim 1 , further comprising a current protection device electrically connected in series with the superconductor matrix.

3. The fault current limiter system of claim 1 , further comprising a shunt reactor connected between the set of terminals, the shunt reactor further connected in parallel with the superconductor matrix.

4. The fault current limiter system of claim 3 , further comprising a first electrical path electrically parallel to a second electrical path, wherein the shunt reactor is connected along the first electrical path, and wherein the set of terminals and the superconductor matrix are connected along the second electrical path.

5. The fault current limiter system of claim 3 , further comprising:
a second set of terminals in communication with a second shunt reactor, wherein the second shunt reactor is electrically connected in series with the shunt reactor;
a second superconductor matrix within a second enclosure, the second superconductor matrix in communication with the second set of terminals; and
a second electrical connection directly electrically connected between the second superconductor matrix and the second enclosure.

6. The fault current limiter system of claim 1 , wherein the enclosure is a cryostat.

7. The fault current limiter system of claim 1 , wherein the superconductor matrix includes a plurality of current limiting modules.

8. The fault current limiter system of claim 7 , wherein each of the plurality of current limiting modules receives a sub-portion of the voltage across the superconductor matrix.

9. The fault current limiter system of claim 7 , wherein the plurality of current limiting modules include at least one of: a resistive fault current limiter, an inductive fault current limiter, a superconductor fault current limiter, or a solid state fault current limiter.

10. The fault current limiter system of claim 1 , further comprising an electrical bushing surrounding each of the set of terminals, wherein each electrical bushing extends through the enclosure.

11. The fault current limiter system of claim 1 , wherein the superconductor matrix includes a first superconductor connected in parallel with a second superconductor.

12. A fault current limiter, comprising:
a superconductor maintained at a first voltage greater than zero voltage; and
an enclosure containing the superconductor, the enclosure maintained at a second voltage greater than zero voltage, wherein the second voltage is different from the first voltage;
wherein the superconductor is a superconductor matrix electrically connected to a set of terminals, and wherein the superconductor matrix is coupled to the enclosure by an electrical connection.

13. The fault current limiter of claim 12 , wherein the first voltage is less than the second voltage.

14. The fault current limiter of claim 12 , further comprising a current protection device electrically connected in series with the superconductor matrix.

15. The fault current limiter of claim 12 , further comprising a shunt reactor connected between the set of terminals, the shunt reactor further connected in parallel with the superconductor matrix.

16. A method of providing symmetrical electrostatic shielding in a fault current limiter, the method comprising:
maintaining a superconductor at a first voltage greater than zero voltage;
maintaining an enclosure at a second voltage greater than zero voltage, wherein the second voltage is different from the first voltage, and wherein the enclosure contains the superconductor;
electrically connecting the superconductor to a set of terminals; and
electrically connecting the superconductor to the enclosure via an electrical connection, wherein the electrical connection permits the first voltage across the superconductor to be less than the second voltage across the set of terminals.

17. The method of claim 16 , further comprising connecting a shunt reactor between the set of terminals, the shunt reactor further connected in parallel with the superconductor.

18. The method of claim 16 , further comprising connecting a current protection device to the superconductor, wherein the current protection device is closed during a superconducting condition and opened during a fault condition.

Assignees

• Varian Semiconductor Equipment Ass Inc

Inventors

• Lubicki Piotr
• Jazebi Saeed
• Morrell David
• Emmanuel George
• Murphy Paul

Classifications

• H02H9/023 Primary

  Current limitation using superconducting elements · CPC title

• H01F6/06

  Coils, e.g. winding, insulating, terminating or casing arrangements therefor · CPC title

• H01F41/048

  Superconductive coils · CPC title

• H02H9/044 Primary

  Physical layout, materials not provided for elsewhere (varistors H01C7/12; spark-gaps H01T; Ovshinsky devices H10N70/00) · CPC title

• Y10T29/49014

  Superconductor · CPC title