Patent DE130167C successfully refreshed from Google Patents.
Patent US3703664A successfully refreshed from Google Patents.
US3703664A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fault current limiter using superconductive element
Assignee: ABB Inc USA
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Filing: 1970-10-05
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Granted: 1972-11-21
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Expires: 1990-10-05
Abstract
Abstract A superconductive impedance element is connected in parallel with a conventional impedance element and is switched from essentially zero impedance to a high impedance during switching operation, thereby to connect the conventional impedance in the circuit to limit the current in the circuit. The impedances switched into the circuit are inductively associated with the superconductive element. A pilot super-conductive element is disclosed for the high accuracy switching of a main superconductive element.
Inventors
- 👤 John C Cronin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:02
CPC Classifications
H; H02; H02H; H02H9/00; H02H9/02; H02H9/023; H10; H10N; H10N60/00; H10N60/30; H10N60/35; H10N60/355; Y; Y02; Y02E; Y02E40/00; Y02E40/60
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
238 words
A current limiting circuit comprising, in combination: an elongated superconductive member; means associated with said superconductive member for normally cooling said superconductive member to a temperature below its transition temperature; an electrical impedance member having first and second terminals; means for electrically coupling said superconductive member and said impedance member, whereby the effective impedance of said electrical impedance member between its said first and second terminals is by-passed when said superconductive member is in a superconducting state; said first and second terminals comprising the terminals for the application of electrical energy in the form of current flow to said superconductive member; said superconductive member being arranged to switch from a superconducting state to a resistive state when the magnetic field due to said current flow reaches the critical value, whereby when said superconductive member switches to said resistive state, the effective impedance between said first and second terminals is increased, thereby to limit the magnitude of current flow between said first and second terminals; and a second superconductive member connected in series with said superconductive member and means for normally cooling said second superconductive member; said second superconductive member having a greater length than said superconductive member; and means for thermally coupling said superconductive member to said second superconductive member whereby, when said superconductive memBer becomes resistive, heat generated therein is coupled to said second superconductive member, thereby to switch said second superconductive member to a resistive state.
Claim 2
Dependent Claim
238 words
A current limiting circuit comprising, in combination: an elongated superconductive member; means associated with said superconductive member for normally cooling said superconductive member to a temperature below its transition temperature; an electrical impedance member having first and second terminals; means for electrically coupling said superconductive member and said impedance member, whereby the effective impedance of said electrical impedance member between its said first and second terminals is by-passed when said superconductive member is in a superconducting state; said first and second terminals comprising the terminals for the application of electrical energy in the form of current flow to said superconductive member; said superconductive member being arranged to switch from a superconducting state to a resistive state when the magnetic field due to said current flow reaches the critical value, whereby when said superconductive member switches to said resistive state, the effective impedance between said first and second terminals is increased, thereby to limit the magnitude of current flow between said first and second terminals; and a second superconductive member connected in series with said superconductive member and means for normally cooling said second superconductive member; said second superconductive member having a greater length than said superconductive member; and means for thermally coupling said superconductive member to said second superconductive member whereby, when said superconductive memBer becomes resistive, heat generated therein is coupled to said second superconductive member, thereby to switch said second superconductive member to a resistive state.
Claim 3
Dependent Claim
238 words
A current limiting circuit comprising, in combination: an elongated superconductive member; means associated with said superconductive member for normally cooling said superconductive member to a temperature below its transition temperature; an electrical impedance member having first and second terminals; means for electrically coupling said superconductive member and said impedance member, whereby the effective impedance of said electrical impedance member between its said first and second terminals is by-passed when said superconductive member is in a superconducting state; said first and second terminals comprising the terminals for the application of electrical energy in the form of current flow to said superconductive member; said superconductive member being arranged to switch from a superconducting state to a resistive state when the magnetic field due to said current flow reaches the critical value, whereby when said superconductive member switches to said resistive state, the effective impedance between said first and second terminals is increased, thereby to limit the magnitude of current flow between said first and second terminals; and a second superconductive member connected in series with said superconductive member and means for normally cooling said second superconductive member; said second superconductive member having a greater length than said superconductive member; and means for thermally coupling said superconductive member to said second superconductive member whereby, when said superconductive memBer becomes resistive, heat generated therein is coupled to said second superconductive member, thereby to switch said second superconductive member to a resistive state.
Claim 4
Dependent Claim
238 words
A current limiting circuit comprising, in combination: an elongated superconductive member; means associated with said superconductive member for normally cooling said superconductive member to a temperature below its transition temperature; an electrical impedance member having first and second terminals; means for electrically coupling said superconductive member and said impedance member, whereby the effective impedance of said electrical impedance member between its said first and second terminals is by-passed when said superconductive member is in a superconducting state; said first and second terminals comprising the terminals for the application of electrical energy in the form of current flow to said superconductive member; said superconductive member being arranged to switch from a superconducting state to a resistive state when the magnetic field due to said current flow reaches the critical value, whereby when said superconductive member switches to said resistive state, the effective impedance between said first and second terminals is increased, thereby to limit the magnitude of current flow between said first and second terminals; and a second superconductive member connected in series with said superconductive member and means for normally cooling said second superconductive member; said second superconductive member having a greater length than said superconductive member; and means for thermally coupling said superconductive member to said second superconductive member whereby, when said superconductive memBer becomes resistive, heat generated therein is coupled to said second superconductive member, thereby to switch said second superconductive member to a resistive state.
Claim 5
Dependent Claim
163 words
In combination, an electrical power source, first and second superconductor members, means for cooling said first and second superconductor members to a temperature below their transition temperatures, and a load; said source, said first and second superconductor members, and said load connected in series, and means thermally coupling said first and second superconductor members; said first superconductor member being substantially longer than said second superconductor member and having a design whereby a magnetic field less than the critical field will be generated at the surface of said first superconductor member by current flow from said source which is below a given magnitude; said second superconductor member being designed to have the critical field thereof reached when a given current flow therethrough is reached; the heat generated in said second superconductor member after switching to its resistive state being applied to said first superconductor member, thereby to raise its temperature above its transition temperature to switch said first superconductor member to its resistive state.
Claim 6
Dependent Claim
163 words
In combination, an electrical power source, first and second superconductor members, means for cooling said first and second superconductor members to a temperature below their transition temperatures, and a load; said source, said first and second superconductor members, and said load connected in series, and means thermally coupling said first and second superconductor members; said first superconductor member being substantially longer than said second superconductor member and having a design whereby a magnetic field less than the critical field will be generated at the surface of said first superconductor member by current flow from said source which is below a given magnitude; said second superconductor member being designed to have the critical field thereof reached when a given current flow therethrough is reached; the heat generated in said second superconductor member after switching to its resistive state being applied to said first superconductor member, thereby to raise its temperature above its transition temperature to switch said first superconductor member to its resistive state.
Claim 7
Dependent Claim
20 words
The combination of claim 2 which further includes an impedance member electrically connected in parallel with said first superconductor member.
Claim 8
Dependent Claim
122 words
In combination, an electrical circuit to be protected and a current limiter for limiting the maximum current which can flow in said circuit; said current limiter comprising a transformer having a primary winding and a secondary winding, and a superconducting member and means for cooling said superconducting member to a temperature below its transition temperature; said primary winding being connected in series with said electrical circuit; said superconducting member being connected in parallel with said secondary winding; the impedance of said superconducting member being reflected into said primary winding and said electrical circuit; said superconducting member carrying a current related to the current of said electrical circuit and generating a magnetic field which reaches the critical value at a given current magnitude.
Claim 9
Dependent Claim
122 words
In combination, an electrical circuit to be protected and a current limiter for limiting the maximum current which can flow in said circuit; said current limiter comprising a transformer having a primary winding and a secondary winding, and a superconducting member and means for cooling said superconducting member to a temperature below its transition temperature; said primary winding being connected in series with said electrical circuit; said superconducting member being connected in parallel with said secondary winding; the impedance of said superconducting member being reflected into said primary winding and said electrical circuit; said superconducting member carrying a current related to the current of said electrical circuit and generating a magnetic field which reaches the critical value at a given current magnitude.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-11-21 | 1976-05-22 | 1976-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-21 | 1980-05-22 | 1980-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-21 | 1984-05-22 | 1984-11-21 | $7700.00 | Window Closed / Lapsed |