Patent US3558986A successfully refreshed from Google Patents.
US3558986A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tieline swing relay
Assignee: United States Department of the Interior
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Filing: 1968-12-02
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Granted: 1971-01-26
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Expires: 1988-12-02
Abstract
Abstract Power and rate of change of power transmitted in an electrical network are used to detect network instability. A power signal, a rate of power change signal, and a residual flow compensating signal are summed to indicate network condition. When a design maximum is exceeded a trip relay initiates sectionalization of the network. Selective response of the relay, to preclude operation by transients, is provided by limiting the rate signal, and by blocking the summation signal where design incorporated maxima are exceeded. D R A W I N G
Inventors
- 👤 Ferber R Schleif
- 👤 Glenn E Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:37
CPC Classifications
H; H02; H02H; H02H1/00; H02H1/04; H02H3/00; H02H3/44
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
96 words
Apparatus for monitoring and controlling power transfer in an electrical circuit comprising: means for measuring the amount of power transfer in the electrical circuit and providing a first output signal representative of that amount; means for measuring the rate of change of power transfer in the electrical circuit and providing a second output signal representative of that rate of change; means for combining the first and second output signals to provide a combined signal; and means selectively responsive to the combined signal for providing a control signal for controlling the power transfer in the electrical circuit.
Claim 2
Dependent Claim
96 words
Apparatus for monitoring and controlling power transfer in an electrical circuit comprising: means for measuring the amount of power transfer in the electrical circuit and providing a first output signal representative of that amount; means for measuring the rate of change of power transfer in the electrical circuit and providing a second output signal representative of that rate of change; means for combining the first and second output signals to provide a combined signal; and means selectively responsive to the combined signal for providing a control signal for controlling the power transfer in the electrical circuit.
Claim 3
Dependent Claim
43 words
An apparatus as described in claim 1, further comprising: means for providing a third output signal representative of residual power transfer in the electrical circuit; and the means for combining further including means for incorporating the third output signal into the combined signal.
Claim 4
Dependent Claim
62 words
An apparatus as described in claim 1 in which: the means for measuring the amount of power transfer includes a power transducer; the means for measuring the rate of change of power transfer includes a differentiator circuit with an input from the power transducer; and the means selectively responsive to the combined signal includes a trip relay which activates a control circuit.
Claim 5
Dependent Claim
62 words
An apparatus as described in claim 2 in which: the means for measuring the amount of power transfer includes a power transducer; the means for measuring the rate of change of power transfer includes a differentiator circuit with an input from the power transducer; and the means selectively responsive to the combined signal includes a trip relay which activates a control circuit.
Claim 6
Dependent Claim
45 words
An apparatus as described in claim 1, further comprising: means for limiting the magnitude of the second output signal; and means for blocking the control signal when the magnitude of the rate of change of power transfer in the electrical circuit exceeds a design limit.
Claim 7
Dependent Claim
45 words
An apparatus as described in claim 2, further comprising: means for limiting the magnitude of the second output signal; and means for blocking the control signal when the magnitude of the rate of change of power transfer in the electrical circuit exceeds a design limit.
Claim 8
Dependent Claim
45 words
An apparatus as described in claim 3, further comprising: means for limiting the magnitude of the second output signal; and means for blocking the control signal when the magnitude of the rate of change of power transfer in the electrical circuit exceeds a design limit.
Claim 9
Dependent Claim
45 words
An apparatus as described in claim 4, further comprising: means for limiting the magnitude of the second output signal; and means for blocking the control signal when the magnitude of the rate of change of power transfer in the electrical circuit exceeds a design limit.
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) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |