US4355241A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means for damping subsynchronous oscillations in an AC power system including overload protection
Assignee: Electric Power Research Institute
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Filing: 1980-08-15
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Granted: 1982-10-19
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Expires: 2000-08-15
Abstract
Abstract Reactance means serially connected in a power line is shunted by selectively bidirectional conduction means which is triggered in response to half-cycle time periods of current waves exceeding a desired half-cycle time period and also in response to an over voltage across the reactance means.
Inventors
- 👤 Narain G. Hingorani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:55
CPC Classifications
H; H02; H02J; H02J3/00; H02J3/001; H02J3/0014; H02J3/00142
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
89 words
Apparatus for damping subsynchronous oscillations in an AC power line comprising reactance means serially connected in said power line, circuit means connected in parallel with said reactance means and including a resistor and a serially connected, selectably bi-directional conduction means, means for triggering said selectably bi-directional conduction means in response to half cycle time periods of current waves on said power lines exceeding a desired half-cycle time period, and means for triggering said selectably bi-directional conduction means in response to voltage across said reactance means exceeding a pre-selected value.
Claim 2
Dependent Claim
89 words
Apparatus for damping subsynchronous oscillations in an AC power line comprising reactance means serially connected in said power line, circuit means connected in parallel with said reactance means and including a resistor and a serially connected, selectably bi-directional conduction means, means for triggering said selectably bi-directional conduction means in response to half cycle time periods of current waves on said power lines exceeding a desired half-cycle time period, and means for triggering said selectably bi-directional conduction means in response to voltage across said reactance means exceeding a pre-selected value.
Claim 3
Dependent Claim
24 words
Apparatus as defined by claim 1 wherein said reactance means comprises at least one tuned circuit having a resonant frequency at a subsynchronous frequency.
Claim 4
Dependent Claim
29 words
Apparatus as defined by claim 2 wherein said reactance means comprises a plurality of serially connected, tuned circuits with each circuit having a resonant frequency at a subsynchronous frequency.
Claim 5
Dependent Claim
84 words
Apparatus for damping subsynchronous oscillations in an AC power line comprising: reactance means serially connected in said power line, said reactance means including at least one tuned circuit having a resonant frequency at a subsynchronous frequency, circuit means connected in parallel with said reactance means including a resistor and a serially connected, selectably bi-directional conduction means, and means for triggering said selectably bi-directional conduction means in response to half-cycle time periods of current waves on said power line exceeding a desired half-cycle time period.
Claim 6
Dependent Claim
84 words
Apparatus for damping subsynchronous oscillations in an AC power line comprising: reactance means serially connected in said power line, said reactance means including at least one tuned circuit having a resonant frequency at a subsynchronous frequency, circuit means connected in parallel with said reactance means including a resistor and a serially connected, selectably bi-directional conduction means, and means for triggering said selectably bi-directional conduction means in response to half-cycle time periods of current waves on said power line exceeding a desired half-cycle time period.
Claim 7
Dependent Claim
29 words
Apparatus as defined by claim 4 wherein said reactance means comprises a plurality of serially connected tuned circuits with each circuit having a resonant frequency at a subsynchronous frequency.
Claim 8
Dependent Claim
13 words
Apparatus as defined by claim 1 wherein said reactance means comprises a capacitor.
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) | 1985-10-18 | 1986-04-19 | 1986-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-18 | 1990-04-19 | 1990-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-18 | 1994-04-19 | 1994-10-19 | $7700.00 | Window Closed / Lapsed |