Patent US3889158A successfully refreshed from Google Patents.
US3889158A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Series capacitor protection equipment with dual sparkover feature
Assignee: ABB Inc USA
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Filing: 1974-08-27
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Granted: 1975-06-10
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Expires: 1994-08-27
Abstract
Abstract Multiple bypass circuit branches are provided across the equipment to be protected and have different sensitivity to overvoltages. Upon sparkover of the apparatus the most sensitive circuit branch is disabled for a time, as by opening a switch in that branch by reason of signals initiated upon breakdown of a subsequent branch. After a time interval, the most sensitive circuit branch is again restored to its operable condition, as by operation of a timer and subsequent reclosing of the referred to switch in the first circuit branch. The arrangement permits a low overvoltage protection level and avoids problems upon reinsertion after a line fault is cleared by being insensitive to system swing currents and post reinsertion transient voltages that may exceed the lower sparkover protective level but not reach the higher sparkover protective level.
Inventors
- 👤 Charles A Peterson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:45
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/16
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
155 words
Protective apparatus for electrical equipment comprising: first, second, and third circuit branches connected electrically in parallel across the equipment to be protected; said first circuit branch including means for bypassing the equipment at a first predetermined over-voltage level; said second circuit branch including means for bypassing the equipment at a second predetermined over-voltage level higher than said first predetermined over-voltage level; said third circuit branch including means for bypassing the equipment at a third overvoltage level higher than said second overvoltage level; voltage cascading means for causing said second and third circuit branches to have their bypassing means operate upon the occurrence of an overvoltage effective to cause operation of the bypass of said first circuit branch; means for disabling said first circuit branch upon the occurrence of the bypass through the third circuit branch and for restoring said first circuit branch to its original operating condition at a predetermined time after it is disabled.
Claim 2
Dependent Claim
155 words
Protective apparatus for electrical equipment comprising: first, second, and third circuit branches connected electrically in parallel across the equipment to be protected; said first circuit branch including means for bypassing the equipment at a first predetermined over-voltage level; said second circuit branch including means for bypassing the equipment at a second predetermined over-voltage level higher than said first predetermined over-voltage level; said third circuit branch including means for bypassing the equipment at a third overvoltage level higher than said second overvoltage level; voltage cascading means for causing said second and third circuit branches to have their bypassing means operate upon the occurrence of an overvoltage effective to cause operation of the bypass of said first circuit branch; means for disabling said first circuit branch upon the occurrence of the bypass through the third circuit branch and for restoring said first circuit branch to its original operating condition at a predetermined time after it is disabled.
Claim 3
Dependent Claim
71 words
The protective apparatus of claim 1 wherein: said first, second and third circuit branches contain spark gaps of successively higher sparkover level and said means for disabling and restoring comprises a mechanical switch in series with the spark gap of said first circuit branch and a current transformer is associated with said spark gap of said third circuit branch initiating electrical signals to cause the opening and reclosing of said switch.
Claim 4
Dependent Claim
30 words
The protective apparatus of claim 2 wherein: capacitive means is provided connected across said spark gap of said second circuit branch for preventing premature sparkover of said second branch gap.
Claim 5
Dependent Claim
126 words
Series capacitor equipment comprising: a main capacitor connected in series in an alternating current transmission line; a first circuit branch connected across said main capacitor and including a first trigger spark gap having a first predetermined overvoltage level to produce sparkover; a second circuit branch connected across said main capacitOr and including a second trigger spark gap having a second predetermined overvoltage level to produce sparkover higher than said first predetermined overvoltage level; a third circuit branch connected across said main capacitor and including a main spark gap; means for disabling said first circuit branch upon the occurrence of a sparkover of said main spark gap and for restoring said first circuit branch to its original operating condition at a predetermined time after it is disabled.
Claim 6
Dependent Claim
126 words
Series capacitor equipment comprising: a main capacitor connected in series in an alternating current transmission line; a first circuit branch connected across said main capacitor and including a first trigger spark gap having a first predetermined overvoltage level to produce sparkover; a second circuit branch connected across said main capacitOr and including a second trigger spark gap having a second predetermined overvoltage level to produce sparkover higher than said first predetermined overvoltage level; a third circuit branch connected across said main capacitor and including a main spark gap; means for disabling said first circuit branch upon the occurrence of a sparkover of said main spark gap and for restoring said first circuit branch to its original operating condition at a predetermined time after it is disabled.
Claim 7
Dependent Claim
34 words
Series capacitor equipment in accordance with claim 4 wherein: said second trigger spark gap sparks over at a voltage selected to be sufficiently low to protect said main capacitor from damage due to overvoltages.
Claim 8
Dependent Claim
47 words
Series capacitor equipment in accordance with claim 5 wherein said first trigger spark gap sparks over at a voltage selected to be low enough to avoid oscillations on the transmission line that are potentially harmful to generating equipment connected thereto while being harmless to said main capacitor.
References Cited (Backward Citations)
US3249813A
Cited
US3586909A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-09 | 1978-12-09 | 1979-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-09 | 1982-12-09 | 1983-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-09 | 1986-12-09 | 1987-06-10 | $7700.00 | Window Closed / Lapsed |