US4628393A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for switching in a three-phase high voltage circuit
Assignee: Hazemeijer BV
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Filing: 1982-03-11
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Granted: 1986-12-09
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Expires: 2002-03-11
Abstract
Abstract A method for interrupting an inductive load in a three-phase, high voltage network by means of a switch having a quick dielectric recovery, in particular a vacuum switch, in which two of the three vacuum switches, having a quick dielectric recovery, open at least 1/3 of a cycle of the network frequency later than the first vacuum switch, augmented with the minimum arcing time in the first vacuum switch, in order to prevent high over-voltages, caused by virtual chopping.
Inventors
- 👤 Bertus Griesen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:17
CPC Classifications
H; H01; H01H; H01H9/00; H01H9/54; H01H9/56; H01H9/563; H01H33/00; H01H33/60; H01H33/66
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
134 words
A method for interrupting power to an inductive load supplied from a three-phase high voltage source to prevent virtual chopping and using a vacuum switch having quick dielectric recovery characteristics in each phase of the high voltage network, comprising the steps of: opening the vacuum switch in a first phase at a given time; and opening at least one of the two remaining vacuum switches at a time subsequent to said given time equal to or greater than at least one-third of the period of the three-phase high voltage network frequency plus the minimum arcing time of the vacuum switch in the said first phase wherein the time of opening said at least one of the two remaining vacuum switches subsequent to said given time is less than one cycle of the power frequency.
Claim 2
Independent Claim
134 words
A method for interrupting power to an inductive load supplied from a three-phase high voltage source to prevent virtual chopping and using a vacuum switch having quick dielectric recovery characteristics in each phase of the high voltage network, comprising the steps of: opening the vacuum switch in a first phase at a given time; and opening at least one of the two remaining vacuum switches at a time subsequent to said given time equal to or greater than at least one-third of the period of the three-phase high voltage network frequency plus the minimum arcing time of the vacuum switch in the said first phase wherein the time of opening said at least one of the two remaining vacuum switches subsequent to said given time is less than one cycle of the power frequency.
Claim 3
Dependent Claim
18 words
A method as in claim 1 wherein said two remaining vacuum switches are opened simultaneously with one another.
References Cited (Backward Citations)
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GB963007A
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US3402324A
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US3555354A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-12-08 | 1990-06-09 | 1990-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-08 | 1994-06-09 | 1994-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-08 | 1998-06-09 | 1998-12-09 | $7700.00 | Window Closed / Lapsed |