US4001643A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for a power circuit breaker controller
Assignee: United States Department of the Interior
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Filing: 1975-05-29
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Granted: 1977-01-04
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Expires: 1995-05-29
Abstract
Abstract A power circuit breaker controller and its method of use. Surge voltages associated with the closing of a high voltage circuit breaker for a polyphase alternating current line are lowered substantially by our invention. Although several lines and phases are involved, each is considered and operated independently of the other. All lines have preinserted closing resistors, to reduce the surge voltages, that are preinserted in parallel across the main contacts of each phase one step prior to the main contact closing. Between the resistor switch closings certain staggering takes place. For example, if 3 phases are involved the resistor closings are staggered by about 60 or more electrical degrees. Further, there is circuitry to insure that the polarity of the bus side phase-to-ground voltage is of the same polarity as the trapped charges on the corresponding phases on the line side of the breaker when the resistor switch contacts are engaged. When the voltage across the main contacts is zero after the resistor is inserted, circuitry provides that the main contacts be directly engaged and the resistors be shortened out.
Inventors
- 👤 Harold C. Ramberg
- 👤 Alvin C. Legate
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:23
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/22; H02H7/222; H01; H01H; H01H33/00; H01H33/02; H01H33/59; H01H33/593; H01H33/04; H01H33/16
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
134 words
A programable method for limiting the voltages surges on a high voltage alternating current power line upon closure of a main contact switch which is connected in parallel with a single normally preinsertable resistor comprising the steps of: first continuously monitoring the polarity of the bus voltage and trapped line charge voltage on both sides of said main switch at the time said switch is opened; second comparing the monitored polarities against each other and when of equal polarity, operatively inserting said resistor into the power line before closure of said main switch; and then predetermining the time of closure of said main switch when the voltage difference between its bus and line sides will be near zero and then effectively by-passing the inserted preinserted single resistor by closure of the main contact switch.
Claim 2
Dependent Claim
134 words
A programable method for limiting the voltages surges on a high voltage alternating current power line upon closure of a main contact switch which is connected in parallel with a single normally preinsertable resistor comprising the steps of: first continuously monitoring the polarity of the bus voltage and trapped line charge voltage on both sides of said main switch at the time said switch is opened; second comparing the monitored polarities against each other and when of equal polarity, operatively inserting said resistor into the power line before closure of said main switch; and then predetermining the time of closure of said main switch when the voltage difference between its bus and line sides will be near zero and then effectively by-passing the inserted preinserted single resistor by closure of the main contact switch.
Claim 3
Dependent Claim
26 words
The method of claim 1 wherein there is a fixed predetermined time interval between the insertion of said resistor and the closure of said main switch.
Claim 4
Dependent Claim
33 words
The method of claim 1 wherein to determine the polarity of said bus and trapped line charged voltages the actual voltage levels are first divided by a factor of at least several hundred.
Claim 5
Dependent Claim
38 words
The method of claim 1 wherein the closure of said main contact switch takes place automatically at a time interval of less than one cycle of the bus voltage after the resistor is inserted into the power line.
Claim 6
Dependent Claim
33 words
The method of claim 1 wherein the polarity of the line trapped charge is determined by observing the performance of the alternating voltage waveform one-half cycle before the main contact switch is opened.
Claim 7
Dependent Claim
148 words
A power circuit breaker controller for use with a circuit breaker on an alternating current high voltage power line comprising: a main contact switch for opening and closing the line between its bus voltage side and its line side; a single preinsertable resistor and switch combination connected in parallel to said main contact switch; circuit means for comparing the detected polarities and for inserting said single resistor operatively into said line before said main switch is closed when the same polarities are detected; means for continuously detecting the zero point on wave of the bus voltage signal; and means for comparing the detected zero point on wave against the signal on the line side and for actuating said main switch to close said main contact switch after said single resistor is inserted and when the bus voltage signal and the signal on the line side are near zero.
Claim 8
Dependent Claim
148 words
A power circuit breaker controller for use with a circuit breaker on an alternating current high voltage power line comprising: a main contact switch for opening and closing the line between its bus voltage side and its line side; a single preinsertable resistor and switch combination connected in parallel to said main contact switch; circuit means for comparing the detected polarities and for inserting said single resistor operatively into said line before said main switch is closed when the same polarities are detected; means for continuously detecting the zero point on wave of the bus voltage signal; and means for comparing the detected zero point on wave against the signal on the line side and for actuating said main switch to close said main contact switch after said single resistor is inserted and when the bus voltage signal and the signal on the line side are near zero.
Claim 9
Dependent Claim
42 words
The controller of claim 6 wherein said circuit means for comparing the detected polarities comprises logic gate circuitry connected to the outputs from polarity memory circuits which are operatively associated with both the bus and line side of said main contact switch.
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) | 1980-01-04 | 1980-07-05 | 1981-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-04 | 1984-07-05 | 1985-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-04 | 1988-07-05 | 1989-01-04 | $7700.00 | Window Closed / Lapsed |