Patent US3238711A successfully refreshed from Google Patents.
Patent US3684951A successfully refreshed from Google Patents.
US3684951A
Expired / Lapsed
US
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Methods of corona location utilizing three-phase voltage distribution patterns
Assignee: Westinghouse Electric Corp
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Filing: 1970-12-09
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Granted: 1972-08-15
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Expires: 1990-12-09
Abstract
Abstract A method of locating a source of corona discharges in an electrical winding, comprising the steps of stressing the winding with a first voltage to provide a first voltage distribution pattern to ground and noting the magnitude of the first voltage at corona inception and corona extinction, and stressing the winding with a second voltage to provide a second voltage distribution pattern to ground, different than the first, and noting the magnitude of the second voltage at corona inception and corona extinction. The first and second voltage distribution patterns at the noted first and second voltages, respectively, for either corona inception or corona extinction, are then compared to determine where in the winding the voltages are identical on the two distribution curves.
Inventors
- 👤 Ronald T Harrold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:56
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/12; G01R31/1227; G01R31/50; G01R31/62
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
201 words
A method of locating a source of corona discharges in a three-phase delta connected electrical winding having first, second and third terminals, comprising the steps of: stressing the three-phase winding with an applied voltage to provide a first voltage distribution pattern in which the winding is stressed uniformly to ground, changing the magnitude of the applied voltage in a predetermined direction, detecting corona discharges in the winding, noting the phase in which they occur, and noting the magnitude of the applied voltage when the corona condition of the winding changes, stressing the three-phase winding with an induced voltage to provide a second voltage distribution pattern, different than the first voltage distribution pattern, which equally and uniformly stresses the phases of the winding turn-to-turn, changing the magnitude of the induced voltage in the same direction as the applied voltage, detecting corona discharges in the winding and noting the magnitude of the induced voltage when the corona condition of the winding changes, and comparing the first and second voltage distribution patterns at the noted magnitudes of the applied and induced voltages, respectively, determining where in the noted phase winding the voltages are of like magnitude in the first and second voltage distribution patterns.
Claim 2
Independent Claim
201 words
A method of locating a source of corona discharges in a three-phase delta connected electrical winding having first, second and third terminals, comprising the steps of: stressing the three-phase winding with an applied voltage to provide a first voltage distribution pattern in which the winding is stressed uniformly to ground, changing the magnitude of the applied voltage in a predetermined direction, detecting corona discharges in the winding, noting the phase in which they occur, and noting the magnitude of the applied voltage when the corona condition of the winding changes, stressing the three-phase winding with an induced voltage to provide a second voltage distribution pattern, different than the first voltage distribution pattern, which equally and uniformly stresses the phases of the winding turn-to-turn, changing the magnitude of the induced voltage in the same direction as the applied voltage, detecting corona discharges in the winding and noting the magnitude of the induced voltage when the corona condition of the winding changes, and comparing the first and second voltage distribution patterns at the noted magnitudes of the applied and induced voltages, respectively, determining where in the noted phase winding the voltages are of like magnitude in the first and second voltage distribution patterns.
Claim 3
Dependent Claim
44 words
The method of claim 1 wherein the first and second voltages are changed to increase their magnitude, an the corona condition of the winding at which the magnitudes of the first and second voltages are noted is the inception of corona in the windings.
Claim 4
Dependent Claim
42 words
The method of claim 1 wherein the first and second voltages are changed to decrease their magnitude, and the corona condition of the winding at which the magnitudes of the first and second voltages are noted is the magnitudes at corona extinction.
Claim 5
Dependent Claim
45 words
The method of claim 1 wherein the steps are repeated a plurality of times and the magnitude of the first and second voltages at inception are averaged, to set the first and second voltage distribution patterns which are compared to locate the source of corona.
Claim 6
Independent Claim
146 words
A method of locating a source of corona discharges in a three-phase delta connected winding having first, second and third terminals, comprising the steps of successively testing the winding with a different terminal grounded during each test, with each test including the steps of inducing a voltage into the winding, changing the voltage Magnitude in a predetermined direction, and noting the magnitude of the winding voltage at which the corona condition of the winding changes, locating the phase in which the corona discharge is occurring and the location of the discharge within the phase by comparing the voltage distribution pattern of each phase when a terminal of the selected phase is grounded, with the voltage distribution pattern of the phase when its terminals are not grounded, and determining in which phase, and where in that phase, the voltages of the distribution patterns are of like magnitude.
Claim 7
Independent Claim
146 words
A method of locating a source of corona discharges in a three-phase delta connected winding having first, second and third terminals, comprising the steps of successively testing the winding with a different terminal grounded during each test, with each test including the steps of inducing a voltage into the winding, changing the voltage Magnitude in a predetermined direction, and noting the magnitude of the winding voltage at which the corona condition of the winding changes, locating the phase in which the corona discharge is occurring and the location of the discharge within the phase by comparing the voltage distribution pattern of each phase when a terminal of the selected phase is grounded, with the voltage distribution pattern of the phase when its terminals are not grounded, and determining in which phase, and where in that phase, the voltages of the distribution patterns are of like magnitude.
Claim 8
Dependent Claim
42 words
The method of claim 5 wherein the first and second voltages are changed to increase their magnitude, and the corona condition of the winding at which the magnitudes of the first and second voltages are noted is the voltages at corona inception.
Claim 9
Dependent Claim
39 words
The method of claim 5 wherein the first and second voltages are changed to decrease their magnitude, and the corona condition of the winding at which the magnitudes of the first and second voltage are noted is corona extinction.
References Cited (Backward Citations)
US2890410A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |