Patent US4623265A successfully refreshed from Google Patents.
US4623265A
Expired / Lapsed
US
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Transformer hot-spot temperature monitor
Assignee: ABB Inc USA
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Filing: 1984-09-26
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Granted: 1986-11-18
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Expires: 2004-09-26
Abstract
Abstract A hot-spot temperature monitor for determining the hot-spot temperature of a transformer. The hot-spot temperature monitor determines the largest current flowing in the transformer and using this value calculates a temperature gradient. The temperature gradient represents the difference in temperature between the hot spot and the top-oil temperature. The top-oil temperature is also measured. The hot-spot temperature is calculated by adding the temperature gradient to the top-oil temperature. The hot-spot temperature sensor controls the transformer cooling units and can activate various alarms and indicators as desired.
Inventors
- 👤 Thomas D. Poyser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 02:02
CPC Classifications
G; G01; G01K; G01K3/00; G01K3/08; G01K3/14; G01K1/00; G01K1/02; G01K1/026
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
208 words
A hot-spot temperature apparatus for determining the hot-spot temperature of a transformer, wherein the transformer is adapted for connection to a power source and wherein the transformer includes a magnetic core, electrical winding means disposed in inductive relation with the magnetic core for establishing a magnetic flux therein, said winding means having one or more phase windings, and a cooling system for circulating a coolant, said hot-spot temperature apparatus comprising: means for determining the phase winding having the largest current in the electrical winding means and for producing a signal representative thereof; means responsive to said signal for deriving a first value representing an average hot-spot temperature rise over an average top-oil temperature at a rated current of said transformer by using a predetermined relationship between the average hot-spot temperature rise over the average top-oil temperature at the rated current of said transformer wherein said first value is a function of the largest current in the electrical winding means; means for calculating a temperature gradient, wherein said temperature gradient is a function of said first value; means for determining coolant temperature at a preselected location proximate the top portion of said coolant; and means for adding said temperature gradient and said coolant temperature for determining the hot-spot temperature.
Claim 2
Dependent Claim
208 words
A hot-spot temperature apparatus for determining the hot-spot temperature of a transformer, wherein the transformer is adapted for connection to a power source and wherein the transformer includes a magnetic core, electrical winding means disposed in inductive relation with the magnetic core for establishing a magnetic flux therein, said winding means having one or more phase windings, and a cooling system for circulating a coolant, said hot-spot temperature apparatus comprising: means for determining the phase winding having the largest current in the electrical winding means and for producing a signal representative thereof; means responsive to said signal for deriving a first value representing an average hot-spot temperature rise over an average top-oil temperature at a rated current of said transformer by using a predetermined relationship between the average hot-spot temperature rise over the average top-oil temperature at the rated current of said transformer wherein said first value is a function of the largest current in the electrical winding means; means for calculating a temperature gradient, wherein said temperature gradient is a function of said first value; means for determining coolant temperature at a preselected location proximate the top portion of said coolant; and means for adding said temperature gradient and said coolant temperature for determining the hot-spot temperature.
Claim 3
Independent Claim
116 words
A method for determining the hot-spot temperature of a transformer, wherein the transformer includes electrical winding means having one or more phase windings and is adapted for connection to a power source, and wherein the transformer includes a cooling system for circulating a coolant, said method comprising the steps of: determining the phase winding having the largest current in the electrical winding means and producing a signal representative thereof; calculating a temperature gradient, wherein said temperature gradient is a function of the largest current in the electrical winding means; determining coolant temperature at a preselected location proximate the top portion of said coolant; adding said temperature gradient and said coolant temperature for deriving the hot-spot temperature.
Claim 4
Independent Claim
116 words
A method for determining the hot-spot temperature of a transformer, wherein the transformer includes electrical winding means having one or more phase windings and is adapted for connection to a power source, and wherein the transformer includes a cooling system for circulating a coolant, said method comprising the steps of: determining the phase winding having the largest current in the electrical winding means and producing a signal representative thereof; calculating a temperature gradient, wherein said temperature gradient is a function of the largest current in the electrical winding means; determining coolant temperature at a preselected location proximate the top portion of said coolant; adding said temperature gradient and said coolant temperature for deriving the hot-spot temperature.
Claim 5
Independent Claim
110 words
An apparatus for measuring the hot-spot temperature of an oil-cooled transformer having one or more phase windings, comprising: means for measuring the current flowing through each of said phase windings; means for determining the single phase winding of said one or more phase windings which has the highest current flowing therethrough; means for determining a temperature gradient, said temperature gradient is a function of said single phase winding and the measured current flowing therethrough; means for measuring the oil temperature at a predetermined location within said oil-cooled transformer; means for calculating the sum of said oil temperature and said temperature gradient, said sum being the hot-spot temperature of said transformer.
Claim 6
Independent Claim
110 words
An apparatus for measuring the hot-spot temperature of an oil-cooled transformer having one or more phase windings, comprising: means for measuring the current flowing through each of said phase windings; means for determining the single phase winding of said one or more phase windings which has the highest current flowing therethrough; means for determining a temperature gradient, said temperature gradient is a function of said single phase winding and the measured current flowing therethrough; means for measuring the oil temperature at a predetermined location within said oil-cooled transformer; means for calculating the sum of said oil temperature and said temperature gradient, said sum being the hot-spot temperature of said transformer.
Claim 7
Dependent Claim
49 words
The hot-spot temperature apparatus of claim 3 wherein the means for determining said temperature gradient includes a look-up table including current values and a temperature gradient for each current value, and wherein the temperature gradient is determined by using the largest current as the current value in said table.
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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) | 1989-11-17 | 1990-05-19 | 1990-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-17 | 1994-05-19 | 1994-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-17 | 1998-05-19 | 1998-11-18 | $7700.00 | Window Closed / Lapsed |