US6294898B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for modifying limit and protection software in a synchronous generator exciter to match the capability of the turbine-generator
Assignee: General Electric Co
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Filing: 2001-01-16
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Granted: 2001-09-25
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Expires: 2021-01-16
Abstract
Abstract A method and apparatus for compensating, consistent with variations in cooling conditions, protection and limit functions of a generator. Limits of the capability curve of the generator, including the overexcited region, underexcited region and region limited by stator current heating, are modified in response to changes in coolant pressure or temperature depending on the type of generator being compensated. Feedback signals and setpoints being provided to fixed protection and limit functions are intercepted and modified in accordance with the relationship between generator rated values and generator performance in view of altered coolant conditions. Protection and limit functions are automatically coordinated. As a result, overall generator performance is improved.
Inventors
- 👤 Rodney A. Lawson
- 👤 William R. Pearson
- 👤 James E. Curran
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:45
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/06; H02H7/065; H02P; H02P9/00; H02P9/10
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
87 words
An apparatus for controlling an electrical generator, comprising: a summing block having as inputs a rating value of said generator and a value indicative of a cooling condition of said generator; a circuit for calculating, based on an output of said summing block, a compensation value for limits of predetermined portions of a capability curve of said generator; and at least one of a ratio block and a setpoint block receiving said compensation value and outputting a feedback signal to a fixed limiter function of said generator.
Claim 2
Independent Claim
87 words
An apparatus for controlling an electrical generator, comprising: a summing block having as inputs a rating value of said generator and a value indicative of a cooling condition of said generator; a circuit for calculating, based on an output of said summing block, a compensation value for limits of predetermined portions of a capability curve of said generator; and at least one of a ratio block and a setpoint block receiving said compensation value and outputting a feedback signal to a fixed limiter function of said generator.
Claim 3
Dependent Claim
23 words
The apparatus of claim 1 , further comprising at least one of a temperature sensor and pressure sensor for monitoring said cooling condition.
Claim 4
Dependent Claim
20 words
The apparatus of claim 2 , further comprising a low pass filtering connected between said sensor and said summing block.
Claim 5
Dependent Claim
25 words
The apparatus of claim 1 , further comprising a switch for automatically selecting one of effecting calculations based on generator coolant temperature and coolant pressure.
Claim 6
Dependent Claim
27 words
The apparatus of claim 1 , wherein said circuit comprises means for calculating a result based on a log—log relationship between generator field current and coolant pressure.
Claim 7
Dependent Claim
28 words
The apparatus of claim 1 , wherein said circuit comprises a means for calculating a result based on a quadratic relationship between generator field current and coolant temperature.
Claim 8
Dependent Claim
38 words
The apparatus of claim 1 , further comprising connection to inputs of at least one of an underexcited fixed limiter function, an overexcited fixed limiter function, an automatic voltage regulator and an inverse time limit and protection function.
Claim 9
Dependent Claim
16 words
The apparatus of claim 1 , further comprising a scaling block connected upstream from summing block.
Claim 10
Dependent Claim
25 words
The apparatus of claim 1 , wherein said apparatus controls the amount of at least one of field current and stator current in said generator.
Claim 11
Dependent Claim
22 words
The apparatus of claim 1 , further comprising a normalizing circuit for normalizing said compensation value with respect to generator terminal voltage.
Claim 12
Dependent Claim
21 words
The apparatus of claim 1 , further comprising a lookup table for emulating at least one portion of said capability curve.
Claim 13
Dependent Claim
18 words
The apparatus of claim 1 , wherein the apparatus comprises a part of an exciter of said generator.
Claim 14
Independent Claim
63 words
A method of controlling an electrical generator, comprising the steps of: determining the rating of said generator; monitoring a cooling condition of said generator; calculating, based on said rating and cooling conditions, a compensation value for limits of predetermined portions of a capability curve of said generator; and modifying a feedback signal to a fixed limiter function in accordance with said compensation value.
Claim 15
Independent Claim
63 words
A method of controlling an electrical generator, comprising the steps of: determining the rating of said generator; monitoring a cooling condition of said generator; calculating, based on said rating and cooling conditions, a compensation value for limits of predetermined portions of a capability curve of said generator; and modifying a feedback signal to a fixed limiter function in accordance with said compensation value.
Claim 16
Dependent Claim
22 words
The method of claim 13 , further comprising monitoring one of a temperature sensor and pressure sensor to monitor said cooling condition.
Claim 17
Dependent Claim
16 words
The method of claim 14 , further comprising low pass filtering an output of said sensor.
Claim 18
Dependent Claim
34 words
The method of claim 13 , further comprising summing a generator rating value with a value indicative of said cooling condition and employing the resulting sum as a multiplier to effect said modifying step.
Claim 19
Dependent Claim
24 words
The method of claim 13 , further comprising automatically selecting one of effecting said calculating step based on generator coolant temperature and coolant pressure.
Claim 20
Dependent Claim
25 words
The method of claim 13 , wherein said calculating step comprises a calculation based on a log—log relationship between generator field current and coolant pressure.
Claim 21
Dependent Claim
25 words
The method of claim 13 , wherein said calculating step comprises a calculation based on a quadratic relationship between generator field current and coolant temperature.
Claim 22
Dependent Claim
39 words
The method of claim 13 , further comprising varying a feedback signal to at least one of an underexcited fixed limiter function, an overexcited fixed limiter function, an automatic voltage regulator and an inverse time limit and protection function.
Claim 23
Dependent Claim
16 words
The method of claim 13 , further comprising scaling a value indicative of said cooling condition.
Claim 24
Dependent Claim
24 words
The method of claim 13 , further comprising controlling the amount of at least one of field current and stator current in said generator.
Claim 25
Dependent Claim
18 words
The method of claim 13 , further comprising normalizing with respect to generator terminal voltage said compensation value.
Claim 26
Dependent Claim
18 words
The method of claim 13 , further comprising electronically emulating at least one portion of said capability curve.
Claim 27
Dependent Claim
26 words
The method of claim 13 , further comprising providing transient-forcing capability for said generator by coordinating said limiter function with a protection function of said generator.
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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) | 2004-09-24 | 2005-03-26 | 2005-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-09-24 | 2009-03-26 | 2009-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-09-24 | 2013-03-26 | 2013-09-25 | $7700.00 | Window Closed / Lapsed |