Patent US4345198A successfully refreshed from Google Patents.
US4345198A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Generator air gap electrical torque monitor
Assignee: General Electric Co
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Filing: 1981-02-20
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Granted: 1982-08-17
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Expires: 2001-02-20
Abstract
Abstract Apparatus is disclosed for continuously monitoring the air gap torque acting on the rotor of a 3-phase electrical generator by sensing certain of the output voltages and currents produced by the generator as it supplies power to a connected load. In a preferred form of the invention, signals representing the three generator output voltages and two of the three line currents are conditioned and combined in electrical circuitry to produce a single output signal which is indicative of the air gap torque. The torque signal so produced is in a form easily handled by conventional means such as computers and recorders, and is appropriate for use by operating personnel in making decisions regarding generator operation.
Inventors
- 👤 John F. Wolfinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:41
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/34; G01R31/343
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
440 words
In combination with a 3-phase electrical generator supplying output voltage and current to a load and having armature windings of known resistance, apparatus for continuously monitoring the air gap torque acting on the rotor of the generator, comprising: first means providing a first load current signal indicative of load current in a first phase of said generator; second means providing a second load current signal indicative of load current in a second phase of said generator; first means providing a first armature voltage drop signal indicative of armature voltage drop in said first phase; second means providing a second armature voltage drop signal indicative of armature voltage drop in said second phase; first subtractor means providing a first interphase voltage signal representing the difference between the output voltage of said first phase and the output voltage of said second phase; second subtractor means providing a second interphase voltage signal representing the difference between the output voltage of a third phase of said generator and the output voltage of said first phase; third subtractor means providing a third interphase voltage difference signal representing the difference between the output voltage of said second phase and the output voltage of said third phase; fourth subtractor means providing a first difference signal representing the difference between said first interphase voltage signal and said third interphase voltage signal; fifth subtractor means providing a second difference signal representing the difference between said second interphase voltage signal and said first interphase voltage signal; first summing means for summing said first difference signal and said second armature voltage drop signal to provide a first summation signal, said first difference signal and said second armature voltage drop signals being of opposite polarity; second summing means for summing said second difference signal and said first armature voltage drop signal to provide a second summation signal, said second difference signal and said first armature voltage drop signals being of opposite polarity; first final integrator means for integrating said first summation signal to provide a first final integration signal; second final integrator means for integrating said second summation signal to provide a second final integration signal; first multiplier means for multiplying said first final integration signal by said first load current signal to provide a first composite signal; second multiplier means for multiplying said second final integration signal by said second load current signal to provide a second composite signal; final subtractor means for subtracting said second composite signal from said first composite signal to produce an air gap torque signal representative of electrically produced torque on the generator rotor; and means for presenting said air gap torque signal to operating personnel.
Claim 2
Dependent Claim
440 words
In combination with a 3-phase electrical generator supplying output voltage and current to a load and having armature windings of known resistance, apparatus for continuously monitoring the air gap torque acting on the rotor of the generator, comprising: first means providing a first load current signal indicative of load current in a first phase of said generator; second means providing a second load current signal indicative of load current in a second phase of said generator; first means providing a first armature voltage drop signal indicative of armature voltage drop in said first phase; second means providing a second armature voltage drop signal indicative of armature voltage drop in said second phase; first subtractor means providing a first interphase voltage signal representing the difference between the output voltage of said first phase and the output voltage of said second phase; second subtractor means providing a second interphase voltage signal representing the difference between the output voltage of a third phase of said generator and the output voltage of said first phase; third subtractor means providing a third interphase voltage difference signal representing the difference between the output voltage of said second phase and the output voltage of said third phase; fourth subtractor means providing a first difference signal representing the difference between said first interphase voltage signal and said third interphase voltage signal; fifth subtractor means providing a second difference signal representing the difference between said second interphase voltage signal and said first interphase voltage signal; first summing means for summing said first difference signal and said second armature voltage drop signal to provide a first summation signal, said first difference signal and said second armature voltage drop signals being of opposite polarity; second summing means for summing said second difference signal and said first armature voltage drop signal to provide a second summation signal, said second difference signal and said first armature voltage drop signals being of opposite polarity; first final integrator means for integrating said first summation signal to provide a first final integration signal; second final integrator means for integrating said second summation signal to provide a second final integration signal; first multiplier means for multiplying said first final integration signal by said first load current signal to provide a first composite signal; second multiplier means for multiplying said second final integration signal by said second load current signal to provide a second composite signal; final subtractor means for subtracting said second composite signal from said first composite signal to produce an air gap torque signal representative of electrically produced torque on the generator rotor; and means for presenting said air gap torque signal to operating personnel.
Claim 3
Dependent Claim
27 words
The combination of claim 1 wherein said first and said second means providing said first and said second load current signals, respectively, are air core current transformers.
Claim 4
Dependent Claim
62 words
The combination of claim 1 wherein said first and said second means providing said first and said second load current signals, respectively, each includes a Rogowski coil current transformer providing a signal indicative of the time derivative of load current; an integrator network for integrating said time derivative signal; and a buffer network electrically isolating said Rogowski coil from said integrator network.
Claim 5
Dependent Claim
86 words
The combination of claims 1, 2, or 3 wherein: said first means providing a first armature voltage drop signal comprises a third multiplier means for multiplying said first load current signal by a factor proportional to said armature resistance to produce said first armature voltage drop signal; and said second means providing a second armature voltage drop signal comprises a fourth multiplier means for multiplying said second load current signal by a factor proportional to said armature resistance to produce said second armature voltage drop signal.
Claim 6
Dependent Claim
26 words
The combination of claim 4 wherein said third and fourth multiplier means each comprises an operational amplifier network whose gain is proportional to said armature resistance.
Claim 7
Dependent Claim
30 words
The combination of claim 5 wherein said first, second, third, fourth, and fifth subtractor means each comprises an operational amplifier circuit configured to provide the difference between two input signals.
Claim 8
Dependent Claim
25 words
The combination of claim 6 wherein said first and said second final integrator means each comprises an operational amplifier circuit configured as an integrator network.
Claim 9
Dependent Claim
18 words
The combination of claim 7 wherein said first and said second multiplier means each comprises an analog multiplier.
Claim 10
Dependent Claim
20 words
The combination of claim 8 wherein said final subtractor means comprises an operational amplifier circuit configured as a subtractor network.
References Cited (Backward Citations)
US3662251A
Cited
US4303882A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-08-16 | 1986-02-15 | 1986-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-16 | 1990-02-15 | 1990-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-16 | 1994-02-15 | 1994-08-17 | $7700.00 | Window Closed / Lapsed |