US4656362A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blade pitch angle control for large wind turbines
Assignee: RTX Corp
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Filing: 1985-04-16
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Granted: 1987-04-07
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Expires: 2005-04-16
Abstract
Abstract A blade pitch angle control system for a wind turbine includes an improved control means (95) for providing a minimum pitch angle reference signal indicative of desired blade pitch at wind velocities less than rated. The control means includes means (35 and 30) for providing signals indicative of generated (output) power or torque and the rotational frequency of the wind turbine rotor. The output and rotor speed signals are input to a function generator which, in response to such signals, provides a signal indicative of the minimum pitch angle.
Inventors
- 👤 Kermit I. Harner
- 👤 Frank R. Niessen
- 👤 Robert Sherman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:41
CPC Classifications
F; F03; F03D; F03D7/00; F03D7/02; F03D7/04; F03D7/042; F03D7/043; F03D7/022; F03D7/0224; F03D9/00; F03D9/20; F03D9/25; F05; F05B; F05B2220/00; F05B2220/70; F05B2220/706; F05B2260/00; F05B2260/70; F05B2260/74; F05B2270/00; F05B2270/30; F05B2270/32; F05B2270/327; F05B2270/335; Y; Y02; Y02E; Y02E10/00; Y02E10/70; Y02E10/72
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
144 words
In a blade pitch angle control system for a wind turbine-generator comprising a rotor having a plurality of variable pitch airfoil blades fixed thereto and driving an electric generator through a drive train, said blade pitch angle control system including control means providing a reference signal indicative of desired blade pitch angle at less than rated wind speed conditions, said control means being characterized by: means providing an output signal indicative of actual wind turbine output; means providing a frequency signal indicative of rotational frequency of said wind turbine; and signal processing means responsive to said output and frequency signals for continuously providing a minimum allowable blade pitch angle reference signal based on the aerodynamic performance capabilities of said airfoil blades and corresponding to attainment by said wind turbine of said output at less than rated wind velocity and at an optimal power ratio.
Claim 2
Dependent Claim
144 words
In a blade pitch angle control system for a wind turbine-generator comprising a rotor having a plurality of variable pitch airfoil blades fixed thereto and driving an electric generator through a drive train, said blade pitch angle control system including control means providing a reference signal indicative of desired blade pitch angle at less than rated wind speed conditions, said control means being characterized by: means providing an output signal indicative of actual wind turbine output; means providing a frequency signal indicative of rotational frequency of said wind turbine; and signal processing means responsive to said output and frequency signals for continuously providing a minimum allowable blade pitch angle reference signal based on the aerodynamic performance capabilities of said airfoil blades and corresponding to attainment by said wind turbine of said output at less than rated wind velocity and at an optimal power ratio.
Claim 3
Dependent Claim
29 words
The blade pitch angle control system according to claim 1 further characterized by said output signal comprising a signal indicative of the actual electrical output of said electric generator.
Claim 4
Dependent Claim
24 words
The blade pitch angle control system according to claim 1 further characterized by said output signal comprising a signal indicative of drive train torque.
Claim 5
Dependent Claim
38 words
The blade pitch angle control system according to claim 1 further characterized by said signal processing means providing said blade pitch angle reference signal further as a function of the nominal frequency of rotation of said wind turbine.
Claim 6
Dependent Claim
58 words
The blade pitch angle control system according to claim 4 further characterized by said signal processing means providing said blade pitch angle reference signal as a function of the product of said output signal and the cube of the quotient of said rotational frequency of said wind turbine and said nominal frequency of rotation of said wind turbine.
References Cited (Backward Citations)
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US2738183A
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US2832895A
Cited
US3269121A
Cited
US3589830A
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Cited
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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) | 1990-04-06 | 1990-10-06 | 1991-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-06 | 1994-10-06 | 1995-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-06 | 1998-10-06 | 1999-04-07 | $7700.00 | Window Closed / Lapsed |