US6420795B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable speed wind turbine generator
Assignee: General Electric Co
•
Filing: 2000-08-16
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Granted: 2002-07-16
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Expires: 2020-08-16
Abstract
Abstract A variable speed system for use in systems, such as, for example, wind turbines, is described. The system comprises a wound rotor induction generator, a torque controller and a proportional, integral derivative (PID) pitch controller. The torque controller controls generator torque using field oriented control, and the PID controller performs pitch regulation based on generator rotor speed.
Inventors
- 👤 Amir S. Mikhail
- 👤 Craig L. Christenson
- 👤 Kevin L. Cousineau
- 👤 William L. Erdman
- 👤 William E. Holley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:22
CPC Classifications
H; H02; H02P; H02P9/00; H02P9/007; H02P9/42; F; F05; F05B; F05B2270/00; F05B2270/10; F05B2270/1016; F05B2270/70; F05B2270/706; H02P2101/00; H02P2101/15
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
106 words
A variable speed wind turbine having a plurality of blades comprising: a doubly-fed generator having a wound rotor; a power converter coupled to the wound rotor of the doubly-fed generator and having a LUT containing an encoded power-speed curve, wherein the power converter samples generator rotor speed, updates a desired output power from the LUT using the generator rotor speed, determines a new torque based on an updated desired output power, and calculates a new current vector that is impressed upon the wound rotor; and a closed loop proportional, integral derivative (PID) pitch controller coupled to pitch the plurality of blades based on generator rotor speed.
Claim 2
Dependent Claim
106 words
A variable speed wind turbine having a plurality of blades comprising: a doubly-fed generator having a wound rotor; a power converter coupled to the wound rotor of the doubly-fed generator and having a LUT containing an encoded power-speed curve, wherein the power converter samples generator rotor speed, updates a desired output power from the LUT using the generator rotor speed, determines a new torque based on an updated desired output power, and calculates a new current vector that is impressed upon the wound rotor; and a closed loop proportional, integral derivative (PID) pitch controller coupled to pitch the plurality of blades based on generator rotor speed.
Claim 3
Dependent Claim
16 words
The turbine defined in claim 1 wherein the power converter and PID pitch controller operate independently.
Claim 4
Dependent Claim
17 words
The turbine defined in claim 1 wherein the power converter holds power constant above rated wind speeds.
Claim 5
Dependent Claim
22 words
The turbine defined in claim 3 wherein the power converter holds power constant by controlling rotor current to provide the proper torque.
Claim 6
Dependent Claim
19 words
The turbine defined in claim 1 wherein the PID pitch controller generates a pitch velocity to perform pitch regulation.
Claim 7
Dependent Claim
30 words
The turbine defined in claim 1 wherein the PID pitch controller pitches the plurality of blades based on a difference in actual generator rotor speed and commanded generator rotor speed.
Claim 8
Dependent Claim
79 words
The turbine defined in claim 1 further comprising: a comparator to generate a speed error indication based on a comparison between a measure generator rotor speed and a target generator rotor speed, and wherein the PID pitch controller generates a pitch velocity command in response to the speed error indication; and a non-linear LUT coupled to output a drive voltage to be applied to a proportional value to accomplish blade pitch motion in response to the pitch velocity command.
Claim 9
Dependent Claim
127 words
A variable speed wind turbine having a plurality of blades comprising: a doubly-fed generation means for generating power, wherein the generation means has a wound rotor; a power converting means for transforming alternating current to direct current, wherein, the power converting means has a LUT containing an encoded power-speed curve, wherein the power converting means includes means for sampling generator rotor speed, means for updating a desired output power from the LUT using the generator rotor speed, means for determining a new torque based on an updated desired output power, and means for calculating a new current vector that is impressed upon the wound rotor; and a closed loop proportional, integral derivative (PID) pitch controlling means for pitching the plurality of blades based on generator rotor speed.
Claim 10
Dependent Claim
127 words
A variable speed wind turbine having a plurality of blades comprising: a doubly-fed generation means for generating power, wherein the generation means has a wound rotor; a power converting means for transforming alternating current to direct current, wherein, the power converting means has a LUT containing an encoded power-speed curve, wherein the power converting means includes means for sampling generator rotor speed, means for updating a desired output power from the LUT using the generator rotor speed, means for determining a new torque based on an updated desired output power, and means for calculating a new current vector that is impressed upon the wound rotor; and a closed loop proportional, integral derivative (PID) pitch controlling means for pitching the plurality of blades based on generator rotor speed.
Claim 11
Dependent Claim
18 words
The turbine defined in claim 8 wherein the power converting means and PID pitch controlling means operate independently.
Claim 12
Dependent Claim
21 words
The turbine defined in claim 8 wherein the power converting means includes means for holding power constant above rated wind speeds.
Claim 13
Dependent Claim
26 words
The turbine defined in claim 10 wherein the power converting means includes means for holding power constant by controlling rotor current to provide the proper torque.
Claim 14
Independent Claim
62 words
A method of controlling generator power comprising the steps of: measuring generator rotor speed; accessing a LUT using measured rotor speed to obtain a target output power; comparing actual output power and the target output power; generating a commanded torque by adjusting a torque calculation to maintain a predetermined output based on comparison of actual output power to the target output power.
Claim 15
Independent Claim
62 words
A method of controlling generator power comprising the steps of: measuring generator rotor speed; accessing a LUT using measured rotor speed to obtain a target output power; comparing actual output power and the target output power; generating a commanded torque by adjusting a torque calculation to maintain a predetermined output based on comparison of actual output power to the target output power.
Claim 16
Dependent Claim
22 words
The method defined in claim 12 wherein the commanded torque comprises a predetermined constant torque to slow down the generator rotor speed.
Claim 17
Dependent Claim
16 words
The method defined in claim 12 wherein the predetermined constant torque comprises a maximum constant torque.
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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) | 2005-07-15 | 2006-01-14 | 2006-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-07-15 | 2010-01-14 | 2010-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-07-15 | 2014-01-14 | 2014-07-16 | $7700.00 | Window Closed / Lapsed |