WE CLAIM:
1. A method for operating a wind turbine (10) so as to increase power production, the method comprising:
defining a first operating region (309) associated with an unsaturated torque range;
defining a second operating region (310) associated with a saturated torque range;
monitoring a torque output of the wind turbine (10); and,
continuously adjusting a tip-speed-ratio set point of the wind turbine (10) based on the torque output so as to operate the wind turbine (10) along a torque constraint boundary (312) of the first and second operating regions (309, 310).
2. The method as claimed in claim 1, wherein continuously adjusting the tip-speed-ratio set point of the wind turbine (10) further comprises increasing the tip-speed-ratio set point when the torque output of the wind turbine (10) is within the second operating region (310).
3. The method as claimed in claim 2, wherein continuously adjusting the tip-speed-ratio set point of the wind turbine (10) further comprises decreasing the tip-speed-ratio set point when the torque output of the wind turbine (10) is within the first operating region (310).
4. The method as claimed in claim 1, comprising determining the torque constraint boundary (312) of the first and second operating regions (309, 310) based upon when the wind turbine (10) switches operating modes.
5. The method as claimed in claim 4, wherein switching operating modes further comprises pitching one or more rotor blades (22) of the wind turbine (10).
6. The method as claimed in claim 5, wherein the saturated torque range occurs when the torque output of the wind turbine (10) reaches a rated torque of the wind turbine (10).
7. The method as claimed in claim 1, comprising continuously adjusting the tip-speed-ratio set point of the wind turbine (10) in a variable wind speed region of a power curve of the wind turbine (10).
8. The method as claimed in claim 1, wherein the unsaturated torque range comprises torque values less than the torque constraint boundary (312) of the wind turbine (10).
9. The method of claim 1, wherein the saturated torque range comprises torque values equal to or greater than the torque constraint boundary (312) of the wind turbine (10).
10. The method as claimed in claim 1, comprising filtering the tip-speed-ratio set point.
11. The method as claimed in claim 1, wherein continuously adjusting the tip-speed-ratio set point of the wind turbine (10) further comprises utilizing sliding-mode control.
12. A system for increasing power production of a wind turbine (10), the system comprising:
one or more sensors (80, 82, 84, 86, 88) configured to monitor a torque output of the wind turbine (10);
a controller (26) communicatively coupled to a processor (60), the processor (60) configured to perform one or more operations, the operations comprising:
defining a first operating region (309) associated with an unsaturated torque range;
defining a second operating region (310) associated with a saturated torque range;
continuously adjusting a tip-speed-ratio set point of the wind turbine (10) based on the torque output so as to operate the wind turbine (10) along a torque constraint boundary (312) of the first and second operating regions (309, 310).
13. A method for operating a wind turbine (10) based on a variable tip-speed-ratio, the method comprising:
determining, via a processor, an initial tip-speed-ratio set point for the wind turbine (10);
monitoring, via one or more sensors (80, 82, 84, 86, 88), a torque output of the wind turbine (10); and,
continuously adjusting the tip-speed-ratio set point of the wind turbine (10) based the torque output so as to maximize a power output of the wind turbine (10).
14. The method as claimed in claim 13, wherein monitoring the torque output of the wind turbine (10) further comprises monitoring the torque output during a first operating region (309) associated with a saturated torque range and monitoring the torque output during a second operating region (310) associated with an unsaturated torque range.
15. The method as claimed in claim 14, wherein continuously adjusting the tip-speed-ratio set point of the wind turbine (10) based the torque output further comprises continuously adjusting the tip-speed-ratio set point so as to operate the wind turbine (10) along a torque constraint boundary (312) of the first and second operating regions (309, 310).