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US 5,289,041 AGranted
Speed control system for a variable speed wind turbine
AssigneeU.S. Windpower, Inc.
InventorWilliam E. Holley
Life of this patent
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AssigneeU.S. Windpower, Inc.
InventorWilliam E. Holley
Estimating the term…
A controller and method is disclosed for operating a variable speed turbine to track wind speed fluctuations for high efficiency in conversion of wind energy to electrical energy. The controller of the invention controls the rotor speed in accordance with a wind speed supplied by a wind observer in order to approximately follow the varying wind speeds. A yaw angle error sensor senses the degree to which the turbine is misaligned with the wind. The wind observer predicts the average wind speed at a subsequent point in time. The average wind speed is applied to a parameter schedule to determine desired values for rotor speed and torque which are used by a rotor speed stabilizer to command a reference load torque. The load torque of the generator is controlled in accordance with the commanded load torque, and therefore the desired rotor speed is approximated. During operation, the wind speed prediction process is repeated at each subsequent time interval, and the load torque, and therefore rotor speed, is controlled accordingly. The wind observer calculates the aerodynamic torque and then calculates net torque. The wind speed is predicted as a function of the present (previously predicted) wind speed and correction terms including net torque, the yaw angle error, and the difference between the predicted and actual rotor speed. The wind observer is useful whenever the wind turbine rotor is turning, whether or not it is producing power.
A controller for a variable speed electrical generator in a wind turbine having at least one aerodynamic surface sweeping a swept area that defines a rotor tip plane having a yaw error angle with respect to a wind that may vary in speed and direction over time, the wind turbine converting the wind energy into a driving torque applied to a generator rotor, said controller comprising:
A method for controlling the rotor speed of a variable speed wind turbine, said method utilizing a parameter schedule of desired operating parameters indexed by the wind speed, said method comprising the steps of:
A method for supplying a control parameter to control a variable speed electrical generator in a wind turbine having rotor speed control dependent upon said control parameter, the wind turbine having at least one aerodynamic surface sweeping a swept area that defines a rotor tip plane at a yaw error angle with respect to a wind that may vary over time, the wind turbine converting the wind energy into a driving torque applied to a generator rotor, said method comprising the steps of:
A method for supplying a control parameter to control a variable speed electrical generator in a wind turbine having rotor speed control dependent upon said control parameter, the wind turbine having at least one aerodynamic surface sweeping a swept area that defines a rotor tip plane with respect to a wind that may vary in direction and speed over time, the wind turbine converting the wind energy into a driving torque applied to a generator rotor, said method comprising the steps of:
Dependencies are inferred from the claim text.