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US 5,155,375 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 better track wind speed fluctuations for greater 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. The wind observer predicts the average wind speed at a subsequent point in time over the cross-section presented to the wind by the wind turbine. The average wind speed is applied to a parameter schedule to determine desired values for rotor speed and torque which are used by arotor 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 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 having a rotor driven with a driving torque supplied by a power source that varies over time, said controller comprising:
A controller for a variable speed electrical generator in a wind turbine having at least one aerodynamic surface sweeping a swept area that presents a cross-section to a wind which may vary over time, the wind turbine converting the wind energy into a driving torque applied to a generator rotor, said controller comprising:
A controller for a variable speed electrical generator in a wind turbine having at least one aerodynamic surface sweeping a swept area that presents a cross-section 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 controller comprising:
A controller for selecting the load torque on a rotor in a variable speed wind turbine electrical generator, the wind supplying a driving torque to the rotor in a direction opposing the load torque, the amount of the driving torque varying over time with the wind speed, said controller comprising:
A wind speed observer for a wind turbine having a rotor driven by a wind applying power to at least one blade, said wind applying a driving torque to the rotor, said wind speed observer predicting an average wind speed over a sweep of the blades, said wind speed observer comprising:
A wind turbine controller for a variable speed wind turbine including a variable speed generator driven by a rotor, said wind turbine having one or more aerodynamic surfaces for converting wind power into a driving torque on the rotor, said controller estimating the wind speed averaged over the sweep of the aerodynamic surfaces, said controller selecting a reference load torque in response to the estimations for the wind speed in order to achieve efficient generator operation, said controller comprising:
A wind turbine controller for a variable speed wind turbine including a variable speed generator driven by a rotor, said wind turbine having one or more aerodynamic surfaces for converting wind power into a driving torque on the rotor, said controller predicting the wind speed averaged over the sweep of the aerodynamic surfaces, said controller selecting a reference load torque in response to the predictions for the wind speed in order to achieve efficient generator operation, said controller comprising:
A wind speed sensing method for operating a variable speed wind turbine, said variable speed wind turbine having at least one blade sweeping over a swept area, the blades turning a rotor in a generator, comprising the steps of:
A method for predicting the wind speed averaged over the sweep of the blades of a wind turbine, said method comprising the steps of:
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 presents a cross-section 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 presents a cross-section 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:
Dependencies are inferred from the claim text.