05155375 is referenced by 90 patents and cites 13 patents.

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.

Title
Speed control system for a variable speed wind turbine
Application Number
7/762924
Publication Number
5155375
Application Date
September 19, 1991
Publication Date
October 13, 1992
Inventor
William E Holley
Pleasanton
CA, US
Agent
Blakely Sokologg Taylor & Zafman
Assignee
U S Windpower
CA, US
IPC
F03D 7/00
H02P 9/00
View Original Source