A wind speed estimation method using adaptive Kalman filtering for a variable speed stall regulated wind turbine

This paper presents a method for the estimation of the effective wind speed acting on the rotor of a wind turbine in order to be used for the control of a variable speed stall regulated wind turbine. The estimation algorithm consists of a Kalman filter, estimating the aerodynamic torque acting on the rotor of the turbine, and a Newton-Raphson method, which derives the effective wind speed from the aerodynamic torque. The Kalman filter is enhanced with adaptive algorithms that estimate the unknown covariances of the measurement and process noise respectively, keeping the filter continuously tuned close to its optimal behavior. The presented algorithm and results are based on a full model of a wind turbine, which entails the presence of two flexible shafts and three moments of inertia. From software and hardware simulation results it can be seen that the method is quite promising.