Adaptive Disturbance Tracking Control for Large Horizontal Axis Wind Turbines with Disturbance Estimator in Region II Operation

A new control problem called Disturbance Tracking Control (DTC), which arises in active control of variable speed horizontal axis wind turbines for electric power generation, was developed previously. Feedback control of a linear plant, which is persistently disturbed, must cause the plant output to track a linear function of the disturbance. This control theory is related to Tip Speed Ratio Tracking for wind turbines operating in Region II. The DTC approach was developed for fixed gain controllers where the parameters of the turbine are very well known. An adaptive version of the DTC Theory for turbines with poorly known parameters was developed previously. However, the adaptive DTC needs measurement of actual wind speed. In this paper we augmented a wind speed estimator and apply the theory to create an adaptive tip speed ratio tracking controller for a horizontal axis wind turbine generator based upon a model of the NREL Controls Advanced Research Turbine (CART).