Robust Model Reference Adaptive Control Design for Wind Turbine Speed Regulation Simulated by Using FAST

As the wind turbine structure flexibility is increased with its larger power capacity, the control system plays a more important role in the effective wind energy generation. This paper presents a robust model reference adaptive control (RMRAC) scheme for turbine speed regulation in the high wind speed region. The existing model reference control (MRC) is designed with respect to the linearized turbine dynamics at the selected operating point, and the adaptive law is introduced that is capable of adjusting the MRC parameters continuously to handle the varying system dynamics. In addition to model reference adaptive control (MRAC), disturbance accommodating control (DAC) is introduced to explicitly cancel out wind disturbances. The authors employ a robust modification mechanism, dead zone with dynamic normalization, to further improve the stability and robustness of the RMRAC. The proposed RMRAC scheme is verified using the high-fidelity turbine simulator FAST, which models an actual utility-scale wind turbine, CART3, located at the National Wind Technology Center (NWTC) in the United States. The proposed scheme is fully evaluated and compared to the baseline linear controls under various wind conditions generated by TurbSim. Under RMRAC, simulation results indicate more accurate generator speed and rotor power regulation performance, as well as enhanced robustness of the closed-loop system.