07 Fakultät Konstruktions-, Produktions- und Fahrzeugtechnik
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/8
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Item Open Access Reduced nonlinear model of a spar-mounted floating wind turbine(2012) Sandner, Frank; Schlipf, David; Matha, Denis; Seifried, Robert; Cheng, Po WenFloating offshore wind turbines (FOWTs) are complex dynamic systems requiring a thorough design for optimal operating performance and stability. Advanced control strategies, like model predictive control, are part of the integrated development of new concepts. This paper presents a simplified and computationally efficient model of the spar-mounted OC3-Hywind FOWT. Applications are, e.g., the real-time integration within the controller or an assessment during conceptual design, possibly within an optimization algorithm. Symbolic equations of motion of a multibody system are available as a set of ordinary differential equations. Aerodynamic forces are computed based on a rotor effective wind speed at hub height using data tables for thrust and torque coefficients. Hydrodynamic impacts on the floating body are modeled in a way that only the wave height serves as the disturbance signal. This estimation is based on potential flow theory and Morison’s formula for slender cylinders. The reduced model code is fully compiled and has a real-time factor of approximately 100. Various simulations of common load cases with a comparison to the certified FAST code have shown to be promising.Item Open Access Look-ahead cyclic pitch control using LIDAR(2010) Schlipf, David; Schuler, Simone; Grau, Patrick; Allgöwer, Frank; Kühn, MartinLIDAR (Light detection and ranging) systems are able to provide preview information of wind disturbances at various distances in front of wind turbines. This information can be used to improve the control of wind turbines. This paper compares a predictive feedforward control structure combined with common PI controllers to a baseline controller and to an H∞ approach showing the advantage of look-ahead control to reduce wind turbine loads. The control design is verified by simulations with a turbulent wind field and a full nonlinear model of the wind turbine.