@article{GeorgHeydeSchulte, author = {Georg, S{\"o}ren and Heyde, Stefan and Schulte, Horst}, title = {Sensor Fault-Tolerant Control of a Drivetrain Test Rig via an Observer-Based Approach within a Wind Turbine Simulation Model}, volume = {570}, number = {8}, issn = {1742-6596}, doi = {10.1088/1742-6596/570/8/082004}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:523-15538}, pages = {1 -- 11}, abstract = {This paper presents the implementation of an observer-based fault reconstruction and fault-tolerant control scheme on a rapid control prototyping system. The observer runs in parallel to a dynamic wind turbine simulation model and a speed controller, where the latter is used to control the shaft speed of a mechanical drivetrain according to the calculated rotor speed obtained from the wind turbine simulation. An incipient offset fault is added on the measured value of one of the two speed sensors and is reconstructed by means of a Takagi-Sugeno sliding-mode observer. The reconstructed fault value is then subtracted from the faulty sensor value to compensate for the fault. The whole experimental set-up corresponds to a sensor-in-the-loop system.}, subject = {Windturbine}, language = {en} } @article{GeorgMuellerSchulte, author = {Georg, S{\"o}ren and M{\"u}ller, Matthias and Schulte, Horst}, title = {Wind Turbine Model and Observer in Takagi-Sugeno Model Structure}, volume = {555}, number = {1}, issn = {1742-6596}, doi = {10.1088/1742-6596/555/1/012042}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:523-15528}, pages = {1 -- 10}, abstract = {Based on a reduced-order, dynamic nonlinear wind turbine model in Takagi- Sugeno (TS) model structure, a TS state observer is designed as a disturbance observer to estimate the unknown effective wind speed. The TS observer model is an exact representation of the underlying nonlinear model, obtained by means of the sector-nonlinearity approach. The observer gain matrices are obtained by means of a linear matrix inequality (LMI) design approach for optimal fuzzy control, where weighting matrices for the individual system states and outputs are included. The observer is tested in simulations with the aero-elastic code FAST for the NREL 5 MW reference turbine, where it shows a stable behaviour in turbulent wind simulations.}, subject = {Windturbine}, language = {en} } @article{SchulteGeorg, author = {Schulte, Horst and Georg, S{\"o}ren}, title = {Nonlinear Control of Wind Turbines with Hydrostatic Transmission Based on Takagi-Sugeno Model}, volume = {524}, number = {1}, issn = {1742-6596}, doi = {10.1088/1742-6596/524/1/012085}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:523-15502}, pages = {1 -- 8}, abstract = {A nonlinear model-based control concept for wind turbines with hydrostatic transmission is proposed. The complete mathematical model of a wind turbine drive train with variable displacement pump and variable displacement motor is presented. The controller design takes into consideration the nonlinearity of the aerodynamic maps and hydrostatic drive train by an convex combination of state space controller with measurable generator speed and hydraulic motor displacement as scheduling parameters. The objectives are the set point control of generator speed and tracking control of the rotor speed to reach the maximum power according to the power curve in the partial-load region.}, subject = {Windturbine}, language = {en} } @article{BernickeGauterinSchulteetal., author = {Bernicke, Olaf and Gauterin, Eckhard and Schulte, Horst and Zajac, Michal}, title = {Control Engineering Analysis of Mechanical Pitch Systems}, volume = {555}, number = {1}, issn = {1742-6596}, doi = {10.1088/1742-6596/555/1/012009}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:523-15516}, pages = {1 -- 10}, abstract = {With the help of a local stability analysis the coefficient range of a discrete damper, used for centrifugal forced, mechanical pitch system of small wind turbines (SWT), is gained for equilibrium points. - By a global stability analysis the gained coefficient range can be validated. An appropriate approach by Takagi-Sugeno is presented in the paper.}, subject = {Windturbine}, language = {en} } @article{GauterinSchulteGeorg, author = {Gauterin, Eckhard and Schulte, Horst and Georg, S{\"o}ren}, title = {Disturbance Compensation by Wind Speed Reconstruction based on a Takagi-Sugeno Wind Turbine Model}, volume = {524}, number = {1}, issn = {1742-6596}, doi = {10.1088/1742-6596/524/1/012072}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:523-15497}, pages = {1 -- 10}, abstract = {In this work, the nonlinear Tagaki-Sugeno modelling method is utilised to set up an observer-based feed-forward control scheme for wind turbines, which can compensate for the influence of the disturbing wind variation on the rotational speed. The applied scheme leads to a reduced thrust force acting on the rotor.}, subject = {Windturbine}, language = {en} } @article{GeorgSchulte, author = {Georg, S{\"o}ren and Schulte, Horst}, title = {Fault-Tolerant Control of Wind Turbines using a Takagi-Sugeno Sliding Mode Observer}, volume = {524}, number = {1}, issn = {1742-6596}, doi = {10.1088/1742-6596/524/1/012053}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:523-15485}, pages = {1 -- 10}, abstract = {In this paper, observer-based fault-tolerant control schemes for actuator and sensor faults are implemented within dynamic wind turbine simulations. The faults are directly reconstructed by means of a Takagi-Sugeno sliding mode observer. As simulation models, both a reduced-order model with 4 degrees of freedom and the aero-elastic code FAST by NREL are used. A fault-tolerant control scheme is set up by subtracting the reconstructed fault from the faulty control signal respectively sensor value. With these fault compensation schemes, the corrected controller behaviour is close to the fault-free case. The global stability of the controller in the full-load region in the presence of faults and with active fault compensation is shown by analysing the derivative of an appropriate Lyapunov function.}, subject = {Windturbine}, language = {en} }