The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Thomas Buhl - One of the best experts on this subject based on the ideXlab platform.
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full scale test of trailing edge flaps on a vestas v27 wind turbine active load reduction and system identification
Wind Energy, 2014Co-Authors: Damien Castaignet, Thomas Buhl, Jens Jakob Wedelheinen, Niels Kjolstad Poulsen, Thanasis K Barlas, Niels Anker Olesen, Christian Bak, Taeseong KimAbstract:A full-scale test was performed on a Vestas V27 wind turbine equipped with one active 70 cm long trailing edge flap on one of its 13 m long Blades. Active load reduction could be observed in spite of the limited spanwise coverage of the single active trailing edge flap. A frequency-weighted model predictive control was tested successfully on this demonstrator turbine. An average flapwise Blade Root load reduction of 14% was achieved during a 38 minute test, and a reduction of 20% of the amplitude of the 1P loads was measured. A system identification test was also performed, and an identified linear model, from trailing edge flap angle to flapwise Blade Root moment, was derived and compared with the linear analytical model used in the model predictive control design model. Flex5 simulations run with the same model predictive control showed a good correlation between the simulations and the measurements in terms of flapwise Blade Root moment spectral densities, in spite of significant differences between the identified linear model and the model predictive control design model. Copyright © 2013 John Wiley & Sons, Ltd.
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Model Predictive Control of Trailing Edge Flaps on a wind turbine Blade
2014Co-Authors: Damien Castaignet, Thomas Buhl, Niels Kjolstad Poulsen, Jens Jakob Wedel-heinenAbstract:Trailing Edge Flaps on wind turbine Blades have been studied in order to achieve fatigue load reduction on the turbine components. We show in this paper how Model Predictive Control can be used to do frequency weighted control of the trailing edge flaps in order to reduce fatigue damage on the Blade Root. The design model is based on a modal model of the Blade structure and a steady state aerodynamic model of the Blade airfoils. Depending on the output filter, loads within different frequency range are decreased. A fine tuning of the Kalman filter and of the cost function allows to decrease significantly the Blade Root loads without damaging excessively the trailing edge flap actuators.
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frequency weighted model predictive control of trailing edge flaps on a wind turbine Blade
IEEE Transactions on Control Systems and Technology, 2013Co-Authors: Damien Castaignet, Thomas Buhl, Ian Couchman, Niels Kjolstad Poulsen, Jens Jakob WedelheinenAbstract:This paper presents the load reduction achieved with trailing edge flaps during a full-scale test on a Vestas V27 wind turbine. The trailing edge flap controller is a frequency-weighted linear model predictive control (MPC) where the quadratic cost consists of costs on the zero-phase filtered flapwise Blade Root moment and trailing edge flap deflection. Frequency-weighted MPC is chosen for its ability to handle constraints on the trailing edge flaps deflection, and to target at loads with given frequencies only. The controller is first tested in servo-aeroelastic simulations, before being implemented on a Vestas V27 wind turbine. Consistent load reduction is achieved during the full-scale test. An average of 13.8% flapwise Blade Root fatigue load reduction is measured.
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deformable trailing edge flaps for modern megawatt wind turbine controllers using strain gauge sensors
Wind Energy, 2010Co-Authors: Peter Bjorn Andersen, Christian Bak, Lars Christian Henriksen, Mac Gaunaa, Thomas BuhlAbstract:The present work contains a deformable trailing edge flap controller integrated in a numerically simulated modern, variablespeed, pitch-regulated megawatt (MW)-size wind turbine. The aeroservoelastic multi-body code HAWC2 acts as a component in the control loop design. At the core of the proposed controller, all unsteady loads are divided by frequency content. Blade pitching and generator moment react to low-frequency excitations, whereas flaps deal with high-frequency excitations. The present work should be regarded as an investigation into the fatigue load reduction potential when applying trailing edge flaps on a wind turbine Blade rather than a conclusive control design with traditional issues like stability and robustness fully investigated. Recent works have shown that the fatigue load reduction by use of trailing edge flaps may be greater than for traditional pitch control methods. By enabling the trailing edge to move independently and quickly along the spanwise position of the Blade, local small flutuations in the aerodynamic forces can be alleviated by deformation of the airfoil flap. Strain gauges are used as input for the flap controller, and the effect of placing strain gauges at various radial positions on the Blade is investigated. An optimization routine minimizes Blade Root fatigue loads. Calculations are based on the 5 MW reference wind turbine part of the UpWind project primarily with a mean turbulent wind speed close to rated power. A fatigue load reduction of 25% in the Blade Root moment was obtained for a continuous 6.3 m long flap. Copyright © 2009 John Wiley & Sons, Ltd.
Damien Castaignet - One of the best experts on this subject based on the ideXlab platform.
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full scale test of trailing edge flaps on a vestas v27 wind turbine active load reduction and system identification
Wind Energy, 2014Co-Authors: Damien Castaignet, Thomas Buhl, Jens Jakob Wedelheinen, Niels Kjolstad Poulsen, Thanasis K Barlas, Niels Anker Olesen, Christian Bak, Taeseong KimAbstract:A full-scale test was performed on a Vestas V27 wind turbine equipped with one active 70 cm long trailing edge flap on one of its 13 m long Blades. Active load reduction could be observed in spite of the limited spanwise coverage of the single active trailing edge flap. A frequency-weighted model predictive control was tested successfully on this demonstrator turbine. An average flapwise Blade Root load reduction of 14% was achieved during a 38 minute test, and a reduction of 20% of the amplitude of the 1P loads was measured. A system identification test was also performed, and an identified linear model, from trailing edge flap angle to flapwise Blade Root moment, was derived and compared with the linear analytical model used in the model predictive control design model. Flex5 simulations run with the same model predictive control showed a good correlation between the simulations and the measurements in terms of flapwise Blade Root moment spectral densities, in spite of significant differences between the identified linear model and the model predictive control design model. Copyright © 2013 John Wiley & Sons, Ltd.
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Model Predictive Control of Trailing Edge Flaps on a wind turbine Blade
2014Co-Authors: Damien Castaignet, Thomas Buhl, Niels Kjolstad Poulsen, Jens Jakob Wedel-heinenAbstract:Trailing Edge Flaps on wind turbine Blades have been studied in order to achieve fatigue load reduction on the turbine components. We show in this paper how Model Predictive Control can be used to do frequency weighted control of the trailing edge flaps in order to reduce fatigue damage on the Blade Root. The design model is based on a modal model of the Blade structure and a steady state aerodynamic model of the Blade airfoils. Depending on the output filter, loads within different frequency range are decreased. A fine tuning of the Kalman filter and of the cost function allows to decrease significantly the Blade Root loads without damaging excessively the trailing edge flap actuators.
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frequency weighted model predictive control of trailing edge flaps on a wind turbine Blade
IEEE Transactions on Control Systems and Technology, 2013Co-Authors: Damien Castaignet, Thomas Buhl, Ian Couchman, Niels Kjolstad Poulsen, Jens Jakob WedelheinenAbstract:This paper presents the load reduction achieved with trailing edge flaps during a full-scale test on a Vestas V27 wind turbine. The trailing edge flap controller is a frequency-weighted linear model predictive control (MPC) where the quadratic cost consists of costs on the zero-phase filtered flapwise Blade Root moment and trailing edge flap deflection. Frequency-weighted MPC is chosen for its ability to handle constraints on the trailing edge flaps deflection, and to target at loads with given frequencies only. The controller is first tested in servo-aeroelastic simulations, before being implemented on a Vestas V27 wind turbine. Consistent load reduction is achieved during the full-scale test. An average of 13.8% flapwise Blade Root fatigue load reduction is measured.
Jens Jakob Wedelheinen - One of the best experts on this subject based on the ideXlab platform.
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full scale test of trailing edge flaps on a vestas v27 wind turbine active load reduction and system identification
Wind Energy, 2014Co-Authors: Damien Castaignet, Thomas Buhl, Jens Jakob Wedelheinen, Niels Kjolstad Poulsen, Thanasis K Barlas, Niels Anker Olesen, Christian Bak, Taeseong KimAbstract:A full-scale test was performed on a Vestas V27 wind turbine equipped with one active 70 cm long trailing edge flap on one of its 13 m long Blades. Active load reduction could be observed in spite of the limited spanwise coverage of the single active trailing edge flap. A frequency-weighted model predictive control was tested successfully on this demonstrator turbine. An average flapwise Blade Root load reduction of 14% was achieved during a 38 minute test, and a reduction of 20% of the amplitude of the 1P loads was measured. A system identification test was also performed, and an identified linear model, from trailing edge flap angle to flapwise Blade Root moment, was derived and compared with the linear analytical model used in the model predictive control design model. Flex5 simulations run with the same model predictive control showed a good correlation between the simulations and the measurements in terms of flapwise Blade Root moment spectral densities, in spite of significant differences between the identified linear model and the model predictive control design model. Copyright © 2013 John Wiley & Sons, Ltd.
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frequency weighted model predictive control of trailing edge flaps on a wind turbine Blade
IEEE Transactions on Control Systems and Technology, 2013Co-Authors: Damien Castaignet, Thomas Buhl, Ian Couchman, Niels Kjolstad Poulsen, Jens Jakob WedelheinenAbstract:This paper presents the load reduction achieved with trailing edge flaps during a full-scale test on a Vestas V27 wind turbine. The trailing edge flap controller is a frequency-weighted linear model predictive control (MPC) where the quadratic cost consists of costs on the zero-phase filtered flapwise Blade Root moment and trailing edge flap deflection. Frequency-weighted MPC is chosen for its ability to handle constraints on the trailing edge flaps deflection, and to target at loads with given frequencies only. The controller is first tested in servo-aeroelastic simulations, before being implemented on a Vestas V27 wind turbine. Consistent load reduction is achieved during the full-scale test. An average of 13.8% flapwise Blade Root fatigue load reduction is measured.
Niels Kjolstad Poulsen - One of the best experts on this subject based on the ideXlab platform.
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full scale test of trailing edge flaps on a vestas v27 wind turbine active load reduction and system identification
Wind Energy, 2014Co-Authors: Damien Castaignet, Thomas Buhl, Jens Jakob Wedelheinen, Niels Kjolstad Poulsen, Thanasis K Barlas, Niels Anker Olesen, Christian Bak, Taeseong KimAbstract:A full-scale test was performed on a Vestas V27 wind turbine equipped with one active 70 cm long trailing edge flap on one of its 13 m long Blades. Active load reduction could be observed in spite of the limited spanwise coverage of the single active trailing edge flap. A frequency-weighted model predictive control was tested successfully on this demonstrator turbine. An average flapwise Blade Root load reduction of 14% was achieved during a 38 minute test, and a reduction of 20% of the amplitude of the 1P loads was measured. A system identification test was also performed, and an identified linear model, from trailing edge flap angle to flapwise Blade Root moment, was derived and compared with the linear analytical model used in the model predictive control design model. Flex5 simulations run with the same model predictive control showed a good correlation between the simulations and the measurements in terms of flapwise Blade Root moment spectral densities, in spite of significant differences between the identified linear model and the model predictive control design model. Copyright © 2013 John Wiley & Sons, Ltd.
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Model Predictive Control of Trailing Edge Flaps on a wind turbine Blade
2014Co-Authors: Damien Castaignet, Thomas Buhl, Niels Kjolstad Poulsen, Jens Jakob Wedel-heinenAbstract:Trailing Edge Flaps on wind turbine Blades have been studied in order to achieve fatigue load reduction on the turbine components. We show in this paper how Model Predictive Control can be used to do frequency weighted control of the trailing edge flaps in order to reduce fatigue damage on the Blade Root. The design model is based on a modal model of the Blade structure and a steady state aerodynamic model of the Blade airfoils. Depending on the output filter, loads within different frequency range are decreased. A fine tuning of the Kalman filter and of the cost function allows to decrease significantly the Blade Root loads without damaging excessively the trailing edge flap actuators.
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frequency weighted model predictive control of trailing edge flaps on a wind turbine Blade
IEEE Transactions on Control Systems and Technology, 2013Co-Authors: Damien Castaignet, Thomas Buhl, Ian Couchman, Niels Kjolstad Poulsen, Jens Jakob WedelheinenAbstract:This paper presents the load reduction achieved with trailing edge flaps during a full-scale test on a Vestas V27 wind turbine. The trailing edge flap controller is a frequency-weighted linear model predictive control (MPC) where the quadratic cost consists of costs on the zero-phase filtered flapwise Blade Root moment and trailing edge flap deflection. Frequency-weighted MPC is chosen for its ability to handle constraints on the trailing edge flaps deflection, and to target at loads with given frequencies only. The controller is first tested in servo-aeroelastic simulations, before being implemented on a Vestas V27 wind turbine. Consistent load reduction is achieved during the full-scale test. An average of 13.8% flapwise Blade Root fatigue load reduction is measured.
Leonardo Bergami - One of the best experts on this subject based on the ideXlab platform.
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high fidelity linear time invariant model of a smart rotor with adaptive trailing edge flaps
Wind Energy, 2017Co-Authors: Leonardo Bergami, Morten Hartvig HansenAbstract:A high-fidelity linear time-invariant model of the aero-servo-elastic response of a wind turbine with trailing-edge flaps is presented and used for systematic tuning of an individual flap controller. The model includes the quasi-steady aerodynamic effects of trailing-edge flaps on wind turbine Blades and is integrated in the linear aeroelastic code HAWCStab2. The dynamic response predicted by the linear model is validated against non-linear simulations, and the quasi-steady assumption does not cause any significant response bias for flap deflection with frequencies up to 2–3 Hz. The linear aero-servo-elastic model support the design, systematic tuning and model synthesis of smart rotor control systems. As an example application, the gains of an individual flap controller are tuned using the Ziegler–Nichols method for the full-order poles. The flap controller is based on feedback of inverse Coleman transformed and low-pass filtered flapwise Blade Root moments to the cyclic flap angles through two proportional-integral controllers. The load alleviation potential of the active flap control, anticipated by the frequency response of the linear closed-loop model, is also confirmed by non-linear time simulations. The simulations report reductions of lifetime fatigue damage up to 17% at the Blade Root and up to 4% at the tower bottom. Copyright © 2016 John Wiley & Sons, Ltd.
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a smart rotor configuration with linear quadratic control of adaptive trailing edge flaps for active load alleviation
Wind Energy, 2015Co-Authors: Leonardo BergamiAbstract:The paper proposes a smart rotor configuration where Adaptive Trailing Edge Flaps (ATEF) are employed for active alleviations of the aerodynamic loads on the Blades of the NREL 5 MW reference turbine. The flaps extend for 20 % of the Blade length, and are controlled by a Linear Quadratic (LQ) algorithm based on measurements of the Blade Root flapwise bending moment. The control algorithm includes frequency weighting to discourage flap activity at frequencies higher than 0.5 Hz. The linear model required by the LQ algorithm is obtained from subspace system identification; periodic disturbance signals described by simple functions of the Blade azimuthal position are included in the identification to avoid biases from the periodic load variations observed on a rotating Blade. The LQ controller uses the same periodic disturbance signals to handle anticipation of the loads periodic component. The effects of active flap control are assessed with aeroelastic simulations of the turbine in normal operation conditions, as prescribed by the IEC standard. The turbine lifetime fatigue damage equivalent loads provide a convenient summary of the results achieved with ATEF control: a 10 % reduction of the Blade Root flapwise bending moment is reported in the simplest control configuration, whereas reductions of approximately 14 % are achieved by including periodic loads anticipation. The simulations also highlight impacts on the fatigue damage loads in other parts of the structure, in particular, an increase of the Blade torsion moment, and a reduction of the tower fore-aft loads.