Hybrid damper with stroke amplification for damping of offshore wind turbines

Brodersen, Mark Laier; Høgsberg, Jan Becker

doi:10.1002/we.1977

Cited by 17 publications

(16 citation statements)

References 27 publications

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“…This stroke amplification property may increase the feasibility of installing the hybrid viscous damper in a flexible structure at a location with inherently small deformations. The numerical simulations conducted in [11,12] demonstrate the large potential and the performance of the hybrid viscous damper concept, which motivates further analysis of the concept. Thus, as the next step the performance of the hybrid damper should be investigated experimentally to verify the concept and in particular to investigate the influence of the drift in the actuator force observed in [12].…”

Section: Introductionmentioning

confidence: 81%

“…When the actuator motion is controlled using a filtered Integral Force Feedback (IFF) scheme as in [11], the hybrid damper introduces a phase lead between damper force and damper velocity, which leads to increased attainable damping. When instead the filter time constant is set to zero, as in [12], a pure IFF scheme is recovered [13]. The hybrid damper then performs like a viscous damper with the force fully in phase with velocity, but also with the ability to increase the amplitude of the displacement over the viscous dash-pot.…”

Section: Introductionmentioning

confidence: 99%

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Analysis of hybrid viscous damper by real time hybrid simulations

Brodersen¹,

Høgsberg³

et al. 2016

Engineering Structures

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Results from real time hybrid simulations are compared to full numerical simulations for a hybrid viscous damper, composed of a viscous dashpot in series with an active actuator and a load cell. By controlling the actuator displacement via filtered integral force feedback the damping performance of the hybrid viscous damper is improved, while for pure integral force feedback the damper stroke is instead increased. In the real time hybrid simulations viscous damping is emulated by a bang-bang controlled Magneto-Rheological (MR) damper. The controller activates high-frequency modes and generates drift in the actuator displacement, and only a fraction of the measured damper force can therefore be used as input to the investigated integral force feedback in the real time hybrid simulations.

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Section: Introductionmentioning

confidence: 81%

Section: Introductionmentioning

confidence: 99%

Analysis of hybrid viscous damper by real time hybrid simulations

Brodersen¹,

Høgsberg³

et al. 2016

Engineering Structures

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“…A series of real‐time hybrid‐testing (RTHT) have been carried out for performance evaluation of a full‐scale tuned liquid damper on tower side‐side vibration control of multi‐megawatt wind turbines, showing excellent performance of the tuned liquid damper and huge potential of applying RTHT in the area of wind energy. Recently, viscous‐type hybrid dampers are proposed to be installed at the bottom of the fixed‐foundation wind turbine tower, as was also tested by means of RTHT. …”

Section: Introductionmentioning

confidence: 99%

Dynamics and control of spar‐type floating offshore wind turbines with tuned liquid column dampers

Zhang

Høeg

2020

Struct Control Health Monit

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Summary This paper investigates the use of tuned liquid column dampers (TLCDs) for vibration control of spar‐type floating offshore wind turbines (FOWTs). A 17‐degree‐of‐freedom (17‐DOF) aero‐hydro‐servo‐elastic model for the FOWT is first established using multi‐body‐based formulation and the Euler–Lagrangian equation, taking into consideration the full coupling of the blade‐drivetrain‐tower‐spar vibrations, a collective pitch controller and a generator controller. The outputs of the model are compared with FAST for model verification. Next, a reduced‐order 5‐DOF model is established for the TLCD‐controlled FOWT in‐plane vibrations including hydrodynamic added mass as well as stiffness contributions from mooring lines and buoyancy. The model enables revealing the fundamental mechanism of the coupled spar‐tower‐TLCD system, as well as an efficient procedure for optimal design of FOWT‐mounted TLCD. It is found from modal analysis of the spar‐tower system that due to the coupling to the spar roll motion, the tower side–side frequency is significantly shifted comparing with the decoupled case, which needs to be accounted for when tuning the TLCD. Based on the 5‐DOF model, a frequency‐domain (FD) method for TLCD optimization is proposed using random vibration theory, and robust optimization of the TLCD can be performed for given environmental conditions. The optimized damper is then incorporated into the more sophisticated 17‐DOF model, and performance of the TLCD is evaluated by means of nonlinear time‐domain (TD) simulations. Both FD and TD results indicate that a well‐designed TLCD effectively reduces the tower side–side vibration as well as the spar roll motion.

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“…However, it might be very challenging to manufacture a full‐scale steel sphere in practice. Recently, viscous‐type hybrid dampers are proposed to be installed at the bottom of the WT tower . The hybrid damper consists of a passive viscous dashpot placed in series with a load cell and an active actuator, providing superior performance comparing with its passive counterpart.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, viscous-type hybrid dampers are proposed to be installed at the bottom of the WT tower. 14 The hybrid damper consists of a passive viscous dashpot placed in series with a load cell and an active actuator, providing superior performance comparing with its passive counterpart. This device has also been tested by means of real-time hybrid simulations (RTHSs).…”

mentioning

confidence: 99%

Real‐time hybrid aeroelastic simulation of wind turbines with various types of full‐scale tuned liquid dampers

2018

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The present paper presents the real‐time hybrid simulation (RTHS) technique for multimegawatt wind turbine (WT) with various types of full‐scale tuned liquid dampers (TLDs). As an evolvement of the pseudodynamic testing technique, the RTHS is executed in real time, thus allowing accurate investigation of the interaction between the aeroelastic WT system and the rate‐dependent nonlinear TLD device. As the numerical substructure, the WT is simulated in the computer using a 13‐degree‐of‐freedom (13‐DOF) aeroelastic model. As the physical substructure, the full‐scale TLDs are manufactured and physically tested. They are synchronized with each other by real‐time controllers. Taking advantage of RTHS technique, 2‐ and 3‐MW WTs have both been simulated under various turbulent wind conditions. TLDs with different configurations have been extensively investigated, eg, various tuning ratios by varying the water level, TLD without and with damping screens (various mesh sizes of the screen considered), and TLD with flat and sloped bottoms. It is shown that a well‐designed TLD is very effective in damping lateral tower vibrations of WTs. Furthermore, RTHS results and results from a proposed theoretical model are compared. This study gives comprehensive guidelines for employing various types of TLDs in large WTs and indicates huge potentials of applying RTHS technique in the area of wind energy.

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Hybrid damper with stroke amplification for damping of offshore wind turbines

Cited by 17 publications

References 27 publications

Analysis of hybrid viscous damper by real time hybrid simulations

Analysis of hybrid viscous damper by real time hybrid simulations

Dynamics and control of spar‐type floating offshore wind turbines with tuned liquid column dampers

Real‐time hybrid aeroelastic simulation of wind turbines with various types of full‐scale tuned liquid dampers

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