Smart Novel Semi-Active Tuned Mass Damper for Fixed-Bottom and Floating Offshore Wind

Abstract

The intention of this paper is to present the results of a novel smart semi-active tuned mass damper (SA-TMD), which mitigates unwanted loads for both fixed-bottom and floating offshore wind systems. The paper will focus on the most challenging water depths for both fixed-bottom and floating systems. A close to 38m Monopile and 55m Tension Leg Platform (TLP) will be considered. A technical development and trade-off analysis will be presented comparing the new system with existing passive non-linear TMD (N-TMD) technology and semi-active. The SA-TMD works passively and activates itself with low power source under unwanted dynamic loading in less than 60msec. It is composed of both variable stiffness and damping elements coupled to a central pendulum mass. The analysis has been done numerically in both FAST (NREL) and Orcaflex (Orcina), and integrated in the Wind Turbine system employing CAD/CAE. The results of this work will pave the way for experimental testing to complete the technology qualification process. The load reductions under extreme and fatigue cases reach up significant levels at tower base, consequently reducing LCOE for fixed-bottom to floating wind solutions. The nacelle acceleration is reduced substantially under severe random wind and sea states, reducing the risks of failure of electromechanical components and blades at the rotor nacelle assembly. The SA-TMD system is a new technology that has not been applied previously in wind solutions. Structural damping devices aim to increase offshore wind turbine system robustness and reliability, which eases multiple substructures installations and global stability.

An investigation on the impacts of passive and semiactive structural control on a fixed bottom and a floating offshore wind turbine

“…Wind speed distribution and wind/wave misalignment probability for each wind speed . [Colour figure can be viewed at wileyonlinelibrary.com]…”

“…GE Haliade 1 * 150‐6 MW on top of a Pelastar TLP and an assessment of floating substructures . [Colour figure can be viewed at wileyonlinelibrary.com]…”

Platform stabilization and load reduction of floating offshore wind turbines with tension‐leg platform using dynamic vibration absorbers

“…Nihei et al conclude that the TLP shows the best performance by experimental evaluations for four platforms using scaled models . Despite its good performance in suppressing tower load increase, there remains room for TLP to further decrease the tower loads by deploying actively controlled dynamic vibration absorbers (DVAs) on the platform or the semiactive TMD in the nacelle . The advantages of using DVAs for platform motion stabilization include simplicity in structural design, cost‐effectiveness in deployment, and consistency in performance with properly designed controllers.…”

“…32 Despite its good performance in suppressing tower load increase, there remains room for TLP to further decrease the tower loads by deploying actively controlled dynamic vibration absorbers (DVAs) on the platform or the semiactive TMD in the nacelle. 27,33,34 The advantages of using DVAs for platform motion stabilization include simplicity in structural design, cost-effectiveness in deployment, and consistency in performance with properly designed controllers. In addition, installation of DVAs at the spokes of TLP, rather than inside the platform or tower top, requires limited modifications to the platform or wind turbine.…”

Vibration control in wind turbines to achieve desired system-level performance under single and multiple hazard loadings

“…Wind turbines are already installed with power electronic devices; therefore, it is easy to control blade and tower vibrations by the use of power electronics‐based controllers as it does not need any additional installations . For the comparison of the passive and semiactive TMDs in terms of performance, dissipated energy and TMD stroke refer to Rezaee and Aly and Tsouroukdissian et al…”