Adaptive bidirectional dynamic response control of offshore wind turbines with time‐varying structural properties

Abstract

Wind, wave and seismic loading induced excessive vibration of offshore wind turbines (OWTs) impairs the wind turbine energy output and escalates its fatigue damage. The present study proposes a three-dimensional adaptive pendulum tuned mass damper (3D-APTMD) to control the bidirectional dynamic responses of monopile OWTs exposed to combined wind, wave, seismic loading, and time-varying structural properties. In terms of the proposed adaptive tuning algorithm, the natural frequency and damping property of the 3D-APTMD are tuned in real time to match the wind turbine time-varying dominant frequency caused by environmental and/or structural property variations. Performance of the developed adaptive damper is examined on a monopile 5-MW (megawatt) baseline wind turbine subjected to representative wind, wave, and seismic loading. Time-varying stiffness of the tower and foundation is introduced to simulate damage evolution during service life. A threedimensional pendulum tuned mass damper (3D-PTMD) and dual linear TMDs (2TMD) are used for comparison. Research results show that when damage occurs, 3D-PTMD and 2TMD become partially off-tuned and less effective. In comparison, the 3D-APTMD which is tuned in real time maintains its effectiveness. It can improve the reduction effect by around 25% and 30% when compared with the 3D-PTMD and 2TMD, respectively. Therefore, the proposed 3D-APTMD is promising for real application to protect OWTs, high-rise buildings, chimneys, and other types of slender structures suffering from excessive bidirectional vibration, and environmental, operational, and/or structural property variations. K E Y W O R D Sbidirectional dynamic response control, offshore wind turbines, three-dimensional adaptive pendulum tuned mass damper, time-varying structural property, wind, wave, and seismic loading | INTRODUCTIONTo protect the deteriorating environment, wind energy production and consumption have been growing exponentially since 2000. In the passed decade, numerous offshore wind farms have been constructed in Europe, China, and the United States. Nowadays, offshore wind farms are becoming increasingly popular due to the advantages including

Three-Dimensional Prestressed Tuned Mass Damper for Passive Vibration Control of Coupled Multiple DOFs Offshore Wind Turbine

“…where v nf and v ns are the absolute generalized velocities of nacelle in F-A and S-S directions, respectively. As shown in Figure 3, the absolute generalized displacements of the infnitesimal unit dr of the blade in the Oxyz coordinate system can be obtained from equation (2) and the local coordinate transformation of the blade as x bej � x ns + r sin θ bj + q j φ bej cos θ bj ,…”

“…Te ofshore wind turbine (OWT) has become more popular in recent years due to advantages of being a cheap energy source, less visual impact, low noisy problem, and without land requirement [1]. Taller and slender large-megawatts OWTs have been constructed ofshore [2] to capture more energy. However, the steel OWT structure has a long vibration period and light damping which make it more vulnerable to signifcant vibrations caused by wind or waves [3].…”

A novel two dimensional nonlinear tuned mass damper inerter and its application in vibration mitigation of wind turbine blade

“…The 3d-PTMD is a passive controller and it might lose its effectiveness in the presence of system and environmental variations. Therefore, Sun et al [22] proposed using a three-dimensional adaptive pendulum TMD (3d-APTMD) to control the bi-directional responses of the tower under time-varying structural properties. The authors compared the effectiveness of the 3d-APTMD with 3d-PTMD and concluded that the 3d-APTMD is more effective in reducing the tower vibrations in the presence of structural property variations.…”

Bi‐tuned semi‐active TMDs: Multi‐hazard design for tall buildings using gradient‐based optimization

“…Most studies on STMDs compare the semi‐active dampers with their passive counterparts and demonstrate the extraordinary capacity of these devices. Additionally, the semi‐active protection based on variable stiffness and damping ratio has been recently proposed for the multi‐hazard control of offshore wind turbines 64,65 . However, no specific STMD has been suggested, to the best of our knowledge, for multi‐hazard purposes applied to buildings.…”

“…Additionally, the semi-active protection based on variable stiffness and damping ratio has been recently proposed for the multi-hazard control of offshore wind turbines. 64,65 However, no specific STMD has been suggested, to the best of our knowledge, for multi-hazard purposes applied to buildings. Additionally, these devices require competent control algorithms governing their properties variation, and reliable systems of sensors and frequency identification.…”