A study on vibration isolation for wind turbine structures

• We demonstrate the use of base isolation in wind turbines, perhaps for the first time.
• Combined wind and seismic simulations are performed.
• Results show that both seismic and wind responses are reduced due to isolation.

This paper discusses the potential use of vibration isolation to reduce the dynamic response of wind turbine structures, with emphasis on structural response to seismic loading. Based on the concept of partial mass isolation, vibration isolators are proposed at the top of the turbine tower, just below the nacelle. The structural idealizations of a wind turbine including a nonlinear isolation system are presented and the responses are simulated using the finite element method. A sample turbine structure is presented and subjected to coherent wind and seismic loading in order to demonstrate the effect of isolation system parameters on the structural response. A parametric study is conducted to study the effect of isolation system parameters on the response of the turbine structure, including the blades. The responses are quantified in terms of several performance indices reflecting the trade-offs associated with implementing an isolation system on flexible structures. Results show that implementing an isolation system may be beneficial for reducing certain key parameters of the turbine’s structural response, and may provide an excellent design option for the design of wind turbines in seismically active parts of the world.