Seismic response mitigation of a wind turbine via inerter-based structural control

This paper studies the application of the inerter-based passive structural control in seismic response mitigation for a wind turbine. The inerter-based passive control system used here is called inerter-based dynamic vibration absorber (IDVA), in which a spring and an inerter-based mechanical network are connected in parallel. A multi-degree-of-freedom (MDOF) system is used to describe the wind turbine system with the consideration of the interaction between wind turbine structure and soil. For the purpose of mitigating seismic response, the inerter-based mechanical network is regarded as a controller to be designed using two different methods. Then, a variety of different network configurations are selected in the fixed-structure method, and only the low-order admittances are taken into account in the network synthesis method. By optimizing the controller parameters with H-2 optimization method, response parameters such as tower-top displacement are improved. The comparisons of the tower-top displacement performance corresponding to the traditional tuned mass damper (TMD) and the inerter-based dynamic vibration absorbers (IDVAs) show that the inerter-based control can use a smaller additional mass ratio to achieve the same tower-top displacement performance as the TMD control. Finally, the numerical simulation results obtained with different types of ground motions for a 5-MW NREL wind turbine also demonstrate the superiority of IDVAs compared to TMD, and a similar decreasing trend is observed for tower-top displacement performance and tower bottom bending moment performance.