Structural Health Monitoring of the Support Structure of a Wind Turbine Using a Wireless Sensing System

Structural Health Monitoring of the Support Structure of a Wind Turbine Using a Wireless Sensing System

Wind turbines depend heavily on the success of their support structures to resist complicated environmental loading, especially offshore wind turbines. How to manage these wind turbines and monitor their structural safety has become an urgent and important issue today. To monitor the support structural safety of a wind turbine, a good understanding of the structural dynamic behaviors of wind turbines is a preliminary requirement. Due to the complicated dynamic behaviors of realistic wind turbines, which include the effects of the soil-structure interaction(SSI), the machine operation loading, the wind interaction, etc., both numerical model study and system identification are required to clarify these complicated structural behaviors. In this study, a wireless sensing system, NTU-WSU, is installed in an onshore large wind turbine(GE 1.5MW) to collect the structural responses, and the system performance of the proposed NTU-WSU was also evaluated in this study. Three measurement layouts and two operational scenarios(operating and stop states of the wind turbine) are considered in this study to clarify the complicated structural dynamic behaviors. Two system identification approaches are adopted to extract and verify the dynamic structural features, namely the direct Fourier spectrum observation method(FFT) and frequency domain decomposition method(FDD).