Impact of terrain on inflow factors and wind turbine vibrational responses: Insight from SCADA data and wind tunnel tests

The operational environment of wind turbines is complex, with vibrations induced by intricate wind conditions significantly affecting their efficiency, lifespan, and maintenance costs. This paper conducts a comprehensive study on the vibration responses of wind turbines in relation to their operational environments, using elevation information and Supervisory Control and Data Acquisition data from 16 wind turbines in a mountainous wind farm. A detailed analysis of terrain complexity and its impact on inflow factors reveals that terrain complexity significantly impacts inflow factors, particularly wind shear and turbulence intensity, thereby affecting turbine vibration responses. Using correlation analysis, we assessed the relationship between terrain complexity and inflow factors and subsequently between inflow factors and vibration acceleration. The results indicate that terrain has the greatest impact on wind shear, which is identified as the primary controlling factor for turbine vibration acceleration. Additionally, five atmospheric boundary layer wind fields were designed for wind tunnel experiments to further study the impact of complex inflow conditions on turbine vibrations. Experimental results indicate that wind shear leads to a significant increase in peak acceleration compared to conditions without wind shear. These findings highlight the importance of understanding terrain-inflow interactions for wind turbine's healthy operations in mountainous areas.