Short-term damping estimation for wind turbine whirling modes

Estimating the effective damping ratios of edgewise whirling modes for large multi-megawatt wind turbines from vibration measurements remains challenging, in part because such damping ratios can be sensitive to changes in environmental and operational conditions. This study presents and tests a method for short-term damping (and natural frequency) estimation, e.g., for wind turbine whirling modes. The proposed method leverages advanced time series modelling, which captures short-term variability by conditioning model coefficients on measured environmental and operational parameters. The method is tested by estimating the damping ratios and natural frequencies of whirling modes from simulation data resembling a Siemens Gamesa SG 10.0-193 DD wind turbine in normal operation. The study demonstrates that the proposed short-term damping estimation method can provide accurate whirling mode damping estimates in the absence of intermittent resonant nP (e.g., 3P or 6P) excitation.