An automatic ridge estimation method for tacholess order tracking of wind turbine gearbox under varying-speed operation

The most widely used method for instantaneous shaft speed estimation of wind turbine gearboxes is based on time-frequency ridge estimation. However, this method requires parameter adjustment and expert knowledge to ensure accurate ridge estimation, which significantly reduces its effectiveness in practical applications. In this paper, we propose an end-to-end automated ridge estimating (ARE) method to address this limitation. The ARE method utilizes the inherent harmonic relationship in the vibration signal of wind turbine gearboxes to construct a selection index for automatically identifying the target ridge with clear physical meaning. Additionally, we propose a sub-region division strategy to mitigate the interference from other components and improve computational efficiency. Furthermore, we introduce a parameter-free objective function that considers both the amplitude and smoothness of the ridge to achieve accurate ridge estimation. To validate the performance of the ARE method, we collected vibration signals from different wind turbine gearboxes on-site. The experimental results demonstrate that the ARE method achieves automatic estimation of the ridge and outperforms other methods in terms of accuracy and computational efficiency.