Dynamic Response Computation of a Wind Turbine Gearbox Under Variable Speed Conditions and its Experimental Validation

Abstract

Purpose: Computation of dynamic response of wind turbine gearbox (WTG) under variable speed conditions is challenging as the mesh stiffness periods vary with speed. Therefore, the purpose of this research is to develop an algorithm that can compute the mesh stiffness function under variable speeds. Methods: In this paper, a time-varying mesh stiffness (TVMS) algorithm is presented to compute the dynamic response of a WTG under variable speed. A TVMS function-containing variable mesh periods is established based on the proposed algorithm. The TVMS obtained is thus incorporated into the dynamic model of a three-stage WTG, and the response is computed numerically using the Newmark beta method. Results: The results show that the dynamic model successfully generates the vibration signals with variable gear mesh frequencies corresponding to speed variation, which can be visualized appropriately in the time–frequency representation (TFR). Comparing constant and variable speed dynamic responses reveals that WTG dynamics significantly change with variable speed. Conclusion: The frequency domain plots are inadequate for vibration response analysis of WTG under variable speed and may lead to misidentification of frequencies. The presented algorithm offers an easy and robust way to build mesh stiffness function under variable speed conditions. The variation in the gear mesh frequency observed in the TFR follows the speed variations. The results obtained through the experimental investigation agree well with the simulated one. © 2022, Krishtel eMaging Solutions Private Limited.