Study on Stability and Reliability of Wind Turbine Transmission Chain under the Coupling of Multiple Physical Fields

The transmission chain of wind turbine has been subjected to the coupling effect of mechanical, electromagnetic, thermal and fluid fields for a long time in complex service environment. It is difficult to reveal its nonlinear failure mechanism by traditional single field analysis method, which restricts the improvement of system stability and reliability. In this paper, the stability and reliability of wind turbine transmission chain under the coupling of multiple physical fields are systematically studied, and a mechanical-electromagnetic-thermal-fluid four-field coupling dynamic model is constructed to quantify the influence law of coupling effect on the dynamic response of transmission chain. A stability evaluation framework based on digital twinning is proposed, which integrates high fidelity simulation, real-time monitoring and machine learning to realize dynamic mapping of multi-field States and early fault warning. Further facing the whole life cycle, the collaborative optimization of structural topology optimization, electromagnetic parameter matching and intelligent lubrication regulation is carried out, which significantly improves the robustness of transmission chain under variable load conditions. The experimental results show that the vibration amplitude of the optimized system is reduced by 33.3%, the torque fluctuation coefficient is reduced by 38.8%, and the maximum temperature rise is reduced by 18.5%. The model prediction is highly consistent with the measured data, which verifies the effectiveness and engineering applicability of the proposed method. The research provides theoretical support and technical path for multi-field coupling analysis and reliability design of wind turbine transmission chain.