Life Modeling Of Wind Turbine Gearbox Considering The Failure Dependency Between Components

As the main transmission parts of wind turbine, gearboxes’performance is an important aspect on affecting the wind turbine’s life. For wind turbine gearbox, it often leads to excessive error when ignoring system’s failure dependency. In this thesis, choosing1.5MW wind turbine gearbox as the research object, the structure of wind turbine gearbox system was calculated and analyzed in detail. By using Copula function, the failure dependency between components was considered. Through using Sklar theorem and the thought of step by step analysis, the life distribution model of wind turbine gearbox was built based on the relating failure of components.Firstly, the influence of variable wind speed to load and order statistic characteristics were considered. On the basis of the stress-strength interference model life distribution model of mechanical parts was established through the life of loading frequency measure dynamic reliability model of mechanical components.Secondly, based on the design parameters of gears of wind turbine gearbox, the life distribution functions of wind turbine gearbox’s components were obtained by using life distribution model of mechanical parts and calculating the gears tooth surface contact fatigue stress and strength. The parameters of life distribution functions’form for parts of wind turbine gearbox were estimated through using least square method. Then the rule of life distribution functions was determined. The life distribution functions were used as the marginal distribution functions of the wind turbine gearbox’s joint distribution function.Thirdly, according to the corresponding parameters, the corresponding frequency histogram was generated. The appropriate Copula function was chosen according to the shape of the frequency histogram and Copula connect density function’s characteristics. It laid the foundation for building wind turbine gearbox’s life distribution model.Finally, by using Sklar theorem, based on the actual working condition’s parameters of wind turbine gearbox, using the thought of step by step analysis to calculate and analyze the wind turbine gearbox’s system in detail. The life modeling of wind turbine gearbox considering the failure dependency between components was obtained. The life distribution function of wind turbine gearbox dynamic curve change over time was fit out, and the validity of the established life distribution model was tested. On the basis of considering the randomness of load and failure correlation among the components, the characteristics of the gearbox’s life distribution function which change over time was analyzed. Wind turbine gearbox’s life distribution model is established, which provides a new theoretical basis for the analysis of the life of gearbox.