Reliability Evaluation Of Wind Turbine Gearbox Based On Multiple Performance Degradation

Due to the bad working conditions,the gearbox failure of wind turbine is frequent.Most wind turbines do not last nearly their designed lives without any failure.Most wind turbines do not continue to operate beyond their designed life without any problems.To reduce the maintenance cost of the gearbox,it is necessary to analyze the variation of its reliability with time.This paper mainly analyzes the performance degradation of highspeed shaft gear and lubricating oil in the wind turbine gearbox.The reliability function curve of the gearbox of the wind turbine is obtained by analyzing the fatigue and wear of gear and the viscosity dilution process of lubricating oil.In this paper,the optimal maintenance time of wind turbine is determined by the reliability life calculated at last.The data and model basis are provided for prolonging the service life of wind turbine gearbox.This paper has completed the following work:(1)A random input speed model of the wind turbine based on random wind speed is established.By establishing the probability distribution model of wind speed and combining the relationship between wind speed and input fan speed,the random speed model is established.(2)A gear wear degradation model based on the Archard model was established.Considering the influence of gear meshing and the finite element simulation data,the key parameters of the Archard model are estimated.(3)A contact fatigue degradation model of tooth surface based on P-S-N curve was established.Using the finite element simulation data as input,the cumulative fatigue damage rate was obtained from the P-S-N curve.(4)A kinematic viscosity degradation model of lubricating oil based on Wiener process was established.Using the kinematic viscosit y data of the lubricating oil in the same gearbox at different times,the parameters of Wiener process are estimated.(5)The reliability of wind turbine gearbox system is evaluated by using the multivariate Copula function.In the Copula function model,the reliability functio n curves obtained from multiple degradation processes are taken as the input.The output is the reliability function curve of the system.