Performance Degradation Modeling And Reliability Analysis Of Wind Turbine Gearbox

Wind energy is a kind of clean energy,and the rational use of wind energy can greatly alleviate the pressure on the global climate and environment.Wind power is an important means of utilizing wind energy,and wind turbine is the medium for converting wind energy into electrical energy.Wind power gearbox is one of the core components of wind turbine.It has complex structure,many components and diverse failure modes.The design,manufacturing and reliability of the gearbox can better reflect the manufacturing level of wind turbine.Therefore,it is very important to analyze the reliability of wind turbine gearbox.This paper takes a certain type of 2MW wind turbine as the research object,and mainly carries out the following research work:(1)Traditional failure mode,effect and criticality analysis(FMECA)method is used to analyze the failure of the entire wind turbine,and the risk priority number is used to determine the more harmful parts in the wind turbine gearbox system.(2)In view of the shortcomings of traditional FMECA in the description of the evaluation indexes of the failure mode,the weight of the evaluation indexes and the importance ranking of the failure mode,the fuzzy set theory is used to improve the expert rating and a new scoring system is constructed.The subjective weights of the three evaluation indexes are calculated by the Analytic Hierarchy Process,and the objective weights are assigned according to entropy weight method.The failure modes based on Technique for Order Preference by Similarity to an Ideal Solution method are ranked.The improved FMECA method is used to determine the criticality ranking of the component failure modes in wind turbine gearbox,and the results are compared with the results obtained by traditional methods.(3)Based on the Gamma stochastic process and Copula theory,the fatigue strength degradation failure process of high-speed gears of wind turbine gearbox is studied.The Gamma stochastic process is used to describe the failure process of gear strength degradation,and the unknown parameters in the Gamma stochastic process are estimated through the P-S-N curve of the material,and a model of the gear strength degradation failure process is constructed.The Copula function model is used to characterize the dependence between the two gears and the failure modes of each gear in the high-speed transmission system,and the Monte Carlo method is used to verify the feasibility of built model.(4)According to the influence of external shocks on the product performance degradation failure process,the product failure process is described in detail,and the product’s competitive failure process model under random shocks is established.Considering that the model function is difficult to obtain an analytical solution,the Monte Carlo method is used to verify the feasibility of built model,and the influence of different parameters on product reliability is studied at the same time.