Vibration And Reliability Analysis Of Wind Turbine Gearbox Transmission System

With the rapid development of the world’s economy and the seriouslyincreasing of theenvironment problem, all countries in the world make efforts to explore new energy to replace the traditional fossil energyconsidering the present situation that the resources are running out.Because windenergy is the most valuable energy for exploitation,wind turbineis developed to be larger and the number of wind turbine is increasing steadily every year.However, so many unprecedented scientific questions have merged due to the large-scale:First, we should consider more factors for the large-scale while modeling. Second, complicated loads made it difficult for us to analyze the dynamic of the wind turbine.Finally, because thesignificant increasing of installed numberand wind turbine’sfailure rate, the key to vigorously developed the wind energy has changed to how to reduce the failure rate.Inview of the foregoing, 2 MW wind turbine gearbox transmission system was chosenas the study object.The theory of gear transmission system dynamics was used to research the wind turbinevibration characteristics; then, we also analyzedthe relationship between its vibration characteristics and reliability with the theory and method of reliability,which provided the basic theory for the design and fabrication of the wind turbine gearbox.The specific contents of the research include the following three aspects:(1) Consideringall the parts own gravity and the shaft bending moment which have a great influence on average loads of the transmission system, the dynamic equation was founded with thedynamictheory of the gear transmission system;the stiffness matrix and mass matrix in the level of system was established by using the method that connecting-components replacesome parts, the correlationsamongeach levels of the transmission system was also achieved, the method has been applied to establish the transmission system. Finally, with the measured windload as the excitation force,the whole system matrix vibration model was established.(2) The natural frequencies and modal vectors was obtainedby usingfrequency-equationto analyze the vibration characteristic of the gearbox transmission system; next, the curves of the vibration response of all the parts was obtainedwith the method of givensolutionsto thevibration differential equation, at the same time, we make the measured wind load as the external excitation of the gearbox transmission system.(3) We found a reliability model with the excitation frequency and the natural frequency based on the methodology of conditional probability, then we got the vibration-reliability of all the parts;Apply the theory of series system reliability to the reliability of all the parts, we can get the reliability model of wind turbine gearbox transmission system, at last, the vibration-reliability of the system was calculated.Based on the above work, we not only analyzed the vibration characteristics of wind turbine gearbox transmission system, but also got the vibration-reliability of the system. At last, the relationship between the vibration characteristics and the vibration-reliabilityof wind turbine gearbox transmission system was explained bythe traditionaldynamics method of founding model, calculating and analyzing,whichprovided basic theoryfor design and fabrication of wind turbine gearbox transmission system.