Transient Characteristics And Dynamic Analysis Of Gear Transmission System Of Wind Turbine With Dynamic Backlash

With the development of wind power generation technology,wind power generation has become an easy way to develop,renewable,green power generation.The gear transmission system is an important part of the wind turbine system.Due to the complex working conditions,such as high layout,high failure rate and maintenance difficulties of the gear transmission system,the clearer understanding of the dynamic characteristics of the gear transmission system,the more beneficial it is to improve the stability of the gear transmission system.Based on the speed-increasing gear transmission system in this paper,the research is carried out step by step.Considering the dynamic clearance,eccentric,friction,time-varying mesh stiffness,mesh damping factors,such as the lumped parameter method is adopted to establish the nonlinear dynamic model of gear transmission system.The fourth order Runge-Kutta method is used to solve the vibration differential equation of the gear transmission system.The dynamic characteristics of gear system under different excitation are obtained.A compound dynamic backlash model based on tooth roughness and vibration characteristics is proposed.The effects of three kinds of dynamic backlash,including dynamic backlash with fractal characteristics,dynamic backlash with center distance varying and composite dynamic backlash,on vibration response of gear transmission system are analyzed.It is found that the compound dynamic backlash is closer to the gear movement state.The energy method was used to calculate the mesh stiffness of the gear pair with different crack depths and the dynamic characteristics of the gear transmission system with root crack fault were studied.The fault frequency characteristics of gear transmission system with root crack were investigated.The nonlinear dynamic model of high-speed-level gear transmission system of wind turbine is established.The wind load change model at the input end and the electromagnetic torque change model at the output end are established respectively.The influence of variable wind load on vibration response of high-speed-level gear transmission system under dynamic backlash condition was investigated.In the case of transient power grid sags,theelectromagnetic torque changes of different fault types and different voltage sags are obtained,and the influence of different transient faults on the dynamic characteristics of high-speed gear transmission system of wind turbine is analyzed.The research content of this paper provides some reference for the optimal design and fault diagnosis of the gear transmission system of wind turbine.