Study On Dynamic Characteristics Of High-speed Level Gear System Of Wind Turbine Under Random Factors

Wind energy has the characteristics of renewable and green environmental protection.Wind power technology is widely used.The wind turbine gearbox is an important part of the wind power system,whose main function is to transfer the mechanical energy generated by the wind turbine to the generator.Due to the random nature of wind speed,the input torque of the wind turbine gearbox fluctuates randomly,which in turn reduces the stability of the gear transmission system in the gearbox.In order to improve the stability of the gear transmission system,it is necessary to study its dynamic characteristics.In this paper,the wind turbine high-speed level gear transmission system is used as the research object.The dynamic characteristics of the gear transmission system under random factors are analyzed.The ball bearing dynamic model is established by using the Hertz contact theory.A dynamic model of high-speed level gear transmission system of wind turbine is established by using the lumped parameter method considering the factors such as toothed clearance,comprehensive transmission error,friction,eccentricity,damping and external excitation.The fourth-order Runge-Kutta numerical method is used to solve the vibration differential equation of the dynamics model of the gear transmission system.The time domain diagram,frequency domain diagram,phase diagram,Poincare cross section diagram and waterfall diagram of vibration response are obtained.The influences of parameters such as tooth clearance,friction coefficient and input torque on the vibration response of the gear transmission system are analyzed.The results of the study provide a theoretical basis for the design of a gear transmission system.Based on the dynamic model of the high-speed level gear transmission system of the wind turbine.At the same time,the parametric stochastic perturbation model with normal distribution characteristics obtained by the Mento-Carlo method and the central limit theorem is considered.The stochastic dynamic model of the high-speed level gear transmission system of the wind turbine is established.The influences of random disturbance of tooth clearance and time-varying meshing stiffness on the vibration response of the gear transmission system are analyzed.The research results show that the parameter random disturbance has a large impact on the displacement of the vibration response of the components of this gear transmission system,which makes the motion state of this gear transmission system change.The AR random wind speed model is used to simulate the actual wind speed,and the virtual imbalanced mass block is used to simulate the blade mass imbalance caused by the breaking and freezing of blades for the freezing or breaking of blades under the actual wind speed.At the same time,based on the dynamics model of the high-speed level gear transmission system of the wind turbine,the stochastic dynamic model of the high-speed level gear transmission system of the wind turbine with blade mass imbalance is established.The influence of blade mass unbalance on the vibration response of the gear transmission system is analyzed.The influence of friction coefficient on the vibration response of gear transmission system with blade mass imbalance is studied.The results of the study show that the blade mass imbalance has a large effect on the input torque of the gear transmission system,causing the gear transmission system to perform the chaotic motion.Two different gear wear models are established.Time-varying meshing stiffness with wear fault is calculated by the method of mechanics of materials.A four-component stochastic wind speed model is used to simulate actual wind speed.Based on the dynamics model of the gear transmission system,considering the wear model and the four-component stochastic wind speed model,the model of the stochastic dynamics of the gear transmission system with wear fault is established.The influence of the gear wear on the vibration response of the gear transmission system under random wind speed is analyzed.The research results provide theoretical support for fault monitoring and diagnosis of the gear transmission system and provide a theoretical basis for optimizing the design of the gear transmission system.