Dynamic Character Analysis Of Wind Turbine Gear Transmission System Under Random Wind

Over hundreds of years, petroleum,natural gas and other mineral energy promote the development of human society. However, the earth’s ecological environment has been greatly damaged with the use of energy. In order to ensure the sustainable development of human society, many countries all over the world begin to put into the development and utilization of new energy. Among them, the using of wind energy, which is pure, pollution-free and abundant, to generate electricity has been quite mature, and provided a tremendous economic benefit.Wind turbines are usually installed in mountains, seaside and other places with adequate wind energy, which is difficult to repair and maintenance. Thus it puts forward a high request to the reliability of wind turbines. However, a high failure rate of wind turbine in some wind field happens in acture operation, in which the fault caused by gearbox failure accounted for more than half. Therefore, in order to improve the system reliability, this paper takes a1.5MW wind turbine gearbox as the research object, studying its dynamic characteristics fully considering the dynamic loads caused by random wind speeds. The main contents are as follows:Determine the basic transmission forms and concrete structure of all levels of the gearbox; establish its physical model; creat the dynamic equations of two stage planetary transmission and high speed parallel shaft transmission under the assumption of rigid body system. According to the coupling conditions, obtain the system’s two order dynamic differential equation; establish its dynamic analysis model; and discuss each main parameter related to the model in detail. In addition, the external excitation of the system is analyzed in the paper. According to the IECKAI wind model; get the time history of wind speed in50s; colligate the modified utilization coefficient of wind power; obtain the input torque curve of the system.On account of the virtual prototyping technology and finite element analysis method, analysis the dynamic characteristics of gear system. Based on the verified simulation model, get the dynamic meshing forces between teeth and the dynamic bearing forces. The result shows that the bearing forces are obviously effected by external applied load, and they have the same trend with the change of the load. Moreover, two stage planetary gear train bears a greater torque than parallel shaft transmission system, so their failurephenomenon happens more frequently when the system runs.Meeting the system normal operation and fatigue strength conditions; according to the definition of reliability, design the reliability model of gear system; set the basic design parameters as variables and achieve optimization design of wind turbine two planetary gear train system. Comparing vibration displacement peak values of the components before and after optimization, we found that the oscillation amplitude of the system after optimization is greatly decreased, the volume and weight of the system is also reduced, and the safe operation reliability of the system is efficiently improved.