Dynamic Characteristics Analysis Of Gearbox In Doubly-fed Wind Turbine

As the conventional energy increasingly become scarce on earth and the environment is destroyed continually by use of these energy, the development of clean energy has become an urgent matter in many countries around the world. Wind energy, as a renewable green energy, becomes the most meaningful and promising new energy. In recent years, China’s wind power industry develops rapidly, and the installed capacity of wind power unit grows at high speed. In order to guarantee the stable operation of the wind turbines, wind power generation technology is constantly faced with new challenges.Gearbox as the key transmission parts of wind turbines, is a large coupled nonlinear system, and is also one of the easiest parts which will occur faults. As a result, the research on dynamic characteristics of a wind turbine gearboxes and analysis of its vibration regularity have a great significance on the fault diagnosis of gearbox and the improvement of wind power technology. In this paper, based on the simulation software, dynamic characteristics of gearbox of a 1.5 MW doubly-fed wind turbine was studied, the main contents are as follows:With the application of professional wind power analysis software S4 WT, parameterized model of gearbox was built, and the modal analysis was carried out. Further more,natural frequencies and corresponding vibration mode was obtained,and by comparing the inherent frequency and excitation frequency, conclusion was that resonance phenomenon did not occur.Besides, the coupling model of wind turbine was built based on S4 WT. With the consideration of the shear effect and shadow effect, dynamic characteristics of gearbox under a variety of operating condition and wind condition was simulated and analyzed. Meanwhile, the dynamic response, the gear meshing force and bearing force of the gearbox system were obtained. Results showed that the dynamic behavior of the gearbox is closely related to the wind load and its working condition, and analysis of the complete machine can more truly reflect the dynamic characteristics of gearbox.Based on dynamics analysis software ADAMS,a wind turbine gearbox multi-rigid-body model was built. The contact parameters and simulation parameters were calculated and set, and practical constraints, drive and load were added to the model. What’s more, simulation results such as the gear angular acceleration, dynamic meshing force at all stages and the contact force between the roller and inner ring, outer ring and cage were analyzed comprehensively in time domain and frequency domain. The results showed that the gearbox will produce coupling effect between the internal parts.The modal neutral files of gear and bearing retainer were generated by using ANSYS software. Then the coupled model of gear transmission system in high speed stage was established in ADAMS, and the dynamic simulation was done. Gear meshing force, dynamic responses of bearing were obtained, and modal, dynamic deformation, stress and maximum stress node information of the flexible body such as the gear and bearing retainer were analyzed in detail.