The Dynamic Characteristics Analysis Of Main Structure On 1.5MW Wind Turbine Yaw System

As the representative of the clean energy, wind energy is used more and more widely and popular all over the world. After decades of intensive study by the experts and scholars from domestic and overseas, wind power generation has made great progress. As the world largest wind power country, China still has deficiencies compared to developed countries. Wind is one kind of random loading, wind turbines keeps pointing to wind direction because of the instantaneity of its direction and value, so that it will have a high conversion rate when the wind energy is being converted into electrical energy. Yaw system is created on this occasion and its main role is to make engine room drive the wind turbines and keep the wind turbines always pointing at the wind direction. Furthermore, another role of yaw system is to provide enough locking torque for wind driven generator and make sure engine room will not deflect and avoid the strenuous vibration of wind turbines. Normally, wind driven generators are built in remote place where it has a complex work environment, so it is not convenient to have maintenance. Therefore, security and stability are crucial during the design period. The author will combine the research actuality of domestic and overseas, and do study on each of gear drive system and bearing support system.For the traditional blade element momentum theorem which does work when it is in yaw status, its problem has been solved after amended, and it is applied to determine the loading of wind driven generator in yaw status and provide data for later calculations. In the process of modeling, regard gear drive system as a simple mathematical model, establish the kinematical equation of meshed gear through coordinate transformation. Then establish the kinematical equation of gear drive based on multi-body theory and Newton collision model. Analyze the drive system dynamic characteristic of yaw gear when the wind driven generator starts awry with ADAMS. Time-history curve will be got through simulating calculation, which reveals the dynamic characteristics of yaw gear when it starts and at the same time calculate the contact stress when the gear meshes through Workbench.For the failure mode of yaw bearing whose outer and inner rings have come off, get the contact stress distribution when yaw bearing is under a loading through Hertz contact theory and Workbench software. Through the analysis of simulation data, get the influence to yaw bearing maximum stress from different constructor parameters. Analyze the maximal contact stress of yaw bearing and value and distribution of structural stress through establishing precise model.