Research Of Current Leakage Failure Of Rolling Bearing At Wind Turbine Gearbox High Speed End

Gearbox is a very important part of wind turbine generator.With the variable load applied on the gearbox,especially the impact load produced by sudden change of wind,high reliability of bearing is required.Thus,it is necessary to monitor the operating condition to avoid the abrupt fault of gearbox.The simulation aims at mechanical damages such as pitting and bearing fluting led by failure of insulation and current leak of wind generator of which the power is about 1.5-2MW.And based on a whole model of the wind turbine,another model—a electric-thermal-stress model to simulate the influence of field of temperature and stress—has been established.The result of this model has been compared with data accumulated by SC AD A system.The next part is a non-liner model of dynamic to simulate the differences of frequency characteristics between normal and fault conditions.This thesis shows that:For wind turbine whose power is about 2MW,the thermal effect of EDM(electrical discharge machining)is not obvious compare with the heat generation of bearing.And the influence of EDM mainly exists in it’s mechanical damage which lead to the pitting or bearing fluting.When the local corrugations such as pitting,pits and fluting are caused by electrical corrosion,the amplitude of the vibration spectrum is non-periodic and the amplitude of the whole vibration increases,and the peak spectrum of the fault spectrum is significantly larger than that of the inherent Frequency peaks.Therefore,for the generator leakage current caused by the high-speed gear box bearing corrosion corrosion,vibration spectrum monitoring has a certain feasibility.