An investigation into the effects of transient events on the wind turbine drive train is presented. Two transient events, normal stop and emergency stop due to grid loss, are studied focusing on the effects that these individual events have on the drive train. The analysis was conducted using two commercial software packages; GH Bladed to simulate the loads on the turbine and RomaxWIND to find the resulting effects of these loads on key bearings within the drive train. Time series of the turbine and overall drive train loads during these transient events are simulated using Bladed and these are applied to a detailed drive train model to find the loads on key bearings. A comparison between the two transient events shows that emergency stops are roughly 3 times more damaging than a controlled normal stop. In addition a comparison between the results obtained from reliability analysis and results from the modeling show that the model does not predict the most damage to be on the high speed shaft bearings as indicated by operational experience, rather, as might be expected from a simplified picture of the turbine, the bearings of the low speed stage are the most damaged. The results thus suggest that other effects such as misalignments are likely to be the cause of the frequent high speed shaft bearing failures rather than the loads applied through the drive train.
|Title of host publication||50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition|
|Publication status||Published - 20 Jun 2012|