Dear Jason,
Thank you very much for your kindness.
1.Sorry, tau is a typo and it is Kg.
2.Stiffness refers to the ability of a material or structure to resist elastic deformation when stressed.Mostly it is very low,only exist in some papers,and can be ignored.
3.I knew coefficient depend on the operating point. And I thought the rotor external damping and generator external damping is located in Gearbox,and they are parameters,whick is can be detected sometimes.I don’t konw how to measure it.In this Relation between Stifness and Inertia? - #2 by Jason.Jonkman told him the value of rotor inertia.
If Kg and Kt must be detected by FAST, tell me how to do it,please.
Best regards,
Ankang.Cao