Loss and heat computations of damper bars in large tubular hydro-generator

To research the loss and heat of damper bars thoroughly, a 2D electromagnetic field FE model of tubular hydro-generator and a 3D temperature field FE model of the rotor are built up respectively. The factors such as rotor motion and nonlinearity of the time-varying electromagnetic field, the anisotropic heat conduction of the rotor core lamination and different heat dissipation conditions on the windward and lee side of the poles are considered. Furthermore, according to the different operating conditions, different rotor structures and materials, compositive calculations about the losses and temperatures of the damper bars of a 36 MW generator are carried out, and the data are compared with the test. The results show that the computation precision is satisfied and the generator design is reasonable.