Calculation of damper winding loss and influence on large hydro-generator temperature

In this paper, the 250 MW generator in Wuqiangxi power station is studied. The solved region and mathematical model are given and the additional losses of the rotor pole surface and damper windings under rated voltage and no-load were calculated by the time stepping finite element method. Two situations are considered for calculating the additional loss of the damper windings. One is that the additional losses of the damper winding and pole surface are distributed in the certain penetration depth. The other is that the two kinds of losses are considered respectively. Based on that, the half-axial section mathematical model of 3D temperature field of the hydro-generator is established and calculated. Then, some useful conclusions are gotten through the analysis of temperature distribution under two situations.