Numerical calculation and analysis of temperature field for stator transposition bar in hydro-generator

Abstract Aiming at the problem that the temperature field in the stator bar with transposition strands is difficult for analysis, a numerical method of evaluating the temperature field of the stator transposition bar is presented. The corresponding heat transfer coefficients of the convective heat transfer surfaces are obtained on the basis of the fluid velocity in radial ventilation groove, and the temperature value of the discrete points in stator transposition bar is obtained by the finite volume method. Additionally, the current phase of upper and lower bar in a single slot is taken into account. In order to validate the presented method, a 250 MW air cooled hydro-generator is taken as an example, and the solving model is established. The copper loss of stator bar is calculated by the presented method. The temperature distribution of stator transposition bar is analyzed and compared in different cases, and the validity of the presented method is verified by evaluating the temperature deviation between the numerical results and the test values.