Full 3D eddy current and temperature field analysis of large hydro-generators in different operating conditions

Accurate and precise determination of 3D eddy current and temperature fields of a large hydro-generator has always been a formidable challenge to engineers and academicians. In this regard, the full three dimensional (3D) finite element models and methods are developed for numerical solutions of the coupled eddy current and temperature fields in the end region of a large hydro-generator. The equivalent medium parameters used in the computations are then comprehensively discussed. The methodology to determine the field and phase currents under different operating states is also presented. Moreover, an approach to effectively deal with the thin skin-depth is introduced. Numerical results on the coupled eddy current and temperature fields in the end region of a 100 MW hydro-generator in three different operating conditions confirm positively the feasibility of the present work.