Comparison of Time-Harmonic and Transient Finite Element Analyses for Eddy Currents in the Stator Clamping System of Synchronous Generators

The reliability of the loss calculation is a very important issue during the electrical design phase of large synchronous generators. The paper presents a fully 3D finite element approach for the computation of eddy current losses in the stator clamping parts of a 450 MVA hydro generator. To take into account for saliency and saturation effects, the analyses utilize the fundamental harmonic wave as well as the third harmonic wave of the excitating end region field. The results obtained from time-harmonic and nonlinear transient analyses are compared regarding the total eddy current losses as well as their local distributions.