Influence of Main Insulation Thermal Aging on Stator Temperature Field in Large Turbo-Generator

The eddy current loss of stator strands in the in-phase slot and out-phase slot was calculated by the finite element method (FEM). 3D static heat transfer equations and equivalent variation equations of large turbo-generator under the Cartesian coordinates system were given. The stator temperature field of large turbo-generator was calculated by using 3D FEM, and the influence of thermal conductivity reduced due to main insulation aging both in in-phase slot and out-phase slot on the stator was analyzed. The obtained conclusions will provide theoretical basis for fault prediction and fault diagnosis.