Diagnosis and numerical simulation of large hydra-generator under steady-state after heating faults of insulation aging

Isoparametric element method of hexahedron and eight nodes is used to calculate the 3D stator temperature fields of large hydro-generator. A SF300-48/1230 hydro-generator is taken for an example, with the strand insulation taken into account the 3D isoparametric finite element method and the theory of similarity for fluid are applied to calculate the 3D stator temperature field. The computed results meet with the measured results very well. The influence of insulation aging and shelling on stator temperature fields is analyzed by numerical simulation method and some useful conclusions are drawn, which provide theoretical basis for real-time temperature monitoring and heat faults diagnosing for generator.