An Electric Vector Potential Method Approach for 3-D Electromagnetic Field in Turbine Generator Stator Core End

Stator core end temperature rise is one of the most important factors in the design of turbine generators. The turbine generator designer is required to predict the precise distribution of stator core end leakage flux and eddy current losses within the stator core. This paper deals with the application of an electric vector potential 3-D finite element method to this problem. In this method, the 3-D electromagnetic field within the laminated core is accounted for by a mathematical model in which the effects of stacking factor and the anisotropy of physical constants are fully taken into consideration. An experimental model closely simulating the stator core end of an actual machine has been analyzed and tested, and the results of the test show a good agreement with those of the analysis. The authors have also obtained much information about matters which have so far defied analysis or measurement, such as the effects of airducts and tooth shape. In addition, the effects of slits provided in the core teeth have been evaluated both by analysis and test.