Eddy Current Analysis Considering Lamination for Stator Core Ends of Turbine Generators

In this paper, we introduce a calculation method for in-plane eddy currents produced by perpendicular flux at stator core-ends of turbine generators. In the method, the laminated core is subdivided into each electrical steel sheet by 3-D finite elements. The insulated layers of the sheets are modeled by the gap elements, which represent the magnetic resistance of the layers. The combination method of double nodes and anisotropic conductivity is proposed to consider the insulation between the steel sheets. It is especially required for the stator teeth with slits. The validity of the calculation method is verified by comparing the measured and calculated results in the case of a simple model that simulates the end part of the turbine generator. The method is also applied to the real machine to clarify the eddy current distribution.