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Keywords: 3-D finite element method, turbine generator, lamination, perpendicular flux, in-plane eddy currentIn this paper, we investigate the method of in-plane eddy current analysis for stator core-ends of turbine generators from both results of experiment and finite element analysis considering the lamination.First, the 3-D finite element analysis considering the lamination of the core is applied to the simple model that simulates the end part of the turbine generator. The calculated losses and flux distributions caused by the perpendicular flux are compared with the measurement to verify the validity of the calculation method. Fig. 1 shows the simple model for the validation of the calculation. The C-shape core is mounted on the Epstein shape core to impose the perpendicular flux. In the analysis, the Epstein core is subdivided into each electrical steel sheet by 3-D finite elements. The gap elements, which represent the magnetic resistance between the steel sheets, are inserted into every layer due to the stacking factor. The insulation between the sheets is considered by assuming the conductivity along the laminated direction as zero. Fig. 2 shows the experimental and calculated exiting current and total loss of the model. The results agree well. The validity of the calculation method is verified.Next, the calculation method is applied to a 250 MVA class turbine generator with the considerations of the laminated stator core. Fig. 3 shows the 3-D finite element mesh. The stator teeth of the generator have the slits, whose directions are alternately changed at each steel sheet and overlapped each other. The condition due to the difference of the electric angles is imposed at the peripheral boundary to reduce the analyzed region as one slot pitch. Fig. 4 shows the calculated eddy current distribution. The result without the slit is also shown for the comparison. Both results indicate that the eddy currents concentrate at the end of the core, especially, top of the stator teeth and bottom of the slots, as well as the copper shield. However, the current density at the teeth is much reduced by the slit. The current distribution and the effect of the slits are clarified by the calculation method.