As rotating machines increase in speed and geometries become more complicated, prediction of
performance by loss calculations become increasingly important. A method, which has also been adopted by
JMAG, of taking into account loss inside laminations during post-processing using the results of
electromagnetic field finite element analysis has been proposed  . This method is a method of obtaining a
loss distribution inside a lamination by 1D analysis using the results of a 2D analysis, where the most accurate
results from the 2D analysis can be obtained as shown in Ref.  (called the “2D + 1D method”). However, when
evaluating the loss of a certain IPM motor model, there was a difference between the results from a 3D analysis
modeling a laminated steel plate and the results of the loss from the 2D + 1D method.
Investigation of the cause of this revealed that the geometry effects from the laminated steel sheet and the
eddy currents and the high frequencies are the reasons for the difference between 3D analysis and 2D+1D
method. In this white paper, based on the results of this analysis, the scenarios where the 2D + 1D method
degrades accuracy are made clear and issues to be addressed in the future are presented.