Hello Khanh,
Thanks for your question.
In Motor-CAD, either analytical or FEA methods can be applied for the Induction Machine calculation. There are various causes for the difference between the results from analytical and FEA, for example, space MMF harmonics, mesh density, limitation in reduced single load point methods, etc.
The analytical results can be further adjusted to match FEA results please refer to the IM Validation tutorial in the tutorial folder.
Thanks
Best regards
Bo REN