A high precision motor design method by finite element analysis considering stress distribution in stator core

In this paper we show a novel motor design method, considering stress distribution in the motor core. This method consists of several steps as follows: (a) measurement of magnetic characteristics of the electrical steel sheets in the state where the stress is added, (b) calculation of deformation and stress distribution using structural analysis, (c) pre-process of the magnetic field analysis, which makes FEM mesh deformed by the stress and changes the properties of each elements of the core corresponding to the distribution of the stress, and (d) magnetic field analysis using the measured data by step-(a) and the FEM mesh generated by step-(c). As an example, we show a result of cogging torque calculation of permanent magnet motors, considering the stress in the stator core resulting from shrink fitting in the frame. As a result, we show that the cogging torque waveform is different depending on the shape of the frame.