Unbalanced magnetic forces in rotational unsymmetrical transverse flux machine

The torque and unbalanced magnetic forces in a small flux concentrating permanent magnet transverse flux machine (FCPM-TFM) in segmented compact structure, which are the resultants of the tangential; axial and normal magnetic forces, respectively, are in general influenced by pole-teeth-winding configuration. The paper calculates the torque and unbalanced magnetic forces using finite element (FE-) method by solving Maxwell stress tensor via utilizing FLUX3D software from Cédrat. To investigate the influence of unsymmetrical winding pattern, in respect to the rotor, on the performance of this FCPM-TFM with distributed windings, a magneto static study followed by transient analysis have been conducted. Calculating the magnetic field components in the air gap, has required an introduction of a 2D grid in the middle of the air gap, whereby good estimations of the forces are obtained. In this machine, the axial magnetic forces exhibit bigger amplitudes compared to the normal forces. Practical results of a prototype motor are demonstrated throughout the analysis.