Influence of Partial Anisotropy of Non-Oriented Electrical Steel Sheet on Induction motor

The article deals with the influence of the partial anisotropy of electrotechnical sheets metal for electrical rotating machine. Standard EN 10106: 2015 specifies tolerances for individual types of electrotechnical sheets metal. Different features in different directions cause asymmetry in magnetic circuit of the asynchronous motor. The effect of the asymmetry of the magnetic circuit is analogical to the effect of the unsymmetrical supply, the deformation of the rotating magnetic field, which causes the higher vibrations, the higher shaft voltage and the torque characteristics deformation. The idea of limiting this phenomenon is to alternately mechanically rotate the plates by 90 degrees and thus to balance in total the magnetic conductivity in one direction. In the article, the difference between losses in different sheet metal rotation is verified according to the standard. Furthermore, dynamic hysteresis curves were measured for different sheet metal rotation. Using the Finite Element Method the effect on the torque characteristic was verified.