Calculations of magnetic field in dynamo sheets taking into account their texture

Magnetic measurements have shown that the most dynamo steel sheets have certain anisotropic properties, which are due to the presence of textures in these sheets. These anisotropic properties have been taken into account usually in a simplified way assuming that iron particles of the dynamo sheets have only one axis of the easy magnetization. In the proposed approach, these particles are treated as grains which have three axes of the easy magnetization, and therefore the magnetization processes can be considered along each of these axes. These processes depend on the actual value and on the direction of the field strength and also on textures occurring in the given dynamo sheet. A method which allows calculations of the field distribution as a function of the assumed changes of external currents is described in this paper.

Influence of magnetic anisotropy on flux density changes in dynamo steel sheets

Magnetic measurements, carried out by means of the Epstein frame, have shown that most typical dynamo steel sheets have certain anisotropic properties. In numerical analysis, anisotropic properties are taken into account with the use of the special function of the grain distribution in the given dynamo sheet. For engineering purposes, it is desirable to assess the influence of these properties on the changes of the magnetic flux density in typical dynamo steel sheets, especially during the rotational magnetization. For this purpose, measurements of the flux density changes and field strength changes in the circular-shaped samples of two selected typical dynamo sheets were performed. These measurements were carried out for several values of the current flowing in windings which generated the axial or rotational magnetic field in the test dynamo sheet. The influence of the magnetic anisotropy on the magnetization process was briefly discussed for both types of the magnetization processes.