Application of the anisometric method for determining polar curves of induction, apparent core loss, and core loss in cold-rolled electrical sheets of Goss texture

Abstract

A method of determining directional properties of electrical sheets of Goss texture is presented. The method is new and very useful for the purpose of calculating magnetic circuits. In order to determine directional properties of sheets it is necessary to make use of the Epstein test with reference to a sample sheared in the rolling direction as well as of anisotropy curves determined by means of an anisometer on samples of a disk shape. The proposed method makes it possible to limit the number of labor-consuming measurements taken in the Epstein test on samples sheared at many angles as well as to examine tapes of random width. Empirical relations between anisotropy of induction \DeltaB , apparent core losses \DeltaV , core losses \DeltaP , and parameters of the anisotropy curve J_{\perp} = f(\varphi) are given. Curves approximating the results obtained experimentally are provided. The proposed method of determining magnetic characteristics makes it possible to draw a polar figure, i.e., a curve illustrating changes of some magnetic properties according to the magnetic flux direction. Experiments covering transformer plates and dynamo sheets of varying orientation and metallurgical composition prove the correctness of applying the described method.