Vector magnetic characteristics of Ultra-Thin Electrical Steel Sheet for development of high efficiency high speed motor

Recent years, developments of high speed motors are required to make high power and small size machines. In this paper, we will report the magnetic characteristics of ultrathin electrical steel sheet. Fig.1 (a) shows the results of measurements on initial magnetization curve of several types of soft magnetic materials. Conventional materials having excellent frequency characteristics show low magnetic permeability or low saturation magnetic flux density. The characteristic of Ultrathin electrical steel sheet is almost equal to NO (35A300) under exciting frequency of 50Hz. Fig.1 (b) shows the frequency characteristic of the Ultrathin electrical steel sheet. The eddy current loss is small than NO because thickness of this sheet is very thin (0.08 mm). Fig.1 (c) shows the (110) pole figure of ultrathin electrical steel sheet. It is confirmed that the roll induced magnetic anisotropy of this sheet is small. Fig.2 shows the laminated core for motor made of the ultrathin electrical steel sheet. By using this sheet to the cores of high speed motors, downsizing, high efficiency and high output can be expected. In the full version of papers, the vector magnetic characteristic and magnetic power loss under various conditions are examined in more detail.