Precise magnetic measurements on electrical sheet steels (collection of individual reports)
The object of this intercomparison was for five national laboratories to determine the specific total power loss and the a.c. permeability of various qualities of sheet steel, used in the construction of electrical machines and transformer cores. The electromagnetic losses of the steels varied from 7.0 W/kg for the non-orientated low silicon steel to 0.8 W/kg for the high B grain orientated silicon steel. The measurements were carried out on Epstein frame samples and toroidal cores at the frequencies of 25, 50 and 75 Hz and at magnetic flux densities of 1.5, 1.7 and 1.8T. The a.c. permeability results agreed within 1.2% between the laboratories. After demagnetisation problems were overcome in one participating laboratory, the maximum deviation of the obtained results was less than 1% for all laboratories on the Epstein frame samples at the "grading conditions" (50 Hz, 1.5T). The deviation of results for the "non grading conditions" was up to 4%. The variation in the results on the toroidal ring cores was about 2% for the "grading conditions" and up to 4% for the "non grading conditions". Further work needs to be done to improve this.
Bibliographic Reference: EUR 11862 EN (1990) 5 pp., MF, ECU 20
Record Number: 199010241 / Last updated on: 1994-12-01
Original language: en
Available languages: en