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CHARACTERIZATION OF MAGNETIC PERMEABILITY OF STEEL PLATES PACKAGE IN DIRECTION OF NORMAL MAGNETIC FLUX
E.V. Kalinin
e-mail: chernmaza@yandex.ru
Nizhny Novgorod State Technical University n.a. R.E. Alekseev
Nizhny Novgorod, Russia
A.I. Chivenkov
ORCID: 0000-0001-7578-8232 e-mail: chyvenkov@mail.ru
Nizhny Novgorod State Technical University n.a. R.E. Alekseev
Nizhny Novgorod, Russia
Abstract. The paper presents the possibilities of determining the magnetic permeability µn = µ0
·µn' from the normal component of the magnetic flux Фn. It is necessary for
3D calculations of additional eddy current losses in laminated cores of high-power electric
power devices. It is shown that it is unjustified to use the concepts of a layered magnetic
circuit with a stacking factor Кз presented in well-known studies, when due to the asymptotic nature of the dependence µn(Кз), an inaccuracy in determining the Кз by 1% leads to
a change in the value µn by 100% or more. An energy approach is proposed – through а
specific eddy currents loss pe from the action of the flow Фn in packages of rectangular
plates and analytical expressions linking µn with losses pe and the dynamics parameter ξ in
conditions of a sharp skin effect. The relative permeability values µn' were determined
using the wattmeter method at a frequency f = 50 Hz with an amplitude of magnetic induction Bm ≤ 0,1 T on samples of cold-rolled steels (40x80) mm: 08PS grade with thickness d
= 0.91 mm without insulating coating and with non-magnetic gaskets of various thicknesses in the range of Kз = (0.9…1.0) – µn' ≥ (90…100); transformer steel grade 3406, d =
0.3mm coated (Kз = 0.96) – µn' ≥ 60.
