Eddy Current Phenomena in Laminated Structures Due to Travelling Electromagnetic Fields

Abstract

Abstract-The distribution of fields travelling in the laminated structure with assumed values for the tangential components of the magnetic field intensities on the top and bottom surfaces of the structure, has been obtained using linear electromagnetic field theory. The treatment takes cognizance of interlaminar capacitance inherently present in a laminated structure. Analysis presented in this paper assumes identical field distribution in each lamination. It has been concluded that convection currents are developed at the interface between iron and insulator regions.

Harmonically Time Varying, Traveling Electromagnetic Fields Along a Plate and a Laminate With a Rectangular Cross Section, Isotropic Materials and Infinite Length

“…One of the conclusions in [6] is that there is a surface current density on the material interfaces in a laminate as a consequence of the deposition of charges caused by the normal component of the total current density. If a charge can reach the surface of a conducting plate, it seems reasonable that it can also slide on the surface.…”

“…An integral equation method [2] and the stream function method [3] have been suggested for estimation of eddy currents in a plate where reaction fields have been neglected. Mukerji et al have used Fourier's method, also called the method of separation of variables, in analyses of electromagnetic fields in a plate [4], and a laminate [5,6]. In [4] and [5], the magnetic field is assumed to be alternating as in a transformer.…”

“…In [4] and [5], the magnetic field is assumed to be alternating as in a transformer. In [6], traveling fields, simplified boundary conditions and no magnetic field in the stacking direction on the boundary are assumed. However, in the end regions of a plate package and the end regions of the stator core of an electric machine, the magnetic field in the stacking direction can be significant for the eddy current loss because of the large plate surfaces without interruptions of eddy currents.…”

A Quasi-Analytical Model for Remote Field Eddy Current Inspection

“…Figure 2 reports a schematic radial representation of the RFEC system, used for the deduction of the quasi-analytical model [28][29][30][31].…”