Re: [femm] Eddy currents in thick laminations

[David Meeker <dmeeker@xxxxxxxxxxxxxxxxx>]

Douglas@xxxxxxxxxxxxx wrote:

> Problem:
>
> How does one approach determining the eddy-current losses in
> a "laminated material" with a thickness of several millimeters and
> where the frequency under consideration is greatly above the more
> usual 50-60Hz range. Surely the skin depth must now become an issue,
> as the lamination is no longer a "thin" conductor with uniform
> current density. The simpler (freshman textbook type) formulas no
> longer apply? Any pearls of wisdom would be most appreciated.
>
> Douglas Stevenson

There is a more general treatment out there that deals with skin effects.
The best reference for this is:

R. L. Stoll, The analysis of eddy currents, Oxford University Press, 1974.

This book is out of print, but it is available in many libraries. You can
sometimes find used copies on Amazon.

There are also a great many papers out there about modeling eddy currents in
laminations. These are good if you are looking for equivalent circuit
representations of cores with eddy currents, including saturation and
hysteresis in the models, and so on. But if you can get it, you should look
at Stoll first.

Dave.


begin:vcard 
n:Meeker;David
tel;fax:781-890-3489
tel;work:781-684-4070
x-mozilla-html:TRUE
url:http://members.aol.com/_ht_a/dcm3c
org:Foster-Miller, Inc.;Electrical and Electronic Systems Group
version:2.1
email;internet:dmeeker@xxxxxxxxxxxxxxxxx
title:Senior Engineer
adr;quoted-printable:;;350 Second Avenue=0D=0A;Waltham;MA;02451-1196;USA
fn:David Meeker, Ph.D.
end:vcard