Analysis of magnetic fields due to three-phase bus bar currents for the design of an optical current transformer

Author

Imamura, Masaaki ; Nakahara, Motonao ; Yamaguchi, Toshinao ; Tamura, Seisaku

Author_Institution

Dept. of Electr. Eng., Fukuoka Inst. of Technol., Japan

Volume

34

Issue

4

fYear

1998

fDate

7/1/1998 12:00:00 AM

Firstpage

2274

Lastpage

2279

Abstract

The dc and ac magnetic fields due to transmission currents flowing through bus bars arranged side-by-side are analyzed to design the three-phase optical current transformer. The structure of optical current transformer with a double core for magnetic shielding is proposed based on the analysis of the interference effect of magnetic fields originated in the three-phase transmission currents and those of the eddy current fields induced by the component of three-phase ac fluxes perpendicular to the wide flat face of plate-form bus bar. It is shown that when a value of 100 is assumed as a relative permeability for the inner shield-core, the eddy current fields which hinder the exact measurement of transmission currents can be decreased by less than 1/10 in the space between the inner core and the outer one, where the magneto-optical field sensor is arranged

Keywords

busbars; current transformers; eddy currents; magnetic fields; magnetic shielding; magneto-optical devices; transformer cores; double core; eddy current; interference effect; magnetic field; magnetic shielding; magneto-optical field sensor; optical current transformer; relative permeability; three-phase bus bar current; transmission current; Bars; Current transformers; Eddy currents; Magnetic analysis; Magnetic cores; Magnetic fields; Magnetic shielding; Optical design; Optical devices; Optical sensors;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.703866

Filename

703866