Magnetic field asymmetry at external phases of shielded single-pole three-phase flat high-current busduct

Dariusz Kusiak,Zygmunt Piątek,Tomasz Szczegielniak,R Nawrowski,L Kasprzyk,A Bugała,J Lorenc,K Budnik,A Tomczewski,Z Nadolny,J Jajczyk

doi:10.1051/itmconf/20192801007

Dariusz Kusiak, Zygmunt Piątek + Show 9 more

Open Access

https://doi.org/10.1051/itmconf/20192801007

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Abstract

The article shows the total magnetic field distribution in two outer conductors of the flat, three-phase single-pole shielded, high-current busduct is asymmetric. The phase currents in the shielded conductors decide about the magnetic field of such a high-current busduct. The components of this field reflect the magnetic field of the reverse reaction fields of the eddy currents induced in the conductors of the adjacent phases as the results of the proximity effect and the skin effect. The field distribution is shown in the outer area of the outer phases as the function of the parameters reflecting the current frequency, the conductivity, and the transverse dimensions of the tubular conductors.

Highlights

In solutions for shielded high-current busducts, a threephase single-pole flat high-current line is used very often - Figure 1.The metal shield for the own phase conductor is the so called open screen and this means that the magnetic field in its external area is the same as in case of lack of shield
The own magnetic field in this area is equal to the field generated by the thread phase conductor with its own phase current
EMFs generated by the alternating magnetic field of currents in phase conductors are induced in the highcurrent busduct shields

Summary

Introduction

In solutions for shielded high-current busducts, a threephase single-pole flat high-current line is used very often. EMFs generated by the alternating magnetic field of currents in phase conductors are induced in the highcurrent busduct shields. If these shields are shorted inter se or earthed, so called return currents [1] will occur in them. Values of these currents depend on methods of shield connection inter se, earthing methods and electrical parameters of the shielded high-current busduct, i.e. self-impedances of phase conductors and shields as well as mutual impedances between conductors and shields [2]. It was shown in the work that the magnetic field distribution in two external conductors of the three-phase flat shielded high-current busduct is not equal in spite of symmetry [9] of the system geometry

Magnetic field distribution

Conclusions