Numerical Analysis of the Magnetic Field of High-Current Busducts and GIL Systems

Petar Sarajcev

doi:10.3390/en4122196

Abstract

This paper presents a numerical computation method for determining the magnetic field of high-current busducts of circular cross-section geometry, based on the subdivision of the busduct phase conductors and screens into the conductor filaments and the subsequent application of the mesh-current method, with the aid of the geometric mean distance method. The mathematical model takes into account the skin effect and the proximity effects, as well as the complete electromagnetic coupling between phase conductors and metal enclosures (i.e., screens) of the single-phase isolated busduct system (of circular cross-section geometry). This model could be readily applied to the computation of the magnetic field of the Gas Insulated Transmission Lines (GIL) as well.

Highlights

High-current busduct systems are usually air insulated single-phase enclosure systems with tubular aluminum or copper conductors encapsulated in the coaxial aluminum enclosure
This paper presents an efficient numerical method for determining the magnetic field of high-current busducts and/or Gas-insulated transmission lines (GIL) systems, based on the conductor filament method, with application of the mesh-current method, aided by the geometric mean distance method, e.g., [12]
In order to determine the field distribution, let us introduce geometry provided in the Figure 2

Summary

Introduction

High-current busduct systems are usually air insulated single-phase enclosure systems with tubular aluminum or copper conductors encapsulated in the coaxial aluminum enclosure (i.e., screen) They are circular in cross-section geometry, laid in horizontal or vertical three-phase formation. The insulating media, facilitates the geometry of the GIL system being very similar (in terms of the cross-section geometry) to that of the high-current busducts It features tubular aluminum phase conductors in single-phase isolated coaxial aluminum screens. The GIL technology has several very promising features, such as: low transmission losses, low capacitive load, power rating of the equivalent overhead transmission line, high reliability, no electric ageing, no thermal ageing, operation equal to that of the overhead transmission line (i.e., auto-reclosure of the distance protection function), low environmental influence, etc All of these beneficial factors will surely add to its increased application in the near future, e.g., for bringing the bulk transmission power to major city centers. It ought to be mentioned that this magnetic field problem could be treated in the purely analytical manner, as described in, e.g., [13,16,17]

Mathematical Model

Numerical Example

Findings

Conclusions