INGENIERÍA ELECTROMECÁNICA

ASIGNATURA: SISTEMAS ELECTRICOS DE POTENCIA

2.8 Inductancia de línea de conductores compuestos.

PRESENTA:

IDALFI SANTANA MOJICA

SEMESTRE: AGOSTO-DICIEMBRE

Manzana 30, Lote 1, Col. El Limón, C.P. 40880, Zihautanejo, Gro.Tels. 755-554-48-51, 755-554-4852, 755-554-54-87, fax. Ext 110

www.itcostagrande.edu.ma e-mail : itcosta@prodigy.net.mx

Subsecretaría de Educación Superior

Dirección General de Educación Superior Tecnológica

Instituto Tecnológico de la Costa Grande

NO. CONTROL

12570172

INSTITUTO TECNOLÓGICO DE LA COSTA GRANDE

INTRODUCTION

In the evaluation of inductance, solid round conductors were considered. However, in practical transmission lines, stranded conductors are used. Also, for reasons of economy, most EHV lines are constructed with bundled conductors. In this section an expression is found for the inductance of composite conductors. The result can be used for evaluating the GMR of stranded or bundled conductors. It is also useful in finding the equivalent GMR and GMD of parallel circuits. Consider a single phase line consisting of two composite conductors (x) and (y) as shown in Figure 4.10.

The current in (x) is (I) reference into the page, and the return current in (y) is (-I). Conductor (x) consists of N identical strands or semiconductors, each with radius (rX). Conductor (y) consists of M identical strands or semiconductors, each with radius (rY). The current is assumed to be equally divided among the semiconductors. The current per strand is (I/N) in x and (I/M) in Y. The application of (4.29) will result in the following expression for the total flux linkage of conductor (a).

Using (4.29), the inductance of other subconductors in (x) are similarly obtained. For example, the inductance of the subconductors n is.

The average inductance of any one subconductor in group x is

Since all the subconductors of conductor x are electrically parallel, the inductance of x will

Substituting the values of la, lb,lc...,ln in (4.47) results in

• GMD is the mnthe root of the mnthe distances between n strands of conductor x m strands. GMRx is the n^2 root of the product of n^2 terms consisting of r´ of every strand times the distance from each strand to all other strands within group x.• The inductance of conductor y can also be similarly obtained. The

geometric mean radius GMRy will be different. The geometric mean distance GMD, however, is the same.