Accurate modelling of rod driven tower footing

Author

Almeida, M.E. ; Correia de Barros, M.T.

Author_Institution

Inst. Superior Tecnico, Tech. Univ. Lisbon, Portugal

Volume

11

Issue

3

fYear

1996

fDate

7/1/1996 12:00:00 AM

Firstpage

1606

Lastpage

1609

Abstract

For evaluating the lightning performance of power transmission lines by computer simulation, accurate modelling of tower footing is very important. In particular, the decrease of the earth resistance observed for high values of the current flowing from the tower to earth has to be considered. In this paper, different modelling approaches allowing the nonlinear behaviour of the tower footing to be taken into account are overviewed, and a new model to describe the soil ionization process is presented. The proposed model corresponds to considering the ionized soil region as an equifield shell. In order to represent the ionization phenomena, the values of the resistivity on the ionized region are decreased according to the local current density, and the electric field is kept at a critical value. Deionization of the soil is also taken into account. Simulation results are presented, and compared to the published results of experimental tests

Keywords

earthing; lightning protection; poles and towers; power overhead lines; power system analysis computing; power transmission lines; accurate modelling; computer simulation; current density; current flow; earth resistance; electric field; equifield shell; lightning performance; power transmission lines; rod driven tower footing; soil ionization process; Computer simulation; Conductivity; Current density; Earth; Grounding; Ionization; Lightning; Poles and towers; Power transmission lines; Soil;

fLanguage

English

Journal_Title

Power Delivery, IEEE Transactions on

Publisher

ieee

ISSN

0885-8977

Type

jour

DOI

10.1109/61.517523

Filename

517523