uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
"Modelling direct lightning attachment to electrified railway system in Sweden"
Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences.
Show others and affiliations
2003 In: Proceedings of 2003 IEEE Bologna Powertech, Bologna, 23rd-26th, June, 2003, no paper no. 72Article in journal (Refereed) Published
Place, publisher, year, edition, pages
2003. no paper no. 72
URN: urn:nbn:se:uu:diva-92150OAI: oai:DiVA.org:uu-92150DiVA: diva2:165122
Available from: 2004-10-12 Created: 2004-10-12Bibliographically approved
In thesis
1. Transient Response of Grounding Systems Caused by Lightning: Modelling and Experiments
Open this publication in new window or tab >>Transient Response of Grounding Systems Caused by Lightning: Modelling and Experiments
2004 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In order to achieve better lightning protection and electromagnetic compatibility (EMC) requirements, the needs for a proper grounding system and the knowledge of its transient behaviour become crucial.

The present work is focused towards developing engineering models for transient analysis of grounding system with sufficient accuracy and simplicity for lightning studies. Firstly, the conventional uniform transmission line approach for a single grounding conductor is modified and extended to grounding grids. Secondly, in order to overcome the drawbacks of all the existing transmission line approaches, for the first time, a non-uniform transmission line approach is developed for modelling the transient behaviour of different types of grounding systems. The important feature of such an approach is in its capability to include the electromagnetic couplings between different parts of the grounding system using space and time dependent per-unit length parameters.

High voltages and currents induced in the grounding systems due to lightning always produce ionization in the soil. This phenomenon should be included during the transient analysis of grounding systems. In the present work, an improved soil ionization model including residual resistivity in ionization region is developed. The fact that there exists residual resistivity in ionization region (7 % of the original soil resistivity) can be proved by the experiments reported in the literature and the experiments carried out at the high voltage lab of Uppsala University. The advantage of including residual resistivity is that the beneficial influence of soil ionization in reducing the potential rise of grounding system will not be overestimated, especially in high resistivity soil.

Finally, the transmission line approaches are adopted for studying the response of grounding systems due to lightning for different applications. These are, influence of soil parameters on the transient behaviour of grounding systems, transient analysis of grounding structures in stratified soils, investigation of the validity of existing definitions for effective length/area of different grounding structures, current distribution in the shields of under ground cables associated with communication tower, and influence of insulator flashover and soil ionization around the pole footing on surge propagation in Swedish railway system.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2004. 89 p.
Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1104-232X ; 1015
Electrical engineering, Grounding system, Lightning protection, Electromagnetic Compatibility, Transient analysis, Soil ionization, Transmission line approach, Elektroteknik
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
urn:nbn:se:uu:diva-4556 (URN)91-554-6041-0 (ISBN)
Public defence
2004-11-04, Häggsalen, Ångströmlaboratoriet, Lägerhyddsv. 1, Uppsala, 10:15
Available from: 2004-10-12 Created: 2004-10-12 Last updated: 2011-01-20Bibliographically approved

Open Access in DiVA

No full text

By organisation
Department of Engineering Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 72 hits
ReferencesLink to record
Permanent link

Direct link