Effects of lightning strikes on 20 kV earthcables

• Published in: 14th International Conference and Exhibition on Electricity Distribution (CIRED 1997 - Distributing Power for the Millennium) pp. 3.28.1 - 3.28.6
• Main Authors: Muhr, M, Pack, S, Haidvogl, H, Kreyca, F
• Format: Conference Proceeding
• Language: English
• Published: London IEE 1997
• Subjects: Applied sciences; Electrical engineering. Electrical power engineering; Electrical power engineering; Exact sciences and technology; Other numerical methods; Power cables; Power networks and lines; Underground and submarine networks; atmospheric discharges; underground power cables; high voltage power cables; protection arrangements; overvoltage; numerical model; power cables; oversheath damage; cable sheathing; earthing; numerical analysis; underground cables; overvoltages; 20 kV; grounding; lightning strikes; Underground cable; Deterioration; Lightning; Lightning overvoltage; High voltage cable; Perturbation; Protection
• ISBN: 9780852966747; 0852966741
• ISSN: 0537-9989
• DOI: 10.1049/cp:19970534

Recently appeared defects on high voltage cables made an urgent evaluation of the impact of lightning strikes necessary. Sometimes overvoltages between the copper wire screen of the cable and earth causes damage to the oversheath. Field measurements with a classification of the voltage impulses at the copper wire screen have been made to evaluate the number of events. Additionally, a numerical model was developed to study the effects of atmospheric discharges on underground power cables with emphasis to the influence on the oversheath. This numerical method was also applied to estimate the effectiveness of different protection arrangements. This contribution presents evaluation methods for overvoltages of power cables and a model used firstly for calculating the stress caused by differential voltages and secondly to determinate the influence of protection measures. (6 pages)