Evaluation of the backflashover performance of 150 kV and 400 kV double-circuit overhead transmission lines as affected by lightning attachment models and peak current distributions

• Published in: Electric power systems research Vol. 235; p. 110839
• Main Authors: Datsios, Zacharias G., Mikropoulos, Pantelis N., Tsovilis, Thomas E.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2024
• Subjects: ATP-EMTP; Backflashover; Insulation coordination; Lightning; Lightning incidence; Overhead transmission lines; Backflashover; ATP-EMTP; Lightning incidence; Insulation coordination; Lightning; Overhead transmission lines
• ISSN: 0378-7796; 1873-2046
• DOI: 10.1016/j.epsr.2024.110839

•Lightning attachment model effects on BFR of overhead lines are assessed.•Lightning peak current distribution effects on BFR of overhead lines are evaluated.•Typical 150 kV and 400 kV double-circuit overhead lines are studied.•Critical backflashover currents are obtained through EMT simulations.•Lightning peak current distributions yield more pronounced effects on BFR. The evaluation of the backflashover performance of overhead transmission lines requires the adoption of a lightning attachment model and a peak current distribution. These affect the estimated backflashover rate, BFR, of the lines. The present study aims to quantify the influence of lightning attachment model and peak current distribution on the BFR of double-circuit overhead lines. This is achieved by evaluating typical 150 kV and 400 kV lines. ATP-EMTP simulations are conducted to obtain the critical currents causing backflashover of line insulation. Then, the critical currents are used in lightning incidence computations to obtain BFR. The influencing parameters taken into account in this work are the low current and low frequency tower ground resistance, the location of lightning strike to the shield wire along the span, and the AC voltage phase angle, all affecting the critical backflashover current. Several lightning attachment models and peak current distributions are evaluated. Their influence on BFR is found to be considerable, especially for lower tower ground resistance values. The lightning peak current distributions yield more pronounced effects on BFR. The results of this study stress the need for computing BFR using a more accurate expression than the simplified one based on CIGRE TB 63.