Computation of lightning flashovers & backflashover voltage levels on 230KV transmission lines

Lightning has been one of the important problems for insulation design of power systems and it is still the main cause of outages of transmission and distribution lines. The lightning return-stroke current and the charge delivered by the stroke are the most important parameters to assess the severity of lightning strokes to power lines and apparatus. This paper presents the effects of tower, grounding parameters on the shield wire backflashovers voltage level failures. Also demonstrate the results used to determine the lightning caused backflashovers on 230 KV lines utilized by Saudi Electric Company (SEC) in Saudi Arabia, using two well known approaches CIGRE, and the simplified methods. The studies include lightning flashovers, backflash analysis, as dependent on the tower design which is considered the main parameters that reduce the rate of lightning backflashovers in such lines. The study results can be applied to reduce the number lightning flashovers and therefore reduce the transmission lines outages.