Scale model test on a novel 400 kV double-circuit composite pylon

This paper investigates lightning shielding performance of a novel 400 kV double-circuit composite pylon, with the method of scale model test. Lightning strikes to overhead lines were simulated by long-gap discharges between a high voltage electrode with an impulse voltage and equivalent conductors fitted in a scale model of the composite pylon. The number of discharge attachments on the equivalent conductors is translated into shielding failure probability. In this way, the spatial shielding failure probability around the composite pylon is obtained. Additionally, the shielding failure region around the pylon is discussed. Combined test results and striking distance equation in electro-geometric model, the approximate maximum lightning current that can lead to shielding failure is calculated. Test results verify that the unusual negative shielding angle of - 60° in the composite pylon meets requirement and the shielding wires provide acceptable protection from lightning strikes.