Study on the Lightning Protection Performance for a 110 kV Non-Shield-Wired Overhead Line with Anti-Thunder and Anti-Icing Composite Insulators

Due to micro landforms and climate, the 110 kV transmission lines crossing mountain areas are exposed severe icing conditions for both their high voltage (HV) conductors shield wires during winter. Ice accumulation on wire causes excessive sag, which leads a reduced clearance between earth HV wires, could eventually result in tripping of line due phase-to-ground flashover. lack effective de-icing techniques removing them completely from existing overhead (OHL) structure becomes reasonable solution prevent accidents. Nevertheless, risk exposure lightning strikes increased significantly after were removed. In order cope with this, anti-thunder anti-icing composite insulator (AACI) is installed OHLs. this article, without considered. The shielding failure installation AACIs studied using strike simulation models established ATP software. stroke flashover tests carried out examine failures various designs AACIs. Assuming tower’s resistance 30 Ω, LWL back direct 630.88 kA 261.33 kA, respectively, an unearthed OHL. unique mechanism AACI, operational level height pylon have neglectable influence its withstand (LWL). When length parallel protective gap increases 450 mm 550 mm, trip-out rate decreases 0.104 times/100 km·a 0.014 km·a, drop reaches 86.5%. Therefore, increasing distance AACI provide additional proven be method reduce rates non-shield-wired