Inspec keywords: power transmission protection; air gaps; lightning protection; poles and towers; insulators; overvoltage protection; power transmission lines; electrodes

Other keywords: lightning protection air-gap configurations; UHV AC double-circuit tower; UHV AC double-circuit line; double-circuit UHV AC power transmission line system; distance 6.5 m; discharge voltage gradient; distance 2.9 m; time 1000.0 mus; tower frame discharge testing; tower air-gap discharge characteristics; inverse V-type insulator tower air-gaps configuration; wavefront switching impulse voltage; lightning impulse; power frequency voltage; distance 7.2 m; inverse V-string; high-voltage electrode; discharge characteristics curves; phase air-gap configurations; insulation coordination; distance 6.7 m

Subjects: Power line supports, insulators and connectors; a.c. transmission; Protection apparatus; Power system protection