架空配電線への雷撃距離特性に関する検討

裸電線と絶縁電線の放電特性

抄録

To clarify characteristics of lightning stroke distance to power distribution lines, experimental studies were done on discharge characteristics of a rod-ground wire (open wire) and a rod-conductor (insulated wire). The experiments were done by using the 12MV impulse generator at Shiobara testing yard of CRIEPI.
50% flashover voltage of a rod-insulated wire gap is higher than that of a rod-open wire gap under negative impulse voltages (2/50_??_250/1700μs) and a positive lightning impulse voltage (2/50μs). These effects become so notable as an insulated part of the insulated wire is thicker. Measurements by using ALPS (Automatic Lightning-Discharge Progressing-Feature Observation System) show that development of an upward leader from an insulated wire is suppressed by the insulated part of the wire. Therefore it is clarified that an insulated wire is more unlikely to attract lightning hits than an open wire.
From these experimental results, characteristics of lightning stroke distance to power distribution lines were studied in the case that a ground wire is removed. Attractive area of direct lightning hit to a conductor (insulated wire) becomes narrower as the peak value of lightning stroke current becomes higher.