External lightning protection of overhead distribution lines against direct lightning strikes

摘要

Lightning protection systems of overhead distribution lines (ODLs) are mainly used with the aim to reduce number of outages caused by indirect lightning strikes. This paper presents an external lightning protection system (EPS) that protected overhead distribution lines against direct lightning strikes. In that way a high efficient lightning protection of critical lines can be achieved. Instead of a standard ground wire, this approach uses one or two external ground wires placed at the top of separate towers located at one or both sides of the protected line. Four critical scenarios in EPS design have been considered and the general dimensioning procedure which is applicable to any ODL is presented. EPS can be used in extreme conditions for protection of short and high risk ODLs.