Lightning Surge Characteristics of an Actual Distribution Line and Validation of a Distribution Line Model for Lightning Overvoltage Studies

For distribution lines in Japan, protection measures against lightning induced overvoltages have been taken and can be considered almost complete. The focus of lightning protection measures has moved to overvoltages due to direct lightning strokes. Studies of such overvoltages require simulations using the EMTP (Electro-Magnetic Transients Program), and components of a distribution line must be modeled appropriately in the EMTP simulation environment. The authors have proposed an EMTP model of a distribution line in a separate paper.This paper consists of two parts. The first part presents surge characteristics of a distribution line obtained by measurement using an actual-scale test distribution line. Especially, the result reveals noteworthy characteristics of the surge impedance of a reinforced concrete pole and the wavefront-time dependence of insulator voltages. The second part presents validation of the distribution line model previously proposed by the authors. The validation shows that the distribution line model accurately reproduces the measured voltage and current waveforms for various wavefront times of injected currents.