Lightning Overvoltage Protective Effect of Distribution Line Arresters

A distribution line model for lightning overvoltage studies

“…In the conventional model [4], high-voltage wires and the overhead ground wire are represented by multiphase distributed-parameter lines, † while the poles are represented by single-phase lossless distributed-parameter lines. Here we repeat the previous reduced-model experiments using such a conventional model.…”

“…Indirect lightning strikes have long been studied [1,2], and appropriate countermeasures have been basically established. In recent years, the focus of lightning protection research has shifted to direct lightning strikes, and lightning surge analysis using EMTP (Electro-Magnetic Transients Program) has been applied to lightning protection effects of overhead ground wires and surge arresters [3,4], burnout of surge arresters [5,6], grounding optimization of surge arresters [7,8], etc.…”

“…Most available studies of direct lightning strikes on distribution lines [3][4][5][6][7][8] consider mild lightning currents with wavefront length of several microseconds, and no reports on steep lightning currents have been published. In many actual waveforms of lightning current, the wavefront rises gradually at first but then rises steeply [9].…”

“…In this time domain, however, the electromagnetic field due to the lightning current around the pole is still being formed, and the transient response of the distribution line (including such phenomena as growth of the electric potential on the pole top with formation of an electromagnetic field around the pole) cannot be analyzed accurately in terms of electric circuit theory. In existing distribution line models [4] (below referred to as conventional models) used for EMTP analysis, high-voltage wires, ground wires, and poles are treated as distributed-parameter lines, and short-time phenomena are ignored. We may consider the possibility of efficient and accurate reproduction of the short-time phenomena by using numerical electromagnetic field analysis techniques to directly solve the Maxwell equations [10], but this requires vast amounts of computation.…”

Lightning surge characteristics of an actual distribution line and validation of a distribution line model for lightning overvoltage studies

“…In this context, indirect lightning strikes have long been studied [1,2], and the appropriate countermeasures have essentially been established. Recent experimental research has shown the feasibility of protection against direct lightning strokes [3], and lightning surge analysis using EMTP (ElectroMagnetic Transients Program) has been applied to the lightning protection effects of overhead ground wires and surge arresters [4,5], burnout of surge arresters [6,7], grounding optimization of surge arresters [8,9], and the like.…”