A lightning return-stroke model of a transmission-line type, which incorporates the wave-front distortion of a channel current and its attenuation as a function of height, is proposed. This model is compared with representative "engineering" return-stroke models in terms of the spatial and temporal distribution of a channel current, and the resultant electromagnetic fields at different distances from an assumed vertical lightning channel. Consequently, it becomes clear that the proposed model can reproduce all the features of typical electric and magnetic fields associated with natural subsequent lightning, observed within 100 μs. In estimating the lightning performance of surge arresters equipped on overhead distribution lines or overhead telecommunication lines, it is important to reproduce the wavetail of a lightning-induced surge, as well as its peak appearing generally within a few microseconds. The proposed lightning return-stroke model can be applied to such a purpose.
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