Analysis of Electromagnetic Fields Generated by Inclined Lightning Channel

Evaluation of electromagnetic fields, which is caused by the lightning channel, is an appealing topic in order to consider the indirect effects of lightning on the power lines. In most computations of lightning electromagnetic fields, the return stroke channel is assumed to be a straight and a vertical channel. However, in reality, the lightning channel is most often inclined and has some tortuosity on scales. This paper provides general expressions for the electric field and the magnetic flux density, at any point, that are radiated from an inclined lightning channel. These general expressions are based on the Maxwell's equations. The proposed equations can estimate the components of the electric field and the magnetic flux density directly at any observation point and for any kind of lightning channel (vertical or inclined). Also, by using the suggested general expressions, the electromagnetic fields can be computed in close, medium and far ranges. The proposed expressions support the notion of the vertical lightning channel by assuming the channel angle with respect to Z-axis equals zero. In this paper, the analysis of the suggested expressions for the electric field and the magnetic flux density that radiated from an inclined lightning channel as well as their verifications by comparing their results with the results of the others is achieved. Also, these suggested expressions are used to investigate the effect of channel geometry, number of the segments to which the channel is sub-divided, position of the observation point with respect to each segment of the channel, and each segment orientations (defined with the azimuth angle I center dot) and inclination angle theta on the electromagnetic field distributions.