How Lightning Tortuosity Affects the Electromagnetic Fields by Augmenting Their Effective Distance

Abstract

Abstract-A novel approach for developing the electromagnetic fields from a lightning return stroke which follows a tortuous path will be presented. The proposed model is unique in that it recognizes that the symmetrical tortuosity of lightning directly impacts the observable distance r, which in turn, alters the resulting electromagnetic fields. In the literature, lightning return stroke models typically employ the assumption that the cloud-to-ground path is straight. Although this assumption yields fairly consistent results across an array of varying approaches, it does not account for lightning's natural physical appearance. Furthermore, straight-line models only account for the cloud-to-ground discharges and do not address branching and/or cloudto-cloud discharges which are far more common. In reality, the "steps" which make up the lightning channel's initial descent are staggered or tortuous with respect to each other. Given this fact, the upward traveling current wavefront which follows this prescribed path will exhibit the same characteristics. In doing so, each current segment, which forms along its respective step, induces electromagnetic fields with angular aggregates that propagate outward from their origin. This, in turn, will generate spatial points where there are fields of higher and lower intensities. The results presented in this paper will show how the effective observable distance due to symmetrical tortuosity alters the resulting electromagnetic fields. Furthermore, it will be shown that as the observable distance r is increased, results from the proposed model closely resemble the straight-line model which strongly suggests that symmetrical tortuosity is only influential at relatively close distances.

Assessment of induced voltages in common and differential‐mode for a PV module due to nearby lightning strikes

“…When the electric field distribution generated by the opposite charges reaches a critical value, the insulating capacity of the air breaks down, generating the lightning discharge. Many studies have investigated on the effect of the LEMP due to the characteristics of the lightning channel, such as its inclination [59,60] and, more recently, its tortuosity [61][62][63]. LC tortuosity can significantly affect the generated fields and consequently the induced voltages.…”

Protection of Naval Systems Against Electromagnetic Effects Due to Lightning

“…The effects on naval systems by induced voltages due to channel tortuosity, horizontal parts and other complexities of the channel, branch currents, etc. should be further studied in detail by applying recently developed sophisticated models [49][50][51][52][53].…”

Estimation of Return Stroke Velocity by Time‐Reversal Reconstruction of Channel Feature Points

“…Cooray and Lundquist (1985) considered that the fine structure on the E‐field waveform is caused by sudden changes in the channel current, channel geometry, or RS velocity. Similarly, many of the fine, microsecond‐scale structures in the E‐field waveform can be attributed to the tortuous channel (Le Vine & Willett, 1995; Meredith et al., 2010; Willett et al., 2008), Shao et al. (2012) suggested that the kink of the fine structure on the E‐field waveform can be caused by the dispersive and lossy current propagation in the RS channel.…”