Representation of Severe Negative Subsequent Return Stroke by Optimization based Channel-Base-Current Function Parameters

Abstract

In this paper, the lightning channel-base-current (CBC) function parameters are identified using four different optimization techniques (such as genetic algorithm (GA), particle swarm optimization (PSO), differential evolution (DE), and sine cosine algorithm (SCA)) to representing the measured data given in IEC standard 62305-1, 2010 for the severe (5%) case negative subsequent return stroke (NSS). The sum of two Heidler’s functions (HFs) is used for representing the desired severe NSS, and its parameters (namely, I01, I02, τ11, τ12, τ21, τ22, n1, and n2) are identified using GA, PSO, DE, and SCA. The data thus generated and reported for approximating the measured severe NSS. During this process, the data obtained by SCA showing a good agreement between the computed and measured CBC as compared to the data obtained by GA, PSO, and DE. However, the data provided by all above mentioned optimization algorithms can be used to observe the behavior of the return stroke current at different heights through a lightning channel, and this will useful in calculation of lightning electromagnetic field (LEMF).