Back scattering response from single, finite and infinite array of nonlinear antennas based on intelligent water drops algorithm

Abstract

Purpose The purpose of this paper is to calculate the back scattering response from single, finite and infinite arrays of nonlinear antennas like the case where the antennas are exposed to high-value signals such as lightning strokes. Design/methodology/approach In this paper, the authors have used a recently introduced optimization technique called intelligent water drop. Findings The results exhibit that the method used by the authors is faster and more accurate than other conventional optimization algorithms, i.e. particle swarm optimization and genetic algorithm. Originality/value A new optimization algorithm is used to solve nonlinear problem accurately and sufficiently. Although the technique is not confined to the mentioned examples in the paper, it can be applied to other nonlinear circuits.

An efficient spectral balance method for transient analysis of single phase overhead lines in the presence of surge arresters

“…To solve Equation (2) with guaranteed convergence, we resort to the IWD algorithm 22 to compute the unknown vector at intermodulation frequencies.…”

“…The next step is that the induced voltage across the arrester is efficiently computed in time domain. To this aim, an efficient optimization algorithm namely IWD algorithm 22 is applied to the cost function in (2). For shortening the paper, mathematical formulation of IWD is ignored and referred to 22 …”

“…Finally, to compute the lightning‐overvoltage across the arrester efficiently, instead of the AOM, an efficient optimization technique, called intelligent water drop (IWD) algorithm, 22 is then used. It is worth mentioning that transient solvers such as electromagnetics transient program (EMTP), 23 are also under assumption of kh ≪ 1.…”

Comprehensive formulae for effective length of multiple grounding electrodes considering different aspects of soils: Simplified multiconductor transmission line‐intelligent water drop approach

“… A is a coefficient as well. Using a number of input‐output pairs computed via the simplified MTL, coefficient A , and powers x , y , z are estimated based on IWD algorithm in order to minimize the following cost function: where N , and denote respectively the number of input‐output pairs, and effective lengths computed by the simplified MTL and the proposed formula in (27).…”

“…The simulation results show that in soils where the two effects are simultaneously occurred, the effective length is a value between the individual ones in only‐dispersive and only‐ionized soils. This fact is more pronounced in highly resistive soils so that it motivates the authors to propose predicting formulae for effective length in such soils based on combining the simplified MTL with an efficient optimization algorithm called intelligent water drop algorithm (IWD) . Finally, using apparent resistivity approximation in inhomogeneous soils, effective length of grounding systems considering three effects simultaneously is easily predicted.…”