Simulation of direct lightning strokes to overhead line towers requires accurate modeling of tower grounding systems.
An expression of the fitting function and the fitting formula of tower grounding resistance are derived theoretically according to application demands.
The shunt coefficients of tower, ground wires and coupling ground wire, and the coupling coefficients are also compared and discussed in situations that the coupling ground wire is mounted in different positions.
The paper presents the application of an ATP-EMTP Monte Carlo procedure for backflashover rate (BFOR) evaluations to HV overhead lines (OHL), equipped with three different types of spatially extended and/or geometrically involved tower grounding systems.
Results are compared to those yielded by both the simplified and 'complete' CIGRE methods for backflashover rate calculations, showing the applicability of the proposed procedure to line configurations characterized by complex tower grounding arrangements.
To improve the design method of foundation of transmission tower in mining subsidence area, and considering the interactions of transmission tower, ground and foundation, this paper presents a contrast research on the anti-deformation performance of two types of foundation (i.e. independent foundation and composite foundation with protecting apron) by finite element simulation.
From the simulation results, it is found that the BFR of transmission lines is markedly affected by the tower footing grounding system model.
From the simulation results, it is found that the outage rate of TLs is markedly affected by the model of the tower footing grounding system.
According to this assessment, in the 40-to-10-Ω 40-to-10-Ω 40-to-10-Ω 40-to-10-Ω rangetance, the CIGRE methofology overestoweres outage rate ofootingine in relation to the reference values (98–21% largroundinge 40-to-10-Ω resistanceower footheg grounding resistanCIGRE
But Korda's narrative stalls when he injects the stories of pilots who fought in the Battle of Britain (he also heaps praise on the valorous men and women who staffed radar control towers, ground control rooms, maintenance crews and all the other units that combined to support Britain's aces in the air).
