Lightning Grounding Grid Model Considering Both the Frequency-Dependent Behavior and Ionization Phenomenon

Abstract

A grounding grid is essential to the lightning protection of power systems. This paper presents a modified partial element equivalent circuit method for predicting the transient behavior of the grounding grid. The frequency-dependent parameters of the grounding grid are obtained first by using the image method. Both modified nodal formulation and vector fitting techniques are applied to derive an extended equivalent network for time-domain simulation. In this method, the soil ionization effect is considered using a nonlinear resistance. The proposed method is verified with experimental results available in the literature. Finally, lightning transients in the grounding grid of a radio base station is presented. The ionization and propagation effects on grounding grid performance are discussed.

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

“…Up to now, the impact of two‐layer soils on the GPR and induced voltage on the soil surface considering ionization effect has been investigated respectively in References . Effective length of vertical rod buried in ionized two‐layer soils, however, has not been addressed yet.…”

“…To this aim, the apparent resistivity ρ a in (26) is adopted. This approximation has been used in Reference for computing GPR of horizontal electrode and grounding grids buried in horizontally two‐layered soils.…”

“…To this aim, transient voltage of the grounding systems (defined as the voltage of point of the injected current to a point at infinite) should be first correctly computed. Hence, to compute this quantity a number of numerical approaches in time domain, frequency domain, and mixed time‐frequency domain have been proposed . In only‐ionized soils, time domain approaches are usually preferable, whereas in only‐dispersive soils, the frequency‐domain techniques are more appealing .…”

“…In only‐ionized soils, time domain approaches are usually preferable, whereas in only‐dispersive soils, the frequency‐domain techniques are more appealing . To consider two effects simultaneously, frequency domain approaches in combining with circuit theory have been proposed.…”

Benefits of the Ground PEEC Modeling Approach—Example of a Residential Building Struck by Lightning

“…For complex systems, a transient analysis is required by designers in order to evaluate the relevance of protection devices. Some examples can be found in literature but either their complexity is far from a realistic configuration [9][10] or they are far from the residential case we propose [11][12].…”