A Nonmeshing Approach for Modeling Grounding

Abstract

Nowadays grounding systems and protection devices are designed in order to protect goods and people at the industrial frequency range (50 Hz). In the future, buildings will include more and more smart and power electronics devices. This implies a need to consider a larger frequency range up to some hundreds MHz. Considering the heterogeneity of large systems including grounding, loads, power converters, and cabling, it could be interesting to benefit from the magnetic partial element equivalent circuit approach for which it is not necessary to mesh the media. This paper presents the force of this method, which leads to an electrical equivalent circuit of grounding and cabling systems directly useful in circuit simulator including power converters, loads, etc. The aim of this paper is to detail the modeling process, given this electrical equivalent circuit of grounding systems, taking into account on one hand the physical characteristics of the earth (resistivity and permittivity) and on the other hand the frequency range of disturbances sources. Using this approach, local values such as the current density along conductors, as well as potential everywhere in the studied domain, can be evaluated. Global values such as equivalent impedances can also be determined in order to improve the grounding design.