Experimental analysis of impulse characteristics of grounding grids with and without rods

Abstract EN

Impulse characteristics of grounding systems have a great influence on proper evaluation of substation equipment stresses from lightning overvoltages, protection and design points of view.

The grounding grid impulse characteristics depend on: grid parameters and soil characteristics as well as on the impulse current shape, magnitude and discharge point.

The addition of driven rods to the grid has an action on grounding grid impulse characteristics.

This paper presents an experimental study for determining the impedance of grounding grid with and without driven rods.

Tests are conducted on three scale models to simulate single-, double- and triplelayer soils.

Also, the impedance of grounding grid calculated mathematically from the generalized equations which matched the impedance, voltage and current wave shapes.

The values of grounding grid impedances determined experimentally and mathematically are compared.

The comparison was closed together and satisfied