Читать книгу Electrical Safety Engineering of Renewable Energy Systems - Rodolfo Araneo - Страница 23

Let us consider two identical hemispheres embedded into the soil at the distance 5ro center-to-center, so that they can be considered independent from each other. The first electrode leaks the current i, whereas, the second electrode receives the same current ( Figure 1.12).

Figure 1.12 Hemispherical electrodes connected in series.

The resulting surface potential V(r) at a generic point r along a line joining the two hemispheres is given by the superposition of the potentials imposed by each electrode (Eq. 1.15).

(1.15)

If r = d/2, which is the center point between the two hemispheres, the value of the surface potential is V(d/2) = 0.

The point of the soil at which the ground potential is zero is the location that must be identified for the correct measurement of the ground resistance RB of an electrode, as further elaborated.