The non linear effects of soil ionisation on the behaviour of earth electrodes are investigated by a finite difference time domain numerical scheme. A time variable soil resistivity is used in order to simulate the soil breakdown; step by step the resistivity value is controlled by the local instantaneous value of the electric field compared with the electrical strength, fixed for the soil. No a priori hypothesis about thegeometrical shape of the ionised zone around the electrodes has to be enforced. Simulation results related to complex earth electrodes of limited extension are reported. The model has been validated by comparing the computed results with data available in technical literature. A discussion about dangerous earth voltagesis reported, by underlining the role of soil ionisation. Electrodes of larger extension can be straightforwardly simulated by means of larger computational resources.
|Number of pages||12|
|Journal||IET SCIENCE, MEASUREMENT & TECHNOLOGY|
|Volume||vol. 2, issue 3, May 2008|
|Publication status||Published - 2008|
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering