Increasing of the electric safety in HV systems by means of the ground resistance of the body

摘要

The dangers of personnel in high voltage stations can be very elevated, so the sharp evaluation of the resistance to ground of human body (R_(EB)) is very useful to establish and improve the safety levels and the plan interventions. The ground resistance of the body R_(EB) is the resistance that the current finds when it leaves the human feet for going into the earth; it depends both on the resistivities of the soils and on the thickness of the insulating layer. The aim of this work is to propose new simplified formulas for the calculation of the ground resistance of plate electrodes placed on two-stratus soil, since feet can be assimilated to plates to evaluate the step voltage and the touch voltage, to which the subject can be submitted in the case of a fault in HV systems. The research have been carried out with numerical methods; the results have been compared with semi empirical equations and with experimental tests.