Electrostatic effect induction formulae

The calculation of induced voltages and short-circuit currents on people is an important step for the determination of tolerable levels of the electrostatic fields of UHV power transmission lines. Formulae for the induced short-circuit current of a hemisphere and a half-cylinder on the ground are derived in this paper. A shape factor, defined as the ratio of the equivalent charge collecting area, S, to an object´s projected area on the ground, is discussed. The short-circuit current, Isc, is obtained from the ground-level voltage gradient, Eg, by means of the equation Isc= J ω ε EgS Different models for predicting the electrostatic induction are compared in the case of a rectangular solid. In order to show how calculations of Iscmay be made for more complicated shapes, a comparison of the results obtained with various approximations is presented.