Ionization Characteristics of Soil in Coaxial Cylindrical Electrode Systems under Impulse Voltage

초록

In this paper, breakdown characteristics of soil in a coaxial cylindrical electrode system stressed by impulse currents were experimentally investigated. The breakdown voltage and current waveforms for 4 types of soils were measured, and the threshold electric field intensity, the ground impedance-time (Z-t) curves and the voltage-current (V-I) curves were analyzed and discussed. As a result, the breakdown voltage and current waveforms are strongly dependent on the type of soil and the voltage and current waveforms for gravel and sand differ from those for silt and loess. The threshold electric field intensity is increased in the order of gravel, sand, loess and silt. The V-I curves for all test samples show a ‘cross-closed loop’ of ∞-shape under ionization.