Experimental investigation of impulse characteristics of practical ground electrode systems

In this work, the results of an experimental study of the impulse characteristic of practical ground electrodes consisting of horizontal conductors of various lengths and full-scale tower footings were reported. These electrodes were installed at an outdoor test site having non-uniform soil, with equipment facilities for generating low- and high-magnitude impulse currents. The tests on the horizontal electrode were used to determine the effective length, the voltage and current distribution along the electrode length and the effect of the injection point along the electrode. The tests on the tower footings were used to determine impulse resistance and demonstrate its non-linear variation with current magnitude. Computer simulations of the test electrodes using the electromagnetic field method showed good agreement with the measured result.