Transient Impedance Behaviors Associated with the Current Injection Point and Lengths of Deeply driven Ground Rod

초록

This paper presents the behaviors of the transient and conventional impulse impedance associated with the current injection points and lengths of deeply driven ground rods. The dynamic characteristics of the deeply driven ground rods subjected to the impulse current were examined. The transient impulse impedance characteristics strongly depend on the lengths of grounding electrode. Also, when the test current was injected into the bottom of grounding electrodes, transient impulse impedance is higher than that for injection into the top of grounding electrodes and the oscillation pulses with high frequency were included on the front of potential rise wave. It was found that the reduction of ground electrode inductance is an important factor to improve the transient impulse impedance characteristics.