| Title |
Effects of the Length of Down Conductors on Transient Ground Impedances |
| Authors |
Bok-Hee Lee ; Su-Bong Lee ; Dong-Cheol Jeong |
| Keywords |
Down conductor ; Impulse ground impedance ; Impulse current ; Ground rod ; Grounding grid |
| Abstract |
This paper presents the transient impedance behaviors according to the length of down conductors of grounding systems to lightning impulse currents. The potential rise and effective impulse ground impedance of the deeply-driven ground rod and grounding grid subjected to the impulse currents were measured and analyzed as a function of the rise time of impulse currents and lengths of down conductor. The transient ground impedances strongly depend on the configuration and size of grounding electrodes, the waveform of impulse currents and the length of down conductors, and the installation methods reducing the inductance of down conductors are an important factor to decrease the transient ground impedances. |