탄소블록과 동봉의 접지성능 비교분석

Abstract

a carbon block(1[m], Φ245[mm]) and a three-linked copper rod of equilateral triangles with 1[m] spacing. Ground impedance depending on applied current source was evaluated by the application of a sine wave current in ranges of 60[Hz]∼3.5[MHz], a fast-rise pulse with rising time of 200[ns], a standard lightning impulse of 8/20[μs] and a 600[Hz] square wave. Ground impedance for both electrodes were almost the same value below 100[kHz], and increased rapidly afterwards. The maximum ground impedance appeared 400[Ω] at around 1.5[MHz]. Ground impedance of the carbon block was lower at the square wave and was higher at the fast-rise pulse than that of the copper rod. Also, ground impedance as ages showed no difference for the last 8 months. From the results, it is likely that ground performance for both electrodes shows no difference against commercial frequency and lightning impulse current, while the copper-rod shows better performance against a fast-rise pulse with rise-time of a few hundred [ns].

This thesis dealt with the comparative analysis on grounding performance of a carbon block and a copper rod. Two types of grounding systems buried at a depth of 0.8[m] were compared