Analysis of Grounding Grid Reconstruction of 35 kV Coal-mine Substation in Fenxi
Yutong Zhou · Insulators and Surge Arresters · 2013
Through careful analysis on lightning disturbance of a coal-mine 35 kV substation in Fenxi,the main reason is that both of the grounding resistance and the impulse grounding impedance are too high.Field test was carried out and the actual situation is combined with the particularity of power supply in coal-mine,the shielding ring is used to decrease the impulse grounding impedance and to improve the potential distribution.Meanwhile,the grounding resistance is decreased by natural grounding conductors and GPF-94 efficient betonies’ reduction in resistance preservatives.After reconstruction,the grounding parameters are in line with requirements.