Influence of Grounding Resistance Connecting to Surge Arrester on Effectiveness of Lightning Protection Caused by Direct Hit for Power Distribution Lines

Abstract

In Japan, the grounding resistance of surge arresters (Arrs) for the lightning protection of power distribution lines is generally maintained below 30 Ω. Therefore, electric power companies have been spending large amounts of money on the construction and maintenance of low grounding resistances. In this paper, the influence of grounding resistance on lightning protection measures for power distribution lines with both a ground wire (GW) and Arrs is investigated by EMTP analysis and experiments. These results showed that even if the grounding resistance of Arrs becomes high, the effectiveness of lightning protection is hardly decreased. The results also indicated that it is more important for constructing a rational lightning protection system to install a large number of lightning protection devices on power distribution lines than to lower the grounding resistance of Arrs.

Optimized Protection of Pole-Mounted Distribution Transformers against Direct Lightning Strikes

“…Experimental results also emphasize the importance of low grounding resistance for better performance of protective devices such as surge arresters [12]. However, the authors in [26], by considering different constant grounding resistances for the surge arrester installed on the MV side of the transformer in a network, concluded that, for their particular configuration, (1) increasing the grounding resistance slightly changes the protective performance of surge arresters, and (2) equipping the system with proper protective devices is much more important than decreasing the grounding resistance. Defining a suitable distance between two grounded poles is yet another critical issue.…”

“…Soil ionization results in decreasing the earthing resistance [24], i.e., under the ionization condition, the resistance is varied by the current. However, in most of the existing works on distribution networks, constant resistances were used to model the grounding resistance [8,25,26]. In [25], the importance of earthing resistance in the performance of surge-protecting devices installed in the LV terminal of the pole-mounted distribution transformer was investigated.…”