There are some problems existing in the traditional grounding mode of the distribution network. To solve them, this paper proposes a flexible grounding method for neutral point. This paper analyzes the advantages and the disadvantages of single-phase ground faults occurring at different neutral grounding points and summarizes the characteristics of several existing grounding arc elimination technologies for distribution networks. Depending on the actual data of a 10-kV substation, the ATP-EMTP was used to build a 10-kV distribution network model, and an arc model based on arc length control was used for single-phase ground fault simulation. According to the simulation results, it was known that the overhead line network of arc suppression coils was compared. Permanent ground faults occur in pure cable networks which are grounded by small resistances. Flexible grounding systems have significant benefits in suppressing the inrush currents at fault points when an intermittent arc single-phase-to-ground fault occurs, the flexible grounding system causes intermittent arcing. The voltage is clearly inhibited. The flexible grounding method has certain reference value for improving the reliability of distribution network power supply and providing the safe operation of the system. INDEX TERMS Flexible grounding, arc suppression coil, ineffective grounding system, arc ground overvoltage.

Conductive concrete has great application potential in grounding and electromagnetic shielding. To verify the effect of conductive concrete on the corrosion of grounded metals, several conductive concrete with different conductive phase, such as Q235 carbon steel, galvanized steel and stainless steel, were prepared. The conductive concrete test specimens are immersed in red soil leachate, their open circuit potential, potentio-dynamic polarization and electrochemical impedance spectroscopy were measured by electrochemical method. Corrosion behaviour of different grounding metals in conductive clays with different conductive phase are compared based on the pre-mentioned three indicators. The results show that conductive concrete can reduce the corrosion of grounded mental effectively compared with ordinary concrete, galvanized steel has better corrosion resistance than Q235 carbon steel, graphite-based conductive concrete can protect the grounding metal better than stainless steel-based conductive concrete, and high conductive phase content can make a low metal corrosion.

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