关键词: 6(10)kV系统, 中性点, 接地, 接地电流保护

Abstract: This paper discusses the main advantages and disadvantages of the commonly used neutral point grounding mode in 6(10)kV system in petrochemical enterprises.It also researches about the relationship between the selection of different grounding modes and reliability of power supply.Then the paper arrives at the conclusion that the neutral point of the 6(10)kV system in petrochemical enterprises should adopt the resistance grounding mode.One of the important and innovative points in this paper is that the resistance grounding mode of the neutral point could be turned to un-grounding mode when necessary,so that grounding protection can be set flexibly and accurate grounding loop can be achieved.Another focus is the research on the distribution of grounding current during grounding fault,which contributes to the selection of current transformer corresponding to the grounding protection accurately so that plausible errors could be avoided.

Key words: 6(10)kV system, Neutral point, Grounding, Grounding current protection