配电网中性点接地方式若干问题的探讨

摘要

对配电网采用什么接地方式，目前业界还没有完全形成共识。讨论了中性点接地方式与分类问题、接地方式对供电质量与人身安全的影响、小电流接地故障选线与定位以及利用瞬时性接地故障信息实现在线监测等问题，指出小电流接地方式能够减少50%以上的故障停电次数，小电阻接地方式在人身安全方面并没有优势，长期以来制约小电流接地故障选线技术的难题已经得到解决，因此，配电网优先考虑采用小电流接地方式，特别要杜绝将已经采用小电流接地的架空网络或架空线路与电缆混合网络改为小电阻接地方式。%A consensus has not been reached on the adaption of the natural neutral grounding modes of distribution networks.The classification of grounding modes,the impacts of grounding modes on power quality and human safety,the faulty feeder identification and fault location techniques,and the online monitoring using transient fault information are discussed.It is pointed out that the small current grounding can reduce more than 50% fault interruptions; the low resistance grounding does not have significant advantages on human safety due to significant breakthroughs of the faulty feeder identification and fault location techniques in recent years.The small current grounding shall be considered as the preferable option for distribution networks.The switching over for small current grounding to low resistance grounding for networks containing overhead lines must always be avoided. This paper is supported by National Natural Science Foundation of China(No.51177096).