小电阻接地系统单相接地分析和继电保护整定

Analysis of Single Phase Grounding Fault and Relay Protection for Low Resistance Grounding Systems

建立了小电阻接地系统的电路模型,计算了系统发生单相接地时的故障电流,分析了影响系统单相接地故障电流的因素,特别是如何选择中性点接地电阻,给出了零序电流保护整定方法以及在石油化工企业中的应用。

This paper establishes the circuit model of the low resistance grounding systems, calculates the short circuit current of the single-phase grounding fault,and analyzes the factors of single-phase grounding faults. The method of selecting the grounding resistance at neutral point is specifically discussed. Finally, the paper suggests the method of zero-sequence overcurrent relay protection and discusses its application in petrochemical industry.