环网电缆零序过电流整定值的优化研究

本文在介绍地铁小电阻接地系统在正常和故障时环网电缆零序电流的基础上,分析了地铁供电系统中环网电缆故障时零序电流的组成和大小,通过理论计算和现场实测数据的分析比较,得出环网电缆零序过电流整定应在原躲过不平衡电流的基础上考虑电缆电容电流校验的结论。

This paper introduces the zero sequence over-current of MV loop in normal and fault cases of the small resistance grounding system in subway.The composition and magnitude of the zero sequence over-current in MV loop during the failure of subway power supply system are analyzed.Through theoretical calculation and field data analysis and comparison,the conclusion is drawn that the cable capacitance current checking should be considered on the basis of the original unbalance current.