谈TN系统电缆出线接地故障保护——兼谈电缆出线最大供电半径的计算

Discussion on Protection of Out-cabling Earthing Accident in TN System

对TN-S和TN-C-S系统的优缺点及应用条件进行了对比分析,介绍了TN系统出线电缆接地故障保护方式及过电流保护动作可靠性要求,还探讨了出线电缆接地故障采用过电流保护时最大供电半径的计算方法,计算结果可供工程设计参考。

The paper compares the features and applying conditions between TN-S system and TN-C-S system. It introduces protective ways of earthing accident happened in the out-cabling in TN system and reliability requirements on over-current protection. The paper also analyses how to compute maxium supplying radius while over-current protection applied in the earthing accident.