110kV系统中性点接地方式的商榷

上海宝钢的 1 1 0kV系统中性点的接地方式是经过小电阻接地 ,最大单相故障电流只有 1 2 0 0A ,与国内 1 1 0kV系统采用中性点直接接地的方式不同。近年来在两个系统中先后发生过 1 1 0kV充油电缆终端爆炸事故 ,两起电缆事故相似但两次造成的破坏则大相径庭 ,前者较小而后者非常严重。由此可见前者的优越性。1 0kV和 3 5kV系统的中性点接地方式已有改为经小电阻接地的 ,1 1 0kV系统是否要改值得研讨。

DISCUSSION ON NEUTRAL GROUNDING MODES OF 110kV SYSTEM

The neutral point of Shanghai Bao steel 110kV system is grounded through a low resistance. Its max. single phase fault current is 1200A only, which is different from the neutral solid ground adopted by domestic 110kV system. Recently, explosion faults of 110kV oil filled cable terminations happened successively in these two systems. Fault conditions of them were similar, but resulted destruction were of vast difference, the former was comparatively trifling, while the latter was very severe.. The formers superiority can thus be seen. The neutral grounding of 10kV & 35kV systems are being changed to low resistance, it is worth studying whether that of 110kV system should be changed too.