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| 摘要: |
| 归纳了对变压器装设零序差动保护必要性的不同论点后指出，零序差动保护仅在变压器绕组靠近中性点(占整个绕组2％)处发生接地故障，相间差动保护灵敏度不足时方才显示出其灵敏度高的优越性。但是一方面在靠近中性点处电压很低，发生故障的几率很小，被短路的匝数少，故障危害不大；另一方面零序差动保护也不可能没有死区，其死区有多大还未深入研究。因此，装设零序差动保护的必要性不大。如果愿意装设零序差动保护作为补充，应将安全性放在首位，宜限制其保护范围。为此，提出用比例判据代替比率制动判据的方案。 |
| 关键词: 接地故障 变压器零序差动保护 接地故障保护 |
| DOI： |
| 分类号:TM772 TM41 |
| 基金项目: |
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| Discussion on transformer zero-sequence current differential orotection |
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ZHU Sheng-shi
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| Abstract: |
| Different opinions about the necessity of transformer zero-sequence current differential protection are summarized.It is pointed out that,only when the earthing fault is near the neu tral point (2%of whole winding)and the sensitivity of inter-phase differential protection is not suf ficient ,could the advantage of zero-sequence current differential protection in high sensitivity ap pear.The earthing fault near the neutral point is not so serious because of its low voltage,low fault pro bability and less turns shorted.Furthermore,there is also possible dead-zone of zero-sequence cur rent diffe-rential protection,which has not thoroughly studied yet.So,it is not essential to configure a ze ro-se-quence current differential protection.If it is applied as a supplementary,the safety should be con si-dered first and the protective range limited.A new earthing fault protection reacted at the ratio of the neu tral current to the line current is suggested. |
| Key words: earthing fault,transformer zero-seguence differential protection,ristricted earth fault |
