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| 摘要: |
| 变压器差动保护中，正确整定是保证差动保护正常工作的前提。首先，分析了差动回路中的不平衡电流大小问题。为保证差动保护区外短路故障时可靠不动作，在计算最大不平衡电流时应考虑仅限制电流互感器变比误差导致不平衡电流增大因素。特别是差动保护两侧电流互感器匹配不好时，尤其应注意此点。然后，分析了制动特性设定问题。这两个新问题的提出，对现场的整定和保护维护有积极的意义。 |
| 关键词: 变压器 差动保护 不平衡电流 制动特性 |
| DOI： |
| 分类号:TM772 |
| 基金项目: |
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| On two factors of transformer differential protection |
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SHI Xiong-jie
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| Abstract: |
| Correct setting is the precondition of proper operation for transformer differential protection.The magnitude of unbalanced current in differential circuit is analyzed.To ensure reliable no-action of differential protection on external short-circuit fault,the increasing of unbalanced current should be taken into account in maximal unbalanced current calculation,which is caused by only restraining the ratio error of current transformer.It is especially important when the current transformers at both sides of differential protection are poorly matched.The setting of restraint characteristic is analyzed.These two factors proposed are significant for site setting and protection maintenance. |
| Key words: transformer,differential protection,unbalanced current,restraint characteristic |
