| 引用本文: | 徐 剑,华建卫,唐志军.基于瞬时漏感参数特性识别电流互感器匝间短路故障[J].电力自动化设备,2012,32(11): |
| XU Jian,HUA Jianwe,TANG Zhijun.Identification of CT interturn short circuit fault based on instantaneous leakage[J].Electric Power Automation Equipment,2012,32(11): |
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| 摘要: |
| 提出一种快捷的电流互感器匝间短路等效瞬时漏感的计算方法，通过二次侧绕组直流电阻、漏感、二次侧负载等相关试验参数和二次电流采样值便可计算出电流互感器匝间短路等效瞬时漏感。对计算结果的分析可知，电流互感器发生匝间短路故障时，其故障相与非故障相的等效瞬时漏感相位相反，且非故障相的等效瞬时漏感为无穷大。仿真实验结果验证了上述特性，其可以作为电流互感器匝间短路故障的判据。另外，仿真实验结果显示，正常运行时，各相等效瞬时漏感的计算值呈现正负交替的特征，可作为电流互感器匝间短路故障的判据。电流互感器正常运行时，根据二次不平衡电流计算出的等效瞬时漏感幅值随不平衡电流变化，利用该特性可防止保护在流过不平衡电流时误动。 |
| 关键词: 电流互感器 在线监测 匝间短路故障 等效瞬时电感 计算瞬时漏感 |
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| Identification of CT interturn short circuit fault based on instantaneous leakage |
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XU Jian, HUA Jianwe, TANG Zhijun
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Fujian Electricity Science Research Institute，Fuzhou 350007，China
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| Abstract: |
| A simple method is proposed for calculating the CT equivalent instantaneous leakage inductance of interturn short circuit，which is based on the test parameters，such as the resistance，leakage inductance and load of secondary winding，and the samplings of secondary current. The analysis of calculated results shows that，the equivalent instantaneous leakage inductance of healthy phase is infinite and it is opposite in phase to that of faulty phase，which is verified by the simulative experimental results. The simulative experimental results also show that the calculated equivalent instantaneous leakage inductance of every phase varies between positive and negative values during normal operation. The two characteristics mentioned above can be taken as the criterions of CT interturn short circuit fault. During normal operation，the amplitude of calculated equivalent instantaneous leakage inductance follows the unbalanced secondary current，which can be used to prevent the protection misoperation caused by the unbalanced current flowing through CT. |
| Key words: current transformer online monitoring interturn short circuit fault equivalent instantaneous inductance calculated instantaneous leakage inductance |
