| 引用本文: | 郑涛,马玉龙,黄婷,刘连光,白加林,高昌培.保护用电流互感器铁芯剩磁衰减规律分析[J].电力自动化设备,2017,37(10): |
| ZHENG Tao,MA Yulong,HUANG Ting,LIU Lianguang,BAI Jialin,GAO Changpei.Attenuation law analysis of core residual magnetism for protective current transformer[J].Electric Power Automation Equipment,2017,37(10): |
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| 摘要: |
| 电流互感器的铁芯具有磁滞效应，运行过程中可能会产生剩磁，进而可能加快电流互感器的饱和，导致保护继电器的误动作。针对该现象，分析了电流互感器剩磁产生的机理及其影响因素；在此基础上，重点研究了电流互感器的剩磁衰减规律。基于分形理论的理论计算公式，可计算短路电流开断后系统无残余电流影响的情况下剩磁的大小；利用PSCAD仿真软件进行试验得到故障后电流互感器一次侧有残余电流情况下磁通的衰减规律，即系统发生短路故障后，电流互感器铁芯内磁通会发生不同程度的衰减，并在局部磁滞回线上运行，既不会在故障切除时刻磁通的基础上运行，也不会衰减至0，为抑制剩磁的产生以及分析电网事故提供了基础理论依据。 |
| 关键词: 电流互感器 电流互感器铁芯 分形理论 剩磁 饱和 衰减规律 磁滞效应 |
| DOI：10.16081/j.issn.1006-6047.2017.10.019 |
| 分类号:TM452 |
| 基金项目:国家重点研发计划智能电网技术与装备重点专项(2016-YFB0900600) |
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| Attenuation law analysis of core residual magnetism for protective current transformer |
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ZHENG Tao1, MA Yulong1, HUANG Ting1, LIU Lianguang1, BAI Jialin2, GAO Changpei2
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1.State Key Laboratory of New Energy Power System, North China Electric Power University, Beijing 102206, China;2.Dispatching and Control Center of Guizhou Power Co.,Ltd.,Guiyang 550002, China
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| Abstract: |
| The hysteresis effect of CT(Current Transformer) iron core may cause residual magnetism in its operation, which may accelerate the saturation of CT and lead to misoperation of protective relay. In view of this phenomenon, the production mechanism and influence factors of CT’s residual magnetism are analyzed, based on which the attenuation law of CT’s residual magnetism is mainly studied. The value of residual magnetism without residual current after short circuit current breaking can be calculated based on theoretical formula of fractal theory. Experiments are simulated in PSCAD software to obtain the attenuation law of residual magnetism when fault occurs and the primary side of CT has residual current. After the short circuit fault in the system, the magnetic flux attenuation in the CT iron core occurs in different degrees and will run along the local hysteresis loop, which neither will run in the flux basis at the fault clearing time, nor will be reduced to 0. The obtained attenuation law provides the basic theory for inhibition of residual magnetism and grid analysis of accidents. |
| Key words: current transformers current transformer iron core fractal theory residual magnetism saturation attenuation law hysteresis effect |
