保护用电流互感器铁芯剩磁衰减规律分析

发布时间：2018-08-19 08:44

【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。
[Abstract]:The core of the current transformer has hysteresis effect, which may produce residual magnetism during operation, which may speed up the saturation of the current transformer and lead to the maloperation of the protection relay. In view of this phenomenon, the mechanism of current transformer remanence and its influencing factors are analyzed, and on this basis, the law of residual magnetic attenuation of current transformer is studied emphatically. Based on the theoretical formula of fractal theory, the magnitude of remanence can be calculated without the influence of residual current on the system after the short-circuit current is switched off. The attenuation law of magnetic flux in the case of residual current at the primary side of the current transformer is obtained by using PSCAD simulation software, that is, after the short circuit fault, the flux in the core of the current transformer will attenuate to different degrees. And running on the local hysteresis loop, it will not run on the basis of magnetic flux at the time of fault removal, nor will it decay to 0, which provides a basic theoretical basis for restraining the generation of remanent magnetism and analyzing power network accidents.
【作者单位】：华北电力大学新能源电力系统国家重点实验室;贵州电网有限责任公司电力调度控制中心;
【基金】：国家重点研发计划智能电网技术与装备重点专项(2016-YFB0900600)~~
【分类号】：TM452

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