地磁感应电流对电流互感器传变特性及差动保护的影响  

Effects of Geomagnetically Induced Current on Transferring Characteristics of Current Transformer and Transformer Differential Protection

作　　者：郑涛 陈佩璐 刘连光 毛安澜[2] 

机构地区：[1]新能源电力系统国家重点实验室,华北电力大学,北京市102206 [2]中国电力科学研究院(武汉),湖北省武汉市430074

出　　处：《电力系统自动化》2013年第22期84-89,共6页Automation of Electric Power Systems

基　　金：国家重点基础研究发展计划(973计划)资助项目(2012CB215206);国家自然科学基金项目(51177045);中央高校基本科研业务费专项资金资助项目(JB2011011)~~

摘　　要：直流偏磁可能影响电流互感器(TA)的暂态传变特性,威胁差动保护的正确动作和电力系统的安全运行。与高压直流输电(HVDC)引起的直流偏磁相比,地磁感应电流(GIC)产生的偏置磁通对TA暂态传变特性的影响情况更为复杂,GIC本身的随机性和时变性决定其不能与纯直流引起的偏磁视为等同,而应加以区分。文中研究了由GIC及由HVDC引发的直流偏磁对TA影响的异同。结合TA等值电路,对GIC引起TA饱和的机理进行分析,并在PSCAD/EMTDC中构建仿真模型,根据GIC的特征用低频余弦量对其进行模拟。仿真分析了由GIC引起的TA暂态饱和及局部暂态饱和现象,研究了其对变压器差动保护的影响。研究表明,GIC可能通过影响TA的暂态传变特性从而对变压器差动保护产生影响,GIC对电网安全稳定运行的威胁需引起重视。DC bias may affect the transferring characteristics of the current transformer, threatening the operation of differential protection. Compared with the DC bias caused by high voltage direct current （HVDC） transmission, the bias magnetic flux resulting from geomagnetically induced current （GIC） is more complex, especially when considering its effects on current transformer transferring characteristics. The differences between GIC bias and DC bias are analyzed in detail. According to the equivalent circuit of current transformer, the mechanism of current transformer saturation due to GIC is discussed. Then based on the characteristics of GIC, simulation models are developed in PSCAD/EMTDC, where low frequency sinusoidal currents are adopted to emulate GIC. Simulations are conducted to analyze current transformer transient saturation and partial transient saturation, the results of which demonstrate that effects of GIC may result in mal-operation of transformer differential protection, and should be given prompt attention. This work is supported by National Basic Research Program of China （973 Program） （No. 2012CB215206）, National Natural Science Foundation of China （No. 51177045） and Fundamental Research Funds for the Central Universities （No. JB2011011）.

关 键 词：直流偏磁 电流互感器 地磁感应电流 局部暂态饱和 

分 类 号：TM452[电气工程—电器]