利用磁环构造配电线路边界的单端量全线速动保护(1):磁环边界特性及模型  

Single-ended Whole-line High-speed Protection by Using Magnetic Ring as Distribution Line Boundary(1):Boundary Characteristics of Magnetic Ring and Its Modeling

作　　者：常仲学 闫吉飞 张志华 张宇轩 王毅钊 宋国兵[1,2] 刘健 CHANG Zhongxue;YAN Jifei;ZHANG Zhihua;ZHANG Yuxuan;WANG Yizhao;SONG Guobing;LIU Jian(School of Electrical Engineering,Xi’an Jiaotong University,Xi’an 710049,Shaanxi Province,China;Shanxi Key Laboratory of Smart Grid(Xi’an Jiaotong University),Xi’an 710049,Shaanxi Province,China;State Grid Shaanxi Electric Power Research Institute,Xi’an 710100,Shaanxi Province,China)

机构地区：[1]西安交通大学电气工程学院,陕西省西安市710049 [2]陕西省智能电网重点实验室(西安交通大学),陕西省西安市710049 [3]国网陕西省电力有限公司电力科学研究院,陕西省西安市710100

出　　处：《电网技术》2023年第5期1855-1863,共9页Power System Technology

基　　金：国家自然科学基金国际合作与交流项目(52061635105);国家电网公司总部科技项目(5226SX22001C)。

摘　　要：针对含多换流器配电网灵活多变拓扑结构导致的单端量保护配合难等问题,提出了利用铁氧体磁环构造线路边界的单端暂态量全线速动保护方案。该文首先介绍了铁氧体磁环的特性,在此基础上对磁环的阻抗特性进行了测试,测试结果表明磁环工频和直流下阻抗很小但高频下阻抗较大,所以充当线路边界时具有不影响系统正常运行的优点;提出了磁环的宽频建模方法,具体包括磁环阻抗频变参数的拟合、电路综合方法以及饱和特性的模拟,最后给出了不同尺寸和磁环个数下仿真模型的参数修正方法。实验和仿真结果的对比验证了所建等效模型的有效性,为后续的理论分析和仿真验证奠定了基础。Aiming at the problem that it is difficult for the converters to cooperate in the existing single-ended protection caused by the flexible and variable topology of the distribution network with multi-converters,a novel boundary protection scheme based on the magnetic rings is proposed to realize the whole-line quick-action with single-ended electrical quantity.In this paper,the characteristics of the magnetic ring are introduced first.On this basis,the impedance characteristics of the magnetic ring are tested.The test results show that the power frequency and DC impedance of the magnetic rings is small while it is far bigger when the frequencies are higher,so it has the advantage of not affecting the normal operation of the system when acting as a line boundary.A wide-band modeling method for the magnetic ring is proposed,including the fitting of the frequency-dependent parameters,the circuit synthesis method and the simulation of saturation characteristics.Finally,a parameter correction method for different sizes and numbers of magnetic rings is introduced.The comparison between the experiment and the simulation results verifies the validity of the equivalent model,which lays a foundation for subsequent theoretical analysis and emulation verification.

关 键 词：配电网 多换流器 铁氧体磁环 边界元件 宽频建模 单端量全线速动保护 

分 类 号：TM721[电气工程—电力系统及自动化]