基于模型参数辨识的串联补偿输电线路纵联保护原理  

Pilot protection principle based on model parameter identification for a series compensated transmission line

作　　者：李鹏 刘玢岩 习伟 尹项根[2] 潘远林 LI Peng;LIU Binyan;XI Wei;YIN Xianggen;PAN Yuanlin(China Southern Power Grid Digital Grid Research Institute Co.,Ltd.,Guangzhou 510663,China;State Key Laboratory of Advanced Electromagnetic Engineering and Technology(Huazhong University of Science and Technology),Wuhan 430074,China)

机构地区：[1]南方电网数字电网研究院有限公司,广东广州510663 [2]强电磁工程与新技术国家重点实验室(华中科技大学),湖北武汉430074

出　　处：《电力系统保护与控制》2022年第22期20-28,共9页Power System Protection and Control

基　　金：国家自然科学基金项目资助(51877089);中国南方电网有限责任公司科技项目资助(ZBKJXM20180500)。

摘　　要：串联电容补偿设备的应用降低了超高压输电线路中差动保护的灵敏度,为解决此问题提出了一种基于模型参数辨识的纵联保护原理。以串补等值阻抗作为辨识参数,引入串补工频阻抗等值模型并结合线路分布参数模型,采用线路两侧电压和电流作为测量量构建了串补等值阻抗辨识方程。辨识阻抗在区外故障时等于串补等值阻抗,在区内故障时与串补等值阻抗有明显差异,基于此构成纵联保护判据。理论分析与仿真结果表明,该保护原理整定简单,可靠性高,受串补本体保护和系统运行方式的影响小,不受分布电容电流的影响。与传统差动保护相比,其保护灵敏度显著提高,可与差动保护配合构成完善的纵联保护方案。The application of series compensation equipment in an EHV transmission line decreases the sensitivity of differential protection. A pilot protection based on model parameter identification is proposed to solve this problem. The equivalent impedance of series compensation equipment is taken as the identification parameter. The power frequency impedance equivalent model of series compensation equipment and the distributed parameter model of the line are considered. The identification equations of equivalent impedance are derived by voltages and currents at two terminals.When the external fault occurs, the identification impedance is equal to the equivalent impedance. When the internal fault occurs, the identification impedance is obviously different from the equivalent impedance. The protection criterion is proposed based on the above characteristics. Theoretical analysis and simulation results prove that the proposed protection is easy to set and has high reliability. It is hardly affected by the distributed capacitive current, the protection of series compensation equipment or the system operation mode. Compared with traditional differential protection, it has better sensitivity. It can cooperate with the differential protection to form a high performance pilot protection scheme.

关 键 词：串联补偿线路 模型参数辨识 分布参数 MOV 纵联保护 

分 类 号：TM773[电气工程—电力系统及自动化]