基于系统阻抗自适应的行波固有频率测距方法  

A Traveling Wave Natural Frequency-Based Single-Ended Fault Location Method Adaptive to System Impedance

作　　者：陈双[1] 林圣[1] 李小鹏[1] 何正友[1] 

机构地区：[1]西南交通大学电气工程学院,四川省成都市610031

出　　处：《电网技术》2013年第6期1739-1745,共7页Power System Technology

基　　金：中央高校基本科研业务费专项资金资助(SWJTU11ZT07)~~

摘　　要：文章研究了在故障线路本端系统阻抗未知或变化情况下的输电线路单端行波固有频率测距方法。该算法通过研究已有的单端固有频率测距算法中系统阻抗的影响机理,假设本端电阻和电感为待识别参数,利用故障行波多次固有频率信息构造非线性目标函数,用Nelder-Mead搜索算法求解局部最优值,得到满足要求的计算阻抗,尽管该计算阻抗不代表实际阻抗值,但由此能得到对应频率下正确的本端反射角,最终得到准确的故障距离。该方法的可靠性及适应性由基于PSCAD/EMTDC的仿真试验验证。大量的仿真表明该算法能在不增加电气量的条件下实现系统阻抗不确定时的精确故障测距,结果不受故障距离、故障类型和过渡电阻的影响,同时计算过程中能实现对测距结果准确度的评价,相比以往方法显著增加了可靠性,具有较好的适应性和实用价值。Under unknown or changed local end impedance of faulty line, a single-ended fault location method using natural frequency of single-ended traveling wave in transmission line is researched. By means of analyzing the influence mechanism of system impedance in existing fault location algorithms based on single-ended natural frequency and assuming that the resistance and inductance of local-end are parameters to be indentifled, a nonlinear objective function is constructed by natural frequencies of fault traveling wave, and its local optima is solved by Nelder-Mead search algorithm to achieve the computing impedance that can meet the requirement. Such computing impedance does not represent the value of actual impedance, however correct local reflection angle under corresponding frequency can be attained by this computing impedance and accurate fault location can be finally implemented. The reliability and adaptability of the proposed method are verified by PSCAD/EMTDC-based simulation experiments. A lot of simulation results show that under uncertain system impedance and without adding electrical variables, accurate fault location can be implemented by the proposed algorithm and the fault location result is independent to fault distance, the type of fault and transition resistance, meanwhile, during the computing process the accuracy of fault location can be evaluated.

关 键 词：输电网 故障定位 固有频率 系统阻抗识别 

分 类 号：TM77[电气工程—电力系统及自动化]