基于纵联阻抗相角的输电线路纵联保护  

Transmission line pilot protection based on pilot impedance angle

作　　者：夏经德[1] 索南加乐[1] 王志恩[1] 王莉[1] 何世恩[1] 刘凯[1] 

机构地区：[1]西安交通大学电气工程学院,陕西西安710049

出　　处：《电力自动化设备》2011年第5期20-27,共8页Electric Power Automation Equipment

基　　金：国家自然科学基金资助项目(50677051;50877061);教育部博士点基金项目(20070698057);国家重点基础研究计划项目(2009CB219704)~~

摘　　要：提出了一种基于2个特定等效纵联阻抗相角之差值的输电线路纵联保护。该纵联阻抗是由线路两端各相电压故障分量相量差与电流故障分量相量和的比值计算而来的。将电压故障分量按测量端的正方向和反方向各平移一个线路全长的距离形成2个等效的纵联阻抗,利用2个等效纵联阻抗的相角差数值判断故障是否发生在区内。区外故障时,该相角差等于0°;区内故障时,该相角差等于180°。该保护不仅易整定,具有自选相功能,性能稳定,动作灵敏,适应性强,而且能有效抵御由线路电容电流和电流互感器(TA)饱和所带来的影响。在EMTP数字仿真和动模仿真中,建立一条1000 kV 500 km和一条500 kV 50 km输电线路的模型,后者考虑了TA饱和,进行了各种故障下仿真,仿真结果表明所述纵联保护都能正确标示各种故障状态。The transmission line pilot protection based on the angle difference between two specified equivalent pilot impedances is proposed. The pilot impedance is the ratio of the phasor difference between the voltage fault components at two line terminals to the phasor summation of the current fault components at two line terminals. The equivalent pilot impedance is formed by displacing the voltage fault component a whole length of the line in the positive or negative direction. The angle difference between positive and negative equivalent pilot impedances is used as a criterion. It is 0° when external fault occurs and 180° when internal fault occurs. Being easy to set and immune to the influence of the line capacitive current and CT saturation,the proposed pilot protection operates stably and sensitively and has independent phase selection function and good adaptability. The EMTP digital simulation and the dynamic test of a 1 000 kV/500 km transmission line and a 500 kV/50 km transmission line with CT saturation are carried out for different faults,and results show that various fault states can be correctly indicated by the pilot protection.

关 键 词：输电线路 故障分量 纵联保护 纵联阻抗 阻抗相角 

分 类 号：TM773[电气工程—电力系统及自动化]