一种基于节点阻抗矩阵快速求取零序电流保护高段保护范围的新方法  

Calculating coverage of zero sequence current protection based on node impedance matrix

作　　者：蔡黎[1] 王星华[2] 石东源[1] 段献忠[1] 

机构地区：[1]华中科技大学电气与电子工程学院,湖北武汉430074 [2]广东工业大学自动化学院,广东广州510090

出　　处：《电力自动化设备》2007年第3期49-52,共4页Electric Power Automation Equipment

摘　　要：提出一种快速求取零序电流保护高段保护范围的新方法,计算量小、结果精确。建立电网的节点阻抗矩阵;设保护范围末端为f点,它距所在线路首端的距离占线路全长为K(0≤K≤1),通过在f点注入单位电流模拟接地短路故障时的情况,得出与K值相关的网络各节点与f点之间的互阻抗及节点f的自阻抗;推导f点故障电流与K值的关系式,将该故障电流注入f点,得到f点发生接地故障时流过保护的电流与K值的关系式;流过保护的电流大小为整定值时,计算K值,得出保护范围。再推导互感线路时的情况,得出的解析式与非互感线路的一样。通过一个6节点网络的算例证明了该方法的有效性。A method for calculating coverage of zero sequence current protection based on node impedance matrix is provided,which has lower calculation load and better precision. The grid node impedance matrix is built first. Suppose the end point of coverage is node f and its distance to the line head is K of total line length. Unit current is then injected into node f to calculate the mutual impedances between f and node and the self impedance of node f. Calculate fault current of node f and inject it into node f to derive the equation of K and the current passing through the protection. Take the current as the protection setting to derive K and then calculate the coverage. The equation of the line with mutual inductance is just the same as the line without mutual inductance. A 6- node grid is emoloved to demonstrate the effectiveness of the method.

关 键 词：整定计算 零序电流保护 保护范围 

分 类 号：TM773[电气工程—电力系统及自动化]