应用两端电流采样值二维空间映射分布特征的线路纵联保护

Transmission line pilot protection applying two-dimensional space mapped distribution characteristics of current sampling values at both ends

针对传统纵联保护在区外故障伴随电流互感器饱和时发生误动作的问题,提出一种基于线路两端电流采样值映射于二维空间分布特征差异的线路纵联保护新方案。该方案以线路两端电流采样点(母线指向线路为正方向)为坐标点映射于二维空间,在线路正常运行和外部故障工况下,映射点位于二维平面坐标系的第二、四象限;而内部故障工况下,映射点位于平面坐标系的第一、三象限。仿真和动模试验结果表明,所提方案能快速有效识别输电线路中出现的各类故障,对伴随电流互感器饱和及异常数据的故障也能正确识别。

In order to solve the mal-operation problem of the traditional protection in case of external faults accompanied by current transformer saturation,a novel scheme for transmission line pilot protection based on the difference of two-dimensional space mapped distribution characteristics of current sampling values at both ends of the line is proposed.The current sampling values at both ends of the transmission line,the positive direction of which is defined as from bus to line,are mapped to the two-dimensional space.Under the normal operation and external fault conditions,the mapping points are located in the second and fourth quadrants of the two-dimensional plane coordinate system,while under the internal fault conditions,the mapping points are located in the first and third quadrants.The results of simulation and dynamic analog tests indicate that the proposed scheme can rapidly and effectively identify various types of faults in transmission lines,including the faults accompanied with current transformer saturation and abnormal data.