一种基于六序网图的同杆双回线故障测距算法

A New Fault Allocation Algorithm for Parallel Transmission Line Based on Six Sequence Network

采用六序分量法分析同杆双回线故障中的非跨线故障,并依照故障时故障点的电气量特征列出方程,进行非跨线故障测距。将同杆双回线故障后的电气量转化为同序正序和反序正序分量,根据单回线各种故障类型的边界条件得到各六序网图的连接关系,利用同序正序和反序正序电流在故障点的特殊关系构成测距方程,从而进行精确故障测距。该测距方法使得同杆双回线的故障测距精度不受故障点过渡电阻、回线故障类型的影响。EMTP仿真显示,该测距方法精度高,计算方便,在过渡电阻较大时仍能满足测距精度要求,且不受系统运行方式变化等因素影响。

Six-sequence component method is used to analyze the single fault for the parallel transmission lines of the same tower. The fault allocation equation based on the characteristics of the electrical measurements at the faulted point can be employed to locate the faulted point. The fault data is transformed to same-sequence positive components and inverted-sequence positive components. The connection relations of six sequence network are obtained according to the boundary conditions of different fault types for single transmission line. From the relation between same-sequence positive current and inverted- sequence positive current at the faulted point, the fault location equations are formed and the accurate fault location is implemented for single line fault. Abundant results of EMTP simulation demonstrate that the new method can give accurate fault location and be implemented easily. The location accuracy is not influenced by factors such as fault resistance, fault type and generation mode.