基于六序分量法的同杆双回线精确故障测距

Accurate Fault Location for Parallel Transmission Line Based on Six-Sequence Fault Components

在对同杆双回线的故障特性进行分析的基础上,提出采用六序分量法进行故障测距.该方法巧妙地解决了两回线间的互感问题,在六序故障分量网络中,线路两侧的序电流故障分量的有效值之比仍然只是线路阻抗、两端系统阻抗和故障距离的函数,由此得出的测距方程简洁明了,易于求解,且不受故障类型和过渡电阻的限制,也不需要两端数据同步.对同杆双回线的各种故障类型进行仿真的结果表明,所提出的方法能够高精度地测定同杆双回线故障距离.对于超长线路,线路的分布电容对故障测距有较大的影响,在测距方程中,将分布电容以集中参数的形式分配到故障点到输电线路的两侧,从而具有很高的测距精度.

Based on the analysis of fault feature of parallel transmission line, a fault location method based on six-sequence fault components was proposed, which resolves the mutual induction between the parallel lines skillfully. In the additional six-sequence fault network, the ratio of the root-mean square (RMS) value of the fault current from two sides is the function of the line resistance, the system resistance and the fault distance away from buses. Thus we educe the succinct fault location equation. There is no restriction of fault type and synchronization of the sampling data. The simulation results show the high accuracy of this method. For the extremely long transmission lines, the distributed capacitance has great influence on the accuracy of fault location, so in the fault location equation, the distributed capacitance is allocated to the two terminals of the transmission line by way of lumped parameter in order to get high accuracy.