基于单端电压行波传输规律的柔直架空线路金属性接地故障测距方法

Metallic Grounding Fault Location Method for Flexible DC Overhead Lines Based on Single-terminal Voltage Traveling Wave Transmission Law

为准确定位双极运行方式下高压柔性直流输电系统单极接地故障,提出一种基于正反向电压行波关系的单极接地故障测距原理及算法。研究了双极运行方式下发生单极接地故障时的边界条件以及故障后正向电压行波和反向电压行波的差模分量和地模分量之间的关系,在此基础上,提出了基于正反向电压行波关系的单极接地故障测距原理,并分析了过渡电阻对该故障测距原理的影响。仿真验证了所提故障测距原理的有效性和可靠性。

To accurately locate the unipolar grounding fault of a flexible high voltage direct current(HVDC)transmission system in bipolar operation mode,the principle for unipolar grounding fault location and the corresponding algorithm are proposed,which are based on the relationship between forward and reverse voltage travelling waves.The boundary conditions when a single-terminal grounding fault occurs in the bipolar operation mode are studied,together with the relationship between the differential-and ground-mode components of the forward and reverse voltage traveling waves after the fault.On this basis,the principle for unipolar grounding fault location based on the relationship between forward and reverse voltage travelling waves is put forward.In addition,the influence of transition resistance on the principle is also analyzed.Simulation results verify the validity and reliability of the proposed fault location principle.