基于实际波速的多端输电线路行波故障测距方法

为进一步提高多端输电线路故障行波测距的准确性,本文提出了一种基于实测波速的多端输电线路故障定位方法。首先使用网格分形算法提取了线路故障时各条母线处初始行波的到达时刻,然后依据线路长度与故障初始行波到达时刻计算多端输电网各线路区间的波速,应用计算所得波速形成故障区间判定矩阵,实现了故障点位置的准确判定。该方法以计算得到的实际波速为依据,解决了现有测距方法中因波速不确定引起的测距误差问题,同时依据双端测距原理实现了故障点的准确定位。仿真结果表明,该方法能够有效判别故障区间,有着较高的定位精度。

Real-time velocity based fault location method of travelling wave for multi-terminal transmission lines

To improve the accuracy of current fault location methods based on travelling wave in multi-terminal transmission lines,a new method based on on-line measured velocities is proposed in this paper.The arriving moments of travelling waves are extracted though fractal method,and the real time velocities of each section are calculated with the length of each section and the arriving moment of travelling waves extracted.An identification matrix used to determine the fault interval is formed with the calculated velocities being its elements.And after the fault interval have been identified,real-time velocities are extracted from normal intervals,and the fault location is calculated based on the principle of double-ended travelling wave method with the real-time velocity.A simulation model of T structure transmission lines is established in PSCAD/EMTDC,and the result proves that this method can identify fault intervals exactly,and it can locate the fault point accurately and quickly.