基于证据理论的铁路电力线故障定位方法

Study on Fault Locating Method for Railway Power Lines with Evidence Theory

多分段多分支结构的铁路电力线单相接地故障造成的供电中断,严重影响到铁路行车安全。为了确保故障的快速排除,本文依据线路的结构特点提出故障处理的区间模型。首先,基于铁路现有的区间结构,采用区间分析法构造区间定位的集中参数区间算法、故障网络分解区间算法及分布参数区间算法。然后,根据相离度定义提出相离度偏差矩阵的构造形式,并以此为基础推导出基本可信度分配函数的表达式。再以D-S证据理论的合成规则对3种区间算法的定位结果进行融合,实现了故障分段区间的可靠识别。最后,依据实际线路模型进行的PSCAD仿真分析,验证了本文方法在处理铁路电力线单相接地故障上的可行性。

Railway power lines are of a multi-segment and multi-branch structure. Electrical power interruptions caused by single-phase-to-ground faults seriously affect railway traffic safety. In order to remove each faults quickly, the interval model is established according to the power line structure characteristics. Firstly, accord- ing to the interval structure of railways, interval analysis is applied to deduce the interval locating algorithms such as the lumped parameter interval algorithm, fault network decomposing interval algorithm and distributed parameter interval algorithm. Then, on the basis of the definition of the deviation degree, the construction form of the difference matrix of the deviation degree is presented. The expression of the basic probability as- signment function is deduced in terms of the difference matrix of the deviation degree. The locating results of the three interval algorithms are combined by the combination rule of the D-S evidence theory, which ensures the reliability of segmented interval recognition of faults. Lastly, PSCAD simulation analysis based on the actual transmission line model is done. The simulation has verified effectively that the proposed method is feasible to handle single-phase-to-ground faults of railway power lines.