A fault locating algorithm based on phase characteristics is proposed for the hybrid transmission line,which defines a new fault locating function. The phase of fault locating function changes abruptly at the fault point only once when the location of reference point changes from its left side to its right side, which can be used to quickly locate the fault point. Without identifying the faulty section,the hybrid transmission line is equalized a line with the same length for fault locating. The proposed fault locating algorithm has no dead zone and is nearly immune to transition resistance,fault type,sampling frequency, fault position and load current, which are verified by PSCAD simulation.%提出一种高压电缆-架空线混合线路相位测距法,该方法定义了一新定位函数.通过分析可知,在混合线路上,当所取参考点与故障点的相对位置不同时,定位函数呈现不同的相位特性；当所取参考点在故障点前后变化时,定位函数的相位会发生唯一一次相位突变,相位发生突变的位置即为故障点,故障特征明显,因此利用此相位突变特征进行混合线路的快速故障定位.该方法无需事先判别故障区段,将混合线路直接等效为一等长线路进行故障测距,测距精度基本上不受过渡电阻、故障类型、采样频率、故障位置和负荷电流等因素的影响,无测距死区,较好地克服了传统方法在混合线路连接点附近有死区的不足.PSCAD软件仿真结果表明该相位测距法正确,测距精度高.
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