架空线—电缆混合线路分布式故障测距方法

针对架空线—电缆混合线路的故障测距问题，提出了一种分布式故障测距方法，在混合线路各连接点及母线处安装三相故障电流检测装置，根据检测到的故障电流极性判断故障支路，再根据故障支路两端检测到故障电流行波的时间进行初步定位并进一步修正。该方法可在线计算出行波波速，并可分析出离故障点较近的检测点所检测到的第二个故障行波的来源。PSCAD仿真验证结果表明，该方法不受过渡电阻、故障类型等因素的影响，误差一般在100 m以内。

Distributed Fault Location Method for Overhead Transmission Lines Combined with Underground Cables

A distributed fault location method for overhead transmission lines combined with underground cables is proposed. The fault current is detected at every connection point of the hybrid lines as well as the buses. According to the polarity of the fault current, the fault branch line can be found, and the location can be calculated based on the time that the fault current waves are detected at each end of the fault branch line. The traveling wave velocity can be calculated online and the source of the second fault current wave detected at the nearest detection can be found. The fault resistance and the fault type will not affect the result, and the maximum error is not larger than 100 m, which is verified by the simulation of PSCAD.