电缆故障预警与精确定位系统

Fault Warning & PositioningFor Cable System

电缆故障预警与精确定位系统主要应用于电缆隧道中110kV及以上等级长距离、大截面的高压电缆线路上，可快速判断故障电缆线路，以及故障点距离电缆线路终端的位置，大大缩短故障测寻时间，快速修复电缆故障，提高供电系统可靠性。本系统采用 GPS双端定位时基法，通过加装于电缆本体或接地线的行波传感器实时采集信号，7x24小时不间断的对电缆进行监测，定位精度可达 1%+10米。采用AC220V供电或CT取电，4G无线通信，确保设备时刻处于在线状态。

The cable fault early warning and precise positioning system is mainly applied to 110kV and above grade long-distance, large-section high-voltage cable lines in cable tunnels. It can quickly determine the faulty cable line and the distance of the fault point from the cable line terminal, greatly shortening the fault detection time, quickly repairing cable faults, and improving the reliability of the power supply system. This system adopts GPS double-ended positioning time-based method, which collects signals in real time through traveling wave sensors installed on the cable body or grounding wire, and monitors the cable 7x24 hours continuously. The positioning accuracy can reach 1%+10 meters. It uses AC220V power supply or CT power acquisition, and 4G wireless communication to ensure that the equipment is always online.

工作原理：

高压电缆发生故障时，会产生幅值很大的非稳态量，并从故障点向两端传播，称为行波。行波传播速度接近光速，约为2.0x108米/秒。可以根据行波到达两端监测点的时刻来确定故障点的位置。和单端定位法相比双端定位法只利用行波第一波头到达线路两端的时刻进行计算，只需捕捉行波第一个波头，不用考虑行波的反射与折射，行波值大，易于辨识。系统可采用 GPS 授时方式与高速集成电路芯片同步，可以保证所测时间差值误差在 30纳秒以内。

Working Principle:

When a high-voltage cable fails, it will generate a non-steady-state quantity with a large amplitude and propagate from the fault point to both ends, which is called a traveling wave. The propagation speed of the traveling wave is close to the speed of light, about 2.0x108 meters/second. The location of the fault point can be determined according to the time when the traveling wave reaches the monitoring points at both ends. Compared with the single-ended positioning method, the double-ended positioning method only uses the time when the first wave head of the traveling wave reaches both ends of the line for calculation. It only needs to capture the first wave head of the traveling wave without considering the reflection and refraction of the traveling wave. The traveling wave value is large and easy to identify. The system can use GPS timing method and high-speed integrated circuit chip synchronization, which can ensure that the measured time difference error is within 30 nanoseconds.

系统拓扑图

System topology diagram