High-voltage cable fault distance measurement and location method

Power cable power supply has been increasingly widely used due to its safety and reliability. However, high-voltage cables are laid underground for a long time and are affected by factors such as moisture and load. Once a high-voltage cable fails, a high-voltage cable fault distance measurement and positioning method is needed to quickly and accurately find the fault point of the high-voltage cable and reduce the losses caused by power outages.

The DFDL-S cable fault tester independently developed by Dingsheng Electric Power R&D Department is one of the important tools for solving high-voltage cable faults and restoring power supply. The cable fault tester uses electromagnetic principle technology to accurately locate faults.

High voltage cable distance measurement method

First, use the DMG2672 electronic megohmmeter to measure the insulation resistance to preliminarily determine the nature of the fault, then use the appropriate distance measurement method according to the fault type to preliminarily measure the distance and location of the fault, and finally carefully detect the fixed points before and after this position along the direction of the cable until the exact fault point is found.

High voltage cable positioning method

The high-voltage cable positioning method uses the principle of low-voltage pulse method to achieve measurement. The low-voltage pulse method was invented under the inspiration of radar principle. A low-voltage pulse is injected into the fault phase of the cable. When the traveling wave signal encounters an impedance mismatch point, such as the terminal head and intermediate joint of the fault point, it will generate reflection and refracted waves. The distance to the fault point is calculated by using the time difference between the received reflected pulse and the transmitted pulse and the wave speed in the cable.