Due to the variability of the power cable laying environment, coupled with the application of various cables and their accessories new materials in the cable line, the difficulty of power cable field fault location is increasing day by day.
The difficulty of on-site cable fault location is highlighted in the fault location of directly buried power cable lines. At present, for high-resistance faults in power cable lines, although there are relevant classic technical documents and advanced fault detectors available. However, when using a professional cable fault locator for localization, some special and difficult faults that cannot be located are sometimes encountered. For example, the creepage flashover fault that occurs locally on the insulation surface of the terminal head and the intermediate head of the medium-voltage cross-linked power cable, the precise location of the metal short-circuit fault, etc., the use of professional cable fault locators often appears powerless or powerless. .
For common cable faults, using market-purchased cable fault locators can generally determine the location of the fault point within minutes or hours. However, when encountering special difficult faults and the detection is not smooth, it may be necessary to call multiple cable fault detectors with different functions to test repeatedly, and take turns to detect and locate, compare and confirm. The types of these fault detectors mainly include various cable fault detectors designed, manufactured and developed based on the principles of the bridge method and the waveform method. In this way, it may take several days or even longer to locate. In this way, when you are lucky, you can determine The location of the fault point, when bad luck, the location of the fault point is still uncertain.
In the northern region of my country, the ground is frozen in winter, so the direct buried cable fails, and the actual fault finding and processing process is actually a very hard work. First of all, the cable fault locating instrument used must have high accuracy, and secondly, there must be corresponding personnel who have a clear understanding of the actual laying route of the cable. Although some cable fault detection instruments are now equipped with a cable path tester, they must also have Only with the cooperation of on-site personnel who know the approximate laying path of the cable can the positioning accuracy be improved. The actual handling process of cable faults is sometimes 30% human and 70% machine.
At present, there are many manufacturers of cable fault detection instruments on the market. There are various types of detectors, but in practice, they cannot locate all cable faults. In actual use, the instrument is often only valid for one or several fault types, and it is still helpless for some faults. The current electric power user department hopes to spend a lot of money to purchase a universal cable fault tester with complete functions and high positioning accuracy (including rough positioning and precise measuring point functions) to quickly and effectively solve all actual cable faults. But it's actually hard to buy. There are a variety of new and updated cable fault detectors on the market. However, on-site actual detection will still encounter some technical difficulties that cannot be located by the cable fault instrument. I think the reasons mainly come from two aspects: First, the various insulation, filling and wrapping materials currently used in cables and their accessories are constantly being developed and updated, resulting in constant changes in the types of cable faults; second, the market for cable fault detectors The demand is limited and the relevant R&D personnel are scarce, resulting in a delay in the availability of portable, high-precision, intelligent and multi-functional cable fault detectors. It is believed that with the advent of the era of intelligent power grid and the rapid development of cable fault detection technology, cable fault location will become a very simple and easy task.