Brief Discussion On The Difficulties Of Fault Localization Of Power Cables

- May 13, 2018-

Due to the variability of the environment in which power cables are laid, and the application of various cables and new materials for accessories in cable lines, it is increasingly difficult to locate faults in the field of power cables.

Difficulties in locating faults at the site are highlighted by the fault location of buried power cable lines. At present, there are related classical technical documents and advanced fault detectors for the high-impedance failures of power cable lines. However, when using a professional cable fault locator to perform positioning on the spot, there are sometimes special difficult problems that cannot be located. For example, the creepage faults that occur on the insulation surface of medium-voltage cross-linked power cables at the terminals and the middle of the power cable, and the precise determination points of metallic short-circuit faults are often incapable of using professional cable fault locators.

For common common cable faults, using the market to purchase a cable fault locator will generally determine the location of the fault within minutes or hours. However, in the case of special difficult faults, when the detection is not successful, multiple cable fault detectors with different functions may need to be called and tested repeatedly to verify the positioning and comparison. The types of these fault instruments mainly include various cable fault detectors designed, manufactured and developed according to the principles of bridge method and waveform method. This positioning may take several days or even longer. In this case, when the luck is good, it can be determined. Fault location, bad luck, the location of the fault can not be determined.

In the northern regions of China, the ground is frozen in winter. In this case, when the buried cable is broken down, the actual fault finding and processing process is actually a rather arduous task. The first to use the cable fault location equipment must be high accuracy, and secondly there must be a relatively clear understanding of the actual installation route of the cable, although some cable fault detection equipment is equipped with a cable path tester, but it must also have In order to improve the positioning accuracy, the on-site personnel who know the approximate route of the cable must cooperate. The actual processing of cable faults is sometimes three-by-three and seven-by-one.

There are many manufacturers of cable fault detection instruments on the market today, and the types of detectors are various. However, in practice, all cable faults cannot be located. The actual use of the instrument is often only valid for one or more types of faults, and it is useless for certain faults. The current electric power users all hope to purchase a versatile cable fault tester with a full-featured and accurate positioning (including rough determination and fine measurement point functions) and solve all actual cable faults quickly and effectively. However, it is actually difficult to buy. On the market, there are a wide variety of replacement cable fault detectors available. However, on-site actual detection still encounters some technical problems that cannot be located using the cable fault meter. I think the reason mainly comes from two aspects: First, current types of insulation, filling, and wrapping materials used in cables and accessories are constantly being researched and updated, causing the types of cable faults to change; second, the cable fault detector market. The limited demand and the scarcity of relevant R&D personnel have caused portable, high-precision, intelligent, multi-functional cable fault detectors to be delayed. It is believed that with the advent of the smart grid era and cable fault detection technology, cable fault location will become a very simple and easy task.