Method for detecting cable fault point by impact oscillating wave principle

Abstract

The invention discloses a method for detecting a cable fault point by an impact oscillating wave principle. The method comprises the following steps: the grounding output end of a pulse signal source is connected with the initial end grounding line of a fault cable to be detected; the high-voltage output end of a signal source is connected with one end of a high-voltage resonance reactor; the other end of the reactor is connected with a fault phase; the terminal end groundling line is cut off; the signal source applies the pulse signal by the reactor so that the fault point forms an instant short circuit electric arc; the fault cable generates a damped oscillating wave and radiates an electromagnetic field signal to the outside; the magnetic field signal in the signal is detected; a damped oscillating wave form for reflecting magnetic field signal change is arranged at the left side in the front of the cable fault point; a damped oscillating wave form for reflecting sharp attenuation of the magnetic field signal change is arranged at the right side behind the cable fault point; and the cable position corresponding to the change place of the magnetic field signal is the position in which the cable fault point is located. The invention is suitable for cable fault positioning under various laying conditions, has the advantages of simple structure and convenience in use and is widely used for power systems and all enterprises and public institutions.

Description

technical field [0001] The invention relates to a method for locating cable faults, in particular to a method for detecting cable fault points using the principle of shock oscillation waves. Background technique [0002] With the rapid development of urbanization, in order to beautify the environment and the needs of national defense, a large number of overhead power lines have been changed to buried cables, so that the use of cables has increased rapidly, and due to frequent municipal construction and other reasons, a large number of cable faults have occurred. In order to quickly and accurately find the fault point of underground cables, it has become a difficult problem for cable repairs to restore power transmission. Especially in the face of more and more branch cables and cables through pipes, the traditional method of detecting cable fault points has certain defects. At present, the main methods are: [0003] 1. The traditional acoustic measurement method, and the su...

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Problems solved by technology

[0005] 3. The audio induction method can only be used for the location of special metal short circuit and open circuit faults. This kind of fault is only a special case in a large number of cable faults.

[0006] 4. There is a public patent on the steel armor current and magnetic field detection method, but it is only theoretically feasible, and it is not practical due to the limitation of the cable laying situation on site. The applicant unit has removed the products developed according to its principle from the company's promotional webpage

[0007] 5. Low-voltage pulse method, high-voltage pulse method (flashover method), secondary pulse method, and multiple pulse method, they can only be used for pre-location of cable faults, not accurate positioning

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