Handheld cable fault detection system and method based on sstdr

Abstract

The invention discloses an SSTDR-based handheld cable fault detection system and method, and belongs to the field of line detection. The method uses an SSTDR method for building hardware models for signal loading, receiving, collection, processing and the like of a detection system; the cable fault positioning, fault type judgment and uninterruptible power online detection are realized; a power supply department is helped to timely and accurately discover and eliminate the fault and to conveniently perform operation inspection work; the power supply reliability is improved. The system and themethod are suitable for the detection and position of the cable gap fault; the cable can be reliably detected under the condition of not interference the normal work signals; the cable fault positioning, fault type judging and uninterruptible power online detection are realized; the system and the method help the power supply department to timely and accurately discover and eliminate the fault; the operation and inspection work is convenient; the power supply reliability is improved.

Description

technical field [0001] The invention relates to a hand-held cable fault detection system and method based on SSTDR, belonging to the field of line detection. Background technique [0002] With the development of social economy and the acceleration of modernization, the electricity consumption of industrial and agricultural production and people's life is increasing day by day, the demand for electricity is increasing, and the requirements for the safe operation of power grid are also getting higher and higher. As a power cable that connects various electrical equipment, transmits and distributes electric energy, it has been more and more widely used because of its safety, less maintenance workload, high stability, good for improving power quality and beautifying the city. There is a tendency to gradually replace overhead lines in the construction of 220kV, 110kV, and 10kV power grids in urban areas. The reliable operation of power cables is directly related to social stabil...

AI Technical Summary

Problems solved by technology

[0011] (1) For high-resistance and flashover faults, due to the relatively large resistance value, the current flowing through the galvanometer is quite weak, which is generally difficult to detect, so such faults are not suitable for fault location by the bridge method

[0012] (2) The bridge method requires that the lead wires must be in good contact in the actual detection, because the measurement error is introduced by the large contact resistance

Also not suitable for in-line testing due to high demands on lead wire connections

[0013] (3) The original data parameters of the cable must also be known during the bridge method detection, which brings a lot of inconvenience to the detection personnel, and the accumulation of parameters will also affect the measurement accuracy

The first problem is to identify the reflected signal. In addition to the reflection at the fault point, the incident signal will also appear reflection and transmission when it encounters other impedance mismatch points. On the other hand, there are various noises in the cable. The reflected signal received in this way is the superposition of various signals, which makes it difficult to extract the reflected signal

In addition, when the signal propagates in the cable, the signal will gradually attenuate as the propagation distance increases, and the greater the frequency of the transmitted signal, the more obvious the attenuation will be, which will cause the signal to be distorted and deformed when it reaches the measurement end, making it difficult to identify the pulse signal , the exact time of signal arrival is also difficult to determine, which will cause a large error in the measurement

The second problem is that online detection cannot be carried out. Since the transmitted high-speed pulse signal interferes with the signal in the cable, when using this method for detection, the detection of the cable needs to be carried out without communication, which will inevitably cause additional losses.

The third problem is that there are measurement blind spots

When a fault occurs near the measurement end, the incident signal and the reflected signal will overlap, so that the reflected wave cannot be identified, so the near end of the cable cannot be detected

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