Short-circuit fault location method and device for high-voltage single-core cable cross-interconnection structure

Abstract

The invention relates to a method for positioning a short circuit of a crossed and interconnected structure of a high-voltage single-core cable. The method is used for positioning a short circuit point of a crossed and interconnected structure of a high-voltage single-core cable which is constituted by a plurality of single-core cables which are crossed and interconnected. The method includes the following steps: based on whether the current at a rear end of a sheath and the current at a front end of a sheath of each section of the single-core cable are opposite in direction, determining the presence of a short circuit in each section of the single-core cable; and if the current at the rear end of the sheath and the current at the front end of the sheath of any section of the single-core cable are opposite in direction, determining that a short circuit has occurred in the section of the single-core cable. According to the invention, the method is easy to implement, has low cost, can conduct online detection, and can rapidly locate a short circuit.

Description

technical field [0001] The invention relates to a method and device capable of quickly locating short-circuit faults in a cross-connection structure of a high-voltage single-core cable based on the sheath current of the cable. Background technique [0002] High-voltage single-core cables have cross-interconnection wiring methods, and their circuit structures are complex. A large number of laying methods such as direct burial, pipe penetration, and cable trenches are used. Once a short-circuit fault occurs on the line, the protection device at the transformer end can only be used to determine the phase of the fault. line, but it is impossible to accurately determine the location of the cable fault. [0003] Some offline fault location methods can effectively locate faults by injecting signals. A current signal of a specific frequency is injected into the grounding line. The injected signal will be injected into the ground along the fault line through the grounding point. Each...

AI Technical Summary

Problems solved by technology

Fault location system devices based on this method either cost too much or take a long time

In addition, this type of method cannot be used for online measurement, and the location of the fault cannot be known immediately after the fault occurs.

[0004] The traveling wave method performs fault location by detecting the propagation time of the transient traveling wave on the fault line between the busbar and the fault point. Since the propagation speed of the transient traveling wave is close to the speed of light, there is noise elimination in the fault location mode based on the traveling wave method And the problem of wave head time extraction, and the sampling rate of the signal acquisition device is high, the cost of the device is high, the algorithm of signal processing is complicated, and it is difficult to realize

[0005] It can be seen that there is no practical method that can quickly locate the short-circuit faults that occur in the cross-connection structure of high-voltage single-core cables.

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