Online failure positioning method for ring main unit cable line

Abstract

The invention discloses an online failure positioning method for a ring main unit cable line, and relates to the technical field of a power cable failure positioning method. The failure positioning method comprises the steps that a failure current monitoring detection system is composed of a plurality of ring main unit monitoring points. Failure current detection of one monitoring point is composed of one set of three three-phase high-frequency pulse current sensors. The three high-frequency pulse current sensors are respectively arranged on a three-phase cable of any one loop cable, and the high-frequency pulse current sensors are connected with an in-place signal processing host through a coaxial line, the trigger time of a received failure signal is precisely compared with satellite time of a GPS, and a 3G wireless data transmission unit is connected with a 3G wireless data receiving unit through a 3G wireless network. When the insulation failure happens to a 10 kV-35 kV power distribution system cable, the failure current pulse can be detected at the first time, the positions of the failure points can be automatically calculated according to the failure signal trigger time detected by substations distributed in a plurality of ring main units, the positioning time is short, the positioning precision is high, and high reliability is achieved.

Description

[0001] Technical field: [0002] The present invention involves the technical field of power cable failure positioning methods, which specifically involves a positioning method applied to the online fault positioning device of the cable applied in the 10KV -35KV power distribution system. Background technique: [0003] The 10KV -35KV cable power distribution system is huge, the number of cables is large, and the laying path is complicated. Once the insulation failure occurs, it is difficult to find the fault point.The fault point positioning is done on the spot. The general method is now that the positioning of the fault point positioning instrument is used to mobilize the positioning test of the fault.The use of this device needs to unlock the terminal of the fault cable and connect one end of the cable to the pulse voltage output end of the positioning device to start the positioning test operation.Due to temporary experiments at the scene, many restrictions on construction c...

AI Technical Summary

Problems solved by technology

Moreover, there is also the problem of signal collection: in reality, the distribution of cables in the 10kV-35kV power distribution system is complicated, and it is difficult to lay optical fibers, which cannot achieve fast, accurate and reliable positioning effects

[0006] In summary, the pulse voltage echo location method has the following defects: 1. When an insulation fault occurs in a cable, it takes a long time to locate the fault point; 2. . The operation of the whole system needs to untie the cable line, which is troublesome to operate; 3. The positioning time is long and the investment in manpower and material resources is large, which increases the safety risk in the emergency repair process

The double-ended positioning method has the following defects: 1. The positioning error is large, the practicability is poor, and the reliability is not high

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