A method for on-line fault diagnosis and early warning of mine-used high-voltage cables

Abstract

An on-line fault diagnosis and prewarning method of a mine high-voltage cable aims at performing on-line fault diagnosis and prewarning for a high-voltage cable by the characteristics signals collected by a plurality of sensors, so as to obtain accurate information. The method of the invention comprises eight steps of: collection and transmission of a single chip, collection and transmission of an FPGA (field programmable gate array), communication of an industrial personal computer, local discharge characteristics extraction, local discharge mode recognition, fault diagnosis and prewarning, database storage and human-computer interface display; wherein after collecting a cable temperature and an insulation resistance, the STC89C51 single chip transmits the data to the FPGA; the FPGA collects local discharge signals, and transmits all characteristics signals to the industrial personal computer; after receiving all the characteristics signals, the industrial personal computer extracts a local discharge statistical characteristics amount from a virtual instrument LabVIEW for recognizing the discharge mode and prewarning the incipient fault, and stores the real-time data and the prewarning information into the industrial personal computer database; an on-ground dispatching centre computer displays and queries the monitoring data, the prewarning information, static parameters, test data and repair records via an Ethernet ring.

Description

technical field [0001] The invention relates to a high-voltage cable fault diagnosis and early warning method, in particular to an online fault diagnosis and early warning method for high-voltage cables used in coal mines. technical background [0002] Mine-used high-voltage cables are an important part of the mine power supply system and the key equipment for safe production in coal mines. They are responsible for transmitting electric energy to various production links. With the extension of the underground working face, the power supply distance of the mine is getting farther and farther, and the distribution of mine high-voltage cables is becoming more and more complicated. Factors such as operating overvoltage of the power supply system, mechanical damage, and environmental humidity have seriously affected the insulation state of mine high-voltage cables, directly leading to a decrease in the reliability of cable power supply. According to incomplete statistics, in coa...

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Problems solved by technology

[0003] Most of the existing cable online fault diagnosis systems only detect the characteristic quantity within the fault range, or monitor a single characteristic quantity, and cannot timely and reliably warn the development trend of the fault.

For example, the "on-line monitoring system for high-voltage cables" mentioned in the Chinese patent No. 200910045471.3 mainly detects the sheath current, core current and cable temperature. It only protects after a fault, but not when the cable insulation deteriorates. Before that, the cable insulation status was warned in time; and as mentioned in the Chinese patent No. 200910272138.6, the "on-line partial discharge detection method and device for high-voltage cross-linked polyethylene cable system" mainly monitors the partial discharge of cables without considering a single type The accuracy and reliability of the data in the sensor measurement scheme, and at the same time, there is no pattern recognition for the collected partial discharge signal, so it is impossible to further judge the insulation state of the cable; the Chinese patent No. 200610041888. The "on-line monitoring method for the insulation state of power cables" also only monitors the insulation resistance, which not only has the disadvantage of a single characteristic quantity, but also cannot comprehensively diagnose the insulation state of the cable.

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