Distribution line fault identification apparatus based on voltage monitoring

Abstract

The invention relates to a distribution line fault identification apparatus based on voltage monitoring. The distribution line fault identification apparatus based on voltage monitoring is characterized in that the distribution line fault identification apparatus based on voltage monitoring acquires the voltage of three-phase lines at the same time; when one phase or multi phases of the lines malfunction, the distribution line fault identification apparatus based on voltage monitoring automatically extracts the data of the forward and backward periods, analyzes the self voltage state of the three phases according to the synchronous period, and determines the practical corresponding different fault types of different combinations of the three-phase voltage state, so that the distribution line fault identification apparatus based on voltage monitoring can identify the following no less than 7 types of faults of the distribution line at the same time: single-phase grounding, single-phase disconnection, two-phase short circuit, two-phase short circuit grounding, three-phase short circuit, three-phase short circuit grounding and instantaneous interference fault.

Description

[0001] A technical field [0002] The technology of the present invention belongs to the field of power distribution network automation in power systems, and specifically belongs to the on-line monitoring of power distribution lines and the judgment, identification and classification of various faults, so as to deal with faults in time and restore the safe power supply of the power grid in time. [0003] Two background technology [0004] So far, my country's power system has widely adopted technology based on line current monitoring to monitor distribution line faults, mainly through three-phase current recording and synthesizing zero-sequence current, and then judging faults, classifying faults, Infer the location of the fault; the premise of the application of this technology is that the three-phase current is required to be symmetrical when the line is working normally; The three-phase current of each line is more difficult to balance at different instants, so that the zero-s...

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Problems solved by technology

[0004] So far, my country's power system has widely adopted the technology based on line current monitoring to monitor distribution line faults. Among them, the zero-sequence current is mainly synthesized by three-phase current recording, and then the fault is judged, classified, and Infer the location of the fault; the premise of the application of this technology is that the three-phase current is required to be symmetrical when the line is working normally; the actual problem here is that the load current of the three-phase lines on the power distribution trunk line is different, and the current of each segment line in each phase line is even more different. The three-phase current of each line is more difficult to balance at different instants, so that the zero-sequence current synthesized at the fault instant is unrealistic, or can not accurately reflect the fault, because it contains the original current imbalance factor, Therefore, the accuracy of fault identification and location is limited.

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