Identification method of single-phase disconnection fault in distribution network based on negative sequence voltage and current characteristics

Abstract

The invention discloses a distribution network single-phase disconnection fault identification method based on negative-sequence voltage and current characteristics, comprising the following steps: S1, collecting the three-phase voltage of a bus and the three-phase current of each line in a substation; S2, extracting the negative-sequence voltage of the bus and the negative-sequence current of each line; S3, getting the derivative of the negative-sequence current of each outgoing line; S4, getting the correlation coefficient between the negative-sequence voltage of the bus and the negative-sequence current of each outgoing line; and S5, comparing the correlation coefficients of the lines, determining that a line is normal if the correlation coefficient is greater than 0, and determining that a line is faulty if the correlation coefficient is smaller than 0. The distribution network single-phase disconnection fault identification method based on negative-sequence voltage and negative-sequence current derivative correlation has bootstrap performance, is not affected by the neutral point grounding mode of a distribution network, and can be used to identify various disconnection faults reliably.

Description

technical field

[0001] The invention relates to the field of distribution network relay protection, in particular to a method for identifying single-phase disconnection faults in a distribution network. Background technique

[0002] With the advancement of distribution network construction, the application of insulated overhead lines is increasing. With the improvement of the line insulation rate, there are more and more disconnection faults caused by lightning strikes. At the same time, there are other reasons for the disconnection faults such as construction. The normal operation of the distribution network will not be affected after a single-phase disconnection occurs in the distribution network, so it is often difficult to find such faults. However, if the disconnection fault cannot be dealt with in time, it will cause accidents such as electric shock to people and animals around, so it is necessary to study the disconnection identification technology of distribution ne...

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