Method for realizing single-phase fault line selection of distribution network by using virtual current comparison principle

Abstract

The invention, which belongs to the technical field of distribution network fault line selection of the power system, discloses a method for realizing single-phase fault line selection of a distribution network by using a virtual current comparison principle. After a single-phase ground fault occurs at an outgoing line of a distribution network, a zero-sequence voltage of a distribution network bus and zero-sequence currents flowing through all outgoing lines are measured; a parallel resistor is switched when an arc suppression coil parameter is held, and a zero-sequence voltage of the distribution network bus, zero-sequence currents flowing through all outgoing lines, and a zero-sequence current flowing through the parallel resistor are measured; and virtual currents of all outgoing lines of the distribution network and a virtual current flow through the parallel resistor after parallel resistor switching are calculated, and a distribution network outgoing line with a virtual current equal to the virtual current of the parallel resistor is selected as a fault line. According to the invention, on the basis of the characteristic that the virtual current corresponding to the fault line is equal to the virtual current of the parallel resistor, distribution network fault line selection is carried out; the fault feature is obvious; the line selection result is reliable; the line selection result is not influenced by the line parameter, the line length, the fault point position, the transition resistor, and the distribution network operation way; and the practicability is high.

Description

technical field [0001] The invention relates to the technical field of line selection for faults in power system distribution networks, in particular to a method for selecting lines for single-phase faults in distribution networks using the principle of virtual current comparison. Background technique [0002] After a single-phase fault occurs on the outlet line of the distribution network whose neutral point is grounded by the arc suppression coil, the inductive current provided by the arc suppression coil compensates the capacitive current of the ground point of the fault line. The zero-sequence current of the line is still small, so that the distribution network fault line selection method based on the zero-sequence current method ("New Criteria for Small Current Grounding Line Selection Based on the Transient Maximum Value of Zero-Sequence Current" published by Zhang Fan, Pan Zhencun, and Zhang Huifen) ) The line selection results are not reliable enough. Due to the com...

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Problems solved by technology

However, the fault signal in the small current grounding system is very weak, and the fault wave head of the fault waveform is difficult to identify, which makes it difficult for the online application of the traveling wave method

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