Single-phase-to-earth fault line selection method in distribution network based on virtual power comparison principle

Abstract

The invention, which belongs to the technical field of distribution network fault line selection of the power system, discloses a virtual-power-comparison-principle-based single-phase ground fault line selection method of a distribution network. 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 the zero-sequence voltage of the distribution network bus, the 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, a virtual current of the parallel resistor, virtual powers of all outgoing lines of the distribution network, and a virtual power of the parallel resistor are calculated, and a distribution network outgoing line with a virtual power equal to the virtual power of the parallel resistor is selected as a fault line. According to the invention, on the basis of the principle that the virtual power corresponding to the fault line is equal to the virtual power 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 power system distribution network fault line selection, in particular to a distribution network single-phase ground fault line selection method based on the principle of virtual power 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 compensation effec...

AI Technical Summary

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

Images