A single-phase-to-ground fault line selection and location method in distribution network based on generalized differential

Abstract

The invention discloses a generalized differential-based single-phase earth fault line selection and positioning method for a power distribution network. The method comprises the steps of starting the single-phase fault line selection and positioning process on the condition that a single-phase voltage of a bus is decreased while the other two phase voltages of the bus are increased; numbering zero-sequence current transformers; comparing collected zero-sequence current data uploaded by the zero-sequence current transformers at the head and tail ends of each outgoing line in all collected corresponding data; determining a fault line according to a comparison result; respectively comparing data uploaded by every two adjacent zero-sequence current transformers in the selected fault line through the inward-tightening and fine-tuning method; determining the fault position according to the comparison result; and displaying the selected fault line and the fault positioning result. According to the technical scheme of the invention, on the premise that no equipment is increased, the single-phase earth fault line of the power distribution network can be selected and positioned. In this way, the defects in the prior art that the conventional fault line selection method is low in sensitivity and reliability and the line selection fails due to the overcompensation of an arc suppression coil can be overcome. Meanwhile, the power supply interruption caused by grounding test pull is reduced.

Description

technical field [0001] The invention relates to the field of fault line selection and positioning of distribution network, in particular to a single-phase ground fault line selection and positioning method of distribution network based on generalized differential. Background technique [0002] In the actual operation of the power system, more than 95% of the blackout accidents occur in the distribution network, and 70% of the accidents are caused by single-phase grounding or busbar faults. Scholars at home and abroad have done a lot of work on fault line selection, and the researched line selection principles can be divided into two categories: fault line selection principles based on steady-state signals and fault line selection principles based on transient signals. A variety of intelligent algorithms are also proposed. When a single-phase ground fault occurs in a neutral point non-effectively grounded system, due to the small ground residual current, the fault characteri...

AI Technical Summary

Problems solved by technology

In the distribution network, when a single-phase ground fault occurs in the low-current grounding system, the regulations stipulate that it can continue to run for 1 to 2 hours. At present, there is no good way to solve it. The only way to find out the fault point as soon as possible is to use a large number of line inspectors to inspect the line at the same time.

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