A small current grounding anti-misselection line method based on five-temporal phase-to-ground incremental current

A technology of small current grounding and line selection method, applied in the direction of fault location, etc., can solve the problems of difficulty in distinguishing the difference of transformer excitation inrush current, single temporal signal of grounding characteristics, misjudgment and false alarm, etc.
CN107728000BActive Publication Date: 2021-05-18CHINA UNIV OF MINING & TECH
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
CHINA UNIV OF MINING & TECH
Publication Date
2021-05-18

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Abstract

The method for preventing mis-selection of low-current grounding lines based on five-temporal phase-to-ground incremental current of the present invention includes (1) measuring and comparing whether the zero-sequence current abrupt change is greater than the set value or the ground phase current sudden change is greater than the amount k of the non-grounded phase. 1S If no, qualitatively determine whether the suspected grounding or leakage occurs; (2) Calculate and compare the incremental current of a certain phase sub-transient phase-to-earth is greater than the corresponding set value and greater than K of the other two phases 1S If no, determine whether to accumulate the number of suspected faults; (3) After the calculation and comparison, the transient incremental current value of this phase is larger than the value K of the other two phases. 2S If no, first judge whether it is the ground phase of the grounding line, or judge whether it is the leakage phase of the intermittent leakage line according to the number of sub-transient faults within 3 seconds; The phase difference or three-phase current is used for double anti-misjudgment; HS If no, monitor whether the fault persists.
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Description

technical field

[0001] The invention relates to a small-current grounding line selection method of a distribution network, in particular to a small-current grounding anti-misselection line method based on five-temporal phase-to-ground incremental currents. Background technique

[0002] In the existing typical monitoring technology methods for small current single-phase grounding of distribution network, there are the following problems:

[0003] 1. The traditional monitoring technology is to compare the steady-state zero-sequence current value and power direction of different branch lines of the same power bus after a ground fault, and determine the maximum zero-sequence current amplitude and zero-sequence power direction from the line pointing to the bus. for the faulty line. This technology can be used in principle in the distribution network lines that were not equipped with arc suppression coils in the past, but after the distribution network is equipped with arc suppre...

Claims

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