Single-phase grounding fault transient line selection method for small-current grounding system

A single-phase grounding fault, small current grounding technology, applied in the direction of measuring electricity, measuring electrical variables, measuring devices, etc., can solve the problems of low accuracy of approximate entropy line selection, insensitivity to small complexity changes, etc. The effect of insensitivity to missing data, high accuracy, and strong data independence

Inactive Publication Date: 2016-10-12
CHENGDU UNIVERSITY OF TECHNOLOGY
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is: the approximate entropy algorithm will inevitably cause deviation due to the vector self-matching included in the statistics, and this deviation directly causes it to be insensitive to small complexity changes. This defect leads to the use of approximate entropy for line selection Not very accurate

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Single-phase grounding fault transient line selection method for small-current grounding system
  • Single-phase grounding fault transient line selection method for small-current grounding system
  • Single-phase grounding fault transient line selection method for small-current grounding system

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0017] Attached below figure 1 Invention is described further with example, and the present invention comprises specific following steps:

[0018] Step 1. Fault line selection logic start: When the system is running normally, the zero-sequence voltage of the small current grounding system is zero, and the three-phase phase voltage is balanced. When a single-phase grounding fault occurs, its zero-sequence voltage is greater than zero, and the fault phase voltage decreases , the non-fault phase voltage rises, therefore, it can be judged by the instantaneous value of the bus zero-sequence voltage being greater than the zero-sequence voltage set value and the rise of the non-fault phase voltage exceeding the set value. When the conditions are met, the fault line selection device Start; the zero-sequence voltage setting value is 0.15 times the bus phase voltage, and the non-fault phase voltage setting value is 1.1 times the bus phase voltage.

[0019] Step 2. After the line select...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a single-phase grounding fault transient line selection method for a small-current grounding system, and the method comprises the following steps: starting a fault line selection logic; collecting the fault transient current data of all branch circuits on a bus; calculating zero sequence fault transient currents of the circuits and bus; calculating the sample entropies of the circuits and bus; and carrying out the line selection according to the sample entropies of the circuits and bus. The method employs the sample entropies to measure the sample entropy of a transient signal, wherein the sample entropy serves as the basis of line selection. The sample entropy solves a problem that the calculation results are not consistent because a statistic quantity is included in self-matching. The method is higher in data independence, is better in consistency, and is more insensitive to data loss, so the method employing the sample entropy for line selection is higher in accuracy than a method employing an approximate entropy for line selection.

Description

technical field [0001] The invention relates to a line selection method for a single-phase ground fault in a small-current grounding system, in particular to a method for line selection using transient information when a single-phase ground fault occurs in a small-current grounding system. Background technique [0002] my country's 3kV ~ 66kV distribution network widely adopts neutral point non-effective grounding methods, which include neutral point non-grounding, neutral point grounding through arc suppression coils and neutral point grounding through high resistance. When a single-phase ground fault occurs in a small-current grounding system, the transient process of fault current and fault voltage contains rich fault information, which is ten to dozens of times larger than the steady-state fault signal. The method has high sensitivity and is not affected by the arc suppression coil, and has been widely used. Fu Ling, He Zhengyou and others disclosed a method in "Applica...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): G01R31/02
CPCG01R31/50
Inventor 顾民葛良全胡传皓张晴李琳琳蒋开明
Owner CHENGDU UNIVERSITY OF TECHNOLOGY
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap