Method for preventing misoperation of zero-sequence direction components without influence of weak feedback

A zero-sequence direction and anti-misoperation technology, which is applied to electrical components, emergency protection circuit devices, etc., can solve problems such as zero-sequence direction components misoperation

Active Publication Date: 2015-07-22
XI AN JIAOTONG UNIV +5
View PDF4 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to provide a zero-sequence directional element anti-misoperation method that is not affected by weak feed to solve the problem of misoperation of traditional zero-sequence directional elements; Occurrence of misoperation of zero-sequence directional components

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
  • Method for preventing misoperation of zero-sequence direction components without influence of weak feedback
  • Method for preventing misoperation of zero-sequence direction components without influence of weak feedback
  • Method for preventing misoperation of zero-sequence direction components without influence of weak feedback

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0039] The present invention will be further described below in conjunction with accompanying drawing.

[0040] The invention recognizes the sound line according to the electrical quantity characteristic difference between the sound line and the faulty line. When a fault occurs on a circuit line, the three-phase current and three-phase voltage mutations at both ends of the healthy line are equal, but the three-phase current and voltage at both ends of the faulty line do not have this feature. For the non-weak infeed system, the three-phase current mutation at both ends of the fault line has a large difference; for the weak infeed system, the three-phase current mutation at the non-weak infeed side of the fault line has a large difference. Although the three-phase current mutations on the weak feeder side of the fault line are approximately equal, the three-phase voltage mutations are quite different. Therefore, the sound line can be identified by combining the three-phase cur...

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 method for preventing misoperation of zero-sequence direction components without influence of weak feedback. The method includes (1), acquiring phase currents and phase voltages of line protection mounting positions; (2), extracting sudden change quantities of the phase currents and the phase voltages; (3), judging whether algorithms for preventing misoperation need to be started or not according to starting criteria for the algorithms for preventing misoperation, and carrying out a step (4) if the algorithms need to be started; (4), computing current error coefficients and voltage error coefficients of two ends of each line, judging whether the lines are perfect lines or not according to comprehensive error coefficient criteria, locking the zero-sequence direction components of the lines if the lines are the perfect lines. The zero-sequence direction components of the lines are not locked if the lines are not the perfect lines. Compared with the prior art, the method has the advantages that the perfect lines and the fault lines can be identified only by the aid of single-end electric quantity information of single-circuit lines; the error coefficients can be computed in time domains, and accordingly the method is low in computational complexity and high in judgment speed and sensitivity; the method is applicable to non-weak-feedback systems and weak feedback systems, and correct actions of the zero-sequence direction components always can be guaranteed.

Description

【Technical field】 [0001] The invention relates to the field of relay protection for power system transmission lines, in particular to a method for preventing maloperation of zero-sequence directional elements. 【Background technique】 [0002] Multi-circuit lines on the same tower can effectively alleviate the shortage of land resources in power grid construction and increase the transmission capacity of unit corridors. Long-distance transmission lines erected in parallel also widely exist in the power grid. Due to the mutual inductance between the circuits, the zero-sequence directional elements applied to single-circuit lines cannot be simply applied to multi-circuit lines on the same tower and long lines erected in parallel, and the protection principle needs to be modified accordingly. [0003] The mutual inductance between the loops is dominated by zero-sequence mutual inductance. When an asymmetrical short-circuit ground fault occurs in any of the loops, the zero-sequen...

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): H02H7/26
Inventor 宋国兵徐海洋
Owner XI AN JIAOTONG UNIV
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