Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Power distribution network single-phase earth fault differentiation processing and fault area isolation method

A technology for single-phase ground faults and fault areas, which is applied to the fault location, detects faults according to conductor types, and electrical components. It can solve problems such as cutting off fault lines, failure of zero-sequence protection, and threats to personal safety at fault points to improve safety. performance, improve the reliability of power supply, and reduce the scope of fault power outages

Active Publication Date: 2020-12-04
李景禄
View PDF6 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] The distribution network neutral point small resistance grounding method is used in the distribution network with zero-sequence protection. During normal operation, the overvoltage level is low. When a single-phase ground fault occurs, the faulty line is cut off through zero-sequence protection. The grounding method has a simple structure and has been widely used in urban power grids. However, the biggest defect of this grounding method is that once a high-impedance grounding such as single-phase disconnection or personal electric shock occurs in the distribution network, the zero-sequence protection will "fail" and cannot be selected in time. And cut off the fault line, so that the fault point poses a greater threat to personal safety. There have been many such accidents in China
When the high-resistance grounding of the cable line occurs, due to the "failure" of the zero-sequence protection, the faulty line cannot be cut off in time, and the long-term arc will cause multiple cables to burn out
If the small resistance grounding method is used in the overhead power grid, the reliability of the power supply will be greatly reduced due to the tripping of the overhead line when it is grounded instantaneously.
[0003] Some distribution lines are long, with many users, and some have many branch lines. If a permanent single-phase ground fault occurs, if the entire line is cut off, it will cause a large-scale power outage, which will affect the reliability of power supply for users. Therefore, it is possible to find an intelligent dynamic resistance grounding device, combined with zero-sequence protection and distribution network intelligent switch, which can reduce the level of internal overvoltage during normal operation of the distribution network In case of single-phase disconnection grounding fault or personal electric shock fault, it can accurately select and quickly remove the fault and realize the area isolation of the fault to ensure the safety of equipment and personal

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0018] The complete device consists of dynamic intelligent resistance grounding device, feeder zero-sequence protection, feeder node zero-sequence current sensor, feeder node intelligent switch and control system. During the normal operation of the distribution network, the dynamic intelligent resistance grounding device works in the medium resistance grounding mode, and detects the neutral point voltage U of the distribution network in real time. 0 and the zero-sequence current i of each feeder j0 . When the distribution network neutral point displacement voltage U N ≥U 0 +ζ, and U Q ≤ U N GL , the zero-sequence current of any feeder satisfies I jmax0 ≥I j0 +η, judging that a high-impedance ground fault occurs in the distribution network, delay ΔT 1 Finally, check the neutral point displacement voltage of the distribution network and the zero-sequence current of the feeder, such as U N 0 +ζ, and I jmax0 j0 +η, the fault is a transient fault, and the fault has been re...

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 relates to a power distribution network single-phase earth fault differentiation processing and fault area isolation method, which is characterized in that complete equipment consists ofa dynamic intelligent resistance grounding device, a feeder zero-sequence protection device, a feeder node zero-sequence current sensor, a feeder node intelligent switch and a control system, and processes faults by different delays in event of single-phase earth fault in a power distribution network. According to the invention, when a high-resistance fault occurs, a grounding fault line is selected, and a fault current path is checked for fault area judgment and isolation; and when a low-resistance fault occurs, differentiated fault processing and fault area isolation are realized through cooperation with feeder zero-sequence protection and a node intelligent switch so as to reduce a power failure range.

Description

technical field [0001] The invention mainly relates to the field of single-phase grounding fault processing of distribution network, and particularly refers to a method for differentiated processing and fault area isolation of single-phase grounding fault of distribution network, which is suitable for single-phase grounding fault processing of 6-66kv distribution network. Background technique [0002] The distribution network neutral point small resistance grounding method is used in the distribution network with zero-sequence protection. During normal operation, the overvoltage level is low. When a single-phase ground fault occurs, the faulty line is cut off through zero-sequence protection. The grounding method has a simple structure and has been widely used in urban power grids. However, the biggest defect of this grounding method is that once a high-impedance grounding such as single-phase disconnection or personal electric shock occurs in the distribution network, the ze...

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): H02H7/26G01R31/08
CPCH02H7/262G01R31/086Y04S10/52
Inventor 李政洋李景禄
Owner 李景禄
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products