Mixed line self-adaptive reclosing method based on traveling wave ranging principle

A hybrid line, traveling wave ranging technology, applied in circuit devices, emergency protection circuit devices, emergency protection devices with automatic disconnection, etc. It is impossible to prejudge the fault point, line section and other problems, so as to achieve the effect of improving the reliability of power supply and the stability of system operation and broad application prospects.

Inactive Publication Date: 2011-05-18
STATE GRID SICHUAN ELECTRIC POWER +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] For the overhead line-cable hybrid line, the conventional reclosing method cannot pre-judge the line section where the fault point is located, so the reclosing action behavior is not selective
For this reason, the recloser had to be deactivated in many places, which obviously greatly reduced the power supply reliability of the hybrid line

Method used

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  • Mixed line self-adaptive reclosing method based on traveling wave ranging principle
  • Mixed line self-adaptive reclosing method based on traveling wave ranging principle
  • Mixed line self-adaptive reclosing method based on traveling wave ranging principle

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Embodiment 1: Use M and N to represent the two ends of the hybrid line, use P to represent the connection point between the cable and the overhead line, the MP segment to be the cable, the NP segment to be the overhead line, and F to represent the fault point. Cable section length L C =7.8km, the length of the overhead line section L O =25km, the propagation speed v of transient traveling wave in the cable C =172km / ms, the propagation speed v of transient traveling wave in the overhead line O = 295 km / ms. use t M and t N Respectively represent the absolute time when the initial traveling wave surge of the line fault reaches the M-terminal and N-terminal buses, ΔL represents the distance measurement margin, and ΔL=0.5km. Assuming that the hybrid line MN fails at time t=0, the fault point F is located in the cable section, and the distance from it to the M end is 4km.

[0016] Use the first method to achieve:

[0017] Step 1. Calculate the total length of the line ...

Embodiment 2

[0026] Embodiment 2: use M and N to represent the two ends of the hybrid line, use P to represent the connection point between the cable and the overhead line, the MP segment to be the cable, the NP segment to be the overhead line, and F to represent the fault point. Cable section length L C =7.8km, the length of the overhead line section L O =25km, the propagation speed v of transient traveling wave in the cable C =172km / ms, the propagation speed v of transient traveling wave in the overhead line O = 295 km / ms. use t M and t N Respectively represent the absolute time when the initial traveling wave surge of the line fault reaches the M-terminal and N-terminal buses, ΔL represents the distance measurement margin, and ΔL=0.5km. Assuming that the hybrid line MN fails at time t=0, the fault point F is located in the overhead line section, and the distance from it to the N terminal is 10km.

[0027] Use the first method to achieve:

[0028] Step 1. Calculate the total lengt...

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Abstract

The invention provides a mixed line self-adaptive reclosing method based on a traveling wave ranging principle, which comprises the following steps of: (1) representing both ends of a mixed line by M and N, wherein M is a cable end bus, and N is an overhead line end bus; calculating line total length L after wave velocity reduction; (2) measuring a difference of time (delta t) spent in surging line failure initial traveling wave to the buses at both ends and calculating distance DMF or DNF between a failure point and any end of a line after wave velocity reduction; (3) confirming a failure zone according to the DMF or DNF; and (4) when the failure point is positioned in the overhead line zone, starting reclosing by a line protecting device after line failure is cut off; and otherwise, locking reclosing. The method realizes mixed line self-adaptive reclosing, improves the power supply reliability and has wide application prospect.

Description

technical field [0001] The invention belongs to the technical field of power system protection, in particular to an adaptive reclosing method for hybrid lines based on the principle of traveling wave ranging. Background technique [0002] With the development of modern urban construction, the city's electricity load continues to increase, and the existing overhead lines can no longer meet the needs of urban development, and the criss-cross overhead lines also affect the overall image of the city. Therefore, replacing the original overhead line power supply with cable network power supply has become an inevitable trend in the development of urban power grids. With the continuous transformation and upgrading of the urban power grid, the urban cable network is gradually developing to a voltage level of 110kV and above. Because the investment cost of high-voltage cables is quite high, most of the paths that can use overhead lines generally do not use simple cable power supply m...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H02H7/26H02H3/06
CPCH02H7/265H02H3/06
Inventor 王伟陈平陈军余锐
Owner STATE GRID SICHUAN ELECTRIC POWER
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