Method for distributed overcurrent protection and phase-to-phase fault isolation in distribution network

A phase-to-phase fault and overcurrent technology, applied in emergency protection circuit devices, electrical components, etc., can solve the problems of inability to meet the requirements of the substation protection allowable range, long fault isolation time, and the impact of switch life, to avoid multiple switch splits. Combined operation, small power failure impact, reducing time-consuming and labor-intensive effects

Inactive Publication Date: 2011-12-07
武汉百叡电力技术有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The problem with this method is that due to the large number of distribution network protection levels, it often cannot meet the requirements of the allowable range of 0.3-0.5s delay and quick-break protection of substations.
It can be seen that the problem with this method is that multiple switching operations are required during the fault isolation process, and the fault isolation time is long, which not only causes a power outage impact on the user, but also has a great impact on the life of the switch

Method used

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  • Method for distributed overcurrent protection and phase-to-phase fault isolation in distribution network
  • Method for distributed overcurrent protection and phase-to-phase fault isolation in distribution network
  • Method for distributed overcurrent protection and phase-to-phase fault isolation in distribution network

Examples

Experimental program
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Effect test

Embodiment 1

[0049] See attached Figure 4 As shown in the radial distribution network with branches, if a phase-to-phase short-circuit fault occurs on the CD line, the distribution switches A, B, and C all detect overcurrent, and the distribution switches D, E, and F do not detect the overcurrent. Switch A inquires that distribution switch B has detected overcurrent, so it is judged that the fault is not in the AB line; power distribution switch B inquires that distribution switch C has detected an overcurrent, so it judges that the fault is not in the BC line; power distribution switch C inquires about the power distribution Switch D does not detect overcurrent, so it is judged that the fault is on the CD line, and the power distribution switch C is disconnected to isolate the fault. If a phase-to-phase short-circuit fault occurs on the BC line, distribution switches A and B monitor overcurrent, and distribution switches C, D, E, and F do not detect overcurrent. Therefore, it is judged t...

Embodiment 2

[0051] See attached Figure 5 As shown, the present invention is applied to the hand-in-hand distribution network. If a phase-to-phase short-circuit fault occurs on the AB line, the distribution switch A detects an overcurrent, and the distribution switch A inquires that the distribution switch B has not detected an overcurrent, so it is judged that the fault occurred on the AB line, and the distribution switch A is disconnected to isolate the fault. . If a phase-to-phase short-circuit fault occurs on the BC line, the distribution switches A and B both monitor the overcurrent, and the distribution switch A inquires that the distribution switch B detects the overcurrent, so it is judged that the fault is not in the AB line; the distribution switch B inquires the power distribution Switch C does not detect overcurrent, so it is judged that the fault occurred on the BC line, and the power distribution switch B is disconnected to isolate the fault. If a phase-to-phase short-circ...

Embodiment 3

[0053] See attached Image 6 As shown, the present invention selects hand in hand multi-contact distribution network for use. If a phase-to-phase short circuit fault occurs on the HI line, the distribution switches I and J both monitor overcurrent, and the distribution switch J inquires that the distribution switch I monitors the overcurrent, so it is judged that the fault is not in the IJ line; the distribution switch I inquires about the power distribution Switches H and K have not detected overcurrent, so it is judged that the fault occurs in the HI line or KI line, the power distribution switch I is disconnected, and the power distribution switches H and K are notified to be disconnected to isolate the fault.

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PUM

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Abstract

The invention provides a method for reducing time limit combination step progression of distribution network relaying protection, comprising the following steps: 1, realizing differential protection (DP) between all incoming switches and all outgoing switches in a distribution switching station or a distribution firewall; and 2.1,, if the DP meets action conditions, tripping off all the incoming switches without time delay; 2.2, if the DP does not meet the action conditions, executing overcurrent criterion on all the outgoing switches: judging whether the overcurrent I is more than set current Iset, namely I is more than Iset; and if the outgoing switches meet the overcurrent criterion at some time, tripping off the outgoing switches. The method is utilized to realize selective actions without time delay for the relaying protection between two-stage panel switches in the distribution switching station (or a distribution firewall), thus reducing the time limit combination step progression of the distribution network relaying protection, and greatly decreasing maintenance workload of relaying protection personnel. The invention also discloses a device for reducing time limit combination step progression of distribution network relaying protection.

Description

technical field [0001] The invention relates to the fields of relay protection and distribution automation, in particular to an overcurrent protection method when a phase-to-phase short-circuit fault occurs in a 10-35kV medium-voltage distribution network and a method for isolating phase-to-phase faults in distribution automation. Background technique [0002] The phase-to-phase short-circuit faults of 10-35kV medium-voltage distribution network (hereinafter referred to as distribution network) include three-phase short-circuit, two-phase short-circuit and two-phase short-circuit to ground. When a phase-to-phase short circuit fault occurs in the distribution network, the resulting overcurrent will exceed the current setting value. However, due to the short distribution line, the distribution load is distributed along the distribution line, and the distribution line passes through multiple distribution switch segments along the line, so the overcurrent protection of the distr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H02H7/26
Inventor 罗毅
Owner 武汉百叡电力技术有限公司
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