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Accident overload blocking method for station domain distance protection stage iii

A distance protection and overload technology, applied in emergency protection circuit devices, electrical components, etc., can solve the problems of inexhaustibility, uncertainty of real-time and reliability, large amount of communication and calculation, etc.

Active Publication Date: 2018-04-10
TSINGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Traditionally, the load limit relay is used to avoid the maximum overload. This method is difficult to set and cannot be absolutely distinguished on the impedance plane.
Patent CN101335450A and patent 101710696B use independent line protection data to distinguish overload and fault, only three-phase overload and fault can be distinguished, and it is not easy to set
[0005] Based on the wide-area information, the overload can be identified by comparing the power flow calculation with the measured value, and enumerating and searching the predicted accident set. There are many uncertainties in real-time and reliability

Method used

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  • Accident overload blocking method for station domain distance protection stage iii
  • Accident overload blocking method for station domain distance protection stage iii
  • Accident overload blocking method for station domain distance protection stage iii

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0073] Embodiment 1 is the accident overload blocking method of the grounding distance III section. In this embodiment, the delay after the protection is started is set to 150ms, and the secondary side negative sequence voltage threshold U 2set 3V, POC 1 Criterion setting setting value O TH is 2, the reliable margin angle θ is 15°, POC 3 Criterion setting setting value O MAX is 0.3, the threshold O of the ratio of zero-sequence current to negative-sequence current D is 0.45, and the delay after opening the grounding distance protection section III is 1.5s;

[0074] Include the following steps:

[0075] 1) After the protection starts, delay 150ms and enter step 2);

[0076] 2) First judge whether it has tripped, if it has tripped, then enter step 11); if it has not tripped, enter step 3);

[0077] 3) Compare 3 times the secondary side negative sequence voltage 3U 2 with 3V, if the 3U 2 Less than or equal to 3V, go to step 4); if 3U 2 greater than 3V, go to step 5);

...

Embodiment 2

[0106] Embodiment 2 is the accident overload blocking method of phase-to-phase distance III. In this embodiment, the delay after the protection is started is set to 150ms, and the secondary side negative sequence voltage threshold U 2set 3V, POC 1 Criterion setting setting value O TH is 2, the reliable margin angle θ is 15°, POC 3 Criterion setting setting value O MAX is 0.3, and the delay after opening the grounding distance protection section III is 1.5s;

[0107] Include the following steps:

[0108] 1) After the protection starts, delay 150ms and enter step 2);

[0109] 2) First judge whether it has tripped, if it has tripped, then enter step 9); if it has not tripped, enter step 3);

[0110] 3) Compare 3 times the secondary side negative sequence voltage 3U 2 with 3V, if the 3U 2 Less than or equal to 3V, go to step 4); if 3U 2 greater than 3V, go to step 5);

[0111] 4) Judgment by the phase-to-phase distance protection section III algorithm, and then enter step...

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Abstract

The invention relates to an accident overload blocking method for section III of station domain distance protection, which belongs to the technical field of power system protection and control. The method includes: when a ground fault occurs, open the overload blocking method, perform protection judgment and cooperate with the main protection Cut off the faulty line, and for accidental overload, block protection to ensure no malfunction; when phase-to-phase and phase-to-phase faults occur, open the overload block, make protection judgments and cooperate with the main protection to cut off the faulty line, and for accidental overload , blocking protection to ensure no misoperation; the method proposed by the invention can ensure that the distance protection section III is reliably blocked under accident overload, and can be reliably opened under phase-to-phase faults, phase-to-phase faults, and single-phase ground faults through small transition resistances. When the single phase is grounded through a large transition resistance, it is reliable and delayed to open to ensure the safe and stable operation of the power system.

Description

technical field [0001] The invention belongs to the technical field of station domain distance protection and control in electric power systems, and in particular relates to an accident overload blocking method applied to section III of station domain distance protection. Background technique [0002] As electricity demand continues to grow, grid overloading is becoming more and more common. When one or more lines trip, the load of the tripped line will be transferred to other operating lines in the parallel transmission section, resulting in overloading of other operating lines. Since such overloads may be caused by faults or non-fault trips, they are collectively referred to as accident overloads. It is also called power flow transfer overload in previous studies. [0003] The accident overload situation is usually accompanied by the characteristics of current increase and voltage decrease, which are similar to faults on the impedance plane, so they may be misjudged as f...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H02H7/26
Inventor 董新洲曹润彬施慎行雷傲宇陈昕倪江
Owner TSINGHUA UNIV
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