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Method for enhancing differential protection performance by coordination of mutation quantity fault discrimination and fuzzy harmonic analysis

A differential protection and fault identification technology, applied in emergency protection circuit devices, electrical components, etc., can solve the problems of differential misoperation, occasional differential misoperation, internal AD failure, etc., to improve safety, prevent False latch protection, the effect of ensuring sensitivity

Active Publication Date: 2011-03-16
NARI TECH CO LTD +1
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Problems solved by technology

[0004] 2. Inrush current, the research on inrush current is gradually in-depth, but differential malfunction caused by inrush current occasionally occurs
[0005] 3. Internal AD failure, multiple on-site wave recordings found that when the protection internal AD fails, the existence of some "bad points" leads to differential misoperation

Method used

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  • Method for enhancing differential protection performance by coordination of mutation quantity fault discrimination and fuzzy harmonic analysis
  • Method for enhancing differential protection performance by coordination of mutation quantity fault discrimination and fuzzy harmonic analysis
  • Method for enhancing differential protection performance by coordination of mutation quantity fault discrimination and fuzzy harmonic analysis

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Embodiment Construction

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and examples. However, the invention is not limited to the examples given.

[0034] Such as figure 2 As shown, the method for improving the performance of differential protection by combining the fuzzy harmonic analysis with the sudden change fault discrimination of the present invention, the specific steps are as follows:

[0035] (1), use the inequality (I) to monitor the braking current sudden change ΔI res Is it greater than the criterion open constant K set1 , if inequality (I) is established, then go to step (2); otherwise repeat this step;

[0036] ΔI res >K set1 (I)

[0037] In the formula, the criterion open constant K set1 The value range of is [0.1Ie, 0.3Ie], Ie is the rated current of the transformer;

[0038] (2), judging whether the inequality (II) is established, if the inequality (II) is established, then the fault type belong...

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Abstract

The invention relates to a method for enhancing differential protection performance by the coordination of mutation quantity fault discrimination and fuzzy harmonic analysis, which utilizes different characteristics of difference current and braking current mutation quantity to distinguish the internal and external faults of an area under different fault conditions. After a fault type is distinguished by the discrimination method, a fuzzy harmonic analysis criterion is combined to enhance the accuracy of fault discrimination so as to enhance the reliability and sensitivity of differential protection. The method is already adopted in a complete set of protection device of a DSA serial transformer and both the simulation results and the site practical situation indicate that the method has good prevention effect on reasons which easily cause differential misoperation, such as TA saturation, sympathetic surge, AD abnormity, and the like.

Description

Technical field [0001] The invention involves a new method of using a new type of failure to judge the combination of harmonic analysis and judgment. Background technique [0002] It cannot meet the needs of the on -site safe operation.At present, the main reasons for the miscalculation of the ratio of ratio include the following points include the following points [0003] 1. TA saturated outside the area. Although the products of each company have anti -TA saturation, it may still cause protection or delay during the TA saturation process. [0004] 2. The current research of Yingyou, the research on the current and Yingyou flow has gradually deepened, but the misunderstanding caused by the influence caused by Yingying also occasionally occurs. [0005] 3. Internal AD faults, repeatedly recording waves found that when protecting the internal AD failure, the presence of some "bad points" caused different movements. Invention content [0006] The technical problem to be solved by...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H02H7/045
Inventor 张庆伟吕浩代莹梁臣杨胜
Owner NARI TECH CO LTD
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