Method for judging short-circuit fault and charging process of direct-current charging pile

A technology of DC charging pile and charging process, which is applied in the direction of measuring electricity, measuring electrical variables, measuring devices, etc., can solve the problem of being unable to distinguish the short-circuit fault of DC charging pile and the charging process, and achieve the effect of avoiding the misoperation of overcurrent protection

Active Publication Date: 2017-01-25
云南巨电科技有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to overcome the deficiency that the existing overcurrent protection cannot distinguish the short-circuit fault of the DC charging pile and the charging process, and propose a method for distinguishing the short-circuit fault of the DC charging pile and the charging process

Method used

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  • Method for judging short-circuit fault and charging process of direct-current charging pile
  • Method for judging short-circuit fault and charging process of direct-current charging pile
  • Method for judging short-circuit fault and charging process of direct-current charging pile

Examples

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Effect test

Embodiment 1

[0037] Embodiment 1: as figure 1 As shown, the harmonic acquisition and detection module is installed in the overcurrent protection device of the DC charging pile. During the charging process of the DC charging pile, the rectifier in the DC charging pile will generate a large number of harmonics of a specific order on the AC side. Harmonic collection and detection The module collects the current data on the AC side in real time, and distinguishes the short-circuit fault of the DC charging pile from the charging process by detecting the relationship between the harmonic and the fundamental wave content in the current on the AC side; The ratio of harmonic content will exceed the threshold, and the harmonic acquisition and detection module will not send blocking protection to the overcurrent protection; if the DC charging pile is in the charging process, the ratio of the fundamental wave of the AC side to the specific order The detection module sends blocking protection to the ov...

Embodiment 2

[0039] Embodiment 2: as figure 1 As shown, the harmonic acquisition and detection module is installed in the overcurrent protection device of the DC charging pile. During the charging process of the DC charging pile, the rectifier in the DC charging pile will generate a large number of harmonics of a specific order on the AC side. Harmonic collection and detection The module collects the current data on the AC side in real time, and distinguishes the short-circuit fault of the DC charging pile from the charging process by detecting the relationship between the harmonic and the fundamental wave content in the current on the AC side; The ratio of harmonic content will exceed the threshold, and the harmonic acquisition and detection module will not send blocking protection to the overcurrent protection; if the DC charging pile is in the charging process, the ratio of the fundamental wave of the AC side to the specific order The detection module sends blocking protection to the ov...

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Abstract

The invention relates to a method for judging a short-circuit fault and a charging process of a direct-current charging pile and belongs to the technical field of power system relay protection. A harmonic acquiring and detecting module is installed in an overcurrent protection device of the direct-current charging pile and acquires current data on the alternating current side in real time, medium-high frequency noise in acquired waveforms is filtered and removed through wavelet transform, and the short-circuit fault and the charging process of the direct-current charging pile are judged by detecting the relation between the content of harmonic waves and the content of fundamental waves in current on the alternating current side; if the short-circuit fault occurs, the content ratio of the fundamental waves to the specific number of harmonic waves on the alternating current side can exceed a threshold, and the harmonic acquiring and detecting module sends no blocking protection to overcurrent protection; if the direct-current charging pile is in the charging process, the content ratio of the fundamental waves to the specific number of harmonic waves on the alternating current side is smaller, and the harmonic acquiring and detecting module sends blocking protection to overcurrent protection. The method can accurately judge the short-circuit fault and the charging process of the direct-current charging pile and prevent overcurrent protection malfunction of the direct-current charging pile in the charging process.

Description

technical field [0001] The invention relates to a method for discriminating a short-circuit fault of a DC charging pile and a charging process, and belongs to the technical field of relay protection of a power system. Background technique [0002] With the maturity of electric vehicle technology, a large number of electric vehicles have been put into use. Due to the poor endurance of electric vehicles, there are often a large number of electric vehicles waiting in line for charging in charging stations. The charging speed of the existing DC charging piles can already exceed 20kW, and a large current will be generated during the charging process. However, it is difficult for the current overcurrent protection in the distribution box to distinguish the charging process of the DC charging piles from the short-circuit fault, resulting in multiple DC charging piles. At the same time, when fast charging electric vehicles, it is easy to be misjudged by the overcurrent protection as...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01R31/02
CPCG01R31/50
Inventor 雷涛樊鑫超杨展
Owner 云南巨电科技有限公司
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