Arc detection method and apparatus using statistical value of electric current

Patent metadata

Field	Value
Publication number	US-11519952-B2
Application number	US-202117500944-A
Country	US
Kind code	B2
Filing date	Oct 14, 2021
Priority date	Feb 14, 2020
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

An embodiment of the present disclosure provides an arc detection method, in which an apparatus detects arcs, comprising the steps of: obtaining time series data for measured values of an electric current flowing in a wire; calculating first statistical values indicating dispersion degrees with time of the measured values or dispersion degrees with time of variances of the measured values from the time series data; and determining that an arc occurs in the wire or that the possibility of arc occurrence in the wire is high in a case when at least one of the first statistical values is out of a predefined range.

First claim

What is claimed is:

1. An arc detection method, in which an apparatus detects arcs, comprising steps of:
obtaining time series data for measured values of an electric current flowing in a wire;
generating N pieces of frequency analysis data by performing N times or more of frequency analyses in different time periods of the time series data, wherein N is a natural number which is 2 or higher; and
determining that an arc occurs in the wire or that the possibility of an arc occurrence in the wire is high in a case when at least one of magnitude variation values of frequencies, verified in the N pieces of frequency analysis data, exceeds a reference value.

2. The arc detection method of claim 1 further comprising a step of calculating statistical values for the dispersion or standard deviation values of magnitudes of respective frequencies in the N pieces of frequency analysis data, and determining that an arc occurs in the wire or the possibility of an arc occurrence in the wire is high in a case when at least one of the statistical values exceeds the reference value.

3. The arc detection method of claim 1 further comprising steps of:
before generating the N pieces of frequency analysis data,
generating M pieces of frequency analysis data by performing M times or more of frequency analyses in different time periods of the time series data, wherein M is a natural number which is 2 or higher; and
generating the reference value by calculating a magnitude variation value for each frequency using the M pieces of frequency analysis data.

4. The arc detection method of claim 3 , wherein the reference value is generated in a time period in which it was determined that no arc occurs.

5. The arc detection method of claim 3 , wherein the reference value is generated within a predetermined time after a relevant apparatus has started to operate.

6. The arc detection method of claim 3 , wherein the M pieces of frequency analysis data are generated using the time series data before a time point when an instantaneous value of the electric current is varied and the N pieces of frequency analysis data are generated using the time series data after the time point.

7. The arc detection method of claim 3 , wherein the M pieces of frequency analysis data are generated using the time series data before the time point when at least one of the dispersion degrees of values corresponding to the electric current or the variances of the electric current is out of a predefined range and the N pieces of frequency analysis data are generated using the time series data after the time point.

8. The arc detection method of claim 1 , wherein the N pieces of frequency analysis data are generated in time periods of the same size and not overlapping with each other.

9. An arc detection apparatus comprising:
a sensing circuit to obtain time series data for measured values of an electric current flowing in a wire; and
an arc determination circuit to generate N pieces of frequency analysis data by performing N times or more of frequency analyses in different time periods, and to determine that an arc occurs in the wire or that the possibility of an arc occurrence in the wire is high in a case when at least one of magnitude variation values of respective frequencies, verified in the N pieces of frequency analysis data, exceeds a reference value, wherein N is a natural number which is 2 or higher.

10. The arc detection apparatus of claim 9 , wherein switching noises of a power converting device flow in through one side of the wire.

11. The arc detection apparatus of claim 9 , wherein the arc determination circuit generates the reference value by generating M (M is a natural number, which is 2 or higher) pieces of frequency analysis data by performing M times or more of frequency analyses for the time series data in a time period before an event is generated and calculating magnitude variation values for respective frequencies using the M pieces of frequency analysis data.

12. The arc detection apparatus of claim 11 , wherein the event is generated by a timer or an external signal.

13. The arc detection apparatus of claim 11 , wherein the arc determination circuit discerns a variation of an instantaneous value of the electric current to generate the event.

14. The arc detection apparatus of claim 11 , wherein the arc determination circuit generates the event in a case when at least one of the dispersion degrees of values corresponding to the electric current or variances of the electric current is out of the predefined range.

15. The arc detection apparatus of claim 11 , wherein the sensing circuit generates the time series data using the measured values of the electric current to which a low-pass filter is applied.

Assignees

• Korea Inst Energy Res

Inventors

• Chae Su Yong
• Kang Mo Se
• Bae Kuk Yeol
• Park Suk In
• Jeong Hak Geun
• Yoon Gi Hwan

Classifications

• G01R23/16

  Spectrum analysis; Fourier analysis · CPC title

• H02H1/0015

  Using arc detectors · CPC title

• G01R31/14 Primary

  Circuits therefor {, e.g. for generating test voltages, sensing circuits (G01R31/1209 - G01R31/1227 take precedence; for testing switches G01R31/327)} · CPC title

• G01R31/1272 Primary

  of cable, line or wire insulation, e.g. using partial discharge measurements (locating faults in cables G01R31/083) · CPC title

• G01R19/252

  using analogue/digital converters of the type with conversion of voltage or current into frequency and measuring of this frequency · CPC title