CN112557825A - Single-phase earth fault line determination method - Google Patents

Single-phase earth fault line determination method Download PDF

Info

Publication number
CN112557825A
CN112557825A CN202011436242.7A CN202011436242A CN112557825A CN 112557825 A CN112557825 A CN 112557825A CN 202011436242 A CN202011436242 A CN 202011436242A CN 112557825 A CN112557825 A CN 112557825A
Authority
CN
China
Prior art keywords
bus
frequency
phase
calculating
line
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202011436242.7A
Other languages
Chinese (zh)
Inventor
徐以超
吴小刚
潘一藩
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Yancheng Power Supply Co of State Grid Jiangsu Electric Power Co Ltd
Original Assignee
Yancheng Power Supply Co of State Grid Jiangsu Electric Power Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Yancheng Power Supply Co of State Grid Jiangsu Electric Power Co Ltd filed Critical Yancheng Power Supply Co of State Grid Jiangsu Electric Power Co Ltd
Priority to CN202011436242.7A priority Critical patent/CN112557825A/en
Publication of CN112557825A publication Critical patent/CN112557825A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/08—Locating faults in cables, transmission lines, or networks
    • G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
    • G01R31/085—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution lines, e.g. overhead
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/08—Locating faults in cables, transmission lines, or networks
    • G01R31/088—Aspects of digital computing
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
    • G01R31/52—Testing for short-circuits, leakage current or ground faults

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Mathematical Physics (AREA)
  • Theoretical Computer Science (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

The invention provides a method for determining a single-phase earth fault line, which comprises the following steps: (1): collecting zero sequence current signals and bus zero sequence voltage signals of each line by taking T as a time interval; (2): performing discrete Fourier transform; (3): performing discrete S transformation; (4): calculating a feature matrix S (i, t); (5): calculating the frequency number n of the component phase of the characteristic matrix G (i, t) at 180-270 DEG1At a frequency number n of 0 DEG to 90 DEG2(ii) a (6): judging n1Whether or not it is greater than n2If yes, the bus is in fault; if not, step (7); (7): calculating n1The ratio to the number of frequencies in the total active band; (8): obtaining n1And the maximum value of the ratio of the frequency number to the total effective frequency band is the fault line. The invention provides a single-phase earth fault line determination method which can accurately determine a specific earth line and improve the safety and reliability of power distribution work.

Description

Single-phase earth fault line determination method
Technical Field
The invention belongs to the technical field of power detection, and particularly relates to a method for determining a single-phase earth fault line.
Background
At present, the distribution network in China mainly adopts a mode that a neutral point is not directly grounded, the tripping times of the distribution network can be reduced, and the power supply reliability is further improved. When a single-phase earth fault occurs in an indirectly-grounded power distribution network, although the power distribution network cannot be tripped immediately, the safe operation of the power distribution network is threatened, a fault line needs to be determined as soon as possible and cut off, and the working safety and reliability of the power distribution network are guaranteed.
In order to determine a specific grounding circuit in time and cut off the specific grounding circuit, the invention provides a single-phase grounding fault circuit determination method which can collect characteristic signals of each circuit under different sampling frequencies, extract characteristic components, determine whether a bus is grounded or a branch is grounded according to the ratio of the frequency number of the characteristic components in a total effective frequency band, determine a specific branch, be suitable for a neutral point ungrounded system and a neutral point arc suppression coil grounded system, and ensure the accuracy of fault circuit determination.
Disclosure of Invention
The invention provides a single-phase earth fault line determination method which can accurately determine a specific earth line and improve the safety and reliability of power distribution work.
The invention specifically relates to a method for determining a single-phase earth fault line, which comprises the following steps:
step (1): the signal acquisition device acquires zero-sequence current signals and bus zero-sequence voltage signals of each line by taking T as a time interval;
step (2): performing discrete Fourier transform on the zero-sequence current signal:
Figure BDA0002828861210000011
f is frequency signal, f is 0,1, N-1, N is sampling point number, i is 0,1, M, M is line number, k is time coefficient, i is time coefficient0Is the zero sequence current signal; performing discrete Fourier transform on the bus zero sequence voltage signal:
Figure BDA0002828861210000012
u0zero sequence voltage signals for the bus;
and (3): carrying out discrete S transformation on the zero sequence current signal:
Figure BDA0002828861210000013
t is the signal time, t is 01, N-1; carrying out discrete S transformation on the bus zero sequence voltage signal:
Figure BDA0002828861210000014
and (4): calculating a feature matrix:
Figure BDA0002828861210000021
and (5): calculating the frequency number n of the component phase of the characteristic matrix G (i, t) at 180-270 DEG1The phase of the component of the feature matrix G (i, t) is within the frequency number n of 0-90 DEG2；
And (6): judging n1Whether or not it is greater than n2If yes, the bus is in fault; if not, entering the step (7);
and (7): calculating the frequency number n of the component phase of the characteristic matrix G (i, t) at 180-270 DEG1The ratio to the number of frequencies in the total active band;
and (8): obtaining the frequency number n of the component phase of the characteristic matrix G (i, t) at 180-270 DEG1And the maximum value of the ratio of the frequency number to the total effective frequency band is the fault line.
The effective frequency band range is
Figure BDA0002828861210000022
fsIs the sampling frequency.
Compared with the prior art, the beneficial effects are: according to the fault line determining method, the characteristic signals of all lines under different sampling frequencies are collected, the characteristic components are extracted, whether the bus is grounded or the branch is grounded is determined according to the ratio of the frequency number of the characteristic components in the total effective frequency band, and the specific branch is determined, so that the method is high in applicability and high in accuracy.
Drawings
Fig. 1 is a flowchart illustrating a method for determining a single-phase earth fault line according to the present invention.
Detailed Description
The following describes in detail a specific embodiment of a single-phase ground fault line determination method according to the present invention with reference to the accompanying drawings.
As shown in fig. 1, the faulty line determination method of the present invention includes the steps of:
step (1): the signal acquisition device acquires zero-sequence current signals and bus zero-sequence voltage signals of each line by taking T as a time interval;
step (2): performing discrete Fourier transform on the zero-sequence current signal:
Figure BDA0002828861210000023
f is frequency signal, f is 0,1, N-1, N is sampling point number, i is 0,1, M, M is line number, k is time coefficient, i is time coefficient0Is the zero sequence current signal; performing discrete Fourier transform on the bus zero sequence voltage signal:
Figure BDA0002828861210000031
u0zero sequence voltage signals for the bus;
and (3): carrying out discrete S transformation on the zero sequence current signal:
Figure BDA0002828861210000032
t is a signal moment, t is 0,1, N-1; carrying out discrete S transformation on the bus zero sequence voltage signal:
Figure BDA0002828861210000033
and (4): calculating a feature matrix:
Figure BDA0002828861210000034
and (5): calculating the frequency number n of the component phase of the characteristic matrix G (i, t) at 180-270 DEG1The phase of the component of the feature matrix G (i, t) is within the frequency number n of 0-90 DEG2；
And (6): judging n1Whether or not it is greater than n2If yes, the bus is in fault; if not, entering the step (7);
and (7): calculating the phase of the component of the feature matrix G (i, t) at 180Frequency number n of DEG-270 DEG1The ratio to the number of frequencies in the total active band;
and (8): obtaining the frequency number n of the component phase of the characteristic matrix G (i, t) at 180-270 DEG1And the maximum value of the ratio of the frequency number to the total effective frequency band is the fault line.
Transient state information when the fault occurs is generally rich, so that data in a period of time after the fault occurs are collected for analysis and processing.
In order to enable the fault line determination method to be applicable to both a neutral point ungrounded system and a neutral point crowbar coil grounded system, the lower limit of the effective frequency band is set to be 100 Hz; in order to ensure that the signal is not distorted, the upper limit of the effective frequency band is set to
Figure BDA0002828861210000035
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the same. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (2)

1. A single-phase earth fault line determination method, characterized by comprising the steps of:
step (1): the signal acquisition device acquires zero-sequence current signals and bus zero-sequence voltage signals of each line by taking T as a time interval;
step (2): performing discrete Fourier transform on the zero-sequence current signal:
Figure FDA0002828861200000011
f is frequency signal, f is 0,1, N-1, N is sampling point number, i is 0,1, M, M is line number, k is time coefficient, i is time coefficient0Is the zero sequence current signal; performing discrete Fourier transform on the bus zero sequence voltage signal:
Figure FDA0002828861200000012
u0zero sequence voltage signals for the bus;
and (3): carrying out discrete S transformation on the zero sequence current signal:
Figure FDA0002828861200000013
t is a signal moment, t is 0,1, N-1; carrying out discrete S transformation on the bus zero sequence voltage signal:
Figure FDA0002828861200000014
and (4): calculating a feature matrix:
Figure FDA0002828861200000015
and (5): calculating the frequency number n of the component phase of the characteristic matrix G (i, t) at 180-270 DEG1The phase of the component of the feature matrix G (i, t) is within the frequency number n of 0-90 DEG2；
And (6): judging n1Whether or not it is greater than n2If yes, the bus is in fault; if not, entering the step (7);
and (7): calculating the frequency number n of the component phase of the characteristic matrix G (i, t) at 180-270 DEG1The ratio to the number of frequencies in the total active band;
and (8): obtaining the frequency number n of the component phase of the characteristic matrix G (i, t) at 180-270 DEG1And the maximum value of the ratio of the frequency number to the total effective frequency band is the fault line.
2. The method as claimed in claim 1, wherein the effective frequency band is within a range of
Figure FDA0002828861200000016
fsIs the sampling frequency.
CN202011436242.7A 2020-12-10 2020-12-10 Single-phase earth fault line determination method Pending CN112557825A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011436242.7A CN112557825A (en) 2020-12-10 2020-12-10 Single-phase earth fault line determination method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011436242.7A CN112557825A (en) 2020-12-10 2020-12-10 Single-phase earth fault line determination method

Publications (1)

Publication Number Publication Date
CN112557825A true CN112557825A (en) 2021-03-26

Family

ID=75060265

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011436242.7A Pending CN112557825A (en) 2020-12-10 2020-12-10 Single-phase earth fault line determination method

Country Status (1)

Country Link
CN (1) CN112557825A (en)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101478149A (en) * 2009-01-16 2009-07-08 西安交通大学 Wire selection method for power distribution network single phase earthing failure based on transient signal
CN101587159A (en) * 2009-06-22 2009-11-25 昆明理工大学 Power distribution network outgoing feeder fault route selecting method by S transform amplitude detection
EP2741389A1 (en) * 2012-12-10 2014-06-11 Alstom Technology Ltd Ground fault direction determination for medium or high voltage distribution networks
CN106646138A (en) * 2016-12-30 2017-05-10 北京四方继保自动化股份有限公司 Method for locating grounding fault of power distribution network based on multi-sample frequency wavelet character energy conversion
CN107064741A (en) * 2017-04-06 2017-08-18 广西电网有限责任公司电力科学研究院 A kind of 2 points of successive ground fault line selecting methods of distribution network line different name phase
CN107144762A (en) * 2017-04-20 2017-09-08 广西电网有限责任公司电力科学研究院 A kind of distribution net work earthing fault localization method based on Small Electric Current Earthing And Routing Device
CN109307824A (en) * 2018-09-18 2019-02-05 福州大学 A kind of one-phase earthing failure in electric distribution network Section Location based on cluster
CN109813993A (en) * 2019-01-07 2019-05-28 西南交通大学 A kind of recognition methods of double tunning DC filter high-voltage capacitor ground fault
CN109856506A (en) * 2019-01-17 2019-06-07 陕西科技大学 Singlephase earth fault area positioning method based on the adjoint point method of difference

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101478149A (en) * 2009-01-16 2009-07-08 西安交通大学 Wire selection method for power distribution network single phase earthing failure based on transient signal
CN101587159A (en) * 2009-06-22 2009-11-25 昆明理工大学 Power distribution network outgoing feeder fault route selecting method by S transform amplitude detection
EP2741389A1 (en) * 2012-12-10 2014-06-11 Alstom Technology Ltd Ground fault direction determination for medium or high voltage distribution networks
CN106646138A (en) * 2016-12-30 2017-05-10 北京四方继保自动化股份有限公司 Method for locating grounding fault of power distribution network based on multi-sample frequency wavelet character energy conversion
CN107064741A (en) * 2017-04-06 2017-08-18 广西电网有限责任公司电力科学研究院 A kind of 2 points of successive ground fault line selecting methods of distribution network line different name phase
CN107144762A (en) * 2017-04-20 2017-09-08 广西电网有限责任公司电力科学研究院 A kind of distribution net work earthing fault localization method based on Small Electric Current Earthing And Routing Device
CN109307824A (en) * 2018-09-18 2019-02-05 福州大学 A kind of one-phase earthing failure in electric distribution network Section Location based on cluster
CN109813993A (en) * 2019-01-07 2019-05-28 西南交通大学 A kind of recognition methods of double tunning DC filter high-voltage capacitor ground fault
CN109856506A (en) * 2019-01-17 2019-06-07 陕西科技大学 Singlephase earth fault area positioning method based on the adjoint point method of difference

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
周铁生 等: "基于S 变换的配电网零序导纳故障选线方法", 《燕山大学学报》 *

Similar Documents

Publication Publication Date Title
CN107064741B (en) A kind of successive ground fault line selecting method of distribution network line different name phase two o'clock
Bo et al. Transient based protection for power transmission systems
Dash et al. Time–frequency transform approach for protection of parallel transmission lines
CN110579684A (en) low-current grounding system line selection method based on fusion algorithm
CN111257698A (en) Low-current grounding power grid continuous line selection system based on impedance change detection
CN113176521A (en) Single-phase earth fault detection method for power transmission and distribution system
CN114384374A (en) Fault study and judgment method and device based on edge calculation FTU and fault indicator
CN111426908A (en) Single-phase earth fault protection method, device and system for small current earthing system
CN110873847A (en) Single-phase earth fault positioning method based on SOGI (system-in-package) fundamental wave removal
CN107765065B (en) Fundamental wave attenuation factor-based power distribution network magnetizing inrush current identification method
CN107179476B (en) Distribution network fault distance measurement method
CN112379302B (en) Small-current ground fault protection method, device and system for integrating time-frequency domain information
CN112067944A (en) Single-phase grounding fault detection control method for power transmission and distribution line
CN117169655A (en) Single-phase ground fault interval and type judging method
CN111257699A (en) Low-current grounding power grid line selection system based on impedance detection
CN112557825A (en) Single-phase earth fault line determination method
CN114527356A (en) High-resistance grounding fault positioning method of small-resistance grounding system
CN110703134A (en) Small current grounding line selection and phase selection method based on fault sequence component
EP4063876B1 (en) Vector analysis calculation-based arc crosstalk signal identification method
CN113219374B (en) Transformer voltage fault detection method
CN114414944A (en) Low-current grounding device based on phase current transient method and detection method
CN113567803A (en) Tanimoto similarity-based small current ground fault positioning method and system
CN113138355A (en) Distribution automation terminal for ground fault judgment and ground fault judgment method
CN114113894A (en) Repetitive fault identification method based on natural frequency characteristics
CN114034973A (en) Fault area identification method, device and system for distribution line ground fault

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication

Application publication date: 20210326

RJ01 Rejection of invention patent application after publication