CN110542823A - Distribution line single-phase earth fault section positioning method - Google Patents
Distribution line single-phase earth fault section positioning method Download PDFInfo
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- CN110542823A CN110542823A CN201910856935.2A CN201910856935A CN110542823A CN 110542823 A CN110542823 A CN 110542823A CN 201910856935 A CN201910856935 A CN 201910856935A CN 110542823 A CN110542823 A CN 110542823A
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- 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
- G01R31/086—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S10/00—Systems supporting electrical power generation, transmission or distribution
- Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
- Y04S10/52—Outage or fault management, e.g. fault detection or location
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Abstract
The invention discloses a distribution line single-phase earth fault section positioning method, which comprises a distribution automation main station system, a single-phase earth fault line selection device, a feeder terminal FTU and a communication system, wherein the single-phase earth fault line selection device comprises a single-phase earth fault line and a single-phase earth fault line; the distribution main station is connected with the single-phase earth fault line selection device and the feeder terminal FTU through a communication system for information exchange; the method can effectively solve the problems that the zero-sequence current power frequency signal is small when the single-phase earth fault occurs, and the positioning sensitivity of the single-phase earth fault section is low; the invention adopts the high-frequency component (500-3000 Hz) of the zero sequence current as the basis of fault detection to detect the fault, and provides a method for positioning the section by using the phase comparison of the main oscillation frequency; the method inherits and improves the traditional fault positioning method, and improves the reliability and the sensitivity of fault detection.
Description
Technical Field
The invention relates to the technical field of power automation, in particular to a method for positioning a single-phase grounding fault section of a distribution line, which is suitable for realizing automatic positioning of the fault section after a single-phase grounding fault occurs to a medium-voltage distribution line (feeder line) with ungrounded neutral point.
background
At present, a medium-voltage distribution network generally adopts an operation mode that a neutral point is not grounded or is grounded through an arc suppression coil, and when a single-phase ground fault occurs, the fault current is smaller. The single-phase earth fault line selection device of the transformer substation can correctly select a fault line. Because the zero sequence current power frequency component of the single-phase earth fault is relatively small, the detection and positioning effects of the power distribution terminal on the single-phase earth fault are not good enough.
when a single-phase earth fault occurs in a distribution line, the power frequency component of zero-sequence current is small, but the high-frequency component (500-3000 Hz) is large, the amplitude can reach more than 20A, and the zero-sequence current can be used as a fault detection component. The direction of the zero sequence current detected upstream of the fault point is the incoming bus and the direction of the zero sequence current detected downstream of the fault point is the outgoing bus. By utilizing the characteristic, the fault section can be judged by adopting a zero sequence current waveform comparison method. However, the zero sequence current contains abundant frequency components, and the waveform comparison method sometimes fails.
Therefore, the improvement of the reliability and sensitivity of fault detection is a technical problem to be solved at the present stage.
Disclosure of Invention
The invention aims to solve the problems that a zero-sequence current power frequency signal is small when a single-phase earth fault occurs, and the positioning sensitivity of a single-phase earth fault section is low.
In order to solve the technical problems, the invention adopts a technical scheme that: the method is characterized by comprising a distribution automation main station system, a single-phase earth fault line selection device, a feeder terminal FTU and a communication system; the distribution main station is connected with the single-phase earth fault line selection device and the feeder terminal FTU through a communication system for information exchange;
when single-phase earth fault happens, the line selection device of the transformer substation completes the line selection function, selects a fault line, reports a distribution automation main station system, starts a fault location algorithm, and then locates a fault section through the following steps:
1) The distribution automation master station system judges a fault line according to a line selection result of the line selection device; the distribution automation master station system carries out frequency transformation on zero sequence current waveform data at the outlet of a fault line, selects the frequency with the maximum amplitude as a main oscillation frequency f, and extracts the phase of the fault moment of the main oscillation frequency and records the phase as phi 0;
2) the distribution automation master station system carries out frequency transformation on fault zero sequence current waveform data collected by each FTU according to the topological relation of distribution lines and the distance from the FTU to a transformer substation in sequence, and extracts a phase value phi n of a fault moment when the nth FTU detects the main oscillation frequency f;
3) if the | φ 0- φ n | is less than 120 degrees, the fault section is below the FTU, and the search is continued; if the | φ 0- φ n | is larger than 120 degrees, the fault is above the FTU, the search is stopped, and a fault section is determined to be between the nth FTU and the n-1 FTUs;
4) If | φ 0- φ n | is >120 ° does not occur up to the very end FTU, the faulty section is considered to be after the nth FTU, i.e., the end of the line.
Preferably, the distribution automation master station system is used for collecting fault information of a substation line selection device and fault information of each feeder terminal FTU on a line, analyzing according to the collected fault current information, and determining a fault section;
Preferably, the single-phase earth fault line selection device is used for acquiring zero-sequence current information of a medium-voltage distribution line outlet circuit breaker of the transformer substation, performing single-phase earth fault line selection and reporting the single-phase earth fault line selection to the distribution main station system.
Preferably, the feeder terminal FTU includes an on-line switch FTU, and is configured to collect fault information of each switch and report the fault information to the distribution master station system.
Preferably, the communication system provides a channel for the communication between the power distribution main station, the single-phase ground fault line selection device and each feeder terminal FTU.
Preferably, when a single-phase earth fault occurs, the direction of the zero-sequence current at the upstream of the fault point is the direction of the zero-sequence current flowing into the bus, and is the same as the direction of the zero-sequence current at the outlet of the line; the direction of the zero sequence current at the downstream of the fault point is the outgoing bus, and is opposite to the direction of the zero sequence current at the outlet of the line. By utilizing the characteristic, the phases of the main oscillation frequencies of the zero-sequence currents are selected for comparison, and the phases with the phase difference of 120 degrees are regarded as upstream of a fault point, and the phases with the phase difference of 120 degrees are regarded as downstream of the fault point.
The method can effectively solve the problems that the zero-sequence current power frequency signal is small when the single-phase earth fault occurs, and the positioning sensitivity of the single-phase earth fault section is low; the invention adopts the high-frequency component (500-3000 Hz) of the zero sequence current as the basis of fault detection to detect the fault, and provides a method for positioning the section by using the phase comparison of the main oscillation frequency; the method inherits and improves the traditional fault positioning method, and improves the reliability and the sensitivity of fault detection.
drawings
in order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without inventive efforts, wherein:
FIG. 1 is a block diagram of a single-phase ground fault section location system for a distribution line;
fig. 2 is a schematic diagram of the installation of the power distribution main station, the line selection device and the FTU.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1-2, a method for positioning a single-phase earth fault section of a distribution line is characterized by comprising a distribution automation master station system, a single-phase earth fault line selection device, a feeder terminal FTU and a communication system; the distribution main station is connected with the single-phase earth fault line selection device and the feeder terminal FTU through a communication system for information exchange;
When single-phase earth fault happens, the line selection device of the transformer substation completes the line selection function, selects a fault line, reports a distribution automation main station system, starts a fault location algorithm, and then locates a fault section through the following steps:
1) the distribution automation master station system judges a fault line according to a line selection result of the line selection device; the distribution automation master station system carries out frequency transformation on zero sequence current waveform data at the outlet of a fault line, selects the frequency with the maximum amplitude as a main oscillation frequency f, and extracts the phase of the fault moment of the main oscillation frequency and records the phase as phi 0;
2) the distribution automation master station system carries out frequency transformation on fault zero sequence current waveform data collected by each FTU according to the topological relation of distribution lines and the distance from the FTU to a transformer substation in sequence, and extracts a phase value phi n of a fault moment when the nth FTU detects the main oscillation frequency f;
3) if the | φ 0- φ n | is less than 120 degrees, the fault section is below the FTU, and the search is continued; if the | φ 0- φ n | is larger than 120 degrees, the fault is above the FTU, the search is stopped, and a fault section is determined to be between the nth FTU and the n-1 FTUs;
4) if | φ 0- φ n | is >120 ° does not occur up to the very end FTU, the faulty section is considered to be after the nth FTU, i.e., the end of the line.
In a specific implementation process, the distribution automation master station system is used for collecting fault information of a substation line selection device and fault information of each Feeder Terminal (FTU) on a line, analyzing according to the collected fault current information, and determining a fault section;
In the specific implementation process, the single-phase earth fault line selection device is used for acquiring zero-sequence current information of the medium-voltage distribution line outlet circuit breaker of the transformer substation, performing single-phase earth fault line selection and reporting the single-phase earth fault line selection to the power distribution main station system.
In a specific implementation process, the feeder terminal FTU includes an on-line switch FTU for acquiring fault information of each switch and reporting the fault information to the distribution master station system.
in a specific implementation process, the communication system provides a channel for the communication between the power distribution main station, the single-phase earth fault line selection device and each feeder terminal FTU.
In the specific implementation process, when a single-phase earth fault occurs, the direction of the zero sequence current at the upstream of a fault point is that the zero sequence current flows into a bus, and is the same as the direction of the zero sequence current at the outlet of a line; the direction of the zero sequence current at the downstream of the fault point is the outgoing bus, and is opposite to the direction of the zero sequence current at the outlet of the line. By utilizing the characteristic, the phases of the main oscillation frequencies of the zero-sequence currents are selected for comparison, and the phases with the phase difference of 120 degrees are regarded as upstream of a fault point, and the phases with the phase difference of 120 degrees are regarded as downstream of the fault point.
As shown in fig. 2, the FTU single-phase earth fault current detection start setting value is set such that the zero-sequence current variation of 500Hz to 3000Hz exceeds 100%, and the FTU starts fault detection and reports 3 cycles (60 ms) of zero-sequence current waveforms to the distribution master station.
after a single-phase earth fault occurs, the line selection device carries out fault line selection and reports 3 cycle (60 ms) zero-sequence current waveforms of a fault line and a fault line outlet to a power distribution main station;
And the power distribution master station performs frequency conversion according to the reported zero sequence current waveform flowing through the outlet circuit breaker, extracts the frequency with the maximum amplitude, and records the frequency as the main oscillation frequency f and the phase phi 0. And sequentially comparing the phases phi n with the zero sequence current waveform frequency f acquired by each FTU and searching the fault sections.
the method can effectively solve the problems that the zero-sequence current power frequency signal is small when the single-phase earth fault occurs, and the positioning sensitivity of the single-phase earth fault section is low; the invention adopts the high-frequency component (500-3000 Hz) of the zero sequence current as the basis of fault detection to detect the fault, and provides a method for positioning the section by using the phase comparison of the main oscillation frequency; the method inherits and improves the traditional fault positioning method, and improves the reliability and the sensitivity of fault detection.
The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by the present specification, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.
Claims (6)
1. A distribution line single-phase earth fault section positioning method is characterized by comprising a distribution automation main station system, a single-phase earth fault line selection device, a feeder terminal FTU and a communication system; the distribution main station is connected with the single-phase earth fault line selection device and the feeder terminal FTU through a communication system for information exchange;
When single-phase earth fault happens, the line selection device of the transformer substation completes the line selection function, selects a fault line, reports a distribution automation main station system, starts a fault location algorithm, and then locates a fault section through the following steps:
1) the distribution automation master station system judges a fault line according to a line selection result of the line selection device; the method comprises the following steps that a distribution automation main station system carries out frequency transformation on zero sequence current waveform data at a fault line outlet, the frequency with the maximum amplitude is selected as a main oscillation frequency f, and the initial phase of the fault moment of the main oscillation frequency is extracted and recorded as phi 0;
2) According to the topological relation of a distribution line, the distribution automation master station system sequentially carries out frequency transformation on fault zero sequence current waveform data collected by each FTU according to the distance from the distribution line to a transformer substation, and extracts an initial phase value phi n of a fault moment when the nth FTU detects the main oscillation frequency f;
3) if the | φ 0- φ n | is less than 120 degrees, the fault section is below the FTU, and the search is continued; if the | φ 0- φ n | is larger than 120 degrees, the fault is above the FTU, the search is stopped, and a fault section is determined to be between the nth FTU and the n-1 FTUs;
4) If | φ 0- φ n | is >120 ° does not occur up to the very end FTU, the faulty section is considered to be after the nth FTU, i.e., the end of the line.
2. The distribution line single-phase ground fault section positioning method according to claim 1, wherein the distribution automation master station system is configured to collect fault information of a substation line selection device and fault information of each feeder terminal FTU on the line, and perform analysis according to the collected fault current information to determine a fault section.
3. The method according to claim 1, wherein the single-phase earth fault line selection device is configured to collect zero-sequence current information of an outlet breaker of the medium-voltage distribution line of the substation, perform single-phase earth fault line selection, and report the single-phase earth fault line selection to the distribution main station system.
4. The distribution line single-phase ground fault section positioning method according to claim 1, wherein the feeder terminal FTU comprises an on-line switch FTU for collecting fault information of each switch and reporting to the distribution main station system.
5. The method of claim 1 wherein the communication system provides a path for the distribution main station, the single-phase ground fault line selector, and the feeder terminals FTU to communicate.
6. The method according to claim 1, wherein when a single-phase earth fault occurs, the direction of the zero-sequence current upstream of the fault point is the same as the direction of the zero-sequence current at the line outlet, and the zero-sequence current flows into the bus; the direction of the zero sequence current at the downstream of the fault point is the outgoing bus, and is opposite to the direction of the zero sequence current at the outlet of the line. By utilizing the characteristic, the phases of the main oscillation frequencies of the zero-sequence currents are selected for comparison, and the phases with the phase difference of 120 degrees are regarded as upstream of a fault point, and the phases with the phase difference of 120 degrees are regarded as downstream of the fault point.
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| CN201910856935.2A CN110542823A (en) | 2019-09-11 | 2019-09-11 | Distribution line single-phase earth fault section positioning method |
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| CN201910856935.2A CN110542823A (en) | 2019-09-11 | 2019-09-11 | Distribution line single-phase earth fault section positioning method |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111624440A (en) * | 2020-05-26 | 2020-09-04 | 襄阳科能机电设备有限公司 | Single phase grounding fault line selection device in neutral point through arc suppression coil grounding system |
| CN113589102A (en) * | 2021-07-31 | 2021-11-02 | 江苏大烨智能电气股份有限公司 | FTU-based broken line fault section positioning method and system |
| CN115420995A (en) * | 2022-08-12 | 2022-12-02 | 国网福建省电力有限公司 | Comprehensive test system and method for studying and judging performance of single-phase earth fault of power distribution terminal |
| CN116359668A (en) * | 2023-03-15 | 2023-06-30 | 国网宁夏电力有限公司银川供电公司 | Power distribution network single-phase earth fault positioning method based on multi-source information comprehensive judgment |
| CN117233542A (en) * | 2023-11-15 | 2023-12-15 | 武汉格蓝若智能技术股份有限公司 | Power distribution network single-phase earth fault section positioning method and system |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060291113A1 (en) * | 2005-05-17 | 2006-12-28 | Abb Oy | System and method for determining location of phase-to-earth fault |
| CN102064537A (en) * | 2010-12-10 | 2011-05-18 | 天津天大求实电力新技术股份有限公司 | Method for judging and processing single-phase earth faults by using electronic mutual inductor |
| CN104155582A (en) * | 2014-08-29 | 2014-11-19 | 上海交通大学 | Distribution network line fault section positioning method based on full-waveform information |
| CN104181442A (en) * | 2014-08-21 | 2014-12-03 | 西安交通大学 | Power distribution network single-phase earth fault section locating method based on correlation analysis |
| CN109188195A (en) * | 2018-08-17 | 2019-01-11 | 国网江苏省电力有限公司电力科学研究院 | A kind of distribution small current grounding fault localization method and system |
-
2019
- 2019-09-11 CN CN201910856935.2A patent/CN110542823A/en not_active Withdrawn
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060291113A1 (en) * | 2005-05-17 | 2006-12-28 | Abb Oy | System and method for determining location of phase-to-earth fault |
| CN102064537A (en) * | 2010-12-10 | 2011-05-18 | 天津天大求实电力新技术股份有限公司 | Method for judging and processing single-phase earth faults by using electronic mutual inductor |
| CN104181442A (en) * | 2014-08-21 | 2014-12-03 | 西安交通大学 | Power distribution network single-phase earth fault section locating method based on correlation analysis |
| CN104155582A (en) * | 2014-08-29 | 2014-11-19 | 上海交通大学 | Distribution network line fault section positioning method based on full-waveform information |
| CN109188195A (en) * | 2018-08-17 | 2019-01-11 | 国网江苏省电力有限公司电力科学研究院 | A kind of distribution small current grounding fault localization method and system |
Non-Patent Citations (2)
| Title |
|---|
| 姜建等: ""基于配电自动化技术的小电流接地故障区段定位方法"", 《电测与仪表》 * |
| 杜向楠: ""基于嵌入式系统的配电线路单相故障定位故障装置的研制"", 《中国优秀硕士学位论文（工程科技II辑）》 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111624440A (en) * | 2020-05-26 | 2020-09-04 | 襄阳科能机电设备有限公司 | Single phase grounding fault line selection device in neutral point through arc suppression coil grounding system |
| CN113589102A (en) * | 2021-07-31 | 2021-11-02 | 江苏大烨智能电气股份有限公司 | FTU-based broken line fault section positioning method and system |
| CN115420995A (en) * | 2022-08-12 | 2022-12-02 | 国网福建省电力有限公司 | Comprehensive test system and method for studying and judging performance of single-phase earth fault of power distribution terminal |
| CN115420995B (en) * | 2022-08-12 | 2024-08-30 | 国网福建省电力有限公司 | Comprehensive testing system and method for single-phase earth fault research and judgment performance of power distribution terminal |
| CN116359668A (en) * | 2023-03-15 | 2023-06-30 | 国网宁夏电力有限公司银川供电公司 | Power distribution network single-phase earth fault positioning method based on multi-source information comprehensive judgment |
| CN117233542A (en) * | 2023-11-15 | 2023-12-15 | 武汉格蓝若智能技术股份有限公司 | Power distribution network single-phase earth fault section positioning method and system |
| CN117233542B (en) * | 2023-11-15 | 2024-02-20 | 武汉格蓝若智能技术股份有限公司 | Power distribution network single-phase earth fault section positioning method and system |
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