CN112255572A - Neutral point indirect grounding fault detection system based on signal injection - Google Patents
Neutral point indirect grounding fault detection system based on signal injection Download PDFInfo
- Publication number
- CN112255572A CN112255572A CN202011186987.2A CN202011186987A CN112255572A CN 112255572 A CN112255572 A CN 112255572A CN 202011186987 A CN202011186987 A CN 202011186987A CN 112255572 A CN112255572 A CN 112255572A
- Authority
- CN
- China
- Prior art keywords
- signal
- unit
- injection
- detection system
- current
- 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
Links
- 238000002347 injection Methods 0.000 title claims abstract description 45
- 239000007924 injection Substances 0.000 title claims abstract description 45
- 238000001514 detection method Methods 0.000 title claims abstract description 29
- 230000007935 neutral effect Effects 0.000 title claims abstract description 15
- 230000003750 conditioning effect Effects 0.000 claims abstract description 22
- 238000004891 communication Methods 0.000 claims abstract description 15
- 238000001914 filtration Methods 0.000 claims description 12
- 238000006243 chemical reaction Methods 0.000 claims description 7
- 238000005516 engineering process Methods 0.000 claims description 3
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
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
- G01R31/50—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
-
- 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
-
- 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
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
- Locating Faults (AREA)
Abstract
The invention provides a neutral point indirect grounding fault detection system based on signal injection, which comprises a signal acquisition unit, a first signal conditioning unit, a signal injection unit, an injection signal acquisition unit, a second signal conditioning unit, a control processing unit, a display unit and a communication unit, wherein the signal acquisition unit is used for acquiring a signal; the fault detection system controls the signal injection unit to inject current signals into the system according to the information acquired by the signal acquisition unit, judges a specific grounding circuit according to the information acquired by the injection signal acquisition unit, displays faults through the display unit and uploads the faults to a remote monitoring center through the communication unit. The invention provides a neutral point indirect grounding fault detection system based on signal injection, which can accurately detect a grounding fault and a specific grounding line and ensure the working reliability of a power distribution system.
Description
Technical Field
The invention belongs to the technical field of power detection, and particularly relates to a neutral point indirect grounding fault detection system based on signal injection.
Background
With more and more power users, a power distribution network becomes more and more complex, and more lines are provided, so that when a line is subjected to single-phase grounding, if the fault cannot be timely eliminated and the line is continuously operated for a long time, a more serious short-circuit fault can be caused, and the normal operation of a power system is seriously influenced. Therefore, when a single-phase earth fault occurs, finding out the fault line as soon as possible has great significance for ensuring the safe and reliable operation of the power system. For a neutral point indirect grounding system, after a grounding fault occurs, because grounding current is small, steady-state characteristic variable quantity of each line is not obvious, and the problem of on-site line selection is not thoroughly solved.
The invention provides a neutral point indirect grounding fault detection system based on signal injection, which preliminarily judges whether a fault occurs according to an acquired zero sequence voltage signal, and then injects a current signal with a specific frequency through a bus voltage transformer, wherein the current signal with the specific frequency only flows along a fault phase of a fault line, and the current signal with the specific frequency is grounded through a fault grounding point, and the specific fault line is determined through the flow direction of the current signal with the specific frequency.
Disclosure of Invention
The invention provides a neutral point indirect grounding fault detection system based on signal injection, which can accurately detect a grounding fault and a specific grounding line and ensure the working reliability of a power distribution system.
The invention particularly relates to a neutral point indirect grounding fault detection system based on signal injection, which comprises a signal acquisition unit, a first signal conditioning unit, a signal injection unit, an injection signal acquisition unit, a second signal conditioning unit, a control processing unit, a display unit and a communication unit, wherein the signal acquisition unit is sequentially connected with the first signal conditioning unit and the control processing unit; the fault detection system controls the signal injection unit to inject current signals into the system according to the information acquired by the signal acquisition unit, judges a specific grounding circuit according to the information acquired by the injection signal acquisition unit, displays faults through the display unit and uploads the faults to a remote monitoring center through the communication unit.
The signal acquisition unit acquires zero-sequence voltage signals through a zero-sequence voltage sensor and acquires zero-sequence current signals of each line through a zero-sequence current sensor.
The first signal conditioning unit comprises an amplifying unit, a first filtering unit and a first A/D conversion unit, wherein the amplifying unit amplifies input signals by adopting an amplifier and outputs signals meeting the input requirements of the first A/D conversion unit, and the first filtering unit adopts a low-pass filter and filters high-frequency interference signals.
The signal injection unit adopts a signal generator to generate a current signal with the frequency of 220HZ and the amplitude of 3A, and the current signal is input into a power distribution network through the secondary side of the bus voltage transformer.
And the injection signal acquisition unit acquires current signals generated by the signal generator and flowing through each line by adopting a signal receiving coil.
The second signal conditioning unit comprises a second filtering unit and a second A/D conversion unit, the second filtering unit filters interference signals by adopting a two-stage band-pass filter, and outputs signals with the frequency of 220 HZ.
The control processing unit adopts a microprocessor to carry out overall control and information analysis and judgment on the fault detection system:
judging whether the zero-sequence voltage signal is greater than a zero-sequence voltage reference value or not, and if not, continuously acquiring the zero-sequence voltage signal; if so, controlling the signal injection unit to inject a current signal to the secondary side of the bus voltage transformer;
the injection signal acquisition unit is controlled to acquire current signals generated by the signal generator and flowing through each line, the interference is filtered by the second signal conditioning unit, and the current signals are converted into digital signals and transmitted to the control processing unit;
a Gaussian white noise signal with the superposition intensity of the current signals flowing through each line and generated by the signal generator being D and the average value being 0 is generated;
and comparing the current signal with a reference value, if the current signal is not greater than the reference value, determining that the bus is in ground fault, and if a line greater than the reference value exists, determining that the bus is in ground fault.
The control processing unit also comprises an input and output serial interface, and the fault detection system information is exported and parameter setting is carried out through the input and output interface.
The display unit adopts an LCD display screen to display the fault information of the fault detection system, and the communication unit adopts a wireless communication technology to upload the fault information of the fault detection system to the remote monitoring center and can receive a control instruction of the remote monitoring center.
Compared with the prior art, the beneficial effects are: the fault detection system preliminarily judges whether a fault occurs according to the collected zero sequence voltage signal, then injects a current signal with specific frequency through the bus voltage transformer, and determines a specific fault line through the flow direction of the current signal with specific frequency.
Drawings
Fig. 1 is a schematic structural diagram of a system for detecting a neutral point indirect ground fault based on signal injection according to the present invention.
Detailed Description
The following describes in detail a specific embodiment of a signal injection based neutral point indirect ground fault detection system according to the present invention with reference to the accompanying drawings.
As shown in fig. 1, the fault detection system of the present invention includes a signal acquisition unit, a first signal conditioning unit, a signal injection unit, an injection signal acquisition unit, a second signal conditioning unit, a control processing unit, a display unit and a communication unit, wherein the signal acquisition unit is sequentially connected to the first signal conditioning unit and the control processing unit, the control processing unit is further respectively connected to the signal injection unit, the injection signal acquisition unit, the second signal conditioning unit, the display unit and the communication unit, and the injection signal acquisition unit is connected to the second signal conditioning unit; the fault detection system controls the signal injection unit to inject current signals into the system according to the information acquired by the signal acquisition unit, judges a specific grounding circuit according to the information acquired by the injection signal acquisition unit, displays faults through the display unit and uploads the faults to a remote monitoring center through the communication unit.
The signal acquisition unit acquires zero-sequence voltage signals through a zero-sequence voltage sensor and acquires zero-sequence current signals of each line through a zero-sequence current sensor.
The first signal conditioning unit comprises an amplifying unit, a first filtering unit and a first A/D conversion unit, wherein the amplifying unit amplifies input signals by adopting an amplifier and outputs signals meeting the input requirements of the first A/D conversion unit, and the first filtering unit adopts a low-pass filter and filters high-frequency interference signals.
The signal injection unit generates a current signal with the frequency of 220HZ and the amplitude of 3A by adopting a signal generator, and the current signal is input into a power distribution network through the secondary side of a bus voltage transformer; the current signal flows only along the fault phase of the fault line and enters the ground through the fault grounding point, and the selection of the fault line can be realized through the detection and the tracking of the current signal.
And the injection signal acquisition unit acquires current signals generated by the signal generator and flowing through each line by adopting a signal receiving coil.
The second signal conditioning unit comprises a second filtering unit and a second A/D conversion unit, the second filtering unit filters interference signals by adopting a two-stage band-pass filter, and outputs signals with the frequency of 220 HZ.
The control processing unit adopts a microprocessor to carry out overall control and information analysis and judgment on the fault detection system:
judging whether the zero-sequence voltage signal is greater than a zero-sequence voltage reference value or not, and if not, continuously acquiring the zero-sequence voltage signal; if so, controlling the signal injection unit to inject a current signal to the secondary side of the bus voltage transformer;
the injection signal acquisition unit is controlled to acquire current signals generated by the signal generator and flowing through each line, the interference is filtered by the second signal conditioning unit, and the current signals are converted into digital signals and transmitted to the control processing unit;
a Gaussian white noise signal with the superposition intensity of the current signals flowing through each line and generated by the signal generator being D and the average value being 0 is generated;
and comparing the current signal with a reference value, if the current signal is not greater than the reference value, determining that the bus is in ground fault, and if a line greater than the reference value exists, determining that the bus is in ground fault.
The control processing unit also comprises an input and output serial interface, and the fault detection system information is exported and parameter setting is carried out through the input and output interface.
The display unit adopts an LCD display screen to display the fault information of the fault detection system, and the communication unit adopts a wireless communication technology to upload the fault information of the fault detection system to the remote monitoring center and can receive a control instruction of the remote monitoring center.
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 (8)
1. A neutral point indirect grounding fault detection system based on signal injection is characterized by comprising a signal acquisition unit, a first signal conditioning unit, a signal injection unit, an injection signal acquisition unit, a second signal conditioning unit, a control processing unit, a display unit and a communication unit, wherein the signal acquisition unit is sequentially connected with the first signal conditioning unit and the control processing unit; the fault detection system controls the signal injection unit to inject current signals into the system according to the information acquired by the signal acquisition unit, judges a specific grounding circuit according to the information acquired by the injection signal acquisition unit, displays faults through the display unit and uploads the faults to a remote monitoring center through the communication unit.
2. The system according to claim 1, wherein the signal acquisition unit acquires the zero-sequence voltage signal via a zero-sequence voltage sensor and the zero-sequence current signal of each line via a zero-sequence current sensor.
3. The system according to claim 2, wherein the first signal conditioning unit includes an amplifying unit, a first filtering unit, and a first a/D converting unit, the amplifying unit amplifies an input signal with an amplifier and outputs a signal meeting the input requirement of the first a/D converting unit, and the first filtering unit filters a high-frequency interference signal with a low-pass filter.
4. The system for detecting the neutral point indirect ground fault based on the signal injection as claimed in claim 3, wherein the signal injection unit adopts a signal generator to generate a current signal with a frequency of 220HZ and an amplitude of 3A, and the current signal is input into a power distribution network through a secondary side of a bus voltage transformer.
5. The system for detecting the neutral point indirect ground fault based on the signal injection of claim 4, wherein the injection signal acquisition unit adopts a signal receiving coil to acquire current signals of signals generated by the signal generator flowing through each line.
6. The system according to claim 5, wherein the second signal conditioning unit comprises a second filtering unit and a second A/D conversion unit, the second filtering unit filters interference signals by using a two-stage band-pass filter, and outputs a signal with a frequency of 220 HZ.
7. The system for detecting the neutral point indirect earth fault based on the signal injection as claimed in claim 6, wherein the control processing unit adopts a microprocessor to perform overall control and information analysis and judgment on the fault detection system:
judging whether the zero-sequence voltage signal is greater than a zero-sequence voltage reference value or not, and if not, continuously acquiring the zero-sequence voltage signal; if so, controlling the signal injection unit to inject a current signal to the secondary side of the bus voltage transformer;
the injection signal acquisition unit is controlled to acquire current signals generated by the signal generator and flowing through each line, the interference is filtered by the second signal conditioning unit, and the current signals are converted into digital signals and transmitted to the control processing unit;
a Gaussian white noise signal with the superposition intensity of the current signals flowing through each line and generated by the signal generator being D and the average value being 0 is generated;
and comparing the current signal with a reference value, if the current signal is not greater than the reference value, determining that the bus is in ground fault, and if a line greater than the reference value exists, determining that the bus is in ground fault.
8. The system according to claim 7, wherein the display unit displays fault information of the fault detection system by using an LCD display screen, and the communication unit uploads the fault information of the fault detection system to the remote monitoring center by using a wireless communication technology, and can receive a control command of the remote monitoring center.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011186987.2A CN112255572A (en) | 2020-10-29 | 2020-10-29 | Neutral point indirect grounding fault detection system based on signal injection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011186987.2A CN112255572A (en) | 2020-10-29 | 2020-10-29 | Neutral point indirect grounding fault detection system based on signal injection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112255572A true CN112255572A (en) | 2021-01-22 |
Family
ID=74267854
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011186987.2A Pending CN112255572A (en) | 2020-10-29 | 2020-10-29 | Neutral point indirect grounding fault detection system based on signal injection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112255572A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102778636A (en) * | 2012-07-26 | 2012-11-14 | 北京飞举电气有限公司 | Single-phase ground fault location method and apparatus |
| CN109782122A (en) * | 2018-12-17 | 2019-05-21 | 济南大学 | A kind of detection method of S Injection Signal |
| CN110579671A (en) * | 2019-07-11 | 2019-12-17 | 国网江苏省电力有限公司徐州供电分公司 | single-phase earth fault detection system and method for neutral point ungrounded system |
| CN110888086A (en) * | 2019-12-06 | 2020-03-17 | 国网江苏省电力有限公司南通供电分公司 | Circuit electric leakage detection positioning system based on signal injection |
-
2020
- 2020-10-29 CN CN202011186987.2A patent/CN112255572A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102778636A (en) * | 2012-07-26 | 2012-11-14 | 北京飞举电气有限公司 | Single-phase ground fault location method and apparatus |
| CN109782122A (en) * | 2018-12-17 | 2019-05-21 | 济南大学 | A kind of detection method of S Injection Signal |
| CN110579671A (en) * | 2019-07-11 | 2019-12-17 | 国网江苏省电力有限公司徐州供电分公司 | single-phase earth fault detection system and method for neutral point ungrounded system |
| CN110888086A (en) * | 2019-12-06 | 2020-03-17 | 国网江苏省电力有限公司南通供电分公司 | Circuit electric leakage detection positioning system based on signal injection |
Non-Patent Citations (1)
| Title |
|---|
| 陈继森 等: "电力系统继电保护", 30 November 1992, 中国电力出版社, pages: 70 - 72 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102636722B (en) | Detection device for preventing switching-on of grounding wires | |
| CN105510773A (en) | Earth fault detection device for direct current system | |
| CN203241494U (en) | Direct current system AC series current fault and insulation fault monitoring line-selection apparatus | |
| CN204116589U (en) | A kind of current transformer for metering secondary circuit failure pick-up unit | |
| CN112230168A (en) | Reactor winding fault detection system based on magnetic field acquisition and detection method thereof | |
| CN105548846A (en) | Signal frequency conversion preposition module of portable intelligent four-channel partial discharge detector | |
| CN111913076A (en) | Power transmission line fault detection system and detection method thereof | |
| CN106842013A (en) | The live detection method and device of the contact of breaker ablation degree based on electromagnetic wave | |
| CN112255571A (en) | Earth fault detection system with neutral point indirectly grounded | |
| CN204287307U (en) | Transformer, current detection circuit based on transformer | |
| CN114552584B (en) | Topology identification system and identification method for low-voltage power grid area | |
| CN206074741U (en) | Detection circuit for grounding grid defect diagnosis | |
| CN103616616A (en) | Fault detection method for large-scale grounding grid | |
| CN110763954A (en) | Power cable fault detection system and method based on signal injection | |
| CN110579679A (en) | power distribution network line fault detection system based on negative sequence current vector analysis and detection method thereof | |
| CN110579671A (en) | single-phase earth fault detection system and method for neutral point ungrounded system | |
| CN110888086A (en) | Circuit electric leakage detection positioning system based on signal injection | |
| CN107462766B (en) | New method for detecting mains voltage and mains frequency and detection circuit | |
| CN111505557B (en) | Portable lightning arrester on-site checking device and method for on-line monitoring device | |
| CN112255572A (en) | Neutral point indirect grounding fault detection system based on signal injection | |
| CN209690439U (en) | A kind of grounding net defect diagnostic system | |
| CN110579672A (en) | Power transmission line fault detection system and method based on energy characteristic analysis | |
| CN104391225B (en) | Fault detection and communication positioning method for transmission line | |
| CN110596519A (en) | Direct current system ground fault detection system based on Fourier transform and detection method thereof | |
| CN110763955A (en) | Cable fault detection system and method based on high-voltage pulse signal injection |
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 |