CN111948575A - Current transformer secondary side neutral line disconnection detection method and device - Google Patents
Current transformer secondary side neutral line disconnection detection method and device Download PDFInfo
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- CN111948575A CN111948575A CN202010771609.4A CN202010771609A CN111948575A CN 111948575 A CN111948575 A CN 111948575A CN 202010771609 A CN202010771609 A CN 202010771609A CN 111948575 A CN111948575 A CN 111948575A
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- 230000007935 neutral effect Effects 0.000 title claims abstract description 49
- 238000001514 detection method Methods 0.000 title abstract description 22
- 238000000034 method Methods 0.000 claims abstract description 20
- 230000003993 interaction Effects 0.000 claims description 4
- 230000002159 abnormal effect Effects 0.000 description 6
- 238000005259 measurement Methods 0.000 description 4
- 238000005034 decoration Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
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- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
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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
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/54—Testing for continuity
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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
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/72—Testing of electric windings
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- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
Abstract
A method and a device for detecting disconnection of a neutral line on a secondary side of a current transformer comprise a first current acquisition module, a second current acquisition module and a judgment module, wherein the first current acquisition module is used for being connected with any phase circuit in a three-phase circuit on the secondary side of the current transformer, the second current acquisition module is used for being connected with the neutral line on the secondary side of the current transformer, the judgment module judges whether the current transformer is in an operating state or not according to the acquisition result of the first current acquisition module, and can judge whether the neutral line is in a disconnection state or not according to the acquisition result of the second current acquisition module after the current transformer is judged to be in the operating state. The detection method and the detection device can judge whether the neutral line on the secondary side of the current transformer is in a broken line state or not, and effectively avoid making wrong judgment when the equipment is powered off through the first current acquisition module, so that the accuracy of a detection result is ensured, and the reliability of the detection device is improved.
Description
Technical Field
The invention relates to the technical field of relay protection, in particular to a method and a device for detecting disconnection of a secondary side neutral wire of a current transformer.
Background
The current transformer is an important component of a measurement system and a relay protection system in an electric power system, and the operation stability of the current transformer affects the measurement accuracy and the reliability of the action of a protection device, so that the protection device is generally required to be arranged on the secondary side of the current transformer to detect the operation state of the current transformer in real time.
However, the conventional protection device generally determines an operating state of the power system by detecting whether or not a current in a three-phase circuit on a secondary side of a current transformer is abnormal, thereby implementing relay protection. When the neutral line in the secondary current loop of the current transformer is disconnected, the current transformer can still normally operate, and three phase currents of the current transformer are basically balanced, so that the protection device cannot find the problem, and at the moment, if the power system has a ground fault, the current measurement of the protection device is abnormal due to the disconnection of the neutral line, so that abnormal conditions such as misoperation or refusal of the relay protection device occur, and the abnormal conditions are unacceptable in the power system.
For the detection of whether the neutral line of the current transformer is broken, the current common method is to analyze according to the recording of the protection device when the power system has an external fault so as to find whether the condition of the neutral line of the current transformer is broken, but the method belongs to post-inspection, can not find the fault in time when the neutral line is broken, is extremely unfavorable for preventing the relay protection device from incorrect action, and can not meet the requirements of the current power grid development when the intelligent power grid is comprehensively implemented today.
The invention aims to improve the intelligent detection level of a power grid, discover the disconnection fault of the neutral line of the current transformer in time and remind the power grid operator by a police guard, thereby greatly reducing the risk of the fault on the safe operation of the power grid.
Disclosure of Invention
The invention aims to provide a method and a device for detecting the disconnection of a neutral line on the secondary side of a current transformer, which can detect whether the neutral line on the secondary side of the current transformer is disconnected or not in real time.
In order to achieve the purpose, the invention provides the following technical scheme:
a method and a device for detecting disconnection of a neutral line on a secondary side of a current transformer comprise a first current acquisition module, a second current acquisition module and a judgment module, wherein the first current acquisition module is used for being connected with any phase circuit in a three-phase circuit on the secondary side of the current transformer, the second current acquisition module is used for being connected with the neutral line on the secondary side of the current transformer, and the judgment module can judge whether the current transformer is in an operating state according to an acquisition result of the first current acquisition module and judge whether the neutral line is in a disconnection state according to an acquisition result of the second current acquisition module after judging that the current transformer is in the operating state.
Preferably, the method and the device for detecting the disconnection of the neutral line on the secondary side of the current transformer further comprise an alarm module which is connected with the judgment module and can send out an alarm signal according to the judgment result of the judgment module.
Preferably, the method and the device for detecting the disconnection of the neutral line on the secondary side of the current transformer further comprise a relay, a buzzer and/or a warning lamp which are connected with the alarm module and can be controlled by the warning signal.
Preferably, the method and device for detecting the disconnection of the neutral line on the secondary side of the current transformer further comprise a storage module connected with the judgment module, and the storage module is used for recording the judgment result of the judgment module.
Preferably, the method and the device for detecting the disconnection of the neutral line on the secondary side of the current transformer further comprise a time setting module which is connected with the storage module and can provide time information for each record of the storage module.
Furthermore, the method and the device for detecting the disconnection of the neutral line on the secondary side of the current transformer further comprise a human-computer interaction module which is connected with the storage module and used for checking the record information of the storage module.
Compared with the prior art, the scheme of the invention has the following advantages:
according to the method and the device for detecting the disconnection of the neutral line on the secondary side of the current transformer, whether the current transformer is in the running state or not is judged according to the acquisition result of the first current acquisition module, whether the neutral line on the secondary side of the current transformer is in the disconnection state or not is judged according to the acquisition result of the second current acquisition module, whether the neutral line is disconnected or not is judged, meanwhile, wrong judgment can be effectively avoided when equipment is powered off through the first current acquisition module, the accuracy of the detection result is guaranteed, and therefore the reliability and the reliability of the detection device are improved.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
The foregoing and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
fig. 1 is a circuit block diagram of a method and an apparatus for detecting a disconnection of a neutral line on a secondary side of a current transformer according to an embodiment of the present invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative only and should not be construed as limiting the invention.
It will be understood by those within the art that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. As used herein, the term "and/or" includes all or any element and all combinations of one or more of the associated listed items.
As shown in fig. 1, an embodiment of the present invention provides a method and an apparatus 1 for detecting a broken neutral line on a secondary side of a current transformer (hereinafter referred to as a "detection method and apparatus") for detecting whether a neutral line on a secondary side of the current transformer 100 is broken or not in real time, which is disposed between the current transformer 100 and a protection apparatus 200 corresponding to the current transformer 100, so as to improve safety performance of the current transformer 100 and avoid situations such as malfunction or failure of relay protection due to abnormal current measurement of the protection apparatus 200 when the neutral line is not turned on.
Specifically, the detection method and device 1 includes a first current collection module 11, a second current collection module 12, and a determination module 13, where output ends of the first current collection module 11 and the second current collection module 12 are both connected to the determination module 13. The first current collecting module 11 includes a first current transformer TA1, and the first current transformer TA1 is used for being connected to any one phase circuit of A, B, C three-phase circuits on the secondary side of the current transformer 100 and detecting the current of the phase circuit in real time. The second current collecting module 12 comprises a second current transformer TA2, and the second current transformer TA2 is used for being connected with a neutral line on the secondary side of the current transformer 100 and detecting the current of the neutral line in real time. The acquisition results of the first current acquisition module 11 and the second current acquisition module 12 are fed back to the judgment module 13 in real time.
Further, a first normal current range and a second normal current range are recorded in the determination module 13 according to the actual parameter of the current transformer 100, the first normal current range is a range of a normal operation current value of any one phase circuit of the A, B, C three-phase circuits on the secondary side of the current transformer 100, and the second normal current range is a range of a normal operation current value of a neutral line on the secondary side of the current transformer 100. The judging module 13 can judge whether the current transformer 100 is in the running state according to whether the acquisition result of the first current acquisition module 11 is in the first preset current value, and can judge whether the neutral line is in the broken line state according to whether the acquisition result of the second current acquisition module 12 is smaller than the second normal current range, so that when the neutral line is judged to be broken, the first current acquisition module 11 can effectively avoid making wrong judgment when the equipment is powered off, the accuracy of the detection result is ensured, and the safety performance of the current transformer 100 is improved.
It should be noted that, since the protection device 200 needs to detect whether the current of each phase circuit of the A, B, C three-phase circuits on the secondary side of the current transformer 100 is abnormal in real time and protect the current transformer 100, the connection structure cannot judge whether the neutral line is broken, and the protection device 200 can only be connected with one current transformer 100, even if a related neutral line detection circuit is arranged in the protection device 200, the detection efficiency is not high. The detection method and the detection device 1 provided by the embodiment of the invention can be arranged in the middle terminal boxes of the plurality of current transformers 100 to monitor the neutral lines on the secondary sides of the plurality of current transformers 100 simultaneously only by configuring the plurality of first current collection modules 11 and the plurality of second current collection modules 12, and have the advantages of good detection accuracy and high efficiency.
Preferably, the detection method and device 1 further include an alarm module 14, and the alarm module 14 is connected to the judgment module 13 and can send out a warning signal according to a judgment result of the judgment module 13, so that a circuit protection function is realized in time and related workers are reminded when the neutral line is disconnected, and the safety of the power system is ensured.
Specifically, the detection method and device 1 further includes a relay, a buzzer, and a warning light, which are connected to the alarm module 14 and can be controlled by the warning signal. When the neutral line is disconnected, the circuit protection function can be automatically realized by the warning signal control relay, and the buzzer and the warning lamp are controlled by the warning signal to remind relevant workers of flickering, so that the maintenance operation of the power system can be completed quickly.
Preferably, the detection method and device 1 further include a storage module 15 and a human-computer interaction module 16, the storage module 15 is connected to the judgment module 13 and is configured to record the judgment result of the judgment module 13 in real time, and the human-computer interaction module 16 is connected to the storage module 15 and is configured to view and store the record information of the storage module 15, so that relevant staff can check and review the record information.
Preferably, the detection method and device 1 further includes a time setting module 17 and an antenna 18 connected to the time setting module 17, and the time setting module 17 is connected to the storage module 15.
Specifically, the time synchronization module 17 may receive an external IRIG-B code time synchronization signal through the antenna 18, and provide time information for each record of the storage module 15, so that each record in the storage module 15 is accompanied by a current time, the state of the neutral line in each time period can be made clear, and accident analysis is facilitated.
The foregoing is only a partial embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (6)
1. The method and the device for detecting the disconnection of the neutral line on the secondary side of the current transformer are characterized by comprising a first current acquisition module, a second current acquisition module and a judgment module, wherein the first current acquisition module is used for being connected with any phase circuit in a three-phase circuit on the secondary side of the current transformer, the second current acquisition module is used for being connected with the neutral line on the secondary side of the current transformer, and the judgment module can judge whether the current transformer is in an operating state according to the acquisition result of the first current acquisition module and judge whether the neutral line is in a disconnection state according to the acquisition result of the second current acquisition module after judging that the current transformer is in the operating state.
2. The method and the device for detecting the disconnection of the neutral line on the secondary side of the current transformer as claimed in claim 1, further comprising an alarm module connected with the judgment module and capable of sending out an alarm signal according to the judgment result of the judgment module.
3. The method and the device for detecting the disconnection of the neutral wire at the secondary side of the current transformer as claimed in claim 2, further comprising a relay, a buzzer and/or a warning lamp which are connected with the alarm module and can be controlled by the warning signal.
4. The method and the device for detecting the disconnection of the neutral line on the secondary side of the current transformer as claimed in claim 1, further comprising a storage module connected with the judgment module, wherein the storage module is used for recording the judgment result of the judgment module.
5. The method and device for detecting the disconnection of the neutral line on the secondary side of the current transformer as claimed in claim 4, further comprising a time setting module connected to the storage module and capable of providing time information for each recording of the storage module.
6. The method and the device for detecting the disconnection of the neutral line on the secondary side of the current transformer as claimed in claim 4 or 5, further comprising a human-computer interaction module connected with the storage module and used for viewing the record information of the storage module.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010771609.4A CN111948575A (en) | 2020-08-04 | 2020-08-04 | Current transformer secondary side neutral line disconnection detection method and device |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010771609.4A CN111948575A (en) | 2020-08-04 | 2020-08-04 | Current transformer secondary side neutral line disconnection detection method and device |
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| CN111948575A true CN111948575A (en) | 2020-11-17 |
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| CN202010771609.4A Pending CN111948575A (en) | 2020-08-04 | 2020-08-04 | Current transformer secondary side neutral line disconnection detection method and device |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112557814A (en) * | 2020-11-27 | 2021-03-26 | 云南电网有限责任公司昆明供电局 | Method for monitoring neutral line disconnection of low-voltage distribution network |
| CN113093060A (en) * | 2021-04-13 | 2021-07-09 | 厦门理工学院 | Method, device and equipment for detecting zero line breakage of power distribution network |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102005720A (en) * | 2010-10-21 | 2011-04-06 | 重庆大学 | Neutral line breakage detection protection method and device |
| CN102801131A (en) * | 2012-09-06 | 2012-11-28 | 重庆大学 | Neutral line breaking detection protection method and device |
-
2020
- 2020-08-04 CN CN202010771609.4A patent/CN111948575A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102005720A (en) * | 2010-10-21 | 2011-04-06 | 重庆大学 | Neutral line breakage detection protection method and device |
| CN102801131A (en) * | 2012-09-06 | 2012-11-28 | 重庆大学 | Neutral line breaking detection protection method and device |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112557814A (en) * | 2020-11-27 | 2021-03-26 | 云南电网有限责任公司昆明供电局 | Method for monitoring neutral line disconnection of low-voltage distribution network |
| CN113093060A (en) * | 2021-04-13 | 2021-07-09 | 厦门理工学院 | Method, device and equipment for detecting zero line breakage of power distribution network |
| CN113093060B (en) * | 2021-04-13 | 2022-05-20 | 厦门理工学院 | Method, device and equipment for detecting zero line breakage of power distribution network |
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Application publication date: 20201117 |
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