CN206977026U - Low pressure protector for null line breaking based on negative sequence current criterion - Google Patents
Low pressure protector for null line breaking based on negative sequence current criterion Download PDFInfo
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- CN206977026U CN206977026U CN201720955453.9U CN201720955453U CN206977026U CN 206977026 U CN206977026 U CN 206977026U CN 201720955453 U CN201720955453 U CN 201720955453U CN 206977026 U CN206977026 U CN 206977026U
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Abstract
Low pressure protector for null line breaking based on negative sequence current criterion,Including power module,Data acquisition module,A/D analog-to-digital conversion modules and single-chip microcomputer,Also include zero line fling-cut switch and digital communication module,Power module connects with three-phase line and zero line,Data acquisition module one end respectively with circuit A,Circuit B,Circuit C connects with zero line N,The other end of data acquisition module connects with A/D analog-to-digital conversion modules,A/D analog-to-digital conversion modules are connected with single-chip microcomputer,Single-chip microcomputer connects with digital communication module and zero line fling-cut switch respectively,Zero line N tail end is connected with zero line fling-cut switch,Zero line fling-cut switch is grounded,The device carries out failure criterion using negative-sequence current caused by low pressure circuit imbalance off zero,Criterion is more accurate,Sensitive and structure setting is more reasonable,It is easy to practical operation,And single-chip microcomputer can notify maintainer in the form of short message after the completion of criterion,The present apparatus is after accurate criterion failure simultaneously,Automatically engaging odd-job ground connection makes motor keep normal operation.
Description
Technical field
The utility model design low-voltage circuit protection field off zero, low pressure of the specific design based on negative sequence current criterion are off zero
Protection device.
Background technology
Low power used system refers to three-phase 380V or single-phase 220V electricity system, is typically used in low power used system
Three-phase four-wire power supply, i.e. three phase lines and a zero line.Zero line plays a very important role in low-voltage power supply system, and it breaks
Afterwards, if threephase load is uneven (the in fact impossible complete equipilibrium of threephase load), neutral voltage will be offset；It is if uneven
Weighing apparatus degree is bigger, and Zero line voltage-offset is bigger, causes certain phase voltage too high or too low, electrical equipment will be caused damage.
The patent of invention that number of patent application is 201510111602.9 discloses low-voltage network zero line break protection device,
The device is made up of switch, voltage relay, A.C. contactor and signal projector, but in the case where load is less big,
Either delta connection or Y connection motor, when a certain phase of system disconnects, such as therein the one of A.C. contactor control voltage
When line is derived from failure phase, then A.C. contactor can be always maintained at attracting state.Number of patent application is 201210543552.8
Patent of invention discloses the protection device of neutral line break in low power used system, and the device includes electric capacity, detection means, controller
And relay, when the device utilizes stator imbalance of three-phase voltage, the residual voltage rise of neutral point over the ground, by being serially connected in electricity
Residual voltage relay on the motivation neutral conductor carries out lacuna protection, but the operation voltage in setting voltage relay is adjusted
Needed during value very prudent.The patent of invention that number of patent application is 201410260004.3, which is disclosed in low-voltage power supply system, to be lacked
Phase, lack zero, neutral line break and short-circuit protection, the device and include auxiliary reclay, button, the contactor of sequential series, this
Device is protected using fracture of wire voltage to threephase asynchronous phase-deficient operation, but the device has limitation using upper, only
Phase-deficient operation it can be shielded to caused by fuse blows, when motor model size and load difference, fracture of wire
Voltage can also change, and the selection to relay brings difficulty.
Utility model content
The utility model devises the low pressure protector for null line breaking based on negative sequence current criterion to solve the above problems,
The device carries out failure criterion using negative-sequence current caused by low pressure circuit imbalance off zero, and the fault detect criterion is more smart
Really, sensitive and structure setting is more reasonable, is easy to practical operation, while the present apparatus is automatically engaged and faced after accurate criterion failure
When working earthing make motor keep normal operation.
In order to realize above-mentioned technical purpose, reach above-mentioned technique effect, the utility model is real by the following technical programs
Existing：
Low pressure protector for null line breaking based on negative sequence current criterion, including power module, data acquisition module, A/D moduluses
Modular converter and single-chip microcomputer, in addition to zero line fling-cut switch and digital communication module, power module and three-phase line and zero line phase
Connect, data acquisition module one end is connected with circuit A, circuit B, circuit C and zero line N respectively, the other end of data acquisition module with
A/D analog-to-digital conversion modules connect, and A/D analog-to-digital conversion modules are connected with single-chip microcomputer, single-chip microcomputer respectively with digital communication module and zero
Line fling-cut switch connects, and zero line N tail end is connected with zero line fling-cut switch, zero line fling-cut switch ground connection；
Described data acquisition module can gather respectively circuit A, circuit B, circuit C electric current and be converted to data signal biography
Transport in single-chip microcomputer, the three-phase electricity flow valuve of collection can be calculated the instantaneous value, virtual value and phase of negative-sequence current simultaneously by single-chip microcomputer
The fault type of negative-sequence current normalized value and negative-sequence current phase place change so as to criterion low-voltage circuit is obtained, single-chip microcomputer is in criterion
By transmitting fault information to digital communication module after the fault type of low-voltage circuit；
Described digital communication module is connected by wireless communication mode with communication base station and by communication base station by low pressure
Line fault is sent into terminal device in the form of short message.
Preferably, the communication modes that described digital communication module is connected with communication base station are GPRS/2G/3G/4G a kind of
It is or a variety of.
The beneficial effects of the utility model are：The device is carried out using negative-sequence current caused by low pressure circuit imbalance off zero
Failure criterion, the fault detect criterion is more accurate, sensitive and structure setting is more reasonable, is easy to practical operation, and criterion is complete
Maintainer can be notified in the form of short message into rear single-chip microcomputer, it is found faulty line in time, ensures the security of user simultaneously
Power supply reliability is improved, while the present apparatus, after accurate criterion failure, automatically engaging odd-job ground connection makes motor keep just
Often operation.
Brief description of the drawings
In order to illustrate more clearly of the technical scheme of the utility model embodiment, make required for being described below to embodiment
Accompanying drawing is briefly described, it should be apparent that, drawings in the following description are only some embodiments of the utility model,
For those of ordinary skill in the art, on the premise of not paying creative work, can also be obtained according to these accompanying drawings
Other accompanying drawings.
Fig. 1 is low-voltage circuit neutral line break equivalent circuit diagram；
Fig. 2 is the elementary diagram of the low pressure protector for null line breaking based on negative sequence current criterion.
In accompanying drawing, the list of parts representated by each label is as follows：
1- low pressure protector for null line breaking, 11- single-chip microcomputers, 12- data acquisition modules, 13-A/D analog-to-digital conversion modules, 14- zero
Line fling-cut switch, 15- digital communication modules, 2- power modules.
Embodiment
Below in conjunction with the accompanying drawing in the utility model embodiment, the technical scheme in the embodiment of the utility model is carried out
Clearly and completely describing, it is clear that described embodiment is only the utility model part of the embodiment, rather than whole
Embodiment.Based on the embodiment in the utility model, those of ordinary skill in the art are not under the premise of creative work is made
The all other embodiment obtained, belong to the scope of the utility model protection.
Refering to shown in Fig. 1-2, the low pressure protector for null line breaking based on negative sequence current criterion, including power module (2), data
Acquisition module (12), A/D analog-to-digital conversion modules (13) and single-chip microcomputer (11), in addition to zero line fling-cut switch (14) and digital communication
Module (15), power module (2) connect with three-phase line and zero line, data acquisition module (12) one end respectively with circuit A, circuit
B, circuit C connects with zero line N, and the other end of data acquisition module (12) connects with A/D analog-to-digital conversion modules (13), A/D moduluses
Modular converter (13) is connected with single-chip microcomputer (11), single-chip microcomputer (11) respectively with digital communication module (15) and zero line fling-cut switch
(14) connect, zero line N tail end is connected with zero line fling-cut switch (14), zero line fling-cut switch (14) ground connection；
Described data acquisition module (12) can gather respectively circuit A, circuit B, circuit C electric current and be converted to digital letter
Number transmit into single-chip microcomputer, the three-phase electricity flow valuve of collection can be calculated the instantaneous value of negative-sequence current, virtual value by single-chip microcomputer (11)
With phase and obtain the fault type of negative-sequence current normalized value and negative-sequence current phase place change so as to criterion low-voltage circuit, monolithic
Machine (11) is after the fault type of criterion low-voltage circuit by transmitting fault information to digital communication module (15)；
Described digital communication module (15) is connected with communication base station by wireless communication mode and will by communication base station
Low-voltage circuit failure is sent into terminal device in the form of short message.
Therein, the communication modes that described digital communication module (15) is connected with communication base station are GPRS/2G/3G/4G
It is one or more.
One of the present embodiment has particular application as：Each sequence current component and power network knot after low-voltage circuit single-phase wire break failure
Structure, power system operating mode, line impedance are directly proportional about and to line load electric current, can be gathered using data acquisition module (12)
To the negative sequence current value of low-voltage circuit and input is into single-chip microcomputer (13), and single-chip microcomputer (13) calculates negative according to the current value of collection
Instantaneous value, virtual value and the phase of sequence electric current simultaneously obtain negative-sequence current normalized value and negative-sequence current phase place change, in circuit not
Break down or failure stable situation under, the normalizing value of the negative-sequence current detected is all maintained near 1, but open-phase fault send out
After life, the amplitude of circuit negative-sequence current will undergo mutation, and now negative-sequence current normalized value is more than 1, when normalized value is more than 2
Shi Ze can determine whether that line fault is open-phase fault；And when meeting that negative-sequence current normalized value is more than 2 condition, it not can be shown that line
Open-phase fault necessarily occurs for road, now needs to be modified criterion, and it is positive direction that obtaining current flows to circuit from bus, line taking road
Flow to electric current on the basis of the negative-sequence current I1 of end of incoming cables transformer, take failure occur after the negative-sequence current I2 of circuit be more electric
Stream, when compare electric current I2 and reference current I1 it is in opposite direction when, be judged as positive failure, and when the phase difference of negative-sequence current meets
Then it can determine whether as open-phase fault during 140 °≤argI1-argI2≤230 °；Single-chip microcomputer (13) believes criterion after making accurate criterion
Breath transmits to digital communication module (15) and sends information to terminal device by digital communication module (15), notifies maintainer
Line fault is repaired in time, while single-chip microcomputer (13) makes feedback regulation according to criterion information and drives zero line fling-cut switch to access
Odd-job is grounded, and makes three-phase voltage keep balance to maintain user equipment normal work.
In the description of this specification, the description of reference term " one embodiment ", " example ", " specific example " etc. means
It is contained in reference to specific features, structure, material or the feature that the embodiment or example describe of the present utility model at least one
In embodiment or example.In this manual, the schematic representation of above-mentioned term is not necessarily referring to identical embodiment or
Example.
The utility model preferred embodiment disclosed above is only intended to help and illustrates the utility model.Preferred embodiment is simultaneously
There is no the details that detailed descriptionthe is all, it is only described embodiment also not limit the utility model.Obviously, according to this theory
The content of bright book, it can make many modifications and variations.This specification is chosen and specifically describes these embodiments, is in order to preferably
Principle and practical application of the present utility model is explained, so that skilled artisan can be best understood by and utilize this
Utility model.The utility model is only limited by claims and its four corner and equivalent.
Claims (2)
1. the low pressure protector for null line breaking based on negative sequence current criterion, including power module, data acquisition module, A/D moduluses turn
Change the mold block and single-chip microcomputer, it is characterised in that：Also include zero line fling-cut switch and digital communication module, power module and three-phase line
And zero line connects, data acquisition module one end is connected with circuit A, circuit B, circuit C and zero line N respectively, data acquisition module
The other end connects with A/D analog-to-digital conversion modules, and A/D analog-to-digital conversion modules are connected with single-chip microcomputer, single-chip microcomputer respectively with digital communication
Module and zero line fling-cut switch connect, and zero line N tail end is connected with zero line fling-cut switch, zero line fling-cut switch ground connection；
Described data acquisition module can gather respectively circuit A, circuit B, circuit C electric current and be converted to digital data transmission extremely
In single-chip microcomputer, the three-phase electricity flow valuve of collection can be calculated instantaneous value, virtual value and the phase of negative-sequence current and obtained by single-chip microcomputer
Negative-sequence current normalized value and negative-sequence current phase place change are so as to the fault type of criterion low-voltage circuit, and single-chip microcomputer is in criterion low pressure
By transmitting fault information to digital communication module after the fault type of circuit；
Described digital communication module is connected by wireless communication mode with communication base station and by communication base station by low-voltage circuit
Failure is sent into terminal device in the form of short message.
2. the low pressure protector for null line breaking according to claim 1 based on negative sequence current criterion, it is characterised in that：Described numeral
The communication modes that communication module is connected with communication base station are GPRS/2G/3G/4G one or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720955453.9U CN206977026U (en) | 2017-08-02 | 2017-08-02 | Low pressure protector for null line breaking based on negative sequence current criterion |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720955453.9U CN206977026U (en) | 2017-08-02 | 2017-08-02 | Low pressure protector for null line breaking based on negative sequence current criterion |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN206977026U true CN206977026U (en) | 2018-02-06 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201720955453.9U Expired - Fee Related CN206977026U (en) | 2017-08-02 | 2017-08-02 | Low pressure protector for null line breaking based on negative sequence current criterion |
Country Status (1)
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107732885A (en) * | 2017-11-02 | 2018-02-23 | 国网山西省电力公司电力科学研究院 | Consider that the suppression grid short circuit electric current broken string order of safety and sensitivity determines method |
| CN111337855A (en) * | 2020-03-18 | 2020-06-26 | 贵州电网有限责任公司 | Active power distribution network disconnection fault protection method based on negative sequence current ratio |
| CN111999678A (en) * | 2020-07-24 | 2020-11-27 | 南京国电南自电网自动化有限公司 | Three-phase PT secondary circuit neutral point N-line disconnection judging method and system |
-
2017
- 2017-08-02 CN CN201720955453.9U patent/CN206977026U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107732885A (en) * | 2017-11-02 | 2018-02-23 | 国网山西省电力公司电力科学研究院 | Consider that the suppression grid short circuit electric current broken string order of safety and sensitivity determines method |
| CN111337855A (en) * | 2020-03-18 | 2020-06-26 | 贵州电网有限责任公司 | Active power distribution network disconnection fault protection method based on negative sequence current ratio |
| CN111999678A (en) * | 2020-07-24 | 2020-11-27 | 南京国电南自电网自动化有限公司 | Three-phase PT secondary circuit neutral point N-line disconnection judging method and system |
| CN111999678B (en) * | 2020-07-24 | 2023-06-16 | 南京国电南自电网自动化有限公司 | Three-phase PT secondary circuit neutral point N line disconnection judging method and system |
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| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20180206 Termination date: 20210802 |