CN206818777U - A kind of main transformer core earth current monitoring device - Google Patents
A kind of main transformer core earth current monitoring device Download PDFInfo
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- CN206818777U CN206818777U CN201720419695.6U CN201720419695U CN206818777U CN 206818777 U CN206818777 U CN 206818777U CN 201720419695 U CN201720419695 U CN 201720419695U CN 206818777 U CN206818777 U CN 206818777U
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- main transformer
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Abstract
The utility model discloses a kind of main transformer core earth current monitoring device, it is related to power system measurement and on-line monitoring technique field.Described main transformer core earth current monitoring device, the current signal in main transformer core earth lead is gathered by magnetic resistance sensor, and by being sent to remote monitoring center by LoRa wireless communication modules after signal processing unit processes；The magnetic resistance sensor is not easily susceptible to the influence of power transformer bad electromagnetic environment, gathers the accuracy height of signal, and uses micro fabrication batch making, and cost is low, good economy performance；The monitoring device realizes telecommunication by LoRa wireless communication modules, remote monitoring center is enabled to obtain the size of current in current main transformer core earth lead in real time, the earth fault of long-range monitoring main transformer, the effectively earth fault of prevention main transformer, realizes intelligent unmanned substation.
Description
Technical field
The utility model belongs to power system measurement and on-line monitoring technique field, more particularly to a kind of main transformer core
Earth current monitoring device.
Background technology
Power transformer is one of a kind of wide variety of infrastructure device in power system, while is also fault rate highest
One of power equipment, its normal operation concern the operation that can power system safe and reliable.According to statistics, in power transformer
In all multiple faults, the fault type of consequence most serious mainly has two kinds after proportion highest, generation：Transformer insulated failure and
Transformer grounding failure.Wherein, transformer insulated failure can effectively be monitored with oil colours spectral method；But to transformer grounding
The on-line monitoring of failure, currently there has been no perfect solution.Transformer grounding failure include transformer multipoint earth faults and
The problems such as transformer grounding D.C. magnetic biasing.On the one hand, for transformer in normal operation, its grounding electrode electric current is ten mA levels, once
Generation multipoint earth faults, transformer grounding electric current will quickly reach ten A levels, and transformer core can be caused to overheat, severe patient's meeting
Burn transformer；On the other hand, in the extremely neighbouring AC transformer of DC system grounding is by by direct current grounding pole on kA
The influence of earth current, once D.C. magnetic biasing problem occurs, transformer vibration aggravation, the rise of AC network harmonic wave, severe patient's iron
Core overheats, and burns transformer.Either transformer multipoint earth faults or transformer grounding D.C. magnetic biasing problem, are required to lead to
Cross and main transformer core earth current is monitored on-line to prevent.A kind of it is therefore proposed that effective main transformer pressure
Device iron core grounding current monitoring method or device are imperative.
Problems with generally be present in current main transformer monitoring device：1）Sensor fault rate is high, and according to statistics, the whole nation becomes
In the failure of depressor on-Line Monitor Device, it is sensor fault to have the failure of more than half；2) sensor-based system short life, due to passing
Induction device needs long-term work, and its life-span is largely depended on out of doors in environment, it is necessary to be powered using battery to it
In the life-span of selected battery（Generally under continuous duty, less than 2 years）；3）Validity is poor, and traditional monitoring device uses
Forcipated mutual-inductor, easily influenceed by bad electromagnetic environment near power transformer and produce wrong report；4）It is less economical, current iron core
Earth current monitoring device market price is that ten thousand yuan of 2-5 is a set of, very expensive, therefore causes transformer core current detection means
Coverage rate is low（Only 0.34%）；5）Telecommunication difficulty is big, on the one hand, nearby electromagnetic environment is severe for power transformer, using nothing
Line, which will carry out communication, to cause rate of false alarm to raise；On the other hand, distance is typically for up to more than ten kilometers between transformer station, it is contemplated that nobody
The demand of Intelligent transformer station on duty is, it is necessary to overlength distance transmission signal.
Utility model content
In view of the shortcomings of the prior art, the utility model provides a kind of main transformer core earth current monitoring device, leads to
Cross magnetic resistance sensor and realize on-line monitoring main transformer core earth current, effectively prevent main transformer earth fault, pass through
LoRa wireless data transfer modules transfer signals to main frame, realize intelligent unmanned substation.
The utility model is that solve above-mentioned technical problem by the following technical solutions：A kind of main transformer core connects
Earth-current monitoring device, including magnetic resistance sensor, the magnet ring with parallel open, signal processing unit and shielding insulation protection
Box；The main transformer core earth lead is placed in shielding insulation protecting box, at the magnet ring center pair with parallel open
Perforation is offered in the shielding insulation protecting box answered, the main transformer core earth lead passes through the perforation；The band is put down
The magnet ring of row opening is placed in shielding insulation protecting box, and is set around main transformer core earth lead；The magneto-resistor passes
Sensor is placed at the parallel open of the magnet ring with parallel open, and the sensitive direction of principal axis of the magnetic resistance sensor is along main transformer pressure
The tangential direction of device iron core grounding wire, the magnetic resistance sensor are connected with the signal processing unit, the signal transacting
Unit is placed in shielding insulation protecting box.
Further, the signal processing unit includes amplification module, filtration module, the logic analysis mould being sequentially connected
Block, LoRa wireless communication modules, the signal processing unit also include power module and clock module, the power module difference
With the magnetic resistance sensor, amplification module, filtration module, logic analysis module, LoRa wireless communication modules and clock mould
Block is connected, and the clock module is connected with logic analysis module and LoRa wireless communication modules respectively；The amplification module, is used for
Amplify the signal of magnetic resistance sensor output, and suppression common mode is disturbed；The filtration module, for filtering out high-frequency electromagnetic interference；
The logic analysis module, for the amplified module of real-time processing stream and the signal of filtration module, analyze the signal corresponding current
Alternating-current magnitude and direct current amplitude, by analysis result according to LoRa home control network communication protocols pack and periodically or in abnormality
Lower wake-up LoRa wireless communication modules carry out remote data transmission, and main transformer ground state is timely transmitted to remotely monitor
Center；The power module, for providing power supply voltage signal for all modules；The clock module, for for logic analysis
Module and LoRa wireless communication modules provide clock signal.
Further, the logic analysis module includes control process module and the power management module being connected with each other, institute
State power management module to be connected with the power module, for carrying out management of charging and discharging to power module, extend power module
Service life.
Further, the power module uses long-life batteries, and its supply voltage is 7.8V.
Further, the filtration module is low pass filter, due to the monitoring for main transformer core earth current
It is concentrated mainly in its power frequency and DC component, therefore, the cut-off frequency of low pass filter is hundred Hz magnitudes, can effectively filter out ring
Electromagnetic interference in border.
Further, the magnetic resistance sensor includes substrate, and TMR sensor unit, the square being arranged on substrate
Shape soft magnetism flux concentrator, bucking coil；The TMR sensor unit is electrically connected to be connected into along the free layer direction of magnetization pushes away magneto-resistor biography
Feel unit string and draw magneto-resistor sensing unit string, and be arranged on gap between the rectangle soft magnetism flux concentrator of adjacent two
Lower section, it is described push away magneto-resistor sensing unit string and draw magneto-resistor sensing unit string and be electrically connected be connected into push-pull type magnetic resistance sensor,
The bucking coil is arranged on the top of the TMR sensor unit and in two adjacent rectangle soft magnetism flux concentration
The lower section in gap between device, the bucking coil is with the positive pole current strap by the TMR sensor unit and passes through rectangle
The cathodal current band of soft magnetism flux concentrator；The magnetic resistance sensor uses micro fabrication batch making, and cost is extremely low, warp
Ji property is splendid.
Further, the shell of the shielding insulation protecting box includes four layers, and outermost layer is the polytetrafluoro of high insulation resistance
Ethene, external insulation protection is provided for the main transformer core earth current monitoring device；The second layer is the copper of high conductivity, and
Grounding is carried out, effectively shields electric jamming and high-frequency electromagnetic wave interference；Third layer is epoxy resin, for isolating；It is most interior
Layer is the permalloy of high magnetic permeability, effective armoured magnetic field interference.
Further, annular magnetic conductive groove is provided with the perforation in the shielding insulation protecting box, in the annular magnetic conduction
At groove, the innermost layer permalloy of shielding insulation protecting box shell and the copper of the second layer are removed, and the magnetic conductive groove is around main transformer
Depressor iron core grounding wire is set in a ring.
Compared with prior art, main transformer core earth current monitoring device provided by the utility model, passes through magnetic
Electric resistance sensor collection main transformer core earth lead in current signal, and by after signal processing unit processes by LoRa
Wireless communication module is sent to remote monitoring center；The magnetic resistance sensor is not easily susceptible to power transformer bad electromagnetic environment
Influence, it is high to gather the accuracy of signal, and uses micro fabrication batch making, and cost is low, good economy performance；Described master
Transformer iron core grounding current monitoring device realizes telecommunication by LoRa wireless communication modules so that remote monitoring center
The size of current in current main transformer core earth lead can be obtained in real time, the long-range earth fault for monitoring main transformer, had
The earth fault of effect prevention main transformer, realizes intelligent unmanned substation.
Brief description of the drawings
It is required in being described below to embodiment to use in order to illustrate more clearly of the technical solution of the utility model
Accompanying drawing is briefly described, it should be apparent that, drawings in the following description are only one embodiment of the present utility model, for
For those of ordinary skill in the art, on the premise of not paying creative work, other can also be obtained according to these accompanying drawings
Accompanying drawing.
Fig. 1 is a kind of structural representation of main transformer core earth current monitoring device of the utility model；
Wherein：1- main transformer core earth leads, magnet rings of the 2- with parallel open, 3- magnetic resistance sensors, 4- amplifications
Module, 5- filtration modules, 6- signal processing units, 7- logic analysis modules, 8-LoRa wireless communication modules, 9- clock modules,
10- power modules, 11- shielding insulation protecting box, the perforation in 12- shielding insulation protecting box.
Embodiment
With reference to the accompanying drawing in the utility model embodiment, technical scheme of this implementation in new is carried out clear, complete
Site preparation describes, it is clear that described embodiment is only the utility model part of the embodiment, rather than whole embodiments.
Based on the embodiment in the utility model, those of ordinary skill in the art are obtained on the premise of creative work is not made
Every other embodiment, belong to the utility model protection scope.
As shown in figure 1, main transformer core earth current monitoring device provided by the utility model, including magneto-resistor pass
Sensor 3, the magnet ring 2 with parallel open, signal processing unit 6 and shielding insulation protecting box 11；The main transformer core connects
Ground wire 1 is placed in shielding insulation protecting box 11, in shielding insulation protecting box corresponding to the center of magnet ring 2 with parallel open
Perforation 12 is offered on 11, the main transformer core earth lead 1 passes through the perforation 12；The magnet ring with parallel open
2 are placed in shielding insulation protecting box 11, and are set around main transformer core earth lead 1；The magnetic resistance sensor 3 is placed in
At the parallel open of the magnet ring 2 with parallel open, the sensitive direction of principal axis of the magnetic resistance sensor 3 is along main transformer core
The tangential direction of earth lead 1, the magnetic resistance sensor 2 are connected with the signal processing unit 6, the signal processing unit
6 are placed in shielding insulation protecting box 11.
The signal processing unit 6 includes amplification module 4, filtration module 5, logic analysis module 7, the LoRa being sequentially connected
Wireless communication module 8, the signal processing unit 6 also include power module 10 and clock module 9, and the power module 10 is distinguished
With the magnetic resistance sensor 3, amplification module 4, filtration module 5, logic analysis module 7, LoRa wireless communication modules 8 with timely
Clock module 9 is connected, and the clock module 9 is connected with logic analysis module 7 and LoRa wireless communication modules 8 respectively.
The logic analysis module 7 includes control process module and the power management module being connected with each other, the power supply pipe
Reason module is connected with the power module 10, and the power module 10 uses long-life batteries, and its supply voltage is 7.8V.
The filtration module 5 is low pass filter, because the monitoring for main transformer core earth current is mainly concentrated
In its power frequency and DC component, therefore, the cut-off frequency of low pass filter is hundred Hz magnitudes, can effectively filter out the electricity in environment
Magnetic disturbance.
The magnetic resistance sensor 3 includes substrate, and the TMR sensor unit, the rectangle soft magnetism that are arranged on substrate lead to
Measure concentrator, bucking coil；The TMR sensor unit is electrically connected to be connected into along the free layer direction of magnetization pushes away magneto-resistor sensing unit string
With draw magneto-resistor sensing unit string, and be arranged on the lower section in gap between the rectangle soft magnetism flux concentrator of adjacent two,
It is described push away magneto-resistor sensing unit string and draw magneto-resistor sensing unit string and be electrically connected be connected into push-pull type magnetic resistance sensor, the compensation
Coil be arranged on the top of the TMR sensor unit and between two adjacent rectangle soft magnetism flux concentrators between
The lower section of gap, the bucking coil is with the positive pole current strap by the TMR sensor unit and passes through rectangle soft magnetism flux
The cathodal current band of concentrator；The magnetic resistance sensor uses micro fabrication batch making, and cost is extremely low, economy pole
It is good.
The shell of the shielding insulation protecting box 11 includes four layers, and outermost layer is the polytetrafluoroethylene (PTFE) of high insulation resistance, is
The main transformer core earth current monitoring device provides external insulation protection；The second layer is the copper of high conductivity, and is connect
Ground processing, effectively shields electric jamming and high-frequency electromagnetic wave interference；Third layer is epoxy resin, for isolating；Innermost layer is height
The permalloy of magnetic conductivity, effective armoured magnetic field interference.
Annular magnetic conductive groove is provided with perforation 12 in the shielding insulation protecting box, at the annular magnetic conductive groove, screen
The copper of the innermost layer permalloy and the second layer that cover insulation protecting box shell is removed, and the magnetic conductive groove is around main transformer core
Earth lead 1 is set in a ring.
The minimum current measured value as little as 100uA of the magnetic resistance sensor 3, frequency measurement scope are direct current to 1MHz,
Power frequency corresponding to main transformer multipoint earth faults and D.C. magnetic biasing failure is completely covered.
When main transformer core earth lead 1 have electric current by when, produced at the parallel open of the magnet ring 2 uniform
Magnetic field, the magnetic field are amplified by magnet ring, and its magnetic field intensity is with the current amplitude in main transformer core earth lead 1 into just
Than being then applied on magnetic resistance sensor 3, the resistance value of the magnetic resistance sensor 3 is led as main transformer core is grounded
Current amplitude changes and changed in line 1, and the differential output signal of the magnetic resistance sensor 3 passes through with common mode inhibition effect
After amplification module 4, low pass filter 5 is transferred to, after the logic analysis module 7 obtains filtered signal, to current amplitude
Reduced, judge whether the alterating and direct current flow component in current main transformer core earth lead 1 has exception, and will determine that knot
Fruit is packed according to LoRa home control network communication protocols, timing or the wake-up LoRa wireless communication modules 8 when being judged as abnormality,
And packed data are sent to remote monitoring center by LoRa wireless communication modules 8, current main transformer is obtained in real time
Size of current in iron core grounding wire 1, the long-range earth fault for monitoring main transformer, effectively prevent the ground connection event of main transformer
Barrier, realizes intelligent unmanned substation.
Above disclosed is only specific embodiment of the present utility model, but the scope of protection of the utility model not office
It is limited to this, any one skilled in the art can readily occur in change in the technical scope that the utility model discloses
Change or modification, should all cover within the scope of protection of the utility model.
Claims (9)
- A kind of 1. main transformer core earth current monitoring device, it is characterised in that：Including magnetic resistance sensor（3）, with parallel The magnet ring of opening（2）, signal processing unit（6）And shielding insulation protecting box（11）；The main transformer core earth lead （1）It is placed in shielding insulation protecting box（11）It is interior, in the magnet ring with parallel open（2）Shielding insulation protecting box corresponding to center （11）On offer perforation（12）, the main transformer core earth lead（1）Through the perforation（12）；The band is parallel to be opened The magnet ring of mouth（2）It is placed in shielding insulation protecting box（11）It is interior, and around main transformer core earth lead（1）Set；The magnetic Electric resistance sensor（3）It is placed in the magnet ring with parallel open（2）Parallel open at, the magnetic resistance sensor（3）Spirit Quick direction of principal axis is along main transformer core earth lead（1）Tangential direction, the magnetic resistance sensor（3）With the signal transacting Unit（6）Connection, the signal processing unit（6）It is placed in shielding insulation protecting box（11）It is interior.
- 2. main transformer core earth current monitoring device as claimed in claim 1, it is characterised in that：The signal transacting list Member（6）Including the amplification module being sequentially connected（4）, filtration module（5）, logic analysis module（7）, LoRa wireless communication modules （8）, the signal processing unit（6）Also include power module（10）And clock module（9）, the power module（10）Respectively with The magnetic resistance sensor（3）, amplification module（4）, filtration module（5）, logic analysis module（7）, LoRa wireless communication modules （8）And clock module（9）Connection, the clock module（9）Respectively with logic analysis module（7）With LoRa wireless communication modules （8）Connection.
- 3. main transformer core earth current monitoring device as claimed in claim 2, it is characterised in that：The logic analysis mould Block（7）Control process module and power management module including interconnection, the power management module and the power module （10）Connection, to power module（10）Carry out management of charging and discharging.
- 4. main transformer core earth current monitoring device as claimed in claim 2, it is characterised in that：The power module （10）Supply voltage be 7.8V.
- 5. main transformer core earth current monitoring device as claimed in claim 2, it is characterised in that：The filtration module （5）For low pass filter, the cut-off frequency of the low pass filter is hundred Hz magnitudes.
- 6. main transformer core earth current monitoring device as claimed in claim 1, it is characterised in that：The magneto-resistor sensing Device（3）Including substrate, and TMR sensor unit, rectangle soft magnetism flux concentrator, the bucking coil being arranged on substrate；Institute State TMR sensor unit and be electrically connected to be connected into push away along the free layer direction of magnetization and magneto-resistor sensing unit string and draw magneto-resistor sensing unit String, and the lower section in gap between the rectangle soft magnetism flux concentrator of adjacent two is arranged on, it is described to push away magneto-resistor sensing list Member string and draw magneto-resistor sensing unit string and be electrically connected and be connected into push-pull type magnetic resistance sensor, the bucking coil is arranged on the TMR The top of sensor unit and between two adjacent rectangle soft magnetism flux concentrators gap lower section, the compensation Coil has the positive pole current strap by the TMR sensor unit and the cathodal current by rectangle soft magnetism flux concentrator Band.
- 7. main transformer core earth current monitoring device as claimed in claim 1, it is characterised in that：The magneto-resistor sensing Device（3）Minimum current measured value as little as 100uA, frequency measurement scope is direct current to 1MHz.
- 8. main transformer core earth current monitoring device as claimed in claim 1, it is characterised in that：The shielding insulation is protected Protect box（11）Shell include four layers, outermost layer be high insulation resistance polytetrafluoroethylene (PTFE)；The second layer is the copper of high conductivity, and Carry out grounding；Third layer is epoxy resin；Innermost layer is the permalloy of high magnetic permeability.
- 9. main transformer core earth current monitoring device as claimed in claim 8, it is characterised in that：In the shielding insulation Protecting box（11）On perforation（12）Place is provided with annular magnetic conductive groove, at the annular magnetic conductive groove, shielding insulation protecting box（11） The innermost layer permalloy of shell and the copper of the second layer are removed, and the magnetic conductive groove is around main transformer core earth lead（1） Set in a ring.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720419695.6U CN206818777U (en) | 2017-04-20 | 2017-04-20 | A kind of main transformer core earth current monitoring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720419695.6U CN206818777U (en) | 2017-04-20 | 2017-04-20 | A kind of main transformer core earth current monitoring device |
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| Publication Number | Publication Date |
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| CN206818777U true CN206818777U (en) | 2017-12-29 |
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| CN201720419695.6U Active CN206818777U (en) | 2017-04-20 | 2017-04-20 | A kind of main transformer core earth current monitoring device |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3521843A1 (en) * | 2018-02-02 | 2019-08-07 | Stadtwerke Karlsruhe GmbH | System for monitoring transformer stations |
| CN110702965A (en) * | 2019-10-15 | 2020-01-17 | 清华大学 | Cable state monitoring sensor device |
| CN112834811A (en) * | 2021-01-04 | 2021-05-25 | 中国电力科学研究院有限公司 | Ground current state monitoring method and device applying magnetic resistance sensing and storage medium |
| CN114062761A (en) * | 2021-11-12 | 2022-02-18 | 国网河南省电力公司检修公司 | Transformer grounding wire AC/DC component detection device |
| CN114236224A (en) * | 2021-12-15 | 2022-03-25 | 中国电力科学研究院有限公司 | Transformer core grounding current measurement system and method |
-
2017
- 2017-04-20 CN CN201720419695.6U patent/CN206818777U/en active Active
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3521843A1 (en) * | 2018-02-02 | 2019-08-07 | Stadtwerke Karlsruhe GmbH | System for monitoring transformer stations |
| CN110702965A (en) * | 2019-10-15 | 2020-01-17 | 清华大学 | Cable state monitoring sensor device |
| CN112834811A (en) * | 2021-01-04 | 2021-05-25 | 中国电力科学研究院有限公司 | Ground current state monitoring method and device applying magnetic resistance sensing and storage medium |
| CN114062761A (en) * | 2021-11-12 | 2022-02-18 | 国网河南省电力公司检修公司 | Transformer grounding wire AC/DC component detection device |
| CN114236224A (en) * | 2021-12-15 | 2022-03-25 | 中国电力科学研究院有限公司 | Transformer core grounding current measurement system and method |
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