CN206281925U - A kind of DC grounding monitor instrument - Google Patents
A kind of DC grounding monitor instrument Download PDFInfo
- Publication number
- CN206281925U CN206281925U CN201621300578.XU CN201621300578U CN206281925U CN 206281925 U CN206281925 U CN 206281925U CN 201621300578 U CN201621300578 U CN 201621300578U CN 206281925 U CN206281925 U CN 206281925U
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- voltage
- electric group
- negative busbar
- ground
- positive
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- 238000001514 detection method Methods 0.000 claims abstract description 15
- 230000005611 electricity Effects 0.000 claims description 36
- 238000009413 insulation Methods 0.000 abstract description 9
- 230000005494 condensation Effects 0.000 description 2
- 238000009833 condensation Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000000087 stabilizing Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 1
- 230000001808 coupling Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
Abstract
The utility model discloses a kind of DC grounding monitor instrument, including balanced bridge circuit, detection bridge circuit, voltage acquisition unit, operational amplifier and analog-digital converter；The utility model DC grounding monitor instrument passes through voltage acquisition unit Real-time Collection straight-flow system positive and negative busbar voltage-to-ground, and send the magnitude of voltage of collection to processor, after there is deviation in device power or positive and negative busbar voltage-to-ground, it is turned on or off by controlling relay on detection bridge, the resistance on detection bridge arm is set to access or exit straight-flow system, positive and negative busbar voltage-to-ground is caused to produce fluctuation, system positive and negative busbar insulation against ground resistance can be calculated using the change of straight-flow system positive and negative busbar voltage-to-ground, system insulating resistance is compared with alarm threshold, outputting alarm signal is used to alert, it is prevented effectively from and declines and causing equipment malfunction problem because insulating, to ensure the property safe and reliable to operation of Distribution Network Equipment.
Description
Technical field
The utility model is related to electrical equipment technical field, particularly a kind of DC grounding monitor instrument.
Background technology
With implementing in full for distribution automation project, the current DTU/FTU quantity that puts into operation is increasing, outdoor electricity distribution
Automation equipment proposes requirements at the higher level to distribution net equipment running environment.Because Distribution Network Equipment is multi-point and wide-ranging, surrounding environment feelings
Condition is complicated, and coastal region is with the humid air, and rainfall is abundant, and outdoor electrical equipment often produces the problems such as condensation, corrosion, so as to draw
System insulation is played to decline.Distribution automation equipment largely uses motor-operating mechanism, once the insulation of equipment control loop declines, produces
Raw DC earthing, will easily cause equipment malfunction, endanger grid equipment and personal safety.
Such as in month in this year 2, urban district automates ring main unit straight-flow system because module failure causes plus earth, while 5#
Interconnection switch shutting-brake control loop produces insulation against ground to decline because of condensation, ultimately results in interconnection switch malfunction combined floodgate, makes two
10kV circuit Electromagnetic couplings, generate great potential safety hazard.To solve problems, environment in cabinet is dehumidified, is blocked,
But positive effect cannot being obtained, equipment has self-defect in addition, when there is DC ground fault, still there is operation wind
Danger.
The content of the invention
The purpose of this utility model is to provide a kind of simple structure, good reliability, safe DC grounding monitor
Instrument.
The technical solution for realizing the utility model purpose is：
A kind of DC grounding monitor instrument, it is characterised in that including balanced bridge circuit, detection bridge circuit, voltage acquisition unit,
Operational amplifier and analog-digital converter；The balanced bridge circuit includes the first electricity group and the second electric group, one end of the first electricity group with
Positive bus-bar is connected, and one end of the second electricity group is connected with negative busbar, and the other end of the first electricity group and the second electricity group is grounded；Institute
Stating detection bridge circuit includes the 3rd electric group, the 4th electric group, first switch and second switch, and one end of the 3rd electricity group is by the
One switch after be connected with positive bus-bar, the 4th electricity group one end by being connected with negative busbar after second switch, the 3rd electricity group and
The other end of the 4th electricity group is grounded；The voltage acquisition unit includes that first voltage collecting unit and second voltage collection are single
Unit, operational amplifier includes the first operational amplifier and the second operational amplifier, and analog-digital converter includes the first analog-digital converter
With the second analog-digital converter；The input of the first voltage collecting unit is in parallel with the two ends of the first electricity group, first voltage
The output end of collecting unit is sequentially connected the first operational amplifier, the second analog-digital converter；The second voltage collecting unit
Input is in parallel with the two ends of the second electricity group, the output end of second voltage collecting unit be sequentially connected the second operational amplifier,
Second analog-digital converter.
Preferably, the first electricity group and the second electricity group are in parallel using 10 metalfilmresistors of 1% precision 50k Ω/2W
Composition.
Preferably, the 3rd electricity group and the 4th electricity group are in parallel using 2 metalfilmresistors of 1% precision 50k Ω/2W
Composition.
Preferably, the first switch and second switch use relay.
The utility model compared with prior art, its remarkable advantage：The utility model DC grounding monitor instrument passes through voltage
Collecting unit Real-time Collection straight-flow system positive and negative busbar voltage-to-ground, and send the magnitude of voltage of collection to processor, in equipment
Electricity or after deviation occurs in positive and negative busbar voltage-to-ground, by controlling being turned on or off for relay on detection bridge, makes detection bridge
Resistance on arm is accessed or exits straight-flow system, causes positive and negative busbar voltage-to-ground to produce fluctuation, using the positive and negative mother of straight-flow system
The change of line-to-earth voltage can calculate system positive and negative busbar insulation against ground resistance, and system insulating resistance is entered with alarm threshold
Row compares, and outputting alarm signal is used to alert, and is prevented effectively from and declining and causing equipment malfunction problem because insulating, to ensure power distribution network
The property safe and reliable to operation of equipment.
The utility model is described in further detail below in conjunction with the accompanying drawings.
Brief description of the drawings
Fig. 1 is the structural representation of the utility model DC grounding monitor instrument.
Specific embodiment
Embodiment 1：
As shown in figure 1, a kind of distribution power automation terminal DC earthing on-line monitoring system, including processor, DC earthing
Monitor, plus earth alarm signal output module, negative pole ground connection alarm signal output module and power module, the processor
Respectively with DC grounding monitor instrument, plus earth alarm signal output module, negative pole ground connection alarm signal output module and power supply
Module is connected；The DC grounding monitor instrument includes balanced bridge circuit, detection bridge circuit, voltage acquisition unit, operation amplifier
Device and analog-digital converter；The balanced bridge circuit include first electricity group R1 and second electricity group R2, first electricity group R1 one end with just
Bus+KM is connected, and one end of the second electricity group R2 is connected with negative busbar-KM, and the first electricity electricity groups of group R1 and second R2's is another
End is grounded；The detection bridge circuit includes the 3rd electricity group R3, the 4th electricity group R4, first switch S1 and second switch S2, described
By being connected with positive bus-bar+KM after first switch S1, one end of the 4th electricity group R4 is opened by second for one end of 3rd electricity group R3
It is connected with negative busbar-KM after closing S2, the other end of the 3rd electricity electricity groups of group R3 and the 4th R4 is grounded；The voltage acquisition list
Unit includes first voltage collecting unit and second voltage collecting unit, and operational amplifier includes the first operational amplifier and the second fortune
Amplifier is calculated, analog-digital converter includes the first analog-digital converter and the second analog-digital converter；The first voltage collecting unit
Input is in parallel with the two ends of the first electricity group R1, and the output end of first voltage collecting unit is sequentially connected the first operation amplifier
Device, the second analog-digital converter, the output end of the second analog-digital converter are connected with processor；The second voltage collecting unit
Input is in parallel with the two ends of the second electricity group R2, and the output end of second voltage collecting unit is sequentially connected the second operation amplifier
Device, the second analog-digital converter, the output end of the second analog-digital converter are connected with processor；Wherein, the DC grounding monitor
Instrument uses passive design, i.e. DC grounding monitor instrument to be powered using DC48V or DC24V, is shared with bus collection port
Same port, without extra power supply port, greatly simplifies field connection, it is adaptable to which various model distribution are automatic
Change the matching of terminal；The first switch S1 and second switch S2 use relay, first switch S1's and second switch S2
Control end is connected with processor；The balanced bridge circuit is used to maintain straight-flow system positive and negative busbar voltage-to-ground equal, institute
Voltage acquisition unit Real-time Collection straight-flow system positive and negative busbar voltage-to-ground, and the magnitude of voltage that will be gathered are stated by operation amplifier
Processor is sent after device, analog-digital converter to, after deviation occur in device power or positive and negative busbar voltage-to-ground, by controlling to examine
Survey first switch S1 and second switch S2 in bridge circuit to be turned on or off, the resistance on bridge arm is accessed or exit direct current system
System, causes positive and negative busbar voltage-to-ground to produce fluctuation, can be calculated using the change of straight-flow system positive and negative busbar voltage-to-ground
System positive and negative busbar insulation against ground resistance R+, R-, system resistance is compared with alarm threshold, and outputting alarm signal is used to accuse
It is alert.
The distribution power automation terminal DC earthing on-line monitoring system also includes communication module and host computer, and processor leads to
Cross communication module to be connected with host computer, alarm signal is transferred to host computer by processor by communication module.
The input of the power module is sequentially connected Voltage stabilizing module, power voltage step down module, bus, and bus is dropped by power supply
DC voltage needed for die block generation device, by the voltage stabilizing chip of high stability, produces 3.3V power supplys to processor and patrols
Collect circuit to power, it is ensured that processor and logic circuit energy normal work.
The first electricity group R1 and second electricity groups R2 is using 10 metalfilmresistors and joint group of 1% precision 50k Ω/2W
Into pressure voltage reaches 330V, the ability of 250V alternating voltages is superimposed with long-term tolerance 48V DC voltages, it is ensured that exchange is scurried into
When balance of plant bridge do not result in damage；3rd electricity group R3 and the 4th electricity groups R4 is using 2 1% precision 50k Ω/2W's
Metalfilmresistor is composed in parallel, it is ensured that device carries out the above earth potential fluctuation caused during earthing detection no more than 10%.
The operation principle of the utility model distribution power automation terminal DC earthing on-line monitoring system：
The utility model distribution power automation terminal DC earthing on-line monitoring system passes through voltage acquisition unit Real-time Collection
Straight-flow system positive and negative busbar voltage-to-ground, and by the magnitude of voltage of collection by sending place after operational amplifier, analog-digital converter to
Reason device, after distribution power automation terminal straight-flow system insulating ground, processor by control detection bridge on resistance input and move back
Go out, computing system positive and negative busbar insulaion resistance over the ground, when positive pole insulaion resistance is less than alarm threshold, plus earth alarm letter
Number output module outputting alarm signal, when negative insulation resistance is less than alarm threshold, negative pole ground connection alarm signal output module
Outputting alarm signal, when positive pole insulaion resistance and negative insulation resistance are respectively less than alarm threshold, plus earth alarm signal is defeated
Go out module and the negative pole ground connection equal outputting alarm signal of alarm signal output module；And processor passes through communication module by alarm signal
It is transferred to host computer.
In sum, the utility model DC grounding monitor instrument is positive and negative by voltage acquisition unit Real-time Collection straight-flow system
Bus Voltage, and send the magnitude of voltage of collection to processor, device power or positive and negative busbar voltage-to-ground occur inclined
After difference, it is turned on or off by controlling relay on detection bridge, the resistance on detection bridge arm is accessed or exit straight-flow system,
Cause positive and negative busbar voltage-to-ground to produce fluctuation, system can be calculated using the change of straight-flow system positive and negative busbar voltage-to-ground
Positive and negative busbar insulation against ground resistance, system insulating resistance is compared with alarm threshold, and outputting alarm signal is used to alert, and has
Effect avoids declining because insulating and causing equipment malfunction problem, to ensure the property safe and reliable to operation of Distribution Network Equipment.
Claims (4)
1. a kind of DC grounding monitor instrument, it is characterised in that including balanced bridge circuit, detection bridge circuit, voltage acquisition unit, fortune
Calculate amplifier and analog-digital converter；The balanced bridge circuit includes the first electric group（R1）With the second electric group（R2）, the first electric group
（R1）One end and positive bus-bar（+KM）It is connected, the second electric group（R2）One end and negative busbar（- KM）It is connected, the first electric group
（R1）With the second electric group（R2）The other end be grounded；The detection bridge circuit includes the 3rd electric group（R3）, the 4th electric group（R4）、
First switch（S1）And second switch（S2）, the described 3rd electric group（R3）One end by first switch（S1）Afterwards with positive bus-bar（+
KM）It is connected, the 4th electric group（R4）One end by second switch（S2）Afterwards with negative busbar（- KM）It is connected, the 3rd electric group
（R3）With the 4th electric group（R4）The other end be grounded；The voltage acquisition unit includes first voltage collecting unit and the second electricity
Pressure collecting unit, operational amplifier includes the first operational amplifier and the second operational amplifier, and analog-digital converter includes the first mould
Number converter and the second analog-digital converter；The input of the first voltage collecting unit and the first electric group（R1）Two ends mutually simultaneously
Connection, the output end of first voltage collecting unit is sequentially connected the first operational amplifier, the second analog-digital converter；The second voltage
The input of collecting unit and the second electric group（R2）Two ends be in parallel, the output end of second voltage collecting unit is sequentially connected
Two operational amplifiers, the second analog-digital converter.
2. DC grounding monitor instrument according to claim 1, it is characterised in that the described first electric group（R1）With the second electric group
（R2）Composed in parallel using the metalfilmresistor of 10 1% precision 50k Ω/2W.
3. DC grounding monitor instrument according to claim 1, it is characterised in that the described 3rd electric group（R3）With the 4th electric group
（R4）Composed in parallel using the metalfilmresistor of 2 1% precision 50k Ω/2W.
4. DC grounding monitor instrument according to claim 1, it is characterised in that the first switch（S1）And second switch
（S2）Use relay.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621300578.XU CN206281925U (en) | 2016-11-30 | 2016-11-30 | A kind of DC grounding monitor instrument |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621300578.XU CN206281925U (en) | 2016-11-30 | 2016-11-30 | A kind of DC grounding monitor instrument |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN206281925U true CN206281925U (en) | 2017-06-27 |
Family
ID=59075224
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201621300578.XU Active CN206281925U (en) | 2016-11-30 | 2016-11-30 | A kind of DC grounding monitor instrument |
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| Country | Link |
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| CN (1) | CN206281925U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108375711A (en) * | 2018-02-26 | 2018-08-07 | 南京华脉科技股份有限公司 | A kind of insulating monitoring method of bipolar earth-free HVDC power-supply systems |
| CN111366785A (en) * | 2020-04-02 | 2020-07-03 | 南方电网电动汽车服务有限公司 | Insulation monitoring circuit and method for direct current charging pile |
-
2016
- 2016-11-30 CN CN201621300578.XU patent/CN206281925U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108375711A (en) * | 2018-02-26 | 2018-08-07 | 南京华脉科技股份有限公司 | A kind of insulating monitoring method of bipolar earth-free HVDC power-supply systems |
| CN111366785A (en) * | 2020-04-02 | 2020-07-03 | 南方电网电动汽车服务有限公司 | Insulation monitoring circuit and method for direct current charging pile |
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