CN206281925U - A kind of DC grounding monitor instrument - Google Patents

A kind of DC grounding monitor instrument Download PDF

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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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China
Prior art keywords
voltage
electric group
negative busbar
ground
positive
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CN201621300578.XU
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Chinese (zh)
Inventor
孙涛
宋承明
江依纯
孙哲夫
杨和义
陈首阳
赵冠群
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Lianyungang Power Supply Co Of State Grid Jingsu Electric Power Company
State Grid Corp of China SGCC
Lianyungang Power Supply Co of State Grid Jiangsu Electric Power Co Ltd
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Lianyungang Power Supply Co Of State Grid Jingsu Electric Power Company
State Grid Corp of China SGCC
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Application filed by Lianyungang Power Supply Co Of State Grid Jingsu Electric Power Company, State Grid Corp of China SGCC filed Critical Lianyungang Power Supply Co Of State Grid Jingsu Electric Power Company
Priority to CN201621300578.XU priority Critical patent/CN206281925U/en
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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

A kind of DC grounding monitor instrument
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.
CN201621300578.XU 2016-11-30 2016-11-30 A kind of DC grounding monitor instrument Active CN206281925U (en)

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)

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CN206281925U true CN206281925U (en) 2017-06-27

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CN201621300578.XU Active CN206281925U (en) 2016-11-30 2016-11-30 A kind of DC grounding monitor instrument

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Cited By (2)

* Cited by examiner, † Cited by third party
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

Cited By (2)

* Cited by examiner, † Cited by third party
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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