CN204203329U - Insulator leakage current sensor - Google Patents
Insulator leakage current sensor Download PDFInfo
- Publication number
- CN204203329U CN204203329U CN201420543303.3U CN201420543303U CN204203329U CN 204203329 U CN204203329 U CN 204203329U CN 201420543303 U CN201420543303 U CN 201420543303U CN 204203329 U CN204203329 U CN 204203329U
- Authority
- CN
- China
- Prior art keywords
- operational amplifier
- current sensor
- resistance
- ground connection
- leakage current
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000012212 insulator Substances 0.000 title claims abstract description 17
- 238000005259 measurement Methods 0.000 abstract description 5
- 230000007246 mechanism Effects 0.000 abstract description 2
- 230000008859 change Effects 0.000 description 6
- 230000035699 permeability Effects 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000011109 contamination Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000005415 magnetization Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 210000003205 muscle Anatomy 0.000 description 1
- 229910052573 porcelain Inorganic materials 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- APTZNLHMIGJTEW-UHFFFAOYSA-N pyraflufen-ethyl Chemical group C1=C(Cl)C(OCC(=O)OCC)=CC(C=2C(=C(OC(F)F)N(C)N=2)Cl)=C1F APTZNLHMIGJTEW-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
Abstract
The utility model discloses a kind of insulator leakage current sensor, relate to the measurement mechanism technical field of electric variable.Current transformer T1 comprises former limit L1, the first secondary L2 and the second secondary L3, and former limit L1 is the signal input part of current sensor; The in-phase input end of the one termination operational amplifier U1 of the first secondary L2, the inverting input of operational amplifier U1 is divided into three tunnels, the first via is connected with the other end of the first secondary L2, and the second tunnel is through resistance R3 ground connection, and the 3rd tunnel is connected with the output terminal of operational amplifier U1 through resistance R4; The output terminal ground connection after capacitance C3, the second secondary L3, variable resistor R1 and resistance R2 successively of operational amplifier U1, the node of the second secondary L3 and variable resistor R1 is the signal output part of current sensor.Described sensor achieves the good linearity by the mode of electromagnetic compensation, has the advantages that measurement data accuracy is high.
Description
Technical field
The utility model relates to the measurement mechanism technical field of electric variable, particularly relates to a kind ofly to measure the high current sensor of insulator leakage current precision.
Background technology
Current sensor, it is a kind of pick-up unit, the current information of testee can be experienced, and can will detect the information experienced, the information being for conversion into electric signal or other desired forms meeting certain standard needs according to certain rules exports, to meet the requirements such as the transmission of information, process, storage, display, record and control.Current sensor also claims Magnetic Sensor, at household electrical appliance, intelligent grid, electric motor car, wind-power electricity generation etc., can all use a lot of Magnetic Sensor in our life, for example, computer hard disc, compass, household electrical appliance etc.
Leakage current sensor is generally the magnet ring be made up of high permeability material.Conventional current sensor is mostly passive, and due to leakage current facing sudden strain of a muscle and overvoltage condition under, there is positive or the pulse of negative leakage current, iron core is made to there is hysteresis effect and magnetization curve is non-linear, so leakage current sensor general linear degree is poor, and flow through the leakage current of any complicated shape insulator surface, it is the signal that a variation range is larger, when usual weather and equipment normally run, the peak-peak of leakage current is that timely microampere is to hundreds of microampere, when environment changes, leakage current can reach several milliamperes, once there is thunderbolt or flashover, leakage current values will up to nearly hundred milliamperes.Leakage current sensor accurately will measure the numerical value of leakage current, but in so large scope, ensure accuracy and the precision of current detecting, and ensure the real-time of current detecting, the sensor of prior art is difficult to meet above-mentioned requirements simultaneously.
Utility model content
Technical problem to be solved in the utility model is to provide a kind of insulator leakage current sensor, and described sensor achieves the good linearity by the mode of electromagnetic compensation, has the advantages that measurement data accuracy is high.
For solving the problems of the technologies described above, technical solution adopted in the utility model is: a kind of insulator leakage current sensor, it is characterized in that: comprise current transformer T1, operational amplifier U1, resistance R1-R4 and electric capacity C1-C3, described current transformer comprises former limit L1, the first secondary L2 and the second secondary L3, and former limit L1 is the signal input part of current sensor; The in-phase input end of the one termination operational amplifier U1 of described first secondary L2, the inverting input of described operational amplifier U1 is divided into three tunnels, the first via is connected with the other end of the first secondary L2, and the second tunnel is through resistance R3 ground connection, and the 3rd tunnel is connected with the output terminal of operational amplifier U1 through resistance R4; The cathode voltage input end of operational amplifier U1 is through electric capacity C1 ground connection, and the cathode voltage input end of operational amplifier U1 is divided into two-way, and a road is connected with Vcc, and the other end is through electric capacity C2 ground connection; The output terminal ground connection after capacitance C3, the second secondary L3, variable resistor R1 and resistance R2 successively of operational amplifier U1, the node of described second secondary L3 and variable resistor R1 is the signal output part of current sensor.
The beneficial effect adopting technique scheme to produce is: described sensor is the leakage current sensor of feedback compensation type, making by the composite magnetic power of iron core is zero, ensure that magnetic permeability is a constant, avoid, because DC component causes the change of magnetic permeability, achieving high linearity.General current transformer only has limit, a source and a secondary, limit, source and secondary should have magnetic balance in the ideal case, but the induced field that under actual conditions, former limit and secondary produce can not reach magnetic balance, this just needs to increase after compensating coil compensates makes resultant magnetic field be zero as far as possible.Compensation principle is as follows: the first secondary two ends produce voltage and export V through amplifier, resistance R1 and R2 of V after capacitance C3 in the second secondary L3 loop produces offset current, offset current goes to the magnetic field compensating the generation of former limit through the magnetic field that the second secondary L3 produces, make induced field reach magnetic balance as much as possible, reach the object improving measuring accuracy.
Accompanying drawing explanation
Below in conjunction with the drawings and specific embodiments, the utility model is described in further detail.
Fig. 1 is schematic diagram of the present utility model;
Fig. 2 is experimental data curve figure.
Embodiment
Below in conjunction with the accompanying drawing in the utility model embodiment, be clearly and completely described the technical scheme in the utility model embodiment, obviously, described embodiment is only a part of embodiment of the present utility model, instead of whole embodiments.Based on the embodiment in the utility model, those of ordinary skill in the art are not making the every other embodiment obtained under creative work prerequisite, all belong to the scope of the utility model protection.
Set forth a lot of detail in the following description so that fully understand the utility model, but the utility model can also adopt other to be different from alternate manner described here to implement, those skilled in the art can when doing similar popularization without prejudice to when the utility model intension, and therefore the utility model is by the restriction of following public specific embodiment.
As shown in Figure 1, the utility model discloses a kind of insulator leakage current sensor, comprise current transformer T1, operational amplifier U1, resistance R1-R4 and electric capacity C1-C3, described current transformer comprises former limit L1, the first secondary L2 and the second secondary L3, and former limit L1 is the signal input part of current sensor; The in-phase input end of the one termination operational amplifier U1 of described first secondary L2, the inverting input of described operational amplifier U1 is divided into three tunnels, the first via is connected with the other end of the first secondary L2, and the second tunnel is through resistance R3 ground connection, and the 3rd tunnel is connected with the output terminal of operational amplifier U1 through resistance R4; The cathode voltage input end of operational amplifier U1 is through electric capacity C1 ground connection, and the cathode voltage input end of operational amplifier U1 is divided into two-way, and a road is connected with Vcc, and the other end is through electric capacity C2 ground connection; The output terminal ground connection after capacitance C3, the second secondary L3, variable resistor R1 and resistance R2 successively of operational amplifier U1, the node of described second secondary L3 and variable resistor R1 is the signal output part of current sensor.
Described sensor is the leakage current sensor of feedback compensation type, and making by the composite magnetic power of iron core is zero, ensure that magnetic permeability is a constant, avoids, because DC component causes the change of magnetic permeability, achieving high linearity.General current transformer only has limit, a source and a secondary, limit, source and secondary should have magnetic balance in the ideal case, but the induced field that under actual conditions, former limit and secondary produce can not reach magnetic balance, this just needs to increase after compensating coil compensates makes resultant magnetic field be zero as far as possible.Compensation principle is as follows: the first secondary two ends produce voltage and export V through amplifier, resistance R1 and R2 of V after capacitance C3 in the second secondary L3 loop produces offset current, offset current goes to the magnetic field compensating the generation of former limit through the magnetic field that the second secondary L3 produces, make induced field reach magnetic balance as much as possible, reach the object improving measuring accuracy.
Figure 2 shows that experimental data curve figure, illustrate this leakage current sensor under input end amplitude wide variation sinusoidal current signal condition, output voltage situation.Wherein, the longitudinal axis is input 0.1mA to 200mA sinusoidal current signal, and transverse axis is the peak-to-peak value (V) that output terminal directly adopts oscillograph and records.
In insulator leakage current sensor installation position selection problem, people select current sensor to be placed on last insulator or between the 2nd insulator reciprocal and last a slice insulator usually.But due in the uneven situation of insulator contamination degree distribution, the voltage's distribiuting on insulator chain can change, thus causes the change of capacitance current.So just cause the change of leakage current.If adopt this modes of emplacement, be difficult to the change detecting that this electric current causes, and then have impact on the prediction to insulator contamination degree.Therefore, take the mode be directly placed on by current sensor between high voltage power transmission line end and first insulator when mounted, thus make to flow through the conduction current of porcelain vase string, various capacitance current and stray current and can be reflected by comprehensive, improve measurement accuracy.
Claims (1)
1. an insulator leakage current sensor, it is characterized in that: comprise current transformer T1, operational amplifier U1, resistance R1-R4 and electric capacity C1-C3, described current transformer comprises former limit L1, the first secondary L2 and the second secondary L3, and former limit L1 is the signal input part of current sensor; The in-phase input end of the one termination operational amplifier U1 of described first secondary L2, the inverting input of described operational amplifier U1 is divided into three tunnels, the first via is connected with the other end of the first secondary L2, and the second tunnel is through resistance R3 ground connection, and the 3rd tunnel is connected with the output terminal of operational amplifier U1 through resistance R4; The cathode voltage input end of operational amplifier U1 is through electric capacity C1 ground connection, and the cathode voltage input end of operational amplifier U1 is divided into two-way, and a road is connected with Vcc, and the other end is through electric capacity C2 ground connection; The output terminal ground connection after capacitance C3, the second secondary L3, variable resistor R1 and resistance R2 successively of operational amplifier U1, the node of described second secondary L3 and variable resistor R1 is the signal output part of current sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420543303.3U CN204203329U (en) | 2014-09-22 | 2014-09-22 | Insulator leakage current sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420543303.3U CN204203329U (en) | 2014-09-22 | 2014-09-22 | Insulator leakage current sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204203329U true CN204203329U (en) | 2015-03-11 |
Family
ID=52661274
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420543303.3U Active CN204203329U (en) | 2014-09-22 | 2014-09-22 | Insulator leakage current sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204203329U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105606963A (en) * | 2015-11-23 | 2016-05-25 | 国网上海市电力公司 | Test circuit for measuring high-frequency leakage current of cable |
-
2014
- 2014-09-22 CN CN201420543303.3U patent/CN204203329U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105606963A (en) * | 2015-11-23 | 2016-05-25 | 国网上海市电力公司 | Test circuit for measuring high-frequency leakage current of cable |
| CN105606963B (en) * | 2015-11-23 | 2019-04-09 | 国网上海市电力公司 | A kind of test circuit leaking high-frequency current for measuring cable |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106771477B (en) | Large-caliber high-sensitivity high-voltage direct current cable leakage current detection sensor | |
| CN204439709U (en) | A kind of information collecting device of electricity load management terminal | |
| CN204214962U (en) | A kind of charger common-mode noise test circuit and proving installation | |
| CN204535644U (en) | Based on the displacement measurement system of differential transformer transducer | |
| CN106291092B (en) | Constant charge soil interference monitoring and electricity method is remedied outside a kind of intelligent electric meter | |
| CN106405209B (en) | Accumulator voltage detection device | |
| CN101806640B (en) | Measurement system of thermal resistance signal | |
| CN203133146U (en) | Transformer neutral point current measuring device | |
| CN104965462A (en) | Sensing detection system | |
| CN203551641U (en) | Broadband voltage collector | |
| CN103116145B (en) | Experimental method of using digital storage oscilloscope to observe alternating current magnetic hysteresis loop | |
| CN203838218U (en) | Electronic current transformer | |
| CN204203329U (en) | Insulator leakage current sensor | |
| CN202171442U (en) | Intelligent gap measuring sensor | |
| CN203838223U (en) | Hall current transformer | |
| CN105181119A (en) | Ultra-low frequency implementation method of magneto-electric intelligent digital vibration velocity sensor | |
| CN105223533A (en) | A kind of superhigh precision responds DC current prover circuit fast | |
| CN104655236A (en) | Liquid level measuring system | |
| CN110412334A (en) | A kind of digital Zero flux leakage current sensor | |
| CN203164811U (en) | Offset voltage compensating circuit of comparator | |
| CN204389668U (en) | A kind of ground voltage influence amount simulator | |
| CN205103294U (en) | Use device that hall sensor detected special high voltage direct current arrester state as framework | |
| CN103823116A (en) | Self-checking type precision battery internal resistance instrument | |
| CN203929849U (en) | Current detection circuit in a kind of electronic type voltage transformer | |
| CN202916326U (en) | Electronic current transformer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |