CN204116431U - A kind of fast-response core-theaded type DC leakage flow sensor - Google Patents
A kind of fast-response core-theaded type DC leakage flow sensor Download PDFInfo
- Publication number
- CN204116431U CN204116431U CN201420505529.4U CN201420505529U CN204116431U CN 204116431 U CN204116431 U CN 204116431U CN 201420505529 U CN201420505529 U CN 201420505529U CN 204116431 U CN204116431 U CN 204116431U
- Authority
- CN
- China
- Prior art keywords
- coil
- circuit
- magnet ring
- excitation oscillator
- fast
- 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
Abstract
The utility model belongs to leakage current test product scope, particularly relates to a kind of fast-response core-theaded type DC leakage flow sensor, comprises AC excitation oscillator coil (W1), equilibrium feedback coil (W2), magnet ring and signal processing module; Tested current lead passes through from magnet ring perforation; Described equilibrium feedback coil (W2) and AC excitation oscillator coil (W1) layering are wound on magnet ring; Internal layer is equilibrium feedback coil (W2); Skin is AC excitation oscillator coil (W1); Described equilibrium feedback coil (W2) connects with the signal transmission port of signal processing module respectively with the signal transmission port of AC excitation oscillator coil (W1); Signal processing module comprises excitatory oscillatory circuit, filtering circuit, amplifying circuit, balance drive circuit and voltage-stabilized power supply circuit.The utility model has nonlinearity erron and temperature drift is little, and antijamming capability is strong, the features such as accuracy of detection is high, good reliability.
Description
Technical field
The utility model belongs to leakage current test product scope, particularly relates to a kind of fast-response core-theaded type DC leakage flow sensor of the leakage current situation in vehicle, DC equipment or device being carried out to detect fast.
Background technology
Using the enterprise of DC power-supply system, as industries such as electric power, telecommunications, railway, metallurgy, the safe operation of straight-flow system requires very strict.If ground connection while that equipment or device not being equipotential 2, can cause the misoperation of equipment and device, cause security incident.Real-Time Monitoring straight-flow system leakage current situation over the ground, especially to the monitoring of the small leakage current over the ground of equipment in straight-flow system, for the generation avoiding accident, just seems and is even more important.Therefore, DC system earth fault hidden danger being eliminated in advance, avoid because of 2 simultaneously harm of bringing of ground connection, and how to get rid of DC system earth fault timely and accurately, is urgent problem for a long time.Particularly along with the development of direct current equipment and a large amount of employings of DC power-supply system, the detection demand of DC leakage current is got more and more especially.
Utility model content
The utility model be intended to overcome the deficiencies in the prior art part and provide a kind of nonlinearity erron and temperature drift little, antijamming capability is strong, and accuracy of detection is high, the fast-response core-theaded type DC leakage flow sensor of good reliability.The utility model fast-response DC leakage flow sensor system adopts magnetic modulation isolation technology to carry out the design of product as the core technology that small area analysis is sampled.
For solving the problems of the technologies described above, the utility model realizes like this.
Fast-response core-theaded type DC leakage flow sensor, it comprises AC excitation oscillator coil W1, equilibrium feedback coil W2, magnet ring and signal processing module; Tested current lead passes through from magnet ring perforation; Described equilibrium feedback coil W2 and AC excitation oscillator coil W1 layering are wound on magnet ring; Internal layer is equilibrium feedback coil W2; Skin is AC excitation oscillator coil W1; Described equilibrium feedback coil W2 connects with the signal transmission port of signal processing module respectively with the signal transmission port of AC excitation oscillator coil W1.
As a kind of preferred version, signal processing module described in the utility model comprises excitatory oscillatory circuit, filtering circuit, amplifying circuit, balance drive circuit and voltage-stabilized power supply circuit; Described excitatory oscillatory circuit produces PWM square wave, and realizes the conversion of pulse signal to DC voltage through filtering circuit; Pending direct current signal delivers to balance drive circuit, with driven equilibrium tickler W2 again after amplifying process.
Further, magnet ring described in the utility model can adopt the loop configuration that high permeability materials are made.
Further, AC excitation oscillator coil W1 described in the utility model and equilibrium feedback coil W2 can adopt high-temperature resistant enamelled wire.
The utility model be for direct current equipment and system in leakage current detection need and design a kind of core-theaded type small electric current sensor product.The Technical Design that this product adopts magnetic modulation principle and magnetic balance principle to combine, the combination property of sensor is greatly improved.Particularly the nonlinearity erron of sensor and temperature drift very little, antijamming capability is comparatively strong, good operating stability, by the selection of rational structural design and device parameters, the response time of sensor is greatly improved, to the real-time measurement of system and protection effect remarkable.
This sensor is mainly used in detecting the DC leakage-current of equipment; be widely used in the industry device such as direct current transportation, electric power storage detection, direct current cabinet, direct supply, larger medical sanitary outfit, photovoltaic, wind-power electricity generation, communication base station; the drain conditions of equipment is fed back; by relevant leakage protection system, equipment is protected; to avoid the generation of accident, guarantee device security and personal safety.In DC equipment and system, use standard according to national associated safety, have certain hard requirement for security protection aspect, DC leakage flow sensor guarantees an indispensable Important Components of equipment safety operation.
The technology of sensor realizes.
(1) adopt low drifting, high stability operational amplifier composition magnetic modulation oscillator circuit, peripheral auxiliary resistance selects temperature drift to be better than the product of 10PPM; Reduce the inductance value of oscillator coil, ensure that the PWM waveform frequency of oscillatory circuit generation is at more than 200Hz, improves the response time of sensor.
(2) electric capacity in active filter circuit adopts the electric capacity of Low Drift Temperature coefficient, ensure that the filter effect of sensor in whole warm area, namely ensure that the ripple control of sensor is in certain level.
(3) adopt high speed, low drifting computing discharger in amplifying circuit and balance feedback circuit, ensure that balance coil currents can offset tested electric current in time.
(4) shielding case adopting the effective siliconized plate of armoured magnetic field to make carries out bulk shielding to test coil and balancing coil, ensures the interference free performance of sensor.
(5) adopt high-temperature-resistant shielding wire as sensor extension line, sensor epoxy resin carries out overall embedding, improves the reliability of product.
Accompanying drawing explanation
Below in conjunction with the drawings and specific embodiments, the utility model is described in further detail.Protection domain of the present utility model is not only confined to the statement of following content.
Fig. 1 is fundamental diagram of the present utility model.
Fig. 2 is circuit diagram of the present utility model.
Embodiment
In order to the temperature characterisitic of response time and output signal of improving product, what the utility model adopted is the technical scheme that magnetic modulation principle and magnetic balance principle combine, and adopts closed iron core, two coil configuration.Sensor is on the Material selec-tion and treatment process of magnetic circuit; in the structural design of sensor; the parameter designing of excitatory oscillator coil and balancing coil takes new techniques and methods; overcome conventional products small current measurement value unstable, response speed does not reach the defect that equipment protection requires.
The utility model, by choosing the design of device parameters of suitable magnetic circuit material, the design of suitable coil inductance and filtering circuit, achieves the high precision to DC leakage current, fast isolation detection.Sensor can the leakage current condition of real-time monitoring system in equipment runs; the drain conditions of equipment is fed back; by relevant leakage protection system, equipment is protected, to reach the generation effectively avoiding accident, guarantee the object of device security and personal safety.
In Fig. 1, W1 is AC excitation oscillator coil, and W2 is equilibrium feedback coil, and magnet ring is made up of the permalloy material of high magnetic permeability, and two groups of coil layerings are wound on magnet ring.Magnetic modulation oscillator circuit is formed by AC excitation oscillator coil W1 and operational amplifier and resistance, capacitor element.What magnetic modulation oscillator circuit produced is PWM square wave, and PWM square wave can obtain the DC voltage linear with signal dutyfactor by RC filtering circuit, thus realizes the conversion from pulse signal to DC voltage.When there being electric current to flow through in magnet ring, the change in duty cycle of PWM ripple can be caused, and then make filtered DC voltage change.D. c. voltage signal after active power filtering inputs to balance drive circuit, driven equilibrium tickler W2 after amplifying, and the electric current in equilibrium feedback coil is I
2then I
2=U
o/ R, according to the principle such as ampere-turn such as grade of magnetic balance sensor, the N when magnetic circuit balances
1i
1=N
2i
2, then: I
1=N
2i
2/ N
1,=N
2u
o/ N
1r.
I.e. sensor output voltage U
owith measured current I
1linear corresponding relation, just obtains tested current value by the output voltage of survey sensor like this.
Because sensor detects for small area analysis, the material that initial permeability is high therefore must be adopted as iron core, to guarantee that very little electric current just causes the change of magnetic flux in magnetic circuit, to improve sensitivity and the stability of sensor.
According to the response time of sensor, the minimum of the PWM waveform frequency that magnetic modulation oscillator circuit produces can be determined, only have the waveform frequency suitably improving PWM, the output of such guarantee sensor is straight line substantially, and namely the ripple of sensor remains on suitable level.PWM waveform frequency depends primarily on the inductance of magnetizing coil, when core volume is fixing, can ensure by the number of turn of adjustment AC excitation oscillator coil the value that the inductor design of coil becomes suitable.
In order to improve the anti-interference of product, outside the good iron core of coiling, added one deck shielding, shielding case selects silicon steel plate packing to form, and is the impact of shielding low frequency magnetic field order, strengthens the anti-interference of product.
What magnetic modulation oscillator circuit produced is PWM square wave.PWM square wave can obtain the DC voltage linear with signal dutyfactor by RC filtering circuit, thus realizes the conversion from pulse signal to DC voltage.
R in filtering circuit, C parameter is directly related with the cycle of PWM and the accuracy requirement of DC voltage.During design PWM ripple RC filtering circuit, according to response time requirement, time constant should be determined, and make RC time constant much larger than the PWM cycle.RC discharge and recharge time constant should be as far as possible equal.Should require to determine RC parameter according to voltage accuracy in addition.
The signal processing module of sensor comprises excitatory oscillatory circuit, filtering circuit, amplifying circuit, balance drive circuit and voltage-stabilized power supply circuit.
As shown in Figure 2, power circuit includes power regulator module U3, U4, electric capacity CA1, CA3, CA5, CA2, CA4, CA6, and the output voltage of power circuit is+9V and-9V; D1 and D2 prevents input power from connecing anti-protection diode; This power supply is the working power of operational amplifier in signal processing circuit, ensures that the amplitude of PWM ripple does not change with the conversion of working sensor power supply.
Operational amplifier U1A, excitatory oscillator coil W1, resistance R1, R2, R3, R4 form PWM oscillatory circuit, and when passing through tested electric current in magnet ring, the inductance of coil W1 changes, and the dutycycle of PWM ripple is changed.
Operational amplifier U1B, electric capacity C1, C4, C5, resistance R6, R20, R21 form RC active filter circuit, and PWM ripple becomes d. c. voltage signal after the filtering of RC filtering circuit.
Operational amplifier U2B, resistance R7, R8, R9 form amplifying circuit, suitably amplify filtered d. c. voltage signal, and electric capacity C6, C7 are to improve filter effect further.
Z1 and Z2 is two voltage stabilizing diodes, forms zero adjustment circuit by resistance R13, R14, R14B, R15, R16, R10 and potentiometer W3, is adjusted the offset output of sensor by adjustment potentiometer.
Operational amplifier U2A is balance drive circuit; it exports wherein one end of termination balancing coil W2; another termination RF1 of balancing coil, the current-limiting resistor network of RF2, RF3, RF4 resistance composition; the Full-span output of sensor is adjusted by the size adjusting network resistor; the 1 pin output terminal of resistance R12 mono-termination operational amplifier U2A; the output signal line of one termination sensor, shields.
When measuring DC leakage current, by the perforation of tested current lead through sensor, the direction of pressing sensor electrical traffic identifier through direction of current lead, otherwise sensor output is negative value.Two wires are passed the through hole of sensor by the mode that electric current is cancelled out each other, the measurement to the current differential in two current lead can also be realized.
When curent change in tested current lead, magnetic field in magnetic circuit can change, and then causing the inductance of W1 coil to change, the inductance of change can cause the dutycycle of the PWM ripple of oscillatory circuit PWM ripple to change, and then makes filtered DC voltage change.D. c. voltage signal after active power filtering inputs to balance drive drives equilibrium feedback coil W2 after amplifying, electric current in equilibrium feedback coil produces reversed magnetic field, the magnetic field produced with tested electric current is offset, reach new functioning equalization, just obtained the size of tested current value like this by the output voltage of survey sensor.
Be understandably, above about specific descriptions of the present utility model, the technical scheme described by the utility model embodiment is only not limited to for illustration of the utility model, those of ordinary skill in the art is to be understood that, still can modify to the utility model or equivalent replacement, to reach identical technique effect; Needs are used, all within protection domain of the present utility model as long as meet.
Claims (4)
1. a fast-response core-theaded type DC leakage flow sensor, is characterized in that: comprise AC excitation oscillator coil (W1), equilibrium feedback coil (W2), magnet ring and signal processing module; Tested current lead passes through from magnet ring perforation; Described equilibrium feedback coil (W2) and AC excitation oscillator coil (W1) layering are wound on magnet ring; Internal layer is equilibrium feedback coil (W2); Skin is AC excitation oscillator coil (W1); Described equilibrium feedback coil (W2) connects with the signal transmission port of signal processing module respectively with the signal transmission port of AC excitation oscillator coil (W1).
2. a kind of fast-response core-theaded type DC leakage flow sensor according to claim 1, is characterized in that: described signal processing module comprises excitatory oscillatory circuit, filtering circuit, amplifying circuit, balance drive circuit and voltage-stabilized power supply circuit; Described excitatory oscillatory circuit produces PWM square wave, and realizes the conversion of pulse signal to DC voltage through filtering circuit; Pending direct current signal delivers to balance drive circuit, with driven equilibrium tickler (W2) again after amplifying process.
3. a kind of fast-response core-theaded type DC leakage flow sensor according to claim 2, is characterized in that: the loop configuration that described magnet ring adopts high permeability materials to make.
4. a kind of fast-response core-theaded type DC leakage flow sensor according to claim 3, is characterized in that: described AC excitation oscillator coil (W1) and equilibrium feedback coil (W2) adopt high-temperature resistant enamelled wire.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420505529.4U CN204116431U (en) | 2014-09-02 | 2014-09-02 | A kind of fast-response core-theaded type DC leakage flow sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420505529.4U CN204116431U (en) | 2014-09-02 | 2014-09-02 | A kind of fast-response core-theaded type DC leakage flow sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204116431U true CN204116431U (en) | 2015-01-21 |
Family
ID=52333727
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420505529.4U Active CN204116431U (en) | 2014-09-02 | 2014-09-02 | A kind of fast-response core-theaded type DC leakage flow sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204116431U (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104215817A (en) * | 2014-09-02 | 2014-12-17 | 沈阳汇博自动化仪表有限公司 | Quick-response core-penetrating type direct-current leakage current sensor |
| CN105403749A (en) * | 2015-07-03 | 2016-03-16 | 宁波星成电子有限公司 | Differential leakage current sensor |
| CN106324394A (en) * | 2016-08-17 | 2017-01-11 | 成都国能龙源科技有限公司 | DC feed line system |
| CN108333412A (en) * | 2018-01-30 | 2018-07-27 | 宜昌市瑞磁科技有限公司 | A kind of current sensing means and method of the PWM output modes with fixed frequency |
| CN105823923B (en) * | 2016-03-22 | 2019-07-05 | 成都国能龙源科技有限公司 | DC feeder insulation against ground reduces and exchanges the device and method scurried into while detected |
| WO2021068832A1 (en) * | 2019-10-09 | 2021-04-15 | 青岛鼎信通讯股份有限公司 | Residual current detection method based on magnetic core working state switching |
-
2014
- 2014-09-02 CN CN201420505529.4U patent/CN204116431U/en active Active
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104215817A (en) * | 2014-09-02 | 2014-12-17 | 沈阳汇博自动化仪表有限公司 | Quick-response core-penetrating type direct-current leakage current sensor |
| CN105403749A (en) * | 2015-07-03 | 2016-03-16 | 宁波星成电子有限公司 | Differential leakage current sensor |
| CN105823923B (en) * | 2016-03-22 | 2019-07-05 | 成都国能龙源科技有限公司 | DC feeder insulation against ground reduces and exchanges the device and method scurried into while detected |
| CN106324394A (en) * | 2016-08-17 | 2017-01-11 | 成都国能龙源科技有限公司 | DC feed line system |
| CN106324394B (en) * | 2016-08-17 | 2019-09-24 | 成都国能龙源科技有限公司 | DC feeder system |
| CN108333412A (en) * | 2018-01-30 | 2018-07-27 | 宜昌市瑞磁科技有限公司 | A kind of current sensing means and method of the PWM output modes with fixed frequency |
| WO2021068832A1 (en) * | 2019-10-09 | 2021-04-15 | 青岛鼎信通讯股份有限公司 | Residual current detection method based on magnetic core working state switching |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN204116431U (en) | A kind of fast-response core-theaded type DC leakage flow sensor | |
| CN202770898U (en) | High precision fast response direct current leakage current sensor | |
| CN104215817A (en) | Quick-response core-penetrating type direct-current leakage current sensor | |
| CA3153829C (en) | Residual current detection method based on magnetic core working state switching | |
| CN104934931A (en) | Residual current protection device | |
| CN106771477B (en) | Large-caliber high-sensitivity high-voltage direct current cable leakage current detection sensor | |
| CN102096019A (en) | Method and device for locating single-phase grounding fault of low-current grounding system | |
| CN103454544B (en) | A kind of detection method based on the linear magnetism elimination circuit of electronic jumper | |
| CN202693658U (en) | Differential current detecting device | |
| CN105807196A (en) | Online monitoring system for lightening arrester for transmission cable | |
| CN202041624U (en) | Direct-current high-voltage test integrated device for internal water cooling generator | |
| CN101949979A (en) | Method for measuring resistance of ground wire of transformer | |
| CN102981061B (en) | Direct-to-ground capacitance measuring instrument in a kind of transformer station distribution system | |
| CN203811737U (en) | Direct-current electric-leakage monitoring and warning device | |
| CN107703823A (en) | One kind charging leakage current detection circuit | |
| CN204101642U (en) | A kind of Dielectric Posts device | |
| CN205643677U (en) | Hand -held type current transformer voltage -current characteristic tester | |
| CN101217232A (en) | A total current type residual current operating device with functions of automatic tripping on element failures | |
| CN202758017U (en) | Anti-islanding test load | |
| CN203883473U (en) | Double-frequency ship shore power device | |
| CN105242228A (en) | Current blanking method and device of transformer iron core grounding current online monitoring equipment | |
| CN205786972U (en) | A kind of power transmission cable arrester on-line monitoring system | |
| CN204008784U (en) | A kind of thief-proof electric leakage device of monitoring primary side AC current transformer no-load voltage ratio | |
| CN209842045U (en) | Portable secondary circuit patrol instrument based on open current transformer | |
| CN204044236U (en) | A kind of leakage current detection circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |