CN117054733A - Probe and single-probe double-range fluxgate current sensor - Google Patents
Probe and single-probe double-range fluxgate current sensor Download PDFInfo
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- CN117054733A CN117054733A CN202311053804.3A CN202311053804A CN117054733A CN 117054733 A CN117054733 A CN 117054733A CN 202311053804 A CN202311053804 A CN 202311053804A CN 117054733 A CN117054733 A CN 117054733A
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- 239000000523 sample Substances 0.000 title claims abstract description 41
- 230000006698 induction Effects 0.000 claims abstract description 13
- 230000005284 excitation Effects 0.000 claims description 29
- 238000005259 measurement Methods 0.000 claims description 11
- 238000011896 sensitive detection Methods 0.000 claims description 11
- 238000004804 winding Methods 0.000 claims description 8
- 238000006243 chemical reaction Methods 0.000 claims description 7
- 238000012360 testing method Methods 0.000 claims description 5
- 229910017052 cobalt Inorganic materials 0.000 claims description 3
- 239000010941 cobalt Substances 0.000 claims description 3
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 3
- 229910000889 permalloy Inorganic materials 0.000 claims description 3
- 230000010363 phase shift Effects 0.000 claims description 3
- 230000003321 amplification Effects 0.000 description 4
- 238000003199 nucleic acid amplification method Methods 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 230000035945 sensitivity Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000005674 electromagnetic induction Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
- G01R1/02—General constructional details
- G01R1/06—Measuring leads; Measuring probes
- G01R1/067—Measuring probes
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
- G01R1/02—General constructional details
- G01R1/06—Measuring leads; Measuring probes
- G01R1/067—Measuring probes
- G01R1/06711—Probe needles; Cantilever beams; "Bump" contacts; Replaceable probe pins
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
- G01R15/18—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
- G01R15/20—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using galvano-magnetic devices, e.g. Hall-effect devices, i.e. measuring a magnetic field via the interaction between a current and a magnetic field, e.g. magneto resistive or Hall effect devices
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
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- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
Abstract
The invention belongs to the technical field of fluxgates and discloses a probe and a single-probe double-range fluxgate current sensor. The sensor can realize the switching of the current measuring range through the microprocessor functional module, the impedance of the related circuit is matched according to the selected circuit after the switching, and the two induction coils of the selected range are subjected to differential output by using the preposed signal amplifying circuit, so that common-mode noise signals can be restrained.
Description
Technical Field
The invention belongs to the technical field of fluxgates, and particularly relates to a probe and a single-probe double-range fluxgate current sensor.
Background
Fluxgate phenomenon is a ubiquitous electromagnetic induction phenomenon that obeys faraday's law of electromagnetic induction. And applying alternating current to an exciting coil on the detection probe to enable the magnetic core to change between supersaturation and unsaturation, and changing magnetic flux in the magnetic core after the change of an environmental magnetic field, wherein the saturation of the magnetic core is advanced or retarded. According to the nonlinear relation between the saturated magnetic core and the environment magnetic field, the strength of the environment magnetic field can be reversely deduced. Based on the characteristics, the fluxgate technology has very strong superiority, and the current sensor manufactured by using the fluxgate technology also has extremely high resolution and sensitivity.
The fluxgate probe is not limited by a theoretical sensitivity threshold, and in order to improve the resolution of the fluxgate current sensor for small currents, the distance between the fluxgate sensor probe and the coil to be measured should be as close as possible. During high current detection, the distance between the fluxgate sensor probe and the coil to be detected should be relatively long again so as to attenuate the magnetic induction intensity.
Currently, fluxgate current sensors are used for detecting different range currents, and different measuring ranges are often needed, so that a lot of inconvenience exists in the practical application process.
Disclosure of Invention
The invention aims to overcome the defects, and provides a probe and a single-probe double-range fluxgate current sensor which can measure large current and small-range current as low as microampere, improve sensitivity and reduce noise.
In order to achieve the above purpose, the probe comprises two wide-range current measuring coils and two small-range current measuring coils, wherein the wide-range current measuring coils and the small-range current measuring coils comprise annular frameworks, grooves are formed in the circumferential direction of the annular frameworks, magnetic conducting magnetic cores are wound in the grooves, the number of turns of the magnetic conducting magnetic cores of the wide-range current measuring coils is 10 times that of the magnetic conducting magnetic cores of the small-range current measuring coils, exciting coils and induction coils are wound on the annular frameworks, the induction coils penetrate through the four annular frameworks, and the exciting coils can be multiplexed into feedback coils.
The inner diameter of the annular framework of the wide-range current measuring coil is 12-16 mm, and the outer diameter is 15-19 mm;
the inner diameter of the annular framework of the small-range current measuring coil is 6-10 mm, and the outer diameter is 9-13 mm;
the outer diameter of the annular frameworks of the wide-range current measuring coil and the small-range current measuring coil is 3-5 mm larger than the inner diameter.
The depth of the groove on the annular framework is one half of the outer diameter of the annular framework minus one half of the inner diameter plus one half of the thickness of the magnetic conductive core.
The magnetic core adopts permalloy strip, cobalt-based amorphous strip or nanocrystalline strip.
The number of turns of the magnetic conductive core of the wide-range current measuring coil is 10-100 turns;
the number of turns of the magnetic conductive core of the small-range current measuring coil is 1-10 turns.
The winding directions of the two excitation coils for the same measuring range are opposite, and the winding directions of the feedback coils are the same.
The single-probe double-range fluxgate current sensor comprises a probe, wherein the probe is connected with a pre-amplification circuit, the pre-amplification circuit is connected with a band-pass filter circuit, the band-pass filter circuit is connected with a phase-sensitive detection circuit, the phase-sensitive detection circuit is connected with an integration circuit, the integration circuit is connected with a power amplification circuit, the power amplification circuit is connected with a test output end and a microprocessor functional module, and the microprocessor functional module is connected with an upper computer and the probe;
the upper computer is used for sending out control information;
the microprocessor functional module is used for adjusting the amplitude of the excitation signal sent to the excitation coil according to the control information sent by the upper computer, so that the amplitude of the current signal in the excitation coil is different from that of the current signal in the feedback coil.
The microprocessor functional module comprises a range switching circuit and an analog-to-digital conversion circuit, one end of the range switching circuit is connected with the power amplifying circuit, the other end of the range switching circuit is connected with the excitation signal generating circuit which is selectively conducted, and the unselected excitation signal generating circuit is used as a feedback coil to be connected into the range switching circuit which is controlled by the upper computer;
the analog-to-digital conversion circuit is used for converting the analog quantity of the voltage signal in the feedback loop into the digital quantity and transmitting the digital quantity to the upper computer.
The pre-amplifying circuit adopts an operational amplifier and an adjustable resistor to limit the amplifying range of the voltage signal to 1-10 times.
The phase sensitive detection circuit is used for shifting the phase of the input double frequency excitation signal and taking the double frequency signal after the phase shift as a switch to control the on and off of the second harmonic sinusoidal signal.
Compared with the prior art, the invention forms the probe by the two wide-range current measuring coils and the two small-range current measuring coils, can realize that one fluxgate current sensor measures alternating current and direct current in two range ranges, the small-range current measuring range is +/-10 mA, the resolution can reach 1 mu A level, the wide-range current measuring range is +/-10A, and the resolution can reach 1mA level.
Furthermore, the excitation coils and the induction coils are wound on the annular frameworks, the induction coils penetrate through the four annular frameworks, the excitation coils can be multiplexed into the feedback coils, the winding directions of the two excitation coils for the same range measurement are opposite, and the winding directions of the feedback coils are the same.
The sensor can realize the switching of the current measuring range through the microprocessor functional module, the impedance of the related circuit is matched according to the selected circuit after the switching, and the two induction coils of the selected range are subjected to differential output by using the preposed signal amplifying circuit, so that the common mode noise signal can be further restrained. The resolution of the fluxgate current sensor can reach 1 mu A level, the measuring range of a small current measuring range is +/-10 mA, the measuring range of a large current measuring range is +/-10A, the bandwidth of the small current measuring range can reach 1kHz, the bandwidth of the large current measuring range can reach 10kHz, and the linearity and the accuracy are all 0.1%.
Drawings
FIG. 1 is a simulated view of a fluxgate current sensor probe of the present invention;
FIG. 2 is a block diagram of a fluxgate current sensor system of the present invention;
FIG. 3 is a functional block diagram of a microprocessor according to the present invention;
1, a wide-range current measuring coil; 2. a small-range current measuring coil; 3. a pre-amplifier circuit; 4. a phase sensitive detection circuit; 6. an integrating circuit; 7. a power amplifying circuit; 8. testing an output end; 9. a microprocessor functional module; 11. a range switching circuit; 12. an analog-to-digital conversion circuit; 13. and a magnetic core.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
Referring to fig. 1, a probe comprises two wide-range current measuring coils 1 and two small-range current measuring coils 2, wherein the wide-range current measuring coils 1 and the small-range current measuring coils 2 comprise annular frameworks, grooves are formed in the circumferential direction of the annular frameworks, magnetic conductive magnetic cores 13 are wound in the grooves, the number of turns of the magnetic conductive magnetic cores 13 of the wide-range current measuring coils 1 is 10 times that of the magnetic conductive magnetic cores 13 of the small-range current measuring coils 2, exciting coils and induction coils are wound on the annular frameworks at equal intervals, the induction coils penetrate through the four annular frameworks, the exciting coils can be multiplexed into feedback coils, the winding directions of the two exciting coils for measuring the same range are opposite, and the winding directions of the feedback coils are the same.
Preferably, the annular skeleton of the wide-range current measuring coil 1 has an inner diameter of 12-16 mm and an outer diameter of 15-19 mm.
Preferably, the annular skeleton of the small-range current measuring coil 2 has an inner diameter of 6-10 mm and an outer diameter of 9-13 mm.
Preferably, the outer diameter of the annular frameworks of the wide-range current measurement coil 1 and the small-range current measurement coil 2 is 3-5 mm larger than the inner diameter.
Preferably, the depth of the groove on the annular skeleton is one half of the outer diameter of the annular skeleton minus one half of the inner diameter plus one half of the thickness of the magnetically permeable core.
Preferably, the magnetically conductive core 13 is a permalloy strip, a cobalt-based amorphous strip, or a nanocrystalline strip.
Preferably, the number of turns of the magnetic conductive core 13 of the wide-range current measuring coil 1 is 10-100.
Preferably, the number of turns of the magnetic conductive core 13 of the small-range current measuring coil 2 is 1-10.
Referring to fig. 2, a single-probe dual-range fluxgate current sensor comprises a probe, wherein the probe is connected with a pre-amplifying circuit 3, the pre-amplifying circuit 3 is connected with a band-pass filter circuit 4, the band-pass filter circuit 4 is connected with a phase-sensitive detection circuit 5, the phase-sensitive detection circuit 5 is connected with an integrating circuit 6, the integrating circuit 6 is connected with a power amplifying circuit 7, the power amplifying circuit 7 is connected with a test output end 8 and a microprocessor functional module 9, and the microprocessor functional module 9 is connected with an upper computer and the probe. The test output 8 can be conveniently debugged and the oscillograph is used for displaying the waveform.
The upper computer is used for sending out control information; the microprocessor functional module 9 is used for adjusting the amplitude of the excitation signal sent to the excitation coil according to the control information sent by the upper computer, so that the amplitude of the current signal in the excitation coil is different from that in the feedback coil. The microprocessor functional module 9 can generate various excitation signals, such as square wave signals, sine wave signals and triangular wave signals, and the frequency amplitude can be adjusted.
After excitation current is introduced into the excitation coil, the high-permeability magnetic core 13 can change between supersaturation and unsaturated, and at the moment, the induction coil generates an induction voltage signal; the amplitude of the directly output induced voltage signal is smaller, the induced voltage signal is firstly subjected to gain through a pre-amplifying circuit 3, then noise and interference are filtered through a band-pass filter circuit 4, and second harmonic is extracted; the magnitude of even harmonic in the induced voltage signal can reflect the magnitude of the magnetic field in the high-permeability magnetic core 13, indirectly reflect the magnitude of current, and adopt the second harmonic with the largest amplitude in the even harmonic for measurement; the induced voltage signal is subjected to phase shifting and detection processing by the phase sensitive detection circuit 5, a full-wave signal is output, and the positive and negative of the current can be judged; the signal is filtered into a direct current signal by the integrating circuit 6 and is output to the power amplifying circuit 7 for feedback driving.
Referring to fig. 3, the microprocessor functional module 9 includes a range switching circuit 11 and an analog-to-digital conversion circuit 12, one end of the range switching circuit 11 is connected with a power amplifying circuit, the other end is connected with a first excitation signal generating circuit, a second excitation signal generating circuit and a feedback loop, and the range switching circuit 11 is controlled by an upper computer; the excitation signal waveforms and frequencies of the first excitation signal generating circuit and the second excitation signal generating circuit are the same, and the amplitudes are different.
The analog-to-digital conversion circuit 12 is configured to convert the analog quantity of the voltage signal in the feedback loop into a digital quantity and transmit the digital quantity to the host computer, convert the voltage signal into a digital signal, and sample the digital signal and transmit the digital signal to the host computer, where the sampling frequency is above 200 kS/s.
Preferably, the pre-amplifying circuit 3 uses an operational amplifier and an adjustable resistor to limit the amplifying range of the voltage signal to 1-10 times.
Preferably, the phase sensitive detection circuit 5 is used for shifting the phase of the input frequency doubling excitation signal, and uses the frequency doubling signal after the phase shift as a switch to control the on and off of the second harmonic sinusoidal signal.
Specific embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the embodiments. Any modification, equivalent replacement, improvement and the like made on the basis of the present invention are all within the protection scope of the present invention.
Claims (10)
1. The utility model provides a probe, a serial communication port, including two wide-range current measurement coils (1) and two little range current measurement coils (2), wide-range current measurement coils (1) and little range current measurement coils (2) all include annular skeleton, annular skeleton circumference sets up the recess, the winding has magnetic conduction magnetic core (13) in the recess, the number of turns of magnetic conduction magnetic core of wide-range current measurement coils (1) is 10 times of the number of turns of magnetic conduction magnetic core of little range current measurement coils (2), the winding has exciting coil and induction coil on the annular skeleton, induction coil passes four annular skeletons, exciting coil can multiplexing to feedback coil.
2. A probe according to claim 1, characterized in that the annular skeleton of the wide-range current measuring coil (1) has an inner diameter of 12-16 mm and an outer diameter of 15-19 mm;
the inner diameter of the annular framework of the small-range current measuring coil (2) is 6-10 mm, and the outer diameter is 9-13 mm;
the outer diameter of the annular frameworks of the wide-range current measuring coil (1) and the small-range current measuring coil (2) is 3-5 mm larger than the inner diameter.
3. A probe according to claim 1 wherein the depth of the groove in the annular former is one half of the outer diameter of the annular former minus one half of the inner diameter plus one half of the thickness of the magnetically permeable core.
4. A probe according to claim 1, wherein the magnetically permeable core is a permalloy strip, cobalt-based amorphous strip or nanocrystalline strip.
5. A probe according to claim 1, characterized in that the number of turns of the magnetically permeable core of the wide range current measuring coil (1) is 10-100 turns;
the number of turns of the magnetic conductive core of the small-range current measuring coil (2) is 1-10 turns.
6. A probe according to claim 1, wherein the two excitation coils for the same range measurement are wound in opposite directions and the feedback coils are wound in the same direction.
7. A single-probe double-range fluxgate current sensor adopting the probe according to claim 1, which is characterized by comprising the probe, wherein the probe is connected with a pre-amplifying circuit (3), the pre-amplifying circuit (3) is connected with a band-pass filter circuit (4), the band-pass filter circuit (4) is connected with a phase-sensitive detection circuit (5), the phase-sensitive detection circuit (5) is connected with an integrating circuit (6), the integrating circuit (6) is connected with a power amplifying circuit (7), the power amplifying circuit (7) is connected with a test output end (8) and a microprocessor functional module (9), and the microprocessor functional module (9) is connected with an upper computer and the probe;
the upper computer is used for sending out control information;
the microprocessor functional module (9) is used for adjusting the amplitude of the excitation signal sent to the excitation coil according to the control information sent by the upper computer, so that the amplitude of the current signal in the excitation coil is different from that of the current signal in the feedback coil.
8. The single-probe double-range fluxgate current sensor according to claim 7, characterized in that the microprocessor functional module (9) comprises a range switching circuit (11) and an analog-to-digital conversion circuit (12), one end of the range switching circuit (11) is connected with a power amplifying circuit, the other end is connected with an excitation signal generating circuit which is selectively conducted, an unselected excitation coil is used as a feedback coil and connected with the range switching circuit (11), and the range switching circuit (11) is controlled by an upper computer;
and the analog-to-digital conversion circuit (12) is used for converting the analog quantity of the voltage signal in the feedback loop into the digital quantity and transmitting the digital quantity to the upper computer.
9. The single-probe dual-range fluxgate current sensor according to claim 7, wherein the pre-amplifying circuit (3) uses an operational amplifier and an adjustable resistor to limit the voltage signal amplifying range to 1-10 times.
10. The single-probe double-range fluxgate current sensor according to claim 7, wherein the phase sensitive detection circuit (5) is used for shifting the phase of the input double-frequency excitation signal, and the double-frequency signal after the phase shift is used as a switch to control the on and off of the second harmonic sinusoidal signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311053804.3A CN117054733A (en) | 2023-08-21 | 2023-08-21 | Probe and single-probe double-range fluxgate current sensor |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311053804.3A CN117054733A (en) | 2023-08-21 | 2023-08-21 | Probe and single-probe double-range fluxgate current sensor |
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| Publication Number | Publication Date |
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| CN117054733A true CN117054733A (en) | 2023-11-14 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202311053804.3A Pending CN117054733A (en) | 2023-08-21 | 2023-08-21 | Probe and single-probe double-range fluxgate current sensor |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117572051A (en) * | 2023-12-05 | 2024-02-20 | 上海深启半导体科技有限公司 | Current detection method with detection accuracy and reliability |
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2023
- 2023-08-21 CN CN202311053804.3A patent/CN117054733A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117572051A (en) * | 2023-12-05 | 2024-02-20 | 上海深启半导体科技有限公司 | Current detection method with detection accuracy and reliability |
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