CN111721993A - High-sensitivity miniaturized current detection system - Google Patents
High-sensitivity miniaturized current detection system Download PDFInfo
- Publication number
- CN111721993A CN111721993A CN202010564943.2A CN202010564943A CN111721993A CN 111721993 A CN111721993 A CN 111721993A CN 202010564943 A CN202010564943 A CN 202010564943A CN 111721993 A CN111721993 A CN 111721993A
- Authority
- CN
- China
- Prior art keywords
- magneto
- optical fiber
- current
- input
- light
- 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.)
- Pending
Links
Images
Classifications
-
- 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
- G01R19/0046—Arrangements for measuring currents or voltages or for indicating presence or sign thereof characterised by a specific application or detail not covered by any other subgroup of G01R19/00
-
- 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
- G01R15/24—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using light-modulating devices
- G01R15/245—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using light-modulating devices using magneto-optical modulators, e.g. based on the Faraday or Cotton-Mouton effect
- G01R15/246—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using light-modulating devices using magneto-optical modulators, e.g. based on the Faraday or Cotton-Mouton effect based on the Faraday, i.e. linear magneto-optic, effect
-
- 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
- G01R19/0092—Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring current only
Abstract
The invention relates to the technical field of current detection in a high-voltage transmission line, and provides a high-sensitivity miniaturized current detection system, which comprises: the optical fiber current sensor comprises an input optical fiber, an input lens, an input polaroid, a magneto-optical material wrapped by a gold film, an output polaroid, an output lens and an output optical fiber; when the current on the high-voltage transmission wire to be measured is measured, the light source emits unpolarized light, the unpolarized light is input into the optical fiber current sensor and is transmitted to the detector through an optical fiber, the magnetic field intensity B is obtained through the Faraday magneto-optical effect and the Malus theorem, and the current intensity I of the wire to be measured is obtained through calculation according to the Biao-Saval theorem and the magnetic field intensity B. The problems that the current detection method in the prior art is large in size, heavy in weight and easy to be interfered by exciting current, and the current detection methods in the prior art are low in detection sensitivity are solved.
Description
Technical Field
The invention relates to the technical field of current detection in a high-voltage transmission line, in particular to a high-sensitivity miniaturized current detection system which is used for rapidly detecting current in a wire by using an optical fiber sensing technology and is suitable for real-time detection of the current of the high-voltage transmission line.
Background
The current detection methods commonly used in the prior art include the following methods:
a flow divider: the principle of the current divider is simple, and the current divider is usually used in low-frequency small-amplitude current measurement, but can generate larger error when being applied to high-frequency large-amplitude current measurement.
An alternating current transformer: the sensing principle of the alternating current transformer is simple, and the precision is high. However, the alternating current transformer is only suitable for measuring alternating current within thousands of amperes, and the measured current is too large, so that the excitation current of the transformer is not ignored any more, and the measurement error is increased.
The direct current transformer utilizes the change of the detected direct current to cause the iron core coil to generate inductive reactance, thereby indirectly changing the current of the auxiliary alternating current circuit to reflect the size of the detected current. The disadvantages are large volume, high price, need of support of external power supply, etc.
The Hall current sensor is a commonly used current measuring device, adopts a Hall element as a sensing unit, realizes the measurement of current through the size of a magnetic field generated by the measured current, is applied to the measurement of large flow, but has the defects of large volume and heavy weight.
In summary, the current detection methods in the prior art have the disadvantages of large size, heavy weight and susceptibility to interference of exciting current, and the current detection methods in the prior art all have the condition of low detection sensitivity.
Disclosure of Invention
In view of the above problems, an object of the present invention is to provide a highly sensitive miniaturized current detection system, which utilizes the characteristic that an optical fiber or a waveguide itself can eliminate the influence of an exciting current, adopts a magneto-optical medium wrapped by a gold film and having an input polarizer and an output polarizer, and eliminates external electromagnetic interference by utilizing the inherent characteristics of the magneto-optical medium including a faraday optical fiber or a faraday waveguide, thereby achieving the purposes of reducing cost and volume.
The above object of the present invention is achieved by the following technical solutions:
a highly sensitive miniaturized current detection system comprising: the optical fiber current sensor comprises an input optical fiber, an input lens, an input polaroid, a magneto-optical material wrapped by a gold film, an output polaroid, an output lens and an output optical fiber, wherein the magneto-optical material wrapped by the gold film is in any one form including a Faraday optical fiber and a Faraday waveguide wrapped by the gold film;
the light source is connected with the optical fiber current sensor, and the optical fiber current sensor is connected with the detector;
when the current on the high-voltage transmission wire to be measured is measured, the light source emits unpolarized light, the unpolarized light is input into the optical fiber current sensor and is transmitted to the detector through an optical fiber, the magnetic field intensity B is obtained through the Faraday magneto-optical effect and the Malus theorem, and the current intensity I of the wire to be measured is obtained through calculation according to the Biot-Saval theorem and the magnetic field intensity B;
wherein the optical fiber current sensor receives the unpolarized light emitted from the light source and guides the unpolarized light as incident light through the input optical fiberThe magneto-sensitive area is focused by the input lens, then is changed into linearly polarized light through the input polaroid, and is incident into the magneto-optical material wrapped by the gold film, and the polarization plane of the incident light is deflected; after passing through the output polarizer, the incident light passing through the magneto-optical material wrapped in a gold film is focused by the output lens into the output optical fiber; after the incident light passes through the magneto-optical material wrapped by the gold film, the light intensity of the incident light is determined by input intensity I0Becomes output light intensity I1。
Further, the fiber optic current sensor further comprises: and the glass tube is used for wrapping a structure comprising an input lens, an input polaroid, a magneto-optical material wrapped by a gold film, an output polaroid and an output lens in the optical fiber current sensor.
Further, the magnetic field strength B is calculated through the faraday magneto-optical effect and the malus theorem, and the current strength I of the wire to be tested is calculated according to the bioto-savart theorem and the magnetic field strength B, specifically:
according to the Faraday magneto-optical effect, when unpolarized light enters the optical fiber current sensor, the unpolarized light is converted into linearly polarized light through the input polarizing plate, when the linearly polarized light is transmitted in the magneto-optical material wrapped by the gold film, a magnetic field is applied to the power transmission line in the direction parallel to the transmission direction of the light, the polarization plane of the light is deflected, and the deflection angle theta is changedFProportional to the product of the magnetic induction B and the length d of light passing through the magneto-optical material wrapped in the gold film:
θF＝VBd (1)
wherein, the proportionality coefficient V is called as Welch constant and is related to the property of the medium and the frequency of the light wave;
deflection angle thetaFAccording to the input light intensity I0And the intensity I of the magnetic field generated by the magneto-optical material wrapped by the gold film1The comparison shows that according to the Malus theorem:
I1＝I0·sin2θF(2)
according to the biot-savart theorem, for an infinitely long straight wire, at a vertical distance r from the wire, the magnetic field strength perpendicular to the wire is as follows:
wherein, mu0Permeability in vacuum, 4 π × 10-7H/m; r is the distance between the measured point and the axis of the lead to be measured, and the unit is m; i is the magnitude of the measured current, in units A.
Theta is obtained by calculation through formula (2)FAnd substituting the magnetic field B into a formula (1) to obtain the magnetic field B, and calculating the current intensity I through a formula (3).
Further, the input polarizer and the output polarizer are perpendicular to each other.
Further, the magneto-optical material wrapped by the gold film is the faraday waveguide or the faraday waveguide wrapped by the gold film with an ultra-short length.
Further, the detector further comprises: a pre-amplification circuit and active band-pass filtering;
the preamplification circuit converts the optical signal into an electric signal and performs operational amplification;
and the active band-pass filtering filters noise in the electric signal to obtain the electric signal containing magnetic field intensity information.
Further, still include: the distance r between the measured point and the axis of the lead to be measured is a constant input in advance.
Further, the magneto-optical material wrapped by the gold film is a magneto-optical medium with an ultrahigh Verdet constant, and specifically can be a terbium-doped Faraday dielectric waveguide or an optical fiber with the surface covered by an Au film.
Compared with the prior art, the invention has the beneficial effects that:
(1) by establishing a highly sensitive miniaturized current detection system comprising: the optical fiber current sensor comprises an input optical fiber, an input lens, an input polaroid, a magneto-optical material wrapped by a gold film, an output polaroid, an output lens and an output optical fiber, wherein the magneto-optical material wrapped by the gold film is in any one form including a Faraday optical fiber and a Faraday waveguide wrapped by the gold film; the light source is connected with the optical fiber current sensor, and the optical fiber current sensor is connected with the detector; when the current on the high-voltage transmission wire to be measured is measured, the light source emits unpolarized light, the unpolarized light is input into the optical fiber current sensor and is transmitted to the detector through an optical fiber, the magnetic field intensity B is obtained through the Faraday magneto-optical effect and the Malus theorem, and the current intensity I of the wire to be measured is obtained through calculation according to the Biao-Saval theorem and the magnetic field intensity B. The technical scheme utilizes the characteristic that the optical fiber or the waveguide can eliminate the influence of exciting current, adopts the magneto-optical material which is wrapped by the gold film and comprises the Faraday optical fiber and the Faraday waveguide which are wrapped by the gold film, and utilizes the inherent characteristics of the optical fiber or the waveguide to eliminate external electromagnetic interference, thereby achieving the purposes of reducing cost and reducing volume.
(2) The gold film is wrapped on the magneto-optical material comprising the Faraday optical fiber and the Faraday waveguide, the wrapped magneto-optical material has an ultrahigh Verdet constant, a larger magnetic field deflection angle is generated under the same current, and the magnetic field deflection angle measuring device has ultrahigh sensitivity when measuring the current of the power transmission conductor, and is particularly suitable for measuring the power transmission conductor with relatively weak current intensity.
(3) According to the invention, by adopting the scheme that the input polaroid is perpendicular to the output polaroid, the sensitivity of the optical fiber current sensor is higher during measurement, and the optical fiber current sensor is more sensitive to a magnetic field.
(4) According to the invention, the current sensor can be integrated into an ultra-small sensor by adopting the Faraday optical fiber and the Faraday waveguide which are preferably wrapped by the ultra-short-length gold film, and the current sensor is hung on the wire, so that the pressure on the optical fiber is small, and the influence is less.
Drawings
FIG. 1 is an overall block diagram of a miniaturized current sensor according to the present invention;
FIG. 2 is a schematic structural view of a Faraday waveguide wrapped with an Au thin film according to the present invention;
FIG. 3 is a schematic diagram of the structure of a Faraday waveguide of the present invention;
FIG. 4 is a diagram illustrating the magneto-optical effect of the present invention;
FIG. 5 is a schematic view of magnetic induction at a distance r from a wire to be measured according to the present invention;
FIG. 6 shows the magnetic field strength B and deflection angle θ when Faraday waveguide has no gold filmFSchematic diagram of the relationship between;
FIG. 7 shows the current I and deflection angle θ when Faraday waveguide has no gold filmFSchematic diagram of the relationship between;
FIG. 8 shows the magnetic field intensity B and deflection angle θ of a Faraday waveguide with a gold thin filmFSchematic diagram of the relationship between;
FIG. 9 shows the current I and deflection angle θ when the Faraday waveguide has a gold thin filmFSchematic diagram of the relationship between them.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments that can be derived by a person skilled in the art from the embodiments given herein without making any inventive work are intended to be within the scope of the present disclosure.
As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Example one
As shown in fig. 1 and fig. 2, the present embodiment provides a highly sensitive miniaturized current detection system, including: the optical fiber current sensor comprises an input optical fiber, an input lens, an input polaroid, a magneto-optical material wrapped by a gold film, an output polaroid, an output lens and an output optical fiber, wherein the magneto-optical material wrapped by the gold film is in any one form including a Faraday optical fiber and a Faraday waveguide wrapped by the gold film; .
The greatest advantage of the invention is that, on the basis of the optical fiber sensor shown in fig. 3, a gold film is wrapped on the magneto-optical material including the faraday optical fiber and the faraday waveguide, so that the wrapped magneto-optical material has an ultrahigh verdet constant, a larger magnetic field deflection angle is generated under the same current, and the measuring method has ultrahigh sensitivity when measuring the current of the power transmission conductor, and is particularly suitable for measuring the power transmission conductor with relatively weak current intensity.
The magneto-optical material wrapped by the gold film of the present invention includes any one of a faraday fiber and a faraday waveguide, or other materials that can be substituted, and the present invention is not limited in any way.
The light source is connected with the optical fiber current sensor, and the optical fiber current sensor is connected with the detector;
according to the high-sensitivity miniaturized current detection system, when the current on the wire to be detected is measured, the light source emits unpolarized light, the unpolarized light is input into the optical fiber current sensor and is transmitted to the detector through the optical fiber, the detector converts an optical signal into an electric signal, the magnetic field intensity B is obtained through Faraday magneto-optical effect and Malus theorem calculation, and the current intensity I of the wire to be detected is obtained through calculation according to the Biao-Saval theorem and the magnetic field intensity B.
Wherein, after receiving the unpolarized light emitted by the light source, the optical fiber current sensor guides the unpolarized light as incident light into the magneto-sensitive area through the input optical fiber, the incident light is focused by the input lens and then becomes linearly polarized light through the input polarizer, and the linearly polarized light is incident into the magneto-optical material wrapped by the gold film,the polarization plane of the incident light is deflected; after passing through the output polarizer, the incident light passing through the magneto-optical material wrapped in a gold film is focused by the output lens into the output optical fiber; after the incident light passes through the magneto-optical material wrapped by the gold film, the light intensity of the incident light is determined by input intensity I0Becomes output light intensity I1。
The technical scheme of the high-sensitivity miniaturized current detection system utilizes the characteristic that the optical fiber or the waveguide can eliminate the influence of exciting current, adopts magneto-optical materials which are provided with input polarizing films and output polarizing films and are wrapped by gold films, and utilizes the inherent characteristics of the optical fiber or the waveguide to eliminate external electromagnetic interference, thereby achieving the purposes of reducing cost and reducing volume.
Further, the fiber optic current sensor further comprises: and the glass tube is used for wrapping a structure comprising an input lens, an input polaroid, a magneto-optical material wrapped by a gold film, an output polaroid and an output lens in the optical fiber current sensor.
Further, the magnetic field strength B is calculated through the faraday magneto-optical effect and the malus theorem, and the current strength I of the wire to be tested is calculated according to the bioto-savart theorem and the magnetic field strength B, and the specific principle is as follows:
as shown in figure 4, according to the Faraday magneto-optical effect, when linearly polarized light propagates in a magneto-optical material wrapped by a gold film, a magnetic field is generated by a power transmission wire in a direction parallel to the propagation direction of the light, the polarization plane of the light is deflected, and the deflection angle theta is changedFProportional to the product of the magnetic induction B and the length d of light passing through the magneto-optical material wrapped in the gold film:
θF＝VBd (1)
wherein, the proportionality coefficient V is called as Welch constant and is related to the property of the medium and the frequency of the light wave;
deflection angle thetaFAccording to the input light intensity I0And the intensity I of the magnetic field generated by the magneto-optical material wrapped by the gold film1The result of the comparison is that,according to the Malus theorem, the following can be known:
I1＝I0·sin2θF(2)
according to the biot-savart theorem, for an infinitely long straight wire, at a vertical distance r from the wire, the magnetic field strength perpendicular to the wire is as follows: a
Wherein, mu0Permeability in vacuum, 4 π × 10-7H/m; r is the distance between the measured point and the axis of the lead to be measured, and the unit is m; i is the magnitude of the measured current, in units A.
Theta is obtained by calculation through formula (2)FAnd substituting the magnetic field B into a formula (1) to obtain the magnetic field B, and calculating the current intensity I through a formula (3).
Further, preferably, the input polarizer and the output polarizer are perpendicular to each other, and since the polarization directions of the two polarizers are perpendicular, the measured intensity of the transmitted light is proportional to the rotation angle of the polarization plane of the light in the faraday transmission medium, that is, proportional to the component of the magnetic field intensity along the crystal axis direction. The current sensor has higher sensitivity and is more sensitive to a magnetic field during measurement. Of course, the mutually perpendicular solution is only a preferred solution, and it still falls within the scope of the present invention if only the polarization directions of the input polarizer and the output polarizer are simply changed.
Further, preferably, the faraday transmission medium wrapped by the gold film adopts the faraday optical fiber and the faraday waveguide with ultra-short lengths, so that the optical fiber current sensor can be integrated into an ultra-small sensor which is hung on a wire, the pressure on the optical fiber is small, and the influence is smaller.
Further, the detector further comprises: a pre-amplification circuit and active band-pass filtering;
the preamplification circuit converts the optical signal into an electric signal and performs operational amplification; and the active band-pass filtering filters noise in the electric signal to obtain the electric signal containing magnetic field intensity information. Specifically, the pre-amplifier circuit converts an optical signal into an electrical signal, but the optical signal and the electrical signal are very weak, so the circuit is designed to be a low-noise and high-gain amplifier circuit. Namely, weak optical signals received by the photoelectric detector are converted into electric signals, and the electric signals are subjected to operational amplification. The use of the operational amplifier not only amplifies the signal but also amplifies noise, and the amplifier itself introduces new noise, so that an electric signal containing magnetic field strength information can be obtained through active band-pass filtering.
Further preferably, the distance r between the measured point and the axis of the lead to be measured may be a constant input in advance.
Specifically, in this embodiment, as shown in fig. 5, when a scheme of measuring by attaching the optical fiber current sensor to the wire to be measured is adopted, the distance from the measured point to the axis of the wire to be measured is fixed, and the distance r can be input into the system in advance without measuring each time, so that the current detection workload is reduced, and the measurement accuracy is improved. It should be noted that, the optical fiber current sensor is tightly attached to the lead to be measured for measurement, which is only a preferred solution of the present invention, and in addition, a series of solutions including holding and fixing by a separate bracket can be designed, and all of them belong to the protection scope of the present invention.
Further, the magneto-optical material wrapped by the gold film is a magneto-optical medium with an ultrahigh Verdet constant, and specifically can be a terbium-doped Faraday dielectric waveguide or an optical fiber with the surface covered by an Au film. Here, by way of example only, any magneto-optical medium having an ultra-high verdet constant may be used in the present invention.
Example two
This example provides a specific example of the measurement using the highly sensitive miniaturized current detection system of the present invention, and the comparison with the detection results of the current detection system without the magneto-optical material coated with the gold film.
(1) Measurement by current detection system of magneto-optical material without gold film wrapping
When a high-concentration terbium-doped silicate optical fiber is used as the faraday optical fiber, the length d is 0.01m, and the Verdet constant (Verdet constant) is V35 rad/(T · m), as is known from the faraday magneto-optical effect, and the length d and the Verdet constant V are known, the deflection angle θ is shown in fig. 6FThe relationship with the magnetic field strength B is:
θF＝VBd＝35rad/(T·m)·0.01m·B＝0.35B(rad)
wherein the unit of the magnetic field strength B is tesla (T). It is also known that the magnetic field strength B and the deflection angle θFIn proportion:
B＝2.86θF
wherein the deflection angle thetaFCan be based on the reference light intensity I0And the intensity I of the light generated by the Faraday fiber or waveguide with polarizer and acted by magnetic field1The comparison shows that according to the Malus theorem:
I1＝I0·sin2θF
then theta can be calculatedFValue according to the deflection angle thetaFThe relationship with the magnetic field strength B allows the magnitude of the magnetic field strength B to be calculated.
When the distance between the Faraday fiber or waveguide and the high-voltage straight conductor in the sensor is r 0.05m, the magnetic permeability is mu0＝4π×10-7H/m, known from the Biot-savart law:
the calculation shows that the current I in the high-voltage straight conductor is in direct proportion to the magnetic field intensity B:
therefore, the current I in the high-voltage straight conductor and the deflection angle thetaFProportional to each other (as shown in fig. 7):
I＝7.14×105θF
from alreadyCalculated deflection angle thetaFThe current I in the final high-voltage straight conductor can be calculated.
(2) Measurement using the current detection system of the magneto-optical material wrapped by a gold film of the present invention
A terbium-doped glass fiber having an Au thin film coated on the surface thereof was used as a faraday fiber, and the length d was 0.01m, and the Verdet constant (Verdet constant) was V134 rad/(T · m), and it was found from the faraday magneto-optical effect that the deflection angle θ was known as shown in fig. 8 when the length d and the Verdet constant V were knownFThe relationship with the magnetic field strength B is:
θF＝VBd＝134rad/(T·m)·0.01m·B＝1.34B(rad)
wherein the unit of the magnetic field strength B is tesla (T). It is also known that the magnetic field strength B and the deflection angle θFIn proportion:
B＝0.746θF
wherein the deflection angle thetaFCan be based on the reference light intensity I0And the intensity I of the light generated by the Faraday fiber or waveguide with polarizer and acted by magnetic field1The comparison shows that according to the Malus theorem:
I1＝I0·sin2θF
then theta can be calculatedFValue according to the deflection angle thetaFThe relationship with the magnetic field strength B allows the magnitude of the magnetic field strength B to be calculated.
When the distance between the Faraday fiber or waveguide and the high-voltage straight conductor in the sensor is r 0.05m, the magnetic permeability is mu0＝4π×10-7H/m, known from the Biot-savart law:
the calculation shows that the current I in the high-voltage straight conductor is in direct proportion to the magnetic field intensity B:
therefore, the current I in the high-voltage straight conductor and the deflection angle thetaFProportional to each other (as shown in fig. 9):
I＝1.87×105θF
from the calculated deflection angle thetaFThe current I in the final high-voltage straight conductor can be calculated.
Therefore, after the optical fiber sensor with the magneto-optical material wrapped by the gold film is used, the magneto-optical material wrapped by the gold film has an ultrahigh Verdet constant, a larger magnetic field deflection angle is generated under the same current, and the magneto-optical fiber sensor has ultrahigh sensitivity when measuring the current of a power transmission conductor, and is particularly suitable for measuring the power transmission conductor with weak current intensity loudness.
The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.
Claims (8)
1. A highly sensitive miniaturized current sensing system comprising: the optical fiber current sensor comprises an input optical fiber, an input lens, an input polaroid, a magneto-optical material wrapped by a gold film, an output polaroid, an output lens and an output optical fiber, wherein the magneto-optical material wrapped by the gold film is in any one form including a Faraday optical fiber and a Faraday waveguide wrapped by the gold film;
the light source is connected with the optical fiber current sensor, and the optical fiber current sensor is connected with the detector;
when the current on the high-voltage transmission wire to be measured is measured, the light source emits unpolarized light, the unpolarized light is input into the optical fiber current sensor and is transmitted to the detector through an optical fiber, the magnetic field intensity B is obtained through the Faraday magneto-optical effect and the Malus theorem, and the current intensity I of the wire to be measured is obtained through calculation according to the Biot-Saval theorem and the magnetic field intensity B;
after receiving the unpolarized light emitted by the light source, the unpolarized light serving as incident light is guided into the magneto-sensitive area by the input optical fiber, is focused by the input lens and then is changed into linearly polarized light by the input polaroid, and the linearly polarized light is incident into the magneto-optical material wrapped by the gold film, so that the polarization plane of the incident light is deflected; after passing through the output polarizer, the incident light passing through the magneto-optical material wrapped in a gold film is focused by the output lens into the output optical fiber; after the incident light passes through the magneto-optical material wrapped by the gold film, the light intensity of the incident light is determined by input intensity I0Becomes output light intensity I1。
2. The highly sensitive miniaturized current detection system of claim 1 wherein said fiber optic current sensor further comprises: and the glass tube is used for wrapping the structure of the optical fiber current sensor, including the input lens, the input polaroid, the magneto-optical material wrapped by the gold film, the output polaroid and the output lens, in the glass tube.
3. The highly sensitive miniaturized current detection system according to claim 1, wherein the magnetic field strength B is calculated by faraday magneto-optical effect and malus theorem, and the current strength I of the lead to be tested is calculated according to biot-savart theorem and the magnetic field strength B, specifically:
according to the Faraday magneto-optical effect, when unpolarized light enters the optical fiber current sensor, the unpolarized light is converted into linearly polarized light through the input polarizing plate, when the linearly polarized light is transmitted in the magneto-optical material wrapped by the gold film, a magnetic field is applied to the power transmission line in the direction parallel to the transmission direction of the light, the polarization plane of the light is deflected, and the deflection angle theta is changedFWith magnetic induction B and light passing through the gold filmThe product of the length d of the magneto-optical material is proportional to:
θF＝VBd (1)
wherein, the proportionality coefficient V is called as Welch constant and is related to the property of the medium and the frequency of the light wave;
deflection angle thetaFAccording to the input light intensity I0And the intensity I of the magnetic field generated by the magneto-optical material wrapped by the gold film1The comparison shows that according to the Malus theorem:
I1＝I0·sin2θF(2)
according to the biot-savart theorem, for an infinitely long straight wire, at a vertical distance r from the wire, the magnetic field strength perpendicular to the wire is as follows:
wherein, mu0Permeability in vacuum, 4 π × 10-7H/m; r is the distance between the measured point and the axis of the lead to be measured, and the unit is m; i is the magnitude of the measured current, in units A.
Theta is obtained by calculation through formula (2)FAnd substituting the magnetic field B into a formula (1) to obtain the magnetic field B, and calculating the current intensity I through a formula (3).
4. The highly sensitive miniaturized current detection system of claim 4 wherein the input polarizer and the output polarizer are perpendicular to each other.
5. The highly sensitive miniaturized current detection system of claim 4 wherein said gold film wrapped magneto-optical material is an ultra short length of said Faraday waveguide or said Faraday waveguide wrapped with gold film.
6. The highly sensitive miniaturized current detection system of claim 1 wherein said probe further comprises: a pre-amplification circuit and active band-pass filtering;
the preamplification circuit converts the optical signal into an electric signal and performs operational amplification;
and the active band-pass filtering filters noise in the electric signal to obtain the electric signal containing magnetic field intensity information.
7. The highly sensitive miniaturized current detection system of claim 3 further comprising: the distance r between the measured point and the axis of the lead to be measured is a constant input in advance.
8. The highly sensitive miniaturized current detection system according to claim 4, wherein said magneto-optical material wrapped by gold film is magneto-optical medium with ultra-high Verdet constant, in particular terbium-doped Faraday dielectric waveguide or optical fiber with Au film covered on the surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010564943.2A CN111721993A (en) | 2020-06-19 | 2020-06-19 | High-sensitivity miniaturized current detection system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010564943.2A CN111721993A (en) | 2020-06-19 | 2020-06-19 | High-sensitivity miniaturized current detection system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111721993A true CN111721993A (en) | 2020-09-29 |
Family
ID=72567620
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010564943.2A Pending CN111721993A (en) | 2020-06-19 | 2020-06-19 | High-sensitivity miniaturized current detection system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111721993A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113533826A (en) * | 2021-07-15 | 2021-10-22 | 深圳普泰电气有限公司 | High-precision current monitoring and processing system |
| CN115112935A (en) * | 2022-06-28 | 2022-09-27 | 中国长江三峡集团有限公司 | Optical fiber terminal device and data transmission system |
| CN116908515A (en) * | 2023-09-14 | 2023-10-20 | 合肥工业大学 | Differential optical current sensor for lightning current detection |
| CN117491924A (en) * | 2023-12-29 | 2024-02-02 | 致真精密仪器(青岛)有限公司 | Magneto-optical effect-based hysteresis loop detection method, magneto-optical effect-based hysteresis loop detection equipment and magneto-optical effect-based hysteresis loop detection medium |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4793356A (en) * | 1985-08-14 | 1988-12-27 | Picker International, Inc. | Surface coil system for magnetic resonance imaging |
| CN1177802A (en) * | 1996-09-20 | 1998-04-01 | 中国科学院物理研究所 | Mn-Bi-Al magneto-optic material with high recording density and preparation method therefor |
| CN1917308A (en) * | 2006-04-26 | 2007-02-21 | 上海致凯捷激光科技有限公司 | Wind cooled, single mold green light laser pumped at end face of semiconductor |
| CN102032880A (en) * | 2010-11-17 | 2011-04-27 | 南京邮电大学 | AC (alternating current) magneto-optical modulation wide angle detection device and method |
| CN103424664A (en) * | 2012-05-14 | 2013-12-04 | 南京弘毅电气自动化有限公司 | Optical sensor achieving switch cabinet flashover detection |
| CN103443639A (en) * | 2012-08-29 | 2013-12-11 | 北京恒信创光电技术有限公司 | Current measurement system, optical current transformer and fixing device thereof, light signal sampler and method thereof |
| CN203631964U (en) * | 2013-12-16 | 2014-06-04 | 北京工业大学 | 976nm Q-switching and mode-locked laser system |
| CN104253375A (en) * | 2014-06-26 | 2014-12-31 | 锐莱特精密光电技术无锡有限公司 | High-repetition frequency and narrow-pulse width single-mode green laser |
| CN106249445A (en) * | 2016-08-31 | 2016-12-21 | 欧阳征标 | The low damage type magneto-optic thin film magnetic surface unidirectional waveguide of turning round of fast mould random angle |
| CN106469887A (en) * | 2015-08-19 | 2017-03-01 | 中国科学院西安光学精密机械研究所 | The Double-pass amplifier of photonic crystal fiber |
| CN107643438A (en) * | 2017-09-14 | 2018-01-30 | 重庆大学 | Optical current sensor and its current measuring method based on Faraday magnetooptical effect |
| CN207704724U (en) * | 2017-07-27 | 2018-08-07 | 杭州精科仪器有限公司 | A kind of Malus' law experimental device for verifying |
| CN109507467A (en) * | 2018-11-07 | 2019-03-22 | 天津大学 | Optical current mutual inductor and its current measuring method based on catoptric arrangement |
| CN110596945A (en) * | 2019-09-20 | 2019-12-20 | 厦门天马微电子有限公司 | Display panel and display device |
-
2020
- 2020-06-19 CN CN202010564943.2A patent/CN111721993A/en active Pending
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4793356A (en) * | 1985-08-14 | 1988-12-27 | Picker International, Inc. | Surface coil system for magnetic resonance imaging |
| CN1177802A (en) * | 1996-09-20 | 1998-04-01 | 中国科学院物理研究所 | Mn-Bi-Al magneto-optic material with high recording density and preparation method therefor |
| CN1917308A (en) * | 2006-04-26 | 2007-02-21 | 上海致凯捷激光科技有限公司 | Wind cooled, single mold green light laser pumped at end face of semiconductor |
| CN102032880A (en) * | 2010-11-17 | 2011-04-27 | 南京邮电大学 | AC (alternating current) magneto-optical modulation wide angle detection device and method |
| CN103424664A (en) * | 2012-05-14 | 2013-12-04 | 南京弘毅电气自动化有限公司 | Optical sensor achieving switch cabinet flashover detection |
| CN103443639A (en) * | 2012-08-29 | 2013-12-11 | 北京恒信创光电技术有限公司 | Current measurement system, optical current transformer and fixing device thereof, light signal sampler and method thereof |
| CN203631964U (en) * | 2013-12-16 | 2014-06-04 | 北京工业大学 | 976nm Q-switching and mode-locked laser system |
| CN104253375A (en) * | 2014-06-26 | 2014-12-31 | 锐莱特精密光电技术无锡有限公司 | High-repetition frequency and narrow-pulse width single-mode green laser |
| CN106469887A (en) * | 2015-08-19 | 2017-03-01 | 中国科学院西安光学精密机械研究所 | The Double-pass amplifier of photonic crystal fiber |
| CN106249445A (en) * | 2016-08-31 | 2016-12-21 | 欧阳征标 | The low damage type magneto-optic thin film magnetic surface unidirectional waveguide of turning round of fast mould random angle |
| CN207704724U (en) * | 2017-07-27 | 2018-08-07 | 杭州精科仪器有限公司 | A kind of Malus' law experimental device for verifying |
| CN107643438A (en) * | 2017-09-14 | 2018-01-30 | 重庆大学 | Optical current sensor and its current measuring method based on Faraday magnetooptical effect |
| CN109507467A (en) * | 2018-11-07 | 2019-03-22 | 天津大学 | Optical current mutual inductor and its current measuring method based on catoptric arrangement |
| CN110596945A (en) * | 2019-09-20 | 2019-12-20 | 厦门天马微电子有限公司 | Display panel and display device |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113533826A (en) * | 2021-07-15 | 2021-10-22 | 深圳普泰电气有限公司 | High-precision current monitoring and processing system |
| CN115112935A (en) * | 2022-06-28 | 2022-09-27 | 中国长江三峡集团有限公司 | Optical fiber terminal device and data transmission system |
| CN115112935B (en) * | 2022-06-28 | 2023-06-20 | 中国长江三峡集团有限公司 | Optical fiber terminal device and data transmission system |
| CN116908515A (en) * | 2023-09-14 | 2023-10-20 | 合肥工业大学 | Differential optical current sensor for lightning current detection |
| CN116908515B (en) * | 2023-09-14 | 2023-12-05 | 合肥工业大学 | Differential optical current sensor for lightning current detection |
| CN117491924A (en) * | 2023-12-29 | 2024-02-02 | 致真精密仪器(青岛)有限公司 | Magneto-optical effect-based hysteresis loop detection method, magneto-optical effect-based hysteresis loop detection equipment and magneto-optical effect-based hysteresis loop detection medium |
| CN117491924B (en) * | 2023-12-29 | 2024-03-19 | 致真精密仪器(青岛)有限公司 | Magneto-optical effect-based hysteresis loop detection method, magneto-optical effect-based hysteresis loop detection equipment and magneto-optical effect-based hysteresis loop detection medium |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111721993A (en) | High-sensitivity miniaturized current detection system | |
| US5631559A (en) | Method and apparatus for performing magnetic field measurements using magneto-optic kerr effect sensors | |
| CN101509962B (en) | Magnetic induction measurement method and apparatus | |
| US4348587A (en) | Fiber optic transducer for measuring current or magnetic field | |
| WO2000019217A9 (en) | In-line electro-optic voltage sensor | |
| CN106093599B (en) | Optical probe and electromagnetic field measuring equipment and measuring method thereof | |
| US2844789A (en) | Microwave magnetic detectors | |
| CN111751596A (en) | Distributed high-voltage transmission line current detection system | |
| CN109507467A (en) | Optical current mutual inductor and its current measuring method based on catoptric arrangement | |
| US6586930B1 (en) | Material thickness measurement using magnetic information | |
| CN111721992B (en) | Optical fiber sensing system for measuring current intensity of three-phase high-voltage conductor | |
| CN111721990A (en) | Miniaturized optical fiber current sensor and information processing system | |
| US5241279A (en) | Microwave measuring apparatus for continuously and without contact measuring the thickness of a thin conducting layer of a running insulating support such as a fiber or a tape | |
| CN107247243A (en) | The micro- hanging bridge fibre optic magnetic field sensing probe of cross based on ultra-magnetic telescopic effect | |
| CN105866506B (en) | A kind of device and method that conductor current is measured using magneto-optic memory technique | |
| CN106932739A (en) | The micro- hanging bridge magnetic field sensing probe of optical fiber based on F P-structure | |
| CN111323635A (en) | Optical fiber sensing system and method for measuring current intensity of high-voltage conductor in non-contact mode | |
| CN206975198U (en) | The micro- hanging bridge magnetic field sensing probe of optical fiber based on F P-structure | |
| CN206975197U (en) | The micro- hanging bridge fibre optic magnetic field sensing probe of cross based on ultra-magnetic telescopic effect | |
| JP3166987B2 (en) | Current sensor | |
| CN109856233A (en) | A kind of Magnetic Flux Leakage Testing System based on Mach-Zehnder fibre optical sensor | |
| US3323364A (en) | Means for rejecting quadrature voltage signals in a flow meter | |
| CN104865547A (en) | Signal injection calibration method of integral pulse magnetic field measurement system | |
| RU2298202C1 (en) | Method of measurement of magnetic field strength | |
| JPS62277947A (en) | Electric field or magnetic field measuring method and apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB03 | Change of inventor or designer information | ||
| CB03 | Change of inventor or designer information |
Inventor after: Tao Yong Inventor after: Zhang Peng Inventor after: Yuan Denghan Inventor after: Shi Xianhe Inventor after: Jiang Chun Inventor after: Jiang Chaokai Inventor after: Xi Yunpeng Inventor after: Hua Wei Inventor after: Li Hong Inventor after: Yan Hao Inventor before: Zhou Qi Inventor before: Jiang Chun Inventor before: Hua Wei Inventor before: Jiang Chaokai Inventor before: Li Hong Inventor before: Wu Hao Inventor before: Shi Xianhe Inventor before: Zhang Peng |