Vector magnetic field optical fiber measuring device and transformer

Abstract

The invention provides a vector magnetic field optical fiber measuring device and a transformer. A light source of the device is connected with the input end of a polarizer; the output end of the polarizer is connected with the input end of the magnetic field sensor; the output end of the magnetic field sensor is connected with the input end of the beam splitter; the first output end of the beam splitter is connected with the first balance photoelectric detector; the second output end of the beam splitter is connected with the input end of the polarization analyzer; the polarization analyzer is connected with the second balance photoelectric detector; the first balance photoelectric detector and the second balance photoelectric detector are both connected with the data processing device; the magnetic field sensor comprises a magneto-optical crystal; the magnetic field sensor is used for decomposing the first linearly polarized light output by the polarizer into two beams of second linearly polarized light through the magneto-optical crystal and outputting all or part of the two beams of second linearly polarized light to the beam splitter. Vector measurement of the leakage magnetic field of the transformer winding can be realized.

Description

Technical Field

[0001] The invention relates to the technical field of online detection of high-voltage electrical equipment, and in particular to a vector magnetic field optical fiber measuring device and a transformer. Background Art

[0002] In recent years, electricity consumption has increased year by year, and the number of transformers put into power systems has also increased. Therefore, the failure rate caused by transformers has also increased accordingly. Most failures occur due to local overheating that damages the insulation layer, reducing the service life of the transformer. It is also possible that the mechanical shape of the transformer changes, destroying the transformer's ability to resist short circuits, and the transformer may not be able to remain stationary and vibrate, damaging the mechanical strength of the transformer.

[0003] By monitoring the changes in the leakage magnetic field, it is possible to determine whether the transformer is partially overheated or whether the winding and other structural components are deformed. When the winding is deformed, the size and distribution of the leakage magnetic field around the transformer will change. By measuring the distribution of the transformer magnetic field online, it is possible to determine in real time whether the transformer winding is deformed, and the degree of deformation of the transformer winding can also be determined based on the change law of the leakage magnetic field.

[0004] Although the Hall sensors commonly used in engineering have high measurement accuracy, if they are used to measure the magnetic field on the transformer windings, a large voltage will be generated between the windings, which may cause insulation breakdown, thereby damaging the windings and sensors, posing a danger to testers. In addition, the electromagnetic environment inside the transformer is complex and is easily affected by electromagnetic interference, which affects the accuracy of magnetic field measurement.

[0005] In addition, since the Hall sensor is not directional, it is difficult to achieve vector measurement, which affects the accuracy of transformer winding state estimation. Although the common magneto-optical crystal magnetic field sensor is directional, it can only measure a single direction. In order to perform vector measurement, multiple sets of sensor systems need to be arranged at the same time, and these systems cooperate with each other to obtain complete measurement information. However, as the number of systems increases, the structure becomes more complex and requires more components and resources to support its operation.

[0006] Therefore, the existing magnetic field sensors have poor insulation performance, are susceptible to electromagnetic interference, and cannot achieve vector measurement of transformer leakage magnetic field, which are technical problems that need to be urgently solved by those skilled in the art. Summary of the invention

[0007] The invention provides a vector magnetic field optical fiber measuring device and a transformer, so as to realize the vector measurement of the leakage magnetic field of the transformer winding.

[0008] In the first aspect, the present invention provides a vector magnetic field optical fiber measurement device, comprising: a light source, a polarizer, a magnetic field sensor, a beam splitter, a first balanced photodetector, an analyzer, a second balanced photodetector and a data processing device; the magnetic field sensor includes a magneto-optical crystal.

[0009] The light source is connected to the input end of the polarizer; the output end of the polarizer is connected to the input end of the magnetic field sensor; the output end of the magnetic field sensor is connected to the input end of the beam splitter; the first output end of the beam splitter is connected to the first balanced photodetector; the second output end of the beam splitter is connected to the input end of the analyzer; the analyzer is connected to the second balanced photodetector; the first balanced photodetector and the second balanced photodetector are both connected to the data processing device.

[0010] The magnetic field sensor is used for decomposing the first linear polarized light outputted by the polarizer into two beams of second linear polarized light through the magneto-optical crystal, and outputting all or part of the two beams of second linear polarized light to the beam splitter.

[0011] In a possible implementation manner, the magnetic field sensor further includes: two coaxial optical fiber collimators and a fixing frame.

[0012] The magneto-optical crystal is placed between two coaxial fiber collimators, and the two coaxial fiber collimators are fixed on the same horizontal line at both ends of a fixing frame.

[0013] One of the two coaxial fiber collimators is used to allow the first linear polarized light output by the polarizer to pass through the magneto-optical crystal, and the magneto-optical crystal decomposes the first linear polarized light into two beams of second linear polarized light. The other of the two coaxial fiber collimators is used to output all or part of the two beams of second linear polarized light to the beam splitter.

[0014] In a possible implementation, the magnetic field sensor further includes an insulating housing encapsulating a magneto-optical crystal, two coaxial optical fiber collimators, and a fixing frame.

[0015] In a possible implementation, the interior of the insulating housing is in a vacuum state.

[0016] In one possible implementation, when the first magnetic field component perpendicular to the optical axis direction of the first linear polarized light in the external environment of the magneto-optical crystal increases, the difference in refractive index of the two second linear polarized light beams increases; when the second magnetic field component parallel to the optical axis direction of the first linear polarized light in the external environment of the magneto-optical crystal increases, the polarization directions of the two second linear polarized light beams rotate.

[0017] In a possible implementation manner, the data processing device is used to:

[0018] receiving first light intensity data from a first balanced photodetector, and determining a value of a first magnetic field component according to the first light intensity data;

[0019] The second light intensity data from the first balanced photodetector is received, the rotation angle of the two second linearly polarized lights is calculated according to the first light intensity data and the second light intensity data, and the value of the second magnetic field component is determined according to the rotation angle.

[0020] In a possible implementation, the beam splitting ratio of the beam splitter is 50:50. In a possible implementation, the first light intensity data, the second light intensity data, and the rotation angles of the two second linearly polarized lights satisfy the following formula:

[0021]

[0022] Wherein, θ is the rotation angle of the two second linearly polarized light beams.

[0023] In a possible implementation, the vector magnetic field optical fiber measurement device based on linear birefringence and Faraday effect further includes an acquisition card.

[0024] The input end of the acquisition card is connected to the output ends of the first balanced photoelectric detector and the second balanced photoelectric detector, and the output end of the acquisition card is connected to the data processing device.

[0025] The acquisition card acquires the first light intensity data and the second light intensity data.

[0026] In a second aspect, the present invention provides a transformer, including implementing the above first aspect or any possible implementation method of the first aspect.

[0027] The invention provides a vector magnetic field optical fiber measuring device, wherein a light source of the device is connected to an input end of a polarizer; an output end of the polarizer is connected to an input end of a magnetic field sensor; an output end of the magnetic field sensor is connected to an input end of a beam splitter; a first output end of the beam splitter is connected to a first balanced photoelectric detector; a second output end of the beam splitter is connected to an input end of an analyzer; the analyzer is connected to a second balanced photoelectric detector; and both the first balanced photoelectric detector and the second balanced photoelectric detector are connected to a data processing device.

[0028] The magnetic field sensor is used for decomposing the first linear polarized light outputted by the polarizer into two beams of second linear polarized light through the magneto-optical crystal, and outputting all or part of the two beams of second linear polarized light to the beam splitter.

[0029] The present invention can be directly installed inside a transformer, has the advantages of vector measurement, high sensitivity, high insulation level, no electromagnetic interference and easy installation, and can realize online monitoring of transformer leakage magnetic flux. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0031] Figure 1 Schematic diagram of the structure of a vector magnetic field optical fiber measurement device based on linear birefringence and Faraday effect provided by an embodiment of the present invention;

[0032] Figure 2 is a schematic diagram of the structure of a magnetic field sensor provided by an embodiment of the present invention;

[0033] Figure 3 is a schematic diagram of the structure of the magnetic field sensor provided by an embodiment of the present invention in a magnetic field environment;

[0034] Figure 4 It is a schematic structural diagram of the change of the first linear polarized light in the magneto-optical crystal provided by an embodiment of the present invention;

[0035] Figure 5 is a schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0037] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0038] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0039] In addition, in the description of the present application specification and the attached claims, the terms "first", "second", "third", or "first", "second", "third", or "first branch", "second branch", "third branch", etc. are only used to distinguish the description and shall not be understood as indicating or implying relative importance.

[0040] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0041] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0042] The following is a detailed description of the implementation of the present invention in conjunction with the specific drawings:

[0043] Figure 1 A schematic diagram of the structure of a vector magnetic field optical fiber measurement device provided by an embodiment of the present invention. Figure 1 The device comprises: a light source 100, a polarizer 200, a magnetic field sensor 300, a beam splitter 400, a first balanced photodetector 500, an analyzer 600, a second balanced photodetector 700 and a data processing device 900. The magnetic field sensor 300 comprises a magneto-optical crystal.

[0044] The light source 100 is connected to the input end of the polarizer 200; the output end of the polarizer 200 is connected to the input end of the magnetic field sensor 300; the output end of the magnetic field sensor 300 is connected to the input end of the beam splitter 400; the first output end of the beam splitter 400 is connected to the first balanced photodetector 500; the second output end of the beam splitter 400 is connected to the input end of the analyzer 600; the analyzer 600 is connected to the second balanced photodetector 700; the first balanced photodetector 500 and the second balanced photodetector 700 are both connected to the data processing device 900.

[0045] The magnetic field sensor 300 is used to decompose the first linear polarized light outputted by the polarizer 200 into two beams of second linear polarized light through a magneto-optical crystal, and output all or part of the two beams of second linear polarized light to the beam splitter 400 .

[0046] In this embodiment, the vector magnetic field optical fiber measurement device further includes an acquisition card 800 .

[0047] Exemplarily, the input ends of the light source 100, polarizer 200, magnetic field sensor 300, beam splitter 400 and first balanced photodetector 500 in this embodiment are connected through polarization-maintaining optical fiber, and the input ends of the light source 100, polarizer 200, magnetic field sensor 300, beam splitter 400, analyzer 600 and second balanced photodetector 700 are connected through polarization-maintaining optical fiber. The main function of polarization-maintaining optical fiber is to solve the problems of polarization rotation or polarization state crossing that may occur in the transmission process of optical signals, and ensure the stable transmission of optical signals.

[0048] Exemplarily, the output end of the first balanced photodetector 500 , the output end of the second balanced photodetector 700 , the acquisition card 800 , and the data processing device 900 are connected via a cable.

[0049] Exemplarily, the light source 100 may be a laser with a wavelength of 1550 nm.

[0050] This embodiment proposes a vector magnetic field optical fiber measurement device, which detects the magnetic field based on the change of light intensity and measures the magnetic field vector based on linear birefringence and Faraday effect:

[0051] When the first magnetic field component perpendicular to the optical axis direction of the first linear polarized light in the external environment of the magneto-optical crystal increases, the two second linear polarized lights propagate forward at different phase velocities. Based on the principle of linear birefringence, the difference in linear refractive index between the two second linear polarized lights increases, causing the light intensity to change when leaving the magnetic field sensor 300.

[0052] When the second magnetic field component parallel to the optical axis direction of the first linearly polarized light increases in the external environment of the magneto-optical crystal, the polarization directions of the two second linearly polarized lights rotate based on the Faraday effect. Since the polarizer 600 can only pass light with a fixed polarization angle, the light intensity changes after passing through the polarizer 700.

[0053] The following will explain in more detail how to achieve vector measurement of magnetic field based on changes in light intensity, see Figure 2 .

[0054] Figure 2 3 is a schematic diagram of the structure of a magnetic field sensor 300 provided in an embodiment of the present invention. As shown in the figure, the magnetic field sensor 300 includes: a magneto-optical crystal 301, two coaxial fiber collimators 302, a fixing frame 303, and an insulating shell 304.

[0055] The magneto-optical crystal 301 is placed between two coaxial fiber collimators 302, and the two coaxial fiber collimators 302 are fixed on the same horizontal line at both ends of the fixing frame 303. The insulating shell 304 is used to encapsulate the magneto-optical crystal 301, the two coaxial fiber collimators 302 and the fixing frame 303, and the interior of the insulating shell 304 is in a vacuum state;

[0056] One of the two coaxial fiber collimators 302 is used to allow the first linear polarized light output by the polarizer 200 to pass through the magneto-optical crystal 301, and the magneto-optical crystal 301 decomposes the first linear polarized light into two beams of second linear polarized light. The other of the two coaxial fiber collimators 302 is used to output all or part of the two beams of second linear polarized light to the beam splitter 400.

[0057] Exemplarily, in this embodiment, the magneto-optical crystal 301 is a Bi:YIG magneto-optical crystal.

[0058] Single crystal garnet is the basis of modern laser and communication, and is the core crystal for preparing laser, magneto-optical switch and magneto-optical isolator. For example, yttrium iron garnet (YIG) single crystal is widely used in microwave and millimeter wave communication devices due to its high resistivity, narrow ferromagnetic resonance line width and high reliability. 3+ When introduced into the central C position of the regular dodecahedron in the yttrium iron garnet YIG crystal, its magneto-optical properties will be enhanced, producing a giant magnetic Faraday rotation effect, which has important application value in isolators and magneto-optical switches for infrared optical communications.

[0059] Optionally, the Bi:YIG magneto-optical crystal is a circular piece with a diameter of 3 mm and a thickness of 1 mm, and is fixed in the middle of the two coaxial fiber collimators 302 with ultraviolet glue, which can improve the coupling efficiency of the two coaxial fiber collimators 302.

[0060] Optionally, the outer diameter of the two coaxial fiber collimators 302 is 2.78 mm, the working distance is 15 mm, and the position of the optical fiber is fine-tuned using a micro-electro-mechanical system (MEMS). After the state is adjusted to the best, they are glued to the circular holes at both ends of the acrylic fixing frame with UV glue. One of the two coaxial fiber collimators 302 is used to convert the first linear polarized light in the polarization-maintaining optical fiber into spatial light for transmission in the glass tube, and the other of the two coaxial fiber collimators 302 is used to couple the spatial light back to the polarization-maintaining optical fiber.

[0061] The fixing frame 303 may be an acrylic fixing frame. For example, the acrylic fixing frame may be a 25mm×5mm×5mm cuboid with a 15mm×5mm×3mm cuboid cut off, with a 2.78mm hole punched at both ends for fixing the two coaxial fiber collimators 302.

[0062] The insulating housing 304 may be a glass tube, and the diameter of the glass tube is 8 mm.

[0063] In the magnetic field environment, how the first linear polarized light changes in the magneto-optical crystal 301 will be described below in conjunction with Figure 3 illustrate.

[0064] Figure 3 This is a structural schematic diagram of the magnetic field sensor provided by an embodiment of the present invention in a magnetic field environment. The first magnetic field component is perpendicular to the optical axis direction of the first linear polarized light, and the second magnetic field component is parallel to the optical axis direction of the first linear polarized light. When the magnetic field changes, both the first magnetic field component and the second magnetic field component will change.

[0065] The detection of the first magnetic field component is realized based on the principle of linear birefringence. The first linear polarized light is decomposed into two beams of second linear polarized light in the Bi:YIG magneto-optical crystal. Due to the inhomogeneity of the Bi:YIG magneto-optical crystal structure, the two beams of second linear polarized light will cause two different refractive indices. The difference in the refractive index of the two beams of second linear polarized light is proportional to the square of the first magnetic field component. As the first magnetic field component increases, the difference in the refractive index of the two beams of polarized light increases, and some of the light will not be able to be coupled back to the polarization-maintaining fiber through the coaxial fiber collimator 302, and the first light intensity will change. For details, see Figure 4 shown.

[0066] The second magnetic field component is detected based on the Faraday effect. The polarization direction of the first linearly polarized light will rotate after passing through the Bi:YIG magneto-optical crystal, and the second light intensity will change after passing through the analyzer 600.

[0067] Exemplarily, after the two second linearly polarized lights pass through the Bi:YIG magneto-optical crystal, the beam splitter 400 splits the changed two second linearly polarized lights into two beams of light at a fractional ratio of 50:50, the first balanced photodetector 500 detects the first light intensity data, and the second balanced photodetector 700 detects the second light intensity data.

[0068] The data processing device 900 receives the first light intensity data from the first balanced photodetector 500 and determines the value of the first magnetic field component according to the first light intensity data.

[0069] The data processing device 900 also receives second light intensity data from the second balanced photodetector 700, calculates the rotation angle of the two second linearly polarized light beams according to the first light intensity data and the second light intensity data, and determines the value of the second magnetic field component according to the rotation angle.

[0070] Exemplarily, this embodiment uses a vector magnetic field optical fiber measuring device to perform a calibration experiment to determine the relationship between light intensity and magnetic field. The equipment required for the calibration experiment also includes an experimental transformer, an electromagnet coil, and a Gaussmeter.

[0071] The transformer and the electromagnet coil are connected, and the magnitude of the current is controlled by adjusting the voltage of the transformer, so that magnetic fields of different magnitudes are generated in the electromagnet coil. The electromagnet coil is placed next to the magnetic field sensor 300, and the light source 100 emits light of a certain wavelength. The magnitude of the current is adjusted. The magnetic field sensor 300 is placed in different magnetic field environments. The magnitude of the first magnetic field component and the first light intensity detected by the first balanced photodetector 500 under different magnetic field environments are recorded with a gauss meter, and the first correspondence between the first magnetic field component and the first light intensity is determined and stored. When the transformer winding leakage magnetic field is actually measured, the magnitude of the first magnetic field component is determined according to this correspondence. According to the second light intensity detected by the second balanced photodetector 700 and the first light intensity, the rotation angle of the two second linearly polarized lights under different magnetic field environments is determined, and the magnitude of the second magnetic field component is measured with a gauss meter, and the correspondence between the second magnetic field component and the rotation angle is obtained and stored. When the transformer winding leakage magnetic field is actually measured, the magnitude of the second magnetic field component is determined according to this correspondence.

[0072] According to the result of this calibration experiment, the value of the first magnetic field component corresponding to the first light intensity data detected by the first balanced photodetector 500 can be determined.

[0073] The first light intensity data, the second light intensity data and the rotation angle of the two second linearly polarized lights satisfy the following formula:

[0074]

[0075] Wherein, θ is the rotation angle of the two second linearly polarized light beams.

[0076] From this rotation angle, the value of the second magnetic field component can be determined.

[0077] The vector magnetic field optical fiber measurement device provided in this embodiment can be used to measure the leakage magnetic field of transformer windings, and the magnetic field sensor 300 can be installed near the transformer clamp or winding.

[0078] When the transformer winding is micro-axially compressed, the transformer axial leakage flux changes; and when the transformer winding is slightly bulged, the transformer lateral leakage flux changes. The change in leakage flux will cause the photoelectric detector to detect changes in light intensity, which has high sensitivity and linearity, and can realize vector detection of transformer winding leakage flux.

[0079] Exemplarily, the functions of the data processing device 900 of the present invention may be implemented by an electronic device.

[0080] Figure 5 Schematic diagram of an electronic device provided by an embodiment of the present invention. Figure 5As shown, the electronic device 5 of this embodiment includes: a processor 50, a memory 51, and a computer program 52 stored in the memory 51 and executable on the processor 51. When the processor 50 executes the computer program 52, the steps in the above-mentioned vector magnetic field optical fiber measurement device embodiment are implemented, or when the processor 50 executes the computer program 52, the functions of each module / unit in the above-mentioned device embodiments are implemented.

[0081] Exemplarily, the computer program 52 may be divided into one or more modules / units, which are stored in the memory 51 and executed by the processor 50 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, which are used to describe the execution process of the computer program 52 in the electronic device 5.

[0082] The electronic device 5 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The electronic device 5 may include, but is not limited to, a processor 50 and a memory 51. Those skilled in the art will appreciate that Figure 5 It is only an example of the electronic device 5 and does not constitute a limitation of the electronic device 5. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the electronic device may also include input and output devices, network access devices, buses, etc.

[0083] The processor 50 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0084] The memory 51 may be an internal storage unit of the electronic device 5, such as a hard disk or memory of the electronic device 5. The memory 51 may also be an external storage device of the electronic device 5, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 5. Further, the memory 51 may also include both an internal storage unit of the electronic device 5 and an external storage device. The memory 51 is used to store the computer program and other programs and data required by the electronic device. The memory 51 may also be used to temporarily store data that has been output or is to be output.

[0085] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0086] The present invention also provides a transformer, comprising a vector magnetic field optical fiber measuring device that implements any possible implementation manner as described above.

[0087] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vector magnetic field optical fiber measuring device, characterized in that: It includes a light source, a polarizer, a magnetic field sensor, a beam splitter, a first balanced photodetector, an analyzer, a second balanced photodetector and a data processing device; the magnetic field sensor includes a magneto-optical crystal; The light source is connected to the input end of the polarizer; the output end of the polarizer is connected to the input end of the magnetic field sensor; the output end of the magnetic field sensor is connected to the input end of the beam splitter; the first output end of the beam splitter is connected to the first balanced photodetector; the second output end of the beam splitter is connected to the input end of the analyzer; the analyzer is connected to the second balanced photodetector; the first balanced photodetector and the second balanced photodetector are both connected to the data processing device; The magnetic field sensor is used to decompose the first linearly polarized light output by the polarizer into two beams of second linearly polarized light through the magneto-optical crystal, and output all or part of the two beams of second linearly polarized light to the beam splitter.

2. A vector magnetic field optical fiber measuring device as claimed in claim 1, characterized in that: The magnetic field sensor also includes: two coaxial optical fiber collimators and a fixing frame; The magneto-optical crystal is placed between the two coaxial fiber collimators, and the two coaxial fiber collimators are fixed on the same horizontal line at both ends of the fixing frame; One of the two coaxial fiber collimators is used to allow the first linear polarized light output by the polarizer to pass through the magneto-optical crystal, and the magneto-optical crystal decomposes the first linear polarized light into the two beams of second linear polarized light. The other of the two coaxial fiber collimators is used to output all or part of the two beams of second linear polarized light to the beam splitter.

3. A vector magnetic field optical fiber measuring device as claimed in claim 2, characterized in that: The magnetic field sensor also includes an insulating shell that encapsulates the magneto-optical crystal, the two coaxial optical fiber collimators and the fixing frame.

4. A vector magnetic field optical fiber measuring device as claimed in claim 3, characterized in that: The interior of the insulating shell is in a vacuum state.

5. A vector magnetic field optical fiber measuring device as claimed in claim 1, characterized in that: When the first magnetic field component perpendicular to the optical axis direction of the first linear polarized light in the external environment of the magneto-optical crystal increases, the difference in refractive index between the two beams of second linear polarized light increases; when the second magnetic field component parallel to the optical axis direction of the first linear polarized light in the external environment of the magneto-optical crystal increases, the polarization directions of the two beams of second linear polarized light rotate.

6. A vector magnetic field optical fiber measuring device as claimed in claim 5, characterized in that: The data processing device is used for: receiving first light intensity data from the first balanced photodetector, and determining a value of the first magnetic field component according to the first light intensity data; Receive second light intensity data from the first balanced photodetector, calculate the rotation angle of the two second linearly polarized lights according to the first light intensity data and the second light intensity data, and determine the value of the second magnetic field component according to the rotation angle.

7. A vector magnetic field optical fiber measuring device as claimed in claim 6, characterized in that: The beam splitter has a beam splitting ratio of 50:

50.

8. The vector magnetic field optical fiber measuring device according to claim 7, wherein the first light intensity data, the second light intensity data and the rotation angle of the two second linearly polarized lights satisfy the following formula: in, θ is the rotation angle of the two second linearly polarized lights.

9. A vector magnetic field optical fiber measuring device as claimed in claim 1, characterized in that: The vector magnetic field optical fiber measuring device also includes an acquisition card; The input end of the acquisition card is connected to the output ends of the first balanced photodetector and the second balanced photodetector, and the output end of the acquisition card is connected to the data processing device. The acquisition card acquires the first light intensity data and the second light intensity data.

10. A transformer, characterized in that: A vector magnetic field optical fiber measuring device comprising the device described in any one of claims 1 to 9.

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