Collaborative Vibration Isolation Structure and Method Based on Multiple Optical Current Transformers

Abstract

This application relates to a collaborative vibration-damping structure and method based on multiple optical current transformers, and pertains to the field of electrical quantity measurement technology in power systems. The aim is to address the problem that the anti-interference effect of a single optical current sensing unit is not ideal. This application comprises four optical current transformers uniformly arranged circumferentially along the current conductor. Each optical current transformer includes a polarizer, a Faraday magneto-optical element, and an analyzer arranged sequentially along the optical path. The analyzer of each optical current transformer has dual output terminals, with the angles between the principal optical axes of the analyzers at the two output terminals and the principal optical axes of the input polarizer being and , respectively. The magnetic field direction of the Faraday magneto-optical element in the optical current transformer coincides with its transmission axis. Adjacent optical current transformers are arranged radially symmetrically in one vibration direction, forming a vibration-damping group. The vibration excitation received by the corresponding output terminals of two optical current transformers within the same vibration-damping group is a common-mode signal, and the measured current signal flowing through the current conductor is a differential-mode signal.

Description

Technical Field

[0001] This application belongs to the field of electrical quantity measurement technology in power systems, and particularly relates to a collaborative vibration-resistant structure and method based on multiple optical current transformers. Background Technology

[0002] Compared to traditional electromagnetic current transformers, optical current transformers (OCTs) offer significant advantages such as superior insulation, absence of transient magnetic saturation, wide dynamic range, and strong resistance to electromagnetic interference. They are also compact, easily integrated with digital devices, making them ideal measurement equipment for high-voltage, high-current applications, with broad prospects in power systems. However, the structure of an optical current transformer is relatively complex, encompassing multiple components including an optical current sensing unit, a transmission fiber optic link, and a secondary photoelectric control and signal processing unit. While the secondary photoelectric control and signal processing unit can be deployed in an indoor control room, the core optical current sensing unit and transmission fiber optic link must be placed outdoors for extended periods, making them significantly susceptible to external vibration interference. This vibration directly affects the optical components and fiber optic link, causing fluctuations in optical signal transmission and becoming a key factor limiting measurement accuracy.

[0003] Specifically, the stress generated by mechanical vibration causes slight changes in the sensor structure, leading to abrupt displacement at the fiber optic connection points. This, in turn, causes irregular abrupt changes in the static working light intensity, ultimately affecting the output superimposed impact signal and the accuracy of the output measurement. The frequency of this impact signal is between tens, hundreds, or even thousands of hertz. If the optical current transformer serves relay protection, its impact on power frequency protection is relatively small, but it will have a serious impact on waveform-based protection.

[0004] Existing research largely focuses on improving the mechanical structure of individual optical current sensing units or implementing vibration-damping arrangements for transmission optical fibers. These are localized optimization methods, and their anti-interference effect is not ideal in practical applications. Therefore, there is an urgent need to propose a system-level vibration reduction approach, based on the overall layout design of a combined structure for optical current transformers, in order to improve the equipment's ability to resist vibration interference. Summary of the Invention

[0005] This application aims to address the problem that the anti-interference effect of a single optical current sensing unit is not ideal. It provides a collaborative anti-vibration structure and method based on multiple optical current transformers, which suppresses the impact of vibration interference on measurement accuracy by optimizing the spatial layout and installation configuration of the optical current transformers.

[0006] The first aspect of this application provides a cooperative vibration-damping structure based on multiple optical current transformers, comprising: four optical current transformers uniformly arranged along the circumference of the current conductor, each optical current transformer including a polarizer, a Faraday magneto-optical element and an analyzer arranged sequentially along the optical path;

[0007] The analyzer output of the optical current transformer has two output terminals, and the angles between the principal optical axis of the analyzer corresponding to the two output terminals and the principal optical axis of the input polarizer are respectively... and In an optical current transformer, the direction of the magnetic field of the Faraday magneto-optical element coincides with its transmission axis.

[0008] Two adjacent optical current transformers are arranged radially symmetrically in one vibration direction to form an anti-vibration group.

[0009] In one possible design, the vibration excitation received by the corresponding output terminals of the two optical current transformers within the same vibration-resistant group is a common-mode signal, and the measured current signal flowing through the current conductor is a differential-mode signal.

[0010] In one possible design, there are two vibration directions, namely the x-axis direction and the y-axis direction which are perpendicular to each other. In the coordinate system formed by the x-axis and the y-axis, the four optical current transformers are located in the four quadrants of the coordinate system.

[0011] Optical current transformers located in the first and second quadrants, and optical current transformers located in the third and fourth quadrants, are arranged radially symmetrically with the y-axis as the axis of symmetry.

[0012] Optical current transformers located in the first and fourth quadrants, and optical current transformers located in the second and third quadrants, are arranged radially symmetrically with the x-axis as the axis of symmetry.

[0013] In one possible design, when vibration is present and the magnetic field direction and light transmission direction are the same, the expression for the output light intensity at the two output terminals of the optical current transformer is:

[0014] ,

[0015] When the magnetic field direction and the light transmission direction are opposite, the expression for the output light intensity at the two output terminals of the optical current transformer is:

[0016] ,

[0017] in, The angle between the optical axis and the input end is The output light intensity at the output end The angle between the optical axis and the input end is The output light intensity at the output end For input light intensity, The current to be measured is... This is a proportionality coefficient related to the properties of optical materials. and These are the vibration influence parameters of the two output terminals of the optical current transformer.

[0018] In one possible design, a dual-optical-path detection method is employed to perform difference-sum processing on the two signals output from the two output terminals of the optical current transformer to obtain the total output light intensity of the optical current transformer. :

[0019] ,or .

[0020] The second aspect of this application provides a collaborative vibration suppression method based on multiple optical current transformers. This collaborative vibration suppression method is implemented using four optical current transformers. Each optical current transformer includes a polarizer, a Faraday magneto-optical element, and an analyzer arranged sequentially along the optical path. The analyzer of each optical current transformer has a dual-output terminal, and the angles between the principal optical axes of the two output terminals and the principal optical axis of the input polarizer are respectively... and In an optical current transformer, the direction of the magnetic field of the Faraday magneto-optical element coincides with its transmission axis.

[0021] The collaborative vibration damping method includes: uniformly arranging the four optical current transformers along the circumference of the current conductor, and arranging adjacent optical current transformers radially symmetrically in one vibration direction to form a vibration damping group.

[0022] In one possible design, the vibration excitation received by the corresponding output terminals of the two optical current transformers within the same vibration-resistant group is a common-mode signal, and the measured current signal flowing through the current conductor is a differential-mode signal.

[0023] In one possible design, there are two vibration directions, namely the x-axis direction and the y-axis direction which are perpendicular to each other. In the coordinate system formed by the x-axis and the y-axis, the four optical current transformers are located in the four quadrants of the coordinate system.

[0024] Optical current transformers located in the first and second quadrants, and optical current transformers located in the third and fourth quadrants, are arranged radially symmetrically with the y-axis as the axis of symmetry.

[0025] Optical current transformers located in the first and fourth quadrants, and optical current transformers located in the second and third quadrants, are arranged radially symmetrically with the x-axis as the axis of symmetry.

[0026] In one possible design, when vibration is present and the magnetic field direction and light transmission direction are the same, the expression for the output light intensity at the two output terminals of the optical current transformer is:

[0027] ,

[0028] When the magnetic field direction and the light transmission direction are opposite, the expression for the output light intensity at the two output terminals of the optical current transformer is:

[0029] ,

[0030] in, The angle between the optical axis and the input end is The output light intensity at the output end The angle between the optical axis and the input end is The output light intensity at the output end For input light intensity, The current to be measured is... This is a proportionality coefficient related to the properties of optical materials. and These are the vibration influence parameters of the two output terminals of the optical current transformer.

[0031] In one possible design, a dual-optical-path detection method is employed to perform difference-sum processing on the two signals output from the two output terminals of the optical current transformer to obtain the total output light intensity of the optical current transformer. :

[0032] ,or .

[0033] The beneficial effects of this application are:

[0034] This application employs a symmetrical layout design of four sets of optical current transformers (OCTs), configuring any two adjacent OCTs as a vibration-resistant unit, ensuring their symmetrical distribution about the target vibration direction. This layout ensures that the vibration excitation received by the two OCTs within the same vibration-resistant unit is a common-mode signal, while configuring the measured current signal in differential-mode transmission. Based on the transmission characteristics of differential-mode and common-mode signals, the common-mode interference signal introduced by vibration excitation can be adaptively canceled in the differential transmission link, retaining only the effective differential-mode signal carrying the measured current information. This structure can significantly suppress the disturbance of vibration on the OCT output signal, effectively improving the measurement accuracy and stability of the system. To verify its vibration resistance performance, impact vibration was applied to the OCTs with a peak impact acceleration of 40g and an impact duration of 10ms. In the test group without the symmetrical layout of this invention (no current differential-mode - vibration common-mode configuration), the amplitude of the impact vibration interference component in the output signal was larger, such as... Figure 3 As shown; however, in the test group using the symmetrical layout of this application, the amplitude of the impact vibration interference component in the output signal was reduced to about 10% of the original interference amplitude, such as... Figure 4As shown in the figure. Experimental results show that the layout scheme proposed in this application can effectively attenuate vibration interference and has excellent anti-vibration and disturbance suppression performance. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of a single optical current transformer, in which: 1 is a light source, 2 is an optical current transformer, 3 is a polarizer, 4 is a Faraday magneto-optical element, and 5 is an analyzer.

[0036] Figure 2 This is a schematic diagram of a collaborative vibration-resistant structure based on multiple optical current transformers;

[0037] Figure 3 This is a schematic diagram illustrating the vibration effect without a symmetrical installation arrangement.

[0038] Figure 4 This is a schematic diagram illustrating the vibration effect after symmetrical installation.

[0039] Figure 5 The layout diagram of the synergistic vibration-resistant structure described in Example 2 is shown in (a), which represents the first completely symmetrical case, (b), which represents the second completely symmetrical case, (c), which represents the first locally slightly asymmetrical case, and (d), which represents the second locally slightly asymmetrical case.

[0040] Figure 6 The layout diagram of the synergistic vibration-resistant structure described in Example 3 is shown in (a), which represents the first completely symmetrical case, (b), which represents the second completely symmetrical case, (c), which represents the first locally slightly asymmetrical case, and (d), which represents the second locally slightly asymmetrical case. Detailed Implementation

[0041] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0042] Specific implementation method one: The cooperative vibration-damping structure based on multiple optical current transformers described in this implementation method includes: four optical current transformers uniformly arranged along the circumference of the current conductor, each optical current transformer including a polarizer, a Faraday magneto-optical element and an analyzer arranged sequentially along the optical path.

[0043] The analyzer output of the optical current transformer has two output terminals, and the angles between the principal optical axis of the analyzer corresponding to the two output terminals and the principal optical axis of the input polarizer are respectively... and In an optical current transformer, the direction of the magnetic field of the Faraday magneto-optical element coincides with its transmission axis.

[0044] Two adjacent optical current transformers are arranged radially symmetrically in one vibration direction to form an anti-vibration group.

[0045] In one embodiment, the vibration excitation received by the corresponding output terminals of the two optical current transformers in the same vibration-damping group is a common-mode signal, and the measured current signal flowing through the current conductor is a differential-mode signal.

[0046] In one embodiment, there are two vibration directions, namely the x-axis direction and the y-axis direction which are perpendicular to each other. In the coordinate system formed by the x-axis and the y-axis, the four optical current transformers are located in the four quadrants of the coordinate system.

[0047] Optical current transformers located in the first and second quadrants, and optical current transformers located in the third and fourth quadrants, are arranged radially symmetrically with the y-axis as the axis of symmetry.

[0048] Optical current transformers located in the first and fourth quadrants, and optical current transformers located in the second and third quadrants, are arranged radially symmetrically with the x-axis as the axis of symmetry.

[0049] In one embodiment, when vibration is present and the magnetic field direction and light transmission direction are the same, the expression for the output light intensity at the two output terminals of the optical current transformer is:

[0050] ,

[0051] When the magnetic field direction and the light transmission direction are opposite, the expression for the output light intensity at the two output terminals of the optical current transformer is:

[0052] ,

[0053] in, The angle between the optical axis and the input end is The output light intensity at the output end The angle between the optical axis and the input end is The output light intensity at the output end For input light intensity, The current to be measured is... This is a proportionality coefficient related to the properties of optical materials. and These are the vibration influence parameters of the two output terminals of the optical current transformer.

[0054] In one embodiment, a dual-optical-path detection method is used to perform difference and sum processing on the two signals output from the two output terminals of the optical current transformer to obtain the total output light intensity of the optical current transformer. :

[0055] ,or .

[0056] Example 1:

[0057] Taking a dual-path optical current transformer as an example, such as Figure 1 As shown, the output of the analyzer 5 includes Output and At the output end, the transmission axis of polarizer 3 is aligned with that of analyzer 5. Output and The included angles of the light transmission axes at the output end are respectively and Assuming The output light intensity at the output end is , The output light intensity at the output end is . Indicates the input light intensity. The magnetic field direction in the Faraday magneto-optical element 4 coincides with the light transmission axis and is the same as the light transmission direction.

[0058] (1) When vibration is not considered, the expression for the output light intensity of the two output terminals is:

[0059] (1),

[0060] in, This represents the proportionality coefficient, which is only related to the properties of optical materials.

[0061] At this point, using a dual-optical-path detection method, after differential division and summation of the two signals, the output light intensity of optical current transformer 2 is... Represented as:

[0062] (2),

[0063] or, (3).

[0064] Substituting formula (1) into (2), we get:

[0065] (4).

[0066] If optical current transformer 2 is determined, then Given a known quantity, then the output current signal The solution can be found using the following formula:

[0067] (5).

[0068] (2) When considering the effect of vibration, the expression for the output light intensity of the two output terminals changes from equation (1) to the following equation:

[0069] When the direction of the magnetic field is the same as the direction of the light: (6),

[0070] When the direction of the magnetic field is opposite to the direction of the light: (7),

[0071] In the formula, and These represent the vibration influence parameters at the two output terminals. Since the positions of the two output terminals are perpendicular and parallel to the optical path, respectively, the impact of vibration on the two output terminals is different, meaning... At this point, a dual-optical-path detection method is used to perform difference and summation processing on the two signals. Substituting equations (6) and (7) into equations (2) and (3) respectively, we get:

[0072] (8),

[0073] (9),

[0074] (10)

[0075] (11),

[0076] Obviously, the result after signal processing Including the influence of vibration, if the output current signal is calculated according to formulas (8), (9), (10), and (11)... :

[0077] (12).

[0078] According to equation (12), the output after data processing is no longer simply the measured current. It is also related to the effect of vibration. Comparing equations (5) and (12), it can be seen that vibration will affect the measurement accuracy of optical current transformer 2.

[0079] according to Figure 1 It is evident that the influence of vibration on the measurement cannot be avoided when using a single optical current transformer 2 for current measurement.

[0080] Observing formula (1), we can see that 1 is the common-mode signal, and the current to be measured is... It is a differential signal. and After processing, the common-mode signal is eliminated, leaving only the differential-mode signal. However, for a single optical current transformer, the vibration effects on its two output terminals are different due to their positional relationship. Therefore, the vibration influence cannot be completely eliminated after differential subtraction. However, for multiple sets of optical current transformers, if any two sets are symmetrical about the vibration direction (i.e., the combination of the polarizer, Faraday magneto-optical element, and analyzer is symmetrical about the vibration direction), then the vibration effects on the output terminals of these two transformers can be considered the same. In this case, if the vibration influence on the two output terminals is designed as a common-mode signal and the current as a differential-mode signal, then subtracting the two signals can preserve the current information while suppressing vibration interference.

[0081] like Figure 2 As shown, in this embodiment, the four optical current transformers 2 are named OCT_1, OCT_2, OCT_3, and OCT_4, respectively. Each optical current transformer 2 has the same composition, including: a polarizer 3, a Faraday magneto-optical element 4, and an analyzer 5. The output terminal of the analyzer 5 includes... Output and At the output end, the transmission axis of polarizer 3 is aligned with that of analyzer 5. Output and The included angles of the light transmission axes at the output end are respectively and .

[0082] The installation layout design of the four optical current transformers 2 is as follows:

[0083] Assumption The output light intensity at the output end is , The output light intensity at the output end is And set as follows Figure 2 As shown, the dashed arrows indicate the direction of the magnetic field in optical current transformer 2, and the solid arrows indicate the direction of light transmission. All output terminals parallel to the light path direction have the same properties; for example, they are all... Output or At the output terminals, all output terminals perpendicular to the optical path have the same characteristics. The polarizer 5 in the four optical current transformers 2... Output and The output light intensity at the output end is expressed as follows: and , and , and , and Since the four optical current transformers are independently illuminated, their static non-operating light intensities are respectively... , , and Any vibration can be decomposed into mutually perpendicular x-axis and y-axis components. OCT_1 and OCT_4, and OCT_2 and OCT_3 are symmetrical about the x-axis, while OCT_1 and OCT_2, and OCT_3 and OCT_4 are symmetrical about the y-axis. Considering that the output terminal parallel to the optical path is unique, while the output terminal perpendicular to the optical path has two directions, there are multiple possible combinations when installing the four optical current transformers 2. Even with adjacent optical current transformers 2 being symmetrical about a certain vibration direction, there are still cases of completely symmetrical installation and cases of slightly asymmetrical installation.

[0084] like Figure 5 (a) and (b) represent two completely symmetrical cases, where the two output terminals of the analyzers 5 of two adjacent optical current transformers 2 are symmetrical about a certain vibration direction; for example... Figure 5 In the diagram, (c) and (d) represent slight asymmetry between the two output terminals of the analyzers of two adjacent optical current transformers about the direction of vibration. For example... Figure 5 In (c), the vertical output terminals of the analyzers 5 of OCT_1 and OCT_2 are slightly asymmetrical about the y-axis; for example... Figure 5 In (d), the vertical output terminals of the analyzers OCT_1 and OCT_4 are slightly asymmetrical about the x-axis. In practice, the selection of the vertical output terminal for each optical current transformer varies, and there are many other cases of this slight asymmetry, which will not be listed here. According to theoretical analysis, a perfectly symmetrical arrangement provides better vibration resistance.

[0085] Specific Implementation Method Two: The collaborative vibration suppression method based on multiple optical current transformers described in this implementation method is based on four optical current transformers. Each optical current transformer includes a polarizer, a Faraday magneto-optical element, and an analyzer arranged sequentially along the optical path. The analyzer of the optical current transformer has dual output terminals, and the angles between the principal optical axes of the two output terminals and the principal optical axis of the input polarizer are respectively... and In an optical current transformer, the direction of the magnetic field of the Faraday magneto-optical element coincides with its transmission axis.

[0086] The collaborative vibration damping method includes: uniformly arranging the four optical current transformers along the circumference of the current conductor, and arranging adjacent optical current transformers radially symmetrically in one vibration direction to form a vibration damping group.

[0087] In one embodiment, the vibration excitation received by the corresponding output terminals of the two optical current transformers in the same vibration-damping group is a common-mode signal, and the measured current signal flowing through the current conductor is a differential-mode signal.

[0088] In one embodiment, there are two vibration directions, namely the x-axis direction and the y-axis direction which are perpendicular to each other. In the coordinate system formed by the x-axis and the y-axis, the four optical current transformers are located in the four quadrants of the coordinate system.

[0089] Optical current transformers located in the first and second quadrants, and optical current transformers located in the third and fourth quadrants, are arranged radially symmetrically with the y-axis as the axis of symmetry.

[0090] Optical current transformers located in the first and fourth quadrants, and optical current transformers located in the second and third quadrants, are arranged radially symmetrically with the x-axis as the axis of symmetry.

[0091] In one embodiment, when vibration is present and the magnetic field direction and light transmission direction are the same, the expression for the output light intensity at the two output terminals of the optical current transformer is:

[0092] ,

[0093] When the magnetic field direction and the light transmission direction are opposite, the expression for the output light intensity at the two output terminals of the optical current transformer is:

[0094] ,

[0095] in, The angle between the optical axis and the input end is The output light intensity at the output end The angle between the optical axis and the input end is The output light intensity at the output end For input light intensity, The current to be measured is... This is a proportionality coefficient related to the properties of optical materials. and These are the vibration influence parameters of the two output terminals of the optical current transformer.

[0096] In one embodiment, a dual-optical-path detection method is used to perform difference and sum processing on the two signals output from the two output terminals of the optical current transformer to obtain the total output light intensity of the optical current transformer. :

[0097] ,or .

[0098] Example 2:

[0099] (1) When only horizontal vibration is considered

[0100] like Figure 2 As shown, since the two mutual inductors OCT_1 and OCT_4 are mirror-symmetric about the x-axis, it can be considered that OCT_1's... Output and The vibration affecting the output terminal is related to that of OCT_4. Output and The output terminal is affected by the same vibration. Specifically, and Both are subjected to the same vibration, which is a common-mode signal. Assume its influence factor on the static working light intensity is... ; and Both are subjected to the same vibrational force, which is a common-mode signal. Assume its influence factor on light intensity is... Since the magnetic field direction of OCT_1 is the same as the light transmission direction, and the magnetic field direction of OCT_4 is opposite to the light transmission direction, the signals at the two output terminals of the two optical current transformers, OCT_1 and OCT_4, can be expressed as follows:

[0101] (13)

[0102] (14)

[0103] From the formulas, we can see that, and as well as and In this context, the current is a differential-mode signal, and the vibration interference is a common-mode signal. Therefore, during signal processing, a design to suppress the common-mode signal is employed to separately... and ,as well as and By performing differential processing separately, vibration interference can be eliminated while retaining the current information to be measured.

[0104] Similarly, such as Figure 2 As shown, since the two mutual inductors OCT_2 and OCT_3 are mirror-symmetric about the x-axis, it can be considered that OCT_2's... Output and The effects of vibration on the output terminal are related to OCT_3. Output and The output terminal is affected by the same vibration. Specifically: and Both are subjected to the same vibration, which is a common-mode signal. Assume its influence factor on the static working light intensity is... ; and Both are subjected to the same vibrational force, which is a common-mode signal. Assume its influence factor on light intensity is... Since the magnetic field direction of OCT_2 is opposite to the light transmission direction, and the magnetic field direction of OCT_3 is the same as the light transmission direction, the signals at the two output terminals of the two optical current transformers OCT_2 and OCT_3 can be expressed as follows:

[0105] (15)

[0106] (16)

[0107] Observing equations (15) and (16), we can see that and as well as and In this signal processing, the current is a differential-mode signal, and the vibration interference is a common-mode signal. Therefore, a common-mode signal suppression design is adopted during signal processing: [The following text appears to be incomplete and requires further context: "separately..."] and ,as well as and By performing differential processing on all samples, vibration interference can be eliminated while retaining the current information to be measured.

[0108] Considering that the four optical current transformers are independently illuminated, and the four static operating light intensities are not equal in real time, the difference and summation operation in the dual optical paths should be used in signal processing to eliminate the influence of the static operating light intensity. Therefore, based on the above design for suppressing common-mode signals, the operational relationship of the eight outputs of the four optical current transformers is designed as follows:

[0109] (17)

[0110] The output light intensity of the multi-optical current transformer cooperative vibration-resistant structure is considered when only horizontal vibration is taken into account.

[0111] Substituting equations (13), (14), (15), and (16) into equation (17), we get:

[0112] (18).

[0113] In practice, It is a very small value, much less than 1, therefore Much larger , Much larger ,and, , , and They are all numbers whose absolute value is usually less than 1, therefore, when Much larger , Much larger Then, equation (18) can be further simplified to:

[0114] (19).

[0115] Equation (19) shows that after Figure 2 When the current transformer is arranged and the signal is processed in equation (17), the horizontal vibration interference in the output signal is basically eliminated.

[0116] (2) When only vertical vibration is considered

[0117] like Figure 2 As shown, since the two mutual inductors OCT_1 and OCT_2 are mirror-symmetric about the y-axis, it can be considered that OCT_1's... Output and The vibration affecting the output terminal is related to OCT_2. Output and The output terminal is affected by the same vibration. Specifically, and Both are subjected to the same vibration, which is a common-mode signal. Assume its influence factor on the static working light intensity is... ; and Both are subjected to the same vibrational force, which is a common-mode signal. Assume its influence factor on light intensity is... Since the magnetic field direction of OCT_1 is the same as the light transmission direction, and the magnetic field direction of OCT_2 is opposite to the light transmission direction, the signals at the two output terminals of the two optical current transformers OCT_1 and OCT_2 can be expressed as follows:

[0118] (20)

[0119] (twenty one),

[0120] Observing equations (20) and (21), we can see that and as well as and In this context, the current is a differential-mode signal, and the vibration interference is a common-mode signal. Therefore, during signal processing, a design to suppress the common-mode signal is employed to separately... and ,as well as and By performing differential processing separately, vibration interference can be eliminated while retaining the current information to be measured.

[0121] Similarly, such as Figure 2 As shown, since the two mutual inductors OCT_3 and OCT_4 are mirror-symmetric about the y-axis, it can be considered that OCT_3's... Output and The vibration affecting the output terminal is related to that of OCT_4. Output and The output terminal is affected by the same vibration. Specifically: and Both are subjected to the same vibration, which is a common-mode signal. Assume its influence factor on the static working light intensity is... ; and Both are subjected to the same vibrational force, which is a common-mode signal. Assume its influence factor on light intensity is... Since the magnetic field direction of OCT_3 is the same as the light transmission direction, and the magnetic field direction of OCT_4 is opposite to the light transmission direction, the signals at the two output terminals of the two optical current transformers OCT_3 and OCT_4 can be represented as follows:

[0122] (twenty two),

[0123] (twenty three),

[0124] Observing equations (22) and (23), we can see that and as well as and In this signal processing, the current is a differential-mode signal, and the vibration interference is a common-mode signal. Therefore, common-mode signal suppression is employed during signal processing to separately suppress the common-mode signal. and ,as well as and By performing differential processing on all samples, vibration interference can be eliminated while retaining the current information to be measured.

[0125] Considering that the four optical current transformers are independently illuminated, and the four static operating light intensities are not equal in real time, the difference and summation operation in the dual optical paths should be used in signal processing to eliminate the influence of the static operating light intensity. Therefore, based on the above design for suppressing common-mode signals, the operational relationship of the eight outputs of the four optical current transformers is designed as follows:

[0126] (twenty four),

[0127] The output light intensity of the multi-optical current transformer cooperative vibration-resistant structure is considered when only vertical vibration is taken into account.

[0128] Substituting equations (20), (21), (22), and (23) into equation (24), we get:

[0129] (25)

[0130] In practice, It is a very small value, much less than 1, therefore Much larger , Much larger ,and, , , and They are all numbers whose absolute value is usually less than 1, therefore, when Much larger ; Much larger Then, equation (17) can be further simplified to

[0131] (26).

[0132] Equation (26) shows that after Figure 2 When the current transformer is arranged and the signal is processed in equation (24), the vertical vibration interference in the output signal is basically eliminated.

[0133] Note that the expressions for equations (17) and (24) are the same; therefore, theoretically, after... Figure 2 With the current transformer layout and signal processing of Equation (24), vibration in any direction will be greatly suppressed, and the output signal will be less affected by vibration.

[0134] Example 3:

[0135] The difference between this embodiment and embodiment 2 is that the current transformers are arranged in reverse, such as... Figure 6 As shown.

[0136] Then we have:

[0137] (1) When only horizontal vibration is considered

[0138] The signals at the two output terminals of the two optical current transformers, OCT_1 and OCT_4, can be represented as follows:

[0139] (27)

[0140] (28).

[0141] The signals at the two output terminals of the two optical current transformers, OCT_2 and OCT_3, can be represented as follows:

[0142] (29)

[0143] (30).

[0144] The operational relationships of the eight outputs of the four optical current transformers are as follows:

[0145] (31),

[0146] Substituting equations (27), (28), (29), and (30) into equation (31), we get:

[0147] (32).

[0148] This can be further simplified to:

[0149] (33).

[0150] Equation (33) shows that after Figure 6 When the current transformer is arranged and the signal is processed in equation (31), the horizontal vibration interference in the output signal is basically eliminated.

[0151] (2) When only vertical vibration is considered

[0152] The signals at the two output terminals of the two optical current transformers, OCT_1 and OCT_2, can be represented as follows:

[0153] (34),

[0154] (35).

[0155] The signals at the two output terminals of the two optical current transformers, OCT_3 and OCT_4, can be represented as follows:

[0156] (36)

[0157] (37).

[0158] The operational relationships of the eight outputs of the four optical current transformers are as follows:

[0159] (38).

[0160] Substituting equations (34), (35), (36), and (37) into equation (38), we get:

[0161] (39).

[0162] Equation (39) can be further simplified to:

[0163] (40).

[0164] Equation (40) shows that after Figure 6 When the current transformer is arranged and the signal is processed in equation (38), the vertical vibration interference in the output signal is basically eliminated.

[0165] Note that in implementation method two, the expressions of equations (31) and (38) are the same. Therefore, theoretically, after... Figure 6 With the current transformer layout and signal processing of Equation (38), vibration in any direction will be greatly suppressed, and the output signal will be less affected by vibration.

[0166] In the two embodiments described above,

[0167] In the layout design of Example 2, the output processing modes of the four current transformers are the same, and the specific relationship among them is as follows:

[0168] (41).

[0169] In the layout design of Example 3, the output processing modes of the four current transformers are the same, and the specific relationship among them is as follows:

[0170] (42).

[0171] Observation shows that when the layout of the four optical current transformers changes from... Figure 5 Become Figure 6 At that time, the output mode of a single current transformer changes.

[0172] While specific embodiments of this application have been described herein with reference to them, it should be understood that these embodiments are merely examples of the principles and applications of this application. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of this application as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A collaborative vibration-damping structure based on multiple optical current transformers, characterized in that, include: Four optical current transformers are evenly arranged around the circumference of the current conductor. Each optical current transformer includes a polarizer, a Faraday magneto-optical element and an analyzer arranged sequentially along the optical path. The analyzer output of the optical current transformer has two output terminals, and the angles between the principal optical axis of the analyzer corresponding to the two output terminals and the principal optical axis of the input polarizer are respectively... and In an optical current transformer, the direction of the magnetic field of the Faraday magneto-optical element coincides with its transmission axis. Two adjacent optical current transformers are arranged radially symmetrically in one vibration direction to form an anti-vibration group; When vibration is present, and the magnetic field direction and the light transmission direction are the same, the expression for the output light intensity at the two output terminals of the optical current transformer is: ， When the magnetic field direction and the light transmission direction are opposite, the expression for the output light intensity at the two output terminals of the optical current transformer is: ， in, The angle between the optical axis and the input end is The output light intensity at the output end The angle between the optical axis and the input end is The output light intensity at the output end For input light intensity, The current to be measured is... A proportionality coefficient related to the properties of optical materials. and These are the vibration influence parameters of the two output terminals of the optical current transformer.

2. The collaborative vibration-damping structure based on multiple optical current transformers according to claim 1, characterized in that, The vibration excitation received by the corresponding output terminals of the two optical current transformers in the same vibration-resistant group is a common-mode signal, and the measured current signal flowing through the current conductor is a differential-mode signal.

3. The collaborative vibration-damping structure based on multiple optical current transformers according to claim 1, characterized in that, The vibration direction is two, namely the x-axis direction and the y-axis direction which are perpendicular to each other. In the coordinate system formed by the x-axis and the y-axis, the four optical current transformers are located in the four quadrants of the coordinate system. Optical current transformers located in the first and second quadrants, and optical current transformers located in the third and fourth quadrants, are arranged radially symmetrically with the y-axis as the axis of symmetry. Optical current transformers located in the first and fourth quadrants, and optical current transformers located in the second and third quadrants, are arranged radially symmetrically with the x-axis as the axis of symmetry.

4. The collaborative vibration-damping structure based on multiple optical current transformers according to claim 1, characterized in that, A dual-optical-path detection method is used to perform difference-division and sum processing on the two signals output from the two output terminals of the optical current transformer to obtain the total output light intensity of the optical current transformer. : ,or .

5. A collaborative vibration suppression method based on multiple optical current transformers, characterized in that, The cooperative vibration damping method is based on four optical current transformers. Each optical current transformer includes a polarizer, a Faraday magneto-optical element, and an analyzer arranged sequentially along the optical path. The analyzer of the optical current transformer has dual output terminals, and the angles between the principal optical axes of the two output terminals and the principal optical axis of the input polarizer are respectively... and In an optical current transformer, the direction of the magnetic field of the Faraday magneto-optical element coincides with its transmission axis. The collaborative vibration damping method includes: uniformly arranging the four optical current transformers along the circumference of the current conductor, and arranging adjacent optical current transformers radially symmetrically in one vibration direction to form a vibration damping group; When vibration is present, and the magnetic field direction and the light transmission direction are the same, the expression for the output light intensity at the two output terminals of the optical current transformer is: ， When the magnetic field direction and the light transmission direction are opposite, the expression for the output light intensity at the two output terminals of the optical current transformer is: ， in, The angle between the optical axis and the input end is The output light intensity at the output end The angle between the optical axis and the input end is The output light intensity at the output end For input light intensity, The current to be measured is... A proportionality coefficient related to the properties of optical materials. and These are the vibration influence parameters of the two output terminals of the optical current transformer.

6. The collaborative vibration suppression method based on multiple optical current transformers according to claim 5, characterized in that, The vibration excitation received by the corresponding output terminals of the two optical current transformers in the same vibration-resistant group is a common-mode signal, and the measured current signal flowing through the current conductor is a differential-mode signal.

7. The collaborative vibration suppression method based on multiple optical current transformers according to claim 5, characterized in that, The vibration direction is two, namely the x-axis direction and the y-axis direction which are perpendicular to each other. In the coordinate system formed by the x-axis and the y-axis, the four optical current transformers are located in the four quadrants of the coordinate system. Optical current transformers located in the first and second quadrants, and optical current transformers located in the third and fourth quadrants, are arranged radially symmetrically with the y-axis as the axis of symmetry. Optical current transformers located in the first and fourth quadrants, and optical current transformers located in the second and third quadrants, are arranged radially symmetrically with the x-axis as the axis of symmetry.

8. The collaborative vibration suppression method based on multiple optical current transformers according to claim 5, characterized in that, A dual-optical-path detection method is used to perform difference-division and sum processing on the two signals output from the two output terminals of the optical current transformer to obtain the total output light intensity of the optical current transformer. : ,or .

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