Transformer vibration monitoring method, system and microsphere sensor preparation method

Abstract

This application discloses a transformer vibration monitoring method, system, and microsphere sensor preparation method. The monitoring method includes: determining an optical fiber vibration sensor located inside the transformer; transmitting a first optical signal to the front end of the optical fiber body so that after the first optical signal passes through the optical fiber body and reaches the microsphere sensor, a second optical signal is returned based on the refractive index of the microsphere sensor; receiving the returned second optical signal, and determining the vibration signal corresponding to the transformer based on the output light intensity of the second optical signal and the degree of change compared to the output light intensity of the microsphere sensor in a normal state. The optical fiber vibration sensor monitors the vibration signal and uses optical fiber as the signal carrier. It has many advantages, such as high sensitivity, wide bandwidth, anti-electromagnetic interference, corrosion resistance, small size, ease of multiplexing, and easy networking, which reduces the impact of high-voltage and strong magnetic environments on online monitoring of transformer conditions.

Description

Technical Field

[0001] The present application relates to the field of transformers, and specifically to a transformer vibration monitoring method, system, and microsphere sensor preparation method. Background Art

[0002] During normal operation, a transformer's internal cooling system, windings, core, and other structures generate various vibrations due to electrical, magnetic, and mechanical forces. Prolonged exposure to vibration can cause the core to loosen or the windings to deform, significantly reducing the transformer's ability to withstand short-circuit currents and even causing core breakdown and winding damage, seriously impacting the transformer's insulation and service life. Furthermore, the vibration characteristics of a transformer can also change when a fault occurs. Therefore, transformer vibration is a key parameter in characterizing its operating status, requiring real-time monitoring and analysis to promptly identify potential faults and ensure safe and reliable operation.

[0003] In the existing technology, transformer vibration monitoring can be divided into two types: online and offline. Offline monitoring uses various electrical methods such as frequency response analysis and short-circuit reactance to measure the charge of an unloaded transformer to determine whether the vibration is abnormal. This method is very cumbersome, and the transformer cannot be put into normal use, resulting in low economic benefits. Therefore, offline monitoring is mostly used for factory testing of transformers and repair of faulty transformers. Online vibration monitoring is more common in power grids. The vibration sensors used in traditional online vibration monitoring technology mainly include displacement sensors, velocity sensors, acceleration sensors, etc., which are essentially piezoelectric sensors. The principle is to directly convert the displacement and pressure changes caused by vibration into electrical signals for measurement. However, because the sensor is usually installed on the outer wall of the transformer, it can only measure the vibration signal transmitted from the winding or core vibration to the outer casing. Therefore, a complex signal propagation inversion algorithm is required to infer internal equipment faults. Summary of the Invention

[0004] In order to solve the above problems, this application proposes a transformer vibration monitoring method based on a microsphere sensor, comprising:

[0005] Determine an optical fiber vibration sensor located inside the transformer, the optical fiber vibration sensor comprising an optical fiber body and a microsphere sensor disposed on an end surface of the optical fiber body;

[0006] Transmitting a first optical signal to the head end of the optical fiber body, so that after the first optical signal passes through the optical fiber body and reaches the microsphere sensor, a second optical signal is returned according to the refractive index of the microsphere sensor;

[0007] The second optical signal is received and a vibration signal corresponding to the transformer is determined based on a degree of change in the output light intensity of the second optical signal compared to the output light intensity of the microsphere sensor in a normal state, where the normal state refers to a state in which the microsphere sensor is not affected by external vibration.

[0008] In one example, determining the vibration signal corresponding to the transformer based on the output light intensity of the second light signal compared to the output light intensity of the microsphere sensor in a normal state specifically includes:

[0009] determining a refractive index corresponding to the microsphere sensor according to a degree of change in the output light intensity of the second light signal compared to the output light intensity of the microsphere sensor in a normal state;

[0010] The resonant wavelength corresponding to the transformer is determined according to the refractive index and the manufacturing parameters corresponding to the microsphere sensor, so as to obtain the vibration signal corresponding to the microsphere sensor according to the resonant wavelength.

[0011] In one example, the manufacturing parameters include size information of the microsphere sensor and a mode order of the microsphere sensor, and the resonant wavelength is positively correlated with the refractive index.

[0012] In one example, determining the resonant wavelength corresponding to the transformer according to the refractive index and the manufacturing parameters corresponding to the microsphere sensor specifically includes:

[0013] By formula The resonant wavelength corresponding to the transformer is obtained, where λ res is the resonant wavelength, n is the effective refractive index of the microsphere sensor, and m is a positive integer representing the mode order of the microsphere sensor.

[0014] On the other hand, the present application also proposes a method for preparing a microsphere sensor. The prepared microsphere sensor is used in the transformer vibration monitoring method based on the microsphere sensor as described in the above example to monitor the vibration of the transformer. The preparation method of the microsphere sensor includes:

[0015] The solid material is melted by heating and melting technology to obtain a colloidal material, wherein the solid material has a light transmission property that meets the preset requirements;

[0016] Immersing a single-mode optical fiber with a flat and clean end surface into the colloid material and vertically pulling it multiple times;

[0017] Wait for the material to solidify until the colloid material shrinks into a spherical shape that meets the preset size on the end surface.

[0018] In one example, the solid material is PETG, and the temperature of the heating melting technology during heating is 68 degrees.

[0019] In one example, the vertical pulling speed is in the range of 0.150 mm / s to 0.200 mm / s;

[0020] The preset size is 500 μm in diameter.

[0021] In one example, before immersing the single-mode optical fiber with a flat and clean end surface into the colloid material and performing multiple vertical pulling, the method further includes:

[0022] The end surface of the single-mode optical fiber with a flat and clean end surface is covered with an affinity material to enhance the adsorption capacity of the end surface.

[0023] In one example, the affinity material is a non-ionic compound resin material that does not contain polysiloxane.

[0024] On the other hand, the present application also proposes a transformer vibration monitoring system based on a microsphere sensor, which is used to implement the transformer vibration monitoring method based on a microsphere sensor as described in any of the above examples. The system includes:

[0025] The wavelength demodulation system includes a narrowband light source, a circulator, a photodetector, a data acquisition and amplification circuit, a data interface, and an optical fiber interface, and controls the narrowband light source to send a first optical signal to the circulator, so that the first optical signal passes through the circulator and then enters the optical fiber vibration sensor through the optical fiber interface;

[0026] The optical fiber vibration sensor includes an optical fiber body and a microsphere sensor disposed on the end surface of the optical fiber body. The head end of the optical fiber body is connected to the wavelength demodulation system via the optical fiber interface. The microsphere sensor is disposed inside the transformer. The head end of the optical fiber body receives the first optical signal, so that after the first optical signal passes through the optical fiber body and reaches the microsphere sensor, a second optical signal is returned based on the refractive index of the microsphere sensor.

[0027] The wavelength demodulation system receives the second optical signal through the circulator, transmits the second optical signal to the photodetector, and then transmits the output light intensity data signal corresponding to the second optical signal to the host computer through the data acquisition and amplification circuit and the data interface after passing through the photodetector.

[0028] The host computer determines the vibration signal corresponding to the transformer based on the output light intensity of the second optical signal compared to the degree of change in the output light intensity of the microsphere sensor in a normal state, where the normal state refers to a state in which the microsphere sensor is not affected by external vibration.

[0029] The transformer vibration monitoring method based on microsphere sensors proposed in this application can bring the following beneficial effects:

[0030] The vibration signal is monitored based on the optical fiber vibration sensor, which uses optical fiber as the signal carrier. It has many characteristics such as high sensitivity, wide bandwidth, anti-electromagnetic interference, corrosion resistance, small size, easy multiplexing, and easy networking. It reduces the impact of high-voltage and strong magnetic environment on the online monitoring of transformer status, makes up for the shortcomings of traditional monitoring methods, and has extremely high application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0032] Figure 1 Schematic diagram of the process of a transformer vibration monitoring method based on a microsphere sensor in an embodiment of the present application;

[0033] Figure 2a and Figure 2b They are respectively a physical picture of the optical fiber vibration sensor in the embodiment of the present application and a schematic diagram of its actual working placement;

[0034] Figure 3a and Figure 3b They are respectively a schematic diagram of the external structure and a schematic diagram of the internal structure of the optical fiber vibration sensor in an embodiment of the present application;

[0035] Figure 4 Schematic diagram of the process for preparing a microsphere sensor in an embodiment of the present application;

[0036] Figure 5 This is a schematic flow chart of a method for preparing a microsphere sensor in one scenario according to an embodiment of the present application;

[0037] Figure 6 Schematic diagram of the structure of the transformer vibration monitoring system based on the microsphere sensor during the experiment in the embodiment of the present application;

[0038] Figure 7a and Figure 7b They are schematic diagrams of the time domain waveform and frequency domain waveform in the experimental results in the embodiments of the present application. DETAILED DESCRIPTION

[0039] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the specific embodiments of this application and the corresponding drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0040] The following describes in detail the technical solutions provided by various embodiments of the present application in conjunction with the accompanying drawings.

[0041] like Figure 1 As shown, the embodiment of the present application provides a transformer vibration monitoring method based on a microsphere sensor, comprising:

[0042] S101: Determine an optical fiber vibration sensor located inside a transformer, where the optical fiber vibration sensor includes an optical fiber body and a microsphere sensor disposed on an end surface of the optical fiber body.

[0043] The fiber optic vibration sensor is pre-placed inside the transformer to monitor the vibration signal generated inside the transformer. Generally speaking, the fiber optic vibration sensor can be placed in the transformer winding, core, shell and other locations. For example, Figure 2a and Figure 2b They are respectively a physical picture of the optical fiber vibration sensor in the embodiment of the present application and a schematic diagram of the actual working placement, such as Figure 2b As shown, in actual working placement, the microsphere sensor at one end is placed inside the transformer to work and realize vibration signal monitoring.

[0044] This fiber-optic vibration sensor lacks an additional cantilever beam and boasts a simple structure, compact size, excellent stability, and omnidirectional vibration sensitivity. Only one sensor is required to monitor vibration signals in a given space. Furthermore, the sensor boasts a wide response bandwidth and excellent electrical insulation, making it suitable for vibration measurement in complex electromagnetic environments.

[0045] During transformer operation, vibration signals from the transformer body (collectively, the core and windings) and cooling system are transmitted to the tank wall through various pathways. The core vibration is transmitted to the tank via two pathways: solid transmission, where the core vibration is transmitted to the tank via its pads; and liquid transmission, where the core vibration is transmitted to the tank via the insulating oil. Winding vibration is primarily transmitted to the tank via the insulating oil, causing vibration in the transformer body. For three-phase transformers operating under three-phase load, the vibration on the tank wall is the result of the vibration of each winding being transmitted and attenuated through dielectrics such as the insulating oil, and then superimposed on the tank wall. This complex vibration pattern causes the transformer to vibrate not only horizontally but also vertically.

[0046] Most existing vibration sensors are single-dimensional and can only detect vibration in a single direction. To achieve omnidirectional vibration detection, multiple sensors must be arranged in different directions at the same location. This approach significantly increases the sensor's footprint. However, the fiber optic microsphere vibration sensor proposed in this paper not only enables a single sensor to monitor the transformer's omnidirectional vibration, but also significantly reduces the space required due to its millimeter-scale microspheres.

[0047] S102: transmitting a first optical signal to a head end of the optical fiber body, so that after the first optical signal passes through the optical fiber body and reaches the microsphere sensor, a second optical signal is returned according to a refractive index of the microsphere sensor.

[0048] Figure 3a and Figure 3b They are respectively a schematic diagram of the external structure and a schematic diagram of the internal structure of the optical fiber vibration sensor in the embodiment of the present application, as shown in FIG. Figure 3a and Figure 3b As shown, after the optical signal is input (called the first optical signal), it is input into the microsphere sensor along the optical fiber body. At this time, the light beam is refracted inside the microsphere sensor (from Figure 3b The light is output from the front surface to the rear surface and then refracted back to the front surface), and then returns along the optical fiber body again (called the second light signal).

[0049] S103: Receive the returned second optical signal, and determine the vibration signal corresponding to the transformer based on the output light intensity of the second optical signal compared to the degree of change in the output light intensity of the microsphere sensor in a normal state, where the normal state refers to a state in which the microsphere sensor is not affected by external vibration.

[0050] The first light signal passes through the optical fiber and enters the microsphere vibration sensor. When the microsphere sensor senses environmental vibration, it generates internal stress in the microsphere sensor at the fiber end. Due to the photoelastic effect, this stress is further converted into a change in the refractive index of the microsphere sensor at the fiber end. This change in refractive index causes a change in the optical path length difference (OPL) experienced by the light signal in the microsphere sensor as it returns to the optical fiber after a return trip. This change is referred to as the first degree of change.

[0051] After processing the optical fiber and the microsphere sensor at its end, a Fizeau interferometer is formed. The first change in the optical path difference created above will cause a change in the Fizeau interferometer's output light intensity, referred to here as the second change. By detecting this second change in the optical fiber's output light intensity, the strength of the vibration signal can be determined. Demodulation technology then converts the light intensity into a specific value for the transformer's vibration signal, facilitating further evaluation of the transformer's vibration health.

[0052] Traditional technologies currently rely on mechanical or electrical sensing systems to monitor transformer vibration signals. Mechanical sensing can deviate over time, affecting vibration signal monitoring. Electrical monitoring systems are susceptible to electromagnetic interference, as the transformer's operating environment is saturated with electromagnetic signals. These traditional methods often suffer from high detection difficulty, low sensitivity and signal-to-noise ratio, low fault detection rate and diagnostic accuracy, incomplete detection information, and susceptibility to interference from strong electromagnetic fields and ambient noise.

[0053] Due to its simple structure (including the optical fiber body and microsphere sensor) and the absence of complex mechanical structures, the optical fiber vibration sensor can still maintain a high degree of accuracy during long-term monitoring. In addition, as a signal carrier, the optical fiber has a strong ability to resist electromagnetic interference, which greatly reduces the impact of high-voltage and strong magnetic environments on online monitoring of transformer status, making up for the shortcomings of traditional monitoring methods and having extremely high application value.

[0054] In one embodiment, according to the optical waveguide mode theory, the mathematical expression of the optical fiber microsphere transmission spectrum is obtained by theoretical calculation: In this formula: E in 、E out are the amplitudes of the input and output optical field components of the light vibration sensor, respectively; R is the coupling coefficient of light from the microsphere sensor back to the optical fiber; n is the effective refractive index of the microsphere sensor; c is the speed of light in vacuum; κ s , κ are the transmission loss of light in the microsphere sensor and the total loss of light in the entire propagation process of the optical fiber vibration sensor, respectively; d is the diameter of the microsphere sensor; m is a positive integer representing the mode order of the microsphere sensor; λ is the wavelength of light propagating in the optical fiber vibration sensor.

[0055] Maxwell's equations can be used to derive a method for calculating the structural characteristics of the optical fiber microsphere. Based on this method, when determining the vibration signal, the refractive index of the microsphere sensor (i.e., the effective refractive index n mentioned above) is determined based on the degree of change in the output intensity of the second optical signal compared to the output intensity of the microsphere sensor in its normal state. This refractive index, along with the manufacturing parameters of the microsphere sensor, can be used to determine the resonant wavelength of the transformer, which can then be used to generate the vibration signal corresponding to the microsphere sensor.

[0056] Furthermore, in this calculation method, the manufacturing parameters include the size information of the microsphere sensor and the mode order of the microsphere sensor, and the resonant wavelength is positively correlated with the refractive index. This can be reflected by the following formula: Among them, λ resis the resonant wavelength, n is the effective refractive index of the microsphere sensor, and m is a positive integer representing the mode order of the microsphere sensor. The mode order m and the diameter d of the microsphere sensor are known parameters that can be measured during manufacturing.

[0057] like Figure 4 As shown, the present application also proposes a method for preparing a microsphere sensor. The microsphere sensor made by this method can be used as the microsphere sensor in the optical fiber vibration sensor mentioned above to form an optical fiber vibration sensor, thereby realizing vibration monitoring of the transformer.

[0058] Figure 5 A schematic diagram of a process for preparing a microsphere sensor in a scenario is shown in FIG. Figure 4 and Figure 5 As shown, the preparation method includes:

[0059] S401: melting the solid material by heating and melting technology to obtain a colloidal material, wherein the solid material has light transmission characteristics that meet preset requirements.

[0060] When selecting materials, it is important to choose one that has good light transmittance and is solid at room temperature. This solid material is melted using a heating and melting technique. The heating temperature affects the viscosity of the melted material, and an appropriate viscosity is conducive to the formation of high-quality microspheres. Therefore, repeated experimentation with the appropriate heating temperature is necessary.

[0061] Specifically, the solid material is selected as PETG (polyethylene terephthalate-1,4-cyclohexadienylidene terephthalate). The thermal deformation temperature of PETG material is 65-70°C. By testing the surface smoothness of the material after curing within this temperature range, it is found that when the temperature is about 68°C, the surface of the prepared microspheres is the smoothest, so it is adopted.

[0062] The raw material used to make the microsphere sensor in this paper is PETG, which not only has good toughness and thermoformability, but more importantly, it has good chemical stability. Since the heat generated during the operation of the transformer causes the entire transformer to be in a high-temperature environment, and the interior of the transformer is immersed in insulating oil, the environment in which the microsphere optical fiber is located is a high-temperature environment immersed in insulating oil. If the selected material undergoes a chemical reaction in a high-temperature oil-immersion environment, the generated substances may reduce the insulating properties of the insulating oil, causing the insulating oil breakdown voltage to decrease, and may cause partial discharge, threatening the safe operation of the transformer. However, the PETG material selected in this application has excellent chemical stability and does not crack in a high-temperature insulating oil environment. In practical applications, it will not affect the insulating properties of the transformer oil.

[0063] S402: Immerse the single-mode optical fiber with a flat and clean end surface into the colloid material and vertically pull it multiple times.

[0064] The end face of a single-mode optical fiber (corresponding to the fiber body mentioned above) is pre-processed to make it flat and clean. The clean, flat end face of the single-mode optical fiber is then immersed in a colloid or molten preparation material and pulled vertically multiple times. The colloid material adheres to the end face of the fiber and, under the influence of gravity and adhesion to the fiber surface, is in equilibrium. Due to surface tension, the material self-organizes and shrinks into a spherical shape at the end face of the fiber.

[0065] Specifically, the preparation effect when the pulling speed is in the range of 0.001mm / s to 0.4mm / s was tested. It was found through observation that when the pulling speed is in the range of 0.150mm / s to 0.200mm / s, the surface of the microspheres is relatively smooth, especially when the pulling speed is 0.180mm / s, the surface of the microspheres prepared is the smoothest and was adopted.

[0066] S403: Waiting for the material to solidify until the colloid material shrinks on the end surface into a spherical shape that meets a preset size.

[0067] After hovering in mid-air and waiting for the material to solidify, it shrinks into a spherical shape, forming microspheres on the end surface, thus forming a microsphere sensor. If the size of the microspheres does not meet the preset size requirements at this point, steps S401-S403 can be repeated, and each repetition increases the geometric size of the microspheres until the preset size requirements are met. Throughout the entire preparation process, the microspheres self-organize and form directly on the end face of the optical fiber, thereby ensuring low coupling loss between the optical fiber and the microspheres.

[0068] Among them, it was found through testing that the microsphere with a diameter of 500 μm has the highest sensitivity to vibration, which is 2 pm / 10 Pa, so it was adopted.

[0069] In one embodiment, the material's adhesion to the optical fiber surface is crucial to the success of fiber microsphere fabrication. If the material lacks adhesion to the optical fiber surface, microspheres cannot be fabricated on the fiber end face. In this case, a method such as vacuum sputtering can be used to coat the optical fiber surface with a material that has a strong affinity for the microsphere material. This enhances the material's adsorption to the optical fiber surface, thereby ensuring successful microsphere fabrication.

[0070] Specifically, before the end face is immersed in the colloidal material, it is first coated with an affinity material to enhance the end face's adsorption capacity. The affinity material used is primarily a non-ionic compound resin material that does not contain polysiloxane. In this case, a water-based epoxy-silane material can be used, which is effective in enhancing the adhesion of optical fibers to the dielectric microsphere surface.

[0071] The present application also proposes a transformer vibration monitoring system based on a microsphere sensor, which includes a wavelength demodulation system, a light vibration sensor and a host computer.

[0072] The wavelength demodulation system includes a narrowband light source, a circulator, a photodetector, a data acquisition and amplification circuit, a data interface, and an optical fiber interface. In actual operation, the narrowband light source is controlled to send a first optical signal to the circulator, so that the first optical signal passes through the circulator and then enters the optical fiber vibration sensor through the optical fiber interface.

[0073] The optical fiber vibration sensor includes an optical fiber body and a microsphere sensor disposed on the end surface of the optical fiber body. The head end of the optical fiber body is connected to the wavelength demodulation system through an optical fiber interface. The microsphere sensor is disposed inside the transformer. The head end of the optical fiber body receives a first optical signal. After the first optical signal passes through the optical fiber body and reaches the microsphere sensor, a second optical signal is returned based on the refractive index of the microsphere sensor.

[0074] The wavelength demodulation system receives the second optical signal through the circulator, transmits the second optical signal to the photodetector, and transmits the output light intensity data signal corresponding to the second optical signal to the host computer through the data acquisition and amplification circuit and the data interface through the photodetector;

[0075] The host computer determines the vibration signal corresponding to the transformer based on the output light intensity of the second optical signal compared to the degree of change in the output light intensity of the microsphere sensor in a normal state. The normal state refers to a state in which the microsphere sensor is not affected by external vibration.

[0076] Figure 6 This is a schematic diagram of the architecture of the transformer vibration monitoring system based on the microsphere sensor during the experiment in the embodiment of the present application. During the experiment, in order to simulate the on-site environment, the transformer is converted into a vibration table, and vibration monitoring points are set on the vibration table. The microsphere sensor is set at the vibration monitoring point, so that the optical fiber microsphere vibration sensor in the figure (which is equivalent to the optical fiber vibration sensor mentioned above) is controlled by the vibration table control host to simulate vibration scenes in various environments, and the actual vibration signal received by the microsphere sensor is monitored through the vibration monitoring point, and compared with the vibration signal obtained by the host computer to complete the relevant experiment.

[0077] During the experiment, the upper computer is connected to the data interface for control, and an adjustable narrowband light source (i.e., the first light signal) is injected into the optical fiber vibration sensor. The optical signal output by the optical fiber vibration sensor (i.e., the second light signal) is collected after photoelectric conversion and amplification. When there is no vibration in the environment, the output of the sensor is 0. When the environment vibrates, the light intensity output by the sensor fluctuates with the change of the vibration signal. By measuring the change in light intensity, the measured vibration signal can be obtained. Figure 7a and Figure 7b They are schematic diagrams of the time domain waveform and frequency domain waveform in the experimental results in the embodiments of the present application, which show the response under the excitation of superimposed vibration signals of several different frequencies.

[0078] The present application also provides a transformer vibration monitoring device based on a microsphere sensor, including:

[0079] at least one processor; and,

[0080] a memory communicatively connected to the at least one processor; wherein,

[0081] The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to:

[0082] Determine an optical fiber vibration sensor located inside the transformer, the optical fiber vibration sensor comprising an optical fiber body and a microsphere sensor disposed on an end surface of the optical fiber body;

[0083] Transmitting a first optical signal to the head end of the optical fiber body, so that after the first optical signal passes through the optical fiber body and reaches the microsphere sensor, a second optical signal is returned according to the refractive index of the microsphere sensor;

[0084] The second optical signal is received and a vibration signal corresponding to the transformer is determined based on a degree of change in the output light intensity of the second optical signal compared to the output light intensity of the microsphere sensor in a normal state, where the normal state refers to a state in which the microsphere sensor is not affected by external vibration.

[0085] The embodiment of the present application further provides a non-volatile computer storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured to:

[0086] Determine an optical fiber vibration sensor located inside the transformer, the optical fiber vibration sensor comprising an optical fiber body and a microsphere sensor disposed on an end surface of the optical fiber body;

[0087] Transmitting a first optical signal to the head end of the optical fiber body, so that after the first optical signal passes through the optical fiber body and reaches the microsphere sensor, a second optical signal is returned according to the refractive index of the microsphere sensor;

[0088] The second optical signal is received and a vibration signal corresponding to the transformer is determined based on a degree of change in the output light intensity of the second optical signal compared to the output light intensity of the microsphere sensor in a normal state, where the normal state refers to a state in which the microsphere sensor is not affected by external vibration.

[0089] The various embodiments in this application are described in a progressive manner. Similar portions between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the device and medium embodiments are generally similar to the method embodiments, so their descriptions are relatively simple. For relevant portions, refer to the descriptions of the method embodiments.

[0090] The devices and media provided in the embodiments of the present application correspond one-to-one to the methods. Therefore, the devices and media also have similar beneficial technical effects to their corresponding methods. Since the beneficial technical effects of the methods have been described in detail above, the beneficial technical effects of the devices and media will not be repeated here.

[0091] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0092] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0093] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0094] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0095] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0096] Memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

[0097] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0098] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0099] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A transformer vibration monitoring method based on a microsphere sensor, characterized in that: include: Determine an optical fiber vibration sensor located inside the transformer, the optical fiber vibration sensor comprising an optical fiber body and a microsphere sensor disposed on an end surface of the optical fiber body; Transmitting a first optical signal to the head end of the optical fiber body, so that after the first optical signal passes through the optical fiber body and reaches the microsphere sensor, a second optical signal is returned according to the refractive index of the microsphere sensor; receiving the returned second optical signal; and determining a vibration signal corresponding to the transformer based on a degree of change in the output light intensity of the second light signal compared to an output light intensity of the microsphere sensor in a normal state, specifically comprising: determining a refractive index corresponding to the microsphere sensor based on a degree of change in the output light intensity of the second light signal compared to an output light intensity of the microsphere sensor in a normal state; determining a resonant wavelength corresponding to the transformer based on the refractive index and manufacturing parameters corresponding to the microsphere sensor, so as to obtain a vibration signal corresponding to the microsphere sensor based on the resonant wavelength; The normal state refers to a state in which the microsphere sensor is not affected by external vibrations; the manufacturing parameters include size information of the microsphere sensor and a mode order of the microsphere sensor, and the resonant wavelength is positively correlated with the refractive index; Determining the resonant wavelength corresponding to the transformer according to the refractive index and the manufacturing parameters corresponding to the microsphere sensor specifically includes: By formula The resonant wavelength corresponding to the transformer is obtained, where λ res is the resonant wavelength, n is the effective refractive index of the microsphere sensor, m is a positive integer representing the mode order of the microsphere sensor, and d is the diameter of the microsphere sensor.

2. A method for preparing a microsphere sensor, characterized in that: The prepared microsphere sensor is used in the transformer vibration monitoring method based on the microsphere sensor as claimed in claim 1 to monitor the vibration of the transformer. The preparation method of the microsphere sensor includes: The solid material is melted by a heating and melting technique to obtain a colloidal material, wherein the solid material has a light transmittance property that meets preset requirements; the solid material is PETG, and the heating and melting technique is performed at a temperature of 68 degrees; The end surface of the single-mode optical fiber with a flat and clean end surface is covered with an affinity material to enhance the adsorption capacity of the end surface; the affinity material is a non-ionic compound resin material that does not contain polysiloxane; Immerse a single-mode optical fiber with a smooth and clean end surface in the colloid material and vertically pull it multiple times; the vertical pulling speed is within the range of 0.150 mm / s to 0.200 mm / s; the preset size is a diameter of 500 μm; Wait for the material to solidify until the colloid material shrinks into a spherical shape that meets the preset size on the end surface.

3. A transformer vibration monitoring system based on microsphere sensors, characterized in that: For implementing the transformer vibration monitoring method based on a microsphere sensor as claimed in claim 1, the system comprises: The wavelength demodulation system includes a narrowband light source, a circulator, a photodetector, a data acquisition and amplification circuit, a data interface, and an optical fiber interface, and controls the narrowband light source to send a first optical signal to the circulator, so that the first optical signal passes through the circulator and then enters the optical fiber vibration sensor through the optical fiber interface; The optical fiber vibration sensor includes an optical fiber body and a microsphere sensor disposed on the end surface of the optical fiber body. The head end of the optical fiber body is connected to the wavelength demodulation system via the optical fiber interface. The microsphere sensor is disposed inside the transformer. The head end of the optical fiber body receives the first optical signal, so that after the first optical signal passes through the optical fiber body and reaches the microsphere sensor, a second optical signal is returned based on the refractive index of the microsphere sensor. The wavelength demodulation system receives the second optical signal through the circulator, transmits the second optical signal to the photodetector, and then transmits the output light intensity data signal corresponding to the second optical signal to the host computer through the data acquisition and amplification circuit and the data interface after passing through the photodetector. The host computer determines the vibration signal corresponding to the transformer based on the degree of change in the output light intensity of the second light signal compared to the output light intensity of the microsphere sensor in a normal state, specifically including: determining a refractive index corresponding to the microsphere sensor based on the degree of change in the output light intensity of the second light signal compared to the output light intensity of the microsphere sensor in a normal state; determining a resonant wavelength corresponding to the transformer based on the refractive index and manufacturing parameters corresponding to the microsphere sensor, so as to obtain the vibration signal corresponding to the microsphere sensor based on the resonant wavelength; The normal state refers to a state in which the microsphere sensor is not affected by external vibrations.

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