A method, device and electronic equipment for testing the acoustic and vibration level of the iron core of a transformer

Abstract

The present invention provides a method, device and electronic equipment for testing the acoustic and vibration level of the iron core of a transformer. The method includes: obtaining an equivalent model of the transformer to be tested based on a preset standard; obtaining the noise level amplification ratio and vibration level amplification ratio of the transformer to be tested compared with the equivalent model; obtaining the vibration level and noise level at different positions of the iron core of the equivalent model; and determining the acoustic and vibration level of the iron core of the transformer to be tested based on the noise level amplification ratio, vibration level amplification ratio, vibration level and noise level. The present invention designs an equivalent model of the actual transformer, which effectively reflects the noise and vibration data of the actual transformer. It can directly load the test conditions on the transformer iron core without oil injection, facilitating the direct testing of the iron core noise and vibration, providing an effective test scheme for the analysis of the acoustic and vibration characteristics of the iron core of high-voltage transformers, and avoiding the deficiencies of conventional testing techniques in aspects such as insulation design and installation.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of acoustic and vibration testing of power equipment, and in particular, to a method, device and electronic equipment for testing the acoustic and vibration level of the iron core of a transformer. Background Art

[0002] With the development of the economic society, the electricity consumption demands of residents and industrial enterprises are continuously increasing. As an important device in the power transmission network, the usage scale of power transformers is also continuously expanding. However, with the continuous increase of the power grid scale and the shortage of urban land resources, more and more substation locations are deep in the city center. To reduce the impact on the surrounding acoustic environment, the noise and vibration level of transformers has become one of the important indicators for product factory testing, and the vibration and noise characteristics, generation mechanism, propagation law, etc. of transformers have become research hotspots in related fields.

[0003] Existing research shows that the noise and vibration of transformers originate from the vibration caused by magnetostriction of the iron core laminations under alternating current conditions. Such vibrations are transmitted to the oil tank through the iron core feet and transformer oil, forming a "secondary vibration source". Therefore, the acoustic and vibration level of the iron core directly determines the overall noise level of the transformer. However, the iron core is located inside the oil tank and is in a high-temperature, oil-immersed and energized state during operation, making it difficult to directly conduct acoustic and vibration tests. Existing research generally focuses on aspects such as the testing and simulation calculation of iron core silicon steel materials. The existing noise and vibration testing technologies generally target the overall product after installing the oil tank. Due to the barrier of insulating oil and the oil tank, the test results cannot directly reflect the acoustic and vibration level of the iron core. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a method, equipment and electronic equipment for testing the acoustic and vibration level of the iron core of a transformer, and obtains the noise level and vibration data of the transformer iron core through a combination of equivalent model construction, simulation and experimental testing.

[0005] In a first aspect, the present invention provides a method for testing the acoustic and vibration level of the iron core of a transformer, the method comprising:

[0006] Based on a preset standard, obtain an equivalent model of the transformer to be tested;

[0007] Obtain the noise level amplification ratio and vibration level amplification ratio of the transformer to be tested compared to the equivalent model;

[0008] Obtain the vibration level and noise level at different positions of the iron core of the equivalent model;

[0009] Based on the noise level amplification ratio, the vibration level amplification ratio, the vibration level and the noise level, determine the acoustic and vibration level of the iron core of the transformer to be tested.

[0010] In a possible implementation, obtaining the equivalent model of the transformer to be tested based on a preset standard is specifically as follows:

[0011] Based on the principles of magnetic field equivalence, material equivalence, and structural equivalence for the core material, winding material, and structural characteristics of the transformer to be tested, the equivalent model of the transformer to be tested is obtained.

[0012] In a possible implementation, the core material and winding material of the equivalent model are the same as those of the transformer to be tested.

[0013] In a possible implementation, the core size of the equivalent model is designed with a scale ratio of 1:3 to 1:5 of the core size of the transformer to be tested.

[0014] In a possible implementation, obtaining the noise level amplification ratio and vibration level amplification ratio of the transformer to be tested compared with the equivalent model specifically includes:

[0015] Establish a multi-physics field coupling simulation model of the cores of the equivalent model and the transformer to be tested, and respectively obtain the noise level amplification ratio and vibration level amplification ratio of the transformer to be tested compared with the equivalent model under the same core magnetic flux density.

[0016] In a possible implementation, obtaining the vibration level and noise level at different positions of the core of the equivalent model is specifically as follows:

[0017] On the premise of not installing the fuel tank and filling with oil, apply voltage or current excitation to the equivalent model, use an accelerometer to test and obtain the vibration levels at different positions, and use a sound level meter to test and obtain the noise level of the core.

[0018] In a possible implementation, determining the acoustic-vibration level of the core of the transformer to be tested based on the noise level amplification ratio, the vibration level amplification ratio, the vibration level, and the noise level specifically includes:

[0019] Multiply the noise level by the noise level amplification ratio to obtain the noise level of the core of the transformer to be tested;

[0020] Multiply the vibration level by the vibration level amplification ratio to obtain the vibration level of the core of the transformer to be tested.

[0021] In a second aspect, the present invention provides an acoustic-vibration level testing device for the core of a transformer, and the device includes:

[0022] An equivalent model module, configured to obtain an equivalent model of a transformer to be tested based on a preset standard;

[0023] An amplification ratio module, configured to obtain the noise level amplification ratio and the vibration level amplification ratio of the transformer under test compared to the equivalent model;

[0024] An acquisition module, configured to acquire the vibration level and the noise level at different positions of the iron core of the equivalent model;

[0025] An acoustic-vibration level module, configured to determine the acoustic-vibration level of the iron core of the transformer under test based on the noise level amplification ratio, the vibration level amplification ratio, the vibration level, and the noise level.

[0026] In a third aspect, the present invention provides an electronic device carrying the resource scheduling system, including a processor, a communication interface, a memory, and a communication bus. Among them, the processor, the communication interface, and the memory complete communication with each other through the communication bus;

[0027] The memory is used to store a computer program;

[0028] The processor, when executing the program stored on the memory, implements the steps of the method for testing the acoustic-vibration level of the iron core of the transformer according to any one of the embodiments in the first aspect.

[0029] In a fourth aspect, the present invention provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for testing the acoustic-vibration level of the iron core of the transformer according to any one of the embodiments in the first aspect are implemented.

[0030] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art:

[0031] The method provided by the embodiments of the present application obtains an equivalent model of the transformer under test based on a preset standard. The noise level amplification ratio and the vibration level amplification ratio of the transformer under test compared to the equivalent model are obtained. The vibration level and the noise level at different positions of the iron core of the equivalent model are obtained. Based on the noise level amplification ratio, the vibration level amplification ratio, the vibration level, and the noise level, the acoustic-vibration level of the iron core of the transformer under test is determined. This method designs an equivalent model of the actual transformer through a preset standard, effectively reflects the noise and vibration data of the actual transformer, can directly load the test conditions on the transformer iron core without oil injection, is convenient for directly testing the noise and vibration of the iron core, and then converts the acoustic-vibration test results of the equivalent model into the acoustic-vibration data of the actual transformer product, avoiding risks such as insulation safety caused by arranging sensors in the actual transformer oil tank. This technical solution provides an effective test solution for the analysis of the acoustic-vibration characteristics of the iron core of high-voltage transformers, and avoids the deficiencies of conventional test technologies in aspects such as insulation design and installation. Description of the Drawings

[0032] Figure 1 Schematic flow chart of the method for testing the acoustic and vibration level of the iron core of a transformer provided by an embodiment of the present invention;

[0033] Figure 2 Flux density simulation diagram of the iron core of the scaled-down equivalent model in Embodiment 1;

[0034] Figure 3 Flux density simulation diagram of the iron core of the transformer to be tested in Embodiment 1;

[0035] Figure 4 Schematic diagram of the iron core structure of the scaled-down equivalent model;

[0036] Figure 5 For Figure 4 Cross-sectional view A-A in;

[0037] Figure 6 Vibration simulation diagram of the iron core of the scaled-down equivalent model in Embodiment 1;

[0038] Figure 7 Vibration simulation diagram of the iron core of the transformer to be tested in Embodiment 1;

[0039] Figure 8 Noise simulation diagram of the iron core of the scaled-down equivalent model in Embodiment 1;

[0040] Figure 9 Noise simulation diagram of the iron core of the transformer to be tested in Embodiment 1;

[0041] Figure 10 Schematic diagram of the noise test of the scaled-down equivalent model;

[0042] Figure 11 Schematic structural diagram of a device for testing the acoustic and vibration level of the iron core of a transformer provided by an embodiment of the present invention;

[0043] Figure 12 Schematic structural diagram of an electronic device provided by an embodiment of the present invention.

[0044] Reference numerals: 1 - laminated iron core structure, 2 - fiber optic accelerometer, 3 - polyester tape. Detailed implementation manners

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0046] For the convenience of understanding the embodiments of the present invention, the following will further explain with specific embodiments in conjunction with the accompanying drawings. The embodiments do not limit the embodiments of the present invention.

[0047] To solve the deficiencies of the prior art, the present invention provides a method for testing the acoustic and vibration levels of the iron core of a transformer. Specifically, refer to Figure 1 as shown Figure 1 which is a schematic flow chart of a method for testing the acoustic and vibration levels of the iron core of a transformer provided by an embodiment of the present invention. As Figure 1 shown, the method includes the following steps:

[0048] Step 110, based on a preset standard, obtain an equivalent model of the transformer to be tested.

[0049] Specifically, the noise of the transformer is mainly generated by the iron core, and the selection of the magnetic density of the iron core is crucial for the noise of the transformer. In one example, based on the principles of magnetic field equivalence, material equivalence, and structural equivalence for the iron core material, winding material, and structural characteristics of the transformer to be tested, an equivalent model of the transformer to be tested is obtained. Through the principles of magnetic field, structure, and material equivalence, the obtained equivalent model of the transformer can effectively reflect the noise and vibration data of the actual transformer product.

[0050] In another example, the iron core material and winding material of the equivalent model are the same as those of the iron core material and winding material of the transformer to be tested.

[0051] In yet another example, the equivalent model obtained in this application is a scaled-down equivalent model. Since under the same structural, operating conditions, and process level, the noise level of the transformer is mainly affected by the capacity and size, and the larger the capacity and size of the transformer, the higher the noise. Therefore, in the design process of the scaled-down model, it is crucial to select an appropriate scaling ratio. If the scaled-down model is too small, the noise will be low, which is not conducive to test measurement, while if the model is too large, it will exceed the power supply capacity in the test station. After comprehensively considering the noise level of the scaled-down model and the limitations of the test capabilities, the iron core size of the equivalent model is designed to be scaled down by a ratio of 1:3 to 1:5 of the iron core size of the transformer to be tested.

[0052] In still another example, the winding size of the equivalent model is not scaled down proportionally. By establishing a simulation analysis model of the iron core magnetic field of the transformer to be tested under rated conditions, the magnetic density level of the iron core is obtained, and based on this, the winding size, number of turns, rated current, and voltage parameters of the equivalent model of the transformer are adjusted to make the magnetic density level of the iron core consistent with that of the transformer to be tested.

[0053] Step 120, obtain the amplification ratios of the noise level and vibration level of the transformer to be tested compared to the equivalent model.

[0054] In one example, a multi-physics coupling simulation model of the equivalent model and the core of the transformer under test is established. Under the same core magnetic flux density, the noise level amplification ratio and the vibration level amplification ratio of the transformer under test compared to the equivalent model are obtained respectively. Among them, the multi-physics coupling simulation model includes: electromagnetic, vibration and noise simulation models.

[0055] Specifically, the electromagnetic, vibration and noise simulation models calculate the vibration levels at the core columns and yokes of the transformer under test and the equivalent model under specific working conditions, as well as the noise level of the envelope surface 0.3 m away from the core surface, and then calculate the noise level amplification ratio and the vibration level amplification ratio of the transformer under test compared to the equivalent model.

[0056] Using simulation analysis technology, the acoustic-vibration level proportionality coefficient of the equivalent model and the transformer under test under the same proportion of working conditions is calculated, and then through proportional conversion, the acoustic-vibration test results of the equivalent model are converted into the acoustic-vibration data of the actual product, avoiding risks such as insulation safety caused by arranging sensors inside the actual transformer tank.

[0057] Step 130, obtain the vibration levels and noise levels at different positions of the core of the equivalent model.

[0058] In one example, on the premise of not installing the oil tank and injecting oil, a voltage or current excitation is applied to the equivalent model, and an accelerometer is used to test the vibration levels at different positions, and a sound level meter is used to test the noise level of the core. Specifically, the sound level meter is arranged on the envelope surface 0.3 m away from the core surface to measure the noise level. The equivalent model designed by the present invention is convenient for assembly and disassembly, has a low voltage level, can directly load the test working conditions on the transformer core without injecting oil, and is convenient for directly testing the noise and vibration of the core.

[0059] In one example, the accelerometer is a fiber optic accelerometer or a laser vibrometer.

[0060] If it is a fiber optic accelerometer, it is fixed to the yoke and core column by polyester tape, and an insulating cardboard is padded between the sensor and the yoke and core column, and at the same time, the binding tape is retracted to ensure that the sensor is in close contact with the insulating cardboard. If it is a laser vibrometer, the vibration is measured directly by the laser signal incident on the measuring point position. The vibration test is carried out by the fiber optic accelerometer or the non-contact laser vibrometer after insulation treatment, ensuring the electrical safety of the measuring equipment.

[0061] Step 140, determine the acoustic-vibration level of the core of the transformer under test based on the noise level amplification ratio, the vibration level amplification ratio, the vibration level and the noise level.

[0062] Specifically, multiply the noise level by the noise level amplification ratio to obtain the noise level of the iron core of the transformer to be tested; multiply the vibration level by the vibration level amplification ratio to obtain the vibration level of the iron core of the transformer to be tested.

[0063] The method provided by the embodiment of the present application obtains an equivalent model of the transformer to be tested based on a preset standard. Obtain the noise level amplification ratio and vibration level amplification ratio of the transformer to be tested compared with the equivalent model. Obtain the vibration level and noise level at different positions of the iron core of the equivalent model. Based on the noise level amplification ratio, the vibration level amplification ratio, the vibration level, and the noise level, determine the acoustic-vibration level of the iron core of the transformer to be tested. This method designs an equivalent model of the actual transformer through a preset standard, effectively reflects the noise and vibration data of the actual transformer, can directly load the test conditions on the transformer iron core without oil injection, is convenient for directly testing the noise and vibration of the iron core, and then converts the acoustic-vibration test results of the equivalent model into the acoustic-vibration data of the actual transformer product, avoiding risks such as insulation safety caused by arranging sensors in the actual transformer oil tank. This technical solution provides an effective test solution for the analysis of the acoustic-vibration characteristics of the iron core of high-voltage transformers and avoids the deficiencies of conventional test technologies in aspects such as insulation design and installation.

[0064] According to the above-described method for testing the acoustic-vibration level of the iron core of a transformer, specific embodiments 1 and 2 are used for detailed description respectively:

[0065] Embodiment 1

[0066] A 110kV 50MVA transformer product produced by a certain equipment factory is about to be put into operation. This actual transformer is used as the transformer to be tested. To master its iron core noise and vibration characteristics, the following scheme is adopted for testing:

[0067] (1) Based on the preset standard, obtain the equivalent model of the transformer to be tested.

[0068] Regarding the material and structural characteristics of the transformer iron core and winding, a transformer equivalent model is designed and manufactured by adopting the principles of magnetic field equivalence, structural equivalence, and material equivalence.

[0069] Considering the limitations of the noise level and test capabilities of the equivalent model, this project selects to scale down by a ratio of 1:3, that is, the size of the equivalent model is reduced to 1 / 3 of the original product size. The designed equivalent model is a scaled-down equivalent model. The specific design parameters of the scaled-down equivalent model are as follows:

[0070] ① Capacity, voltage, and connection group

[0071] Number of phases: 3 phases

[0072] Rated capacity: 800 kVA

[0073] Rated voltage: 10 kV

[0074] Connection group: YNd11

[0075] ② Core material and structure

[0076] Grade of silicon steel sheet: B30P105

[0077] Core type: Three-phase three-column with inclined joints

[0078] Core magnetic density: 1.748 T

[0079] Number of core steps: 15

[0080] Lap length: 18 mm

[0081] ③ Winding structure

[0082] Designed according to capacity voltage level without scaling down proportionally. The number of turns of the high-voltage winding is 425, and the number of turns of the low-voltage winding is 28. The winding height is 330 mm, the inner diameter is 340 mm, and the outer diameter is 430 mm.

[0083] ④ Tank structure

[0084] Tank type: Bell type

[0085] Tank external dimensions: Scaled down proportionally

[0086] Tank thickness: Selected according to the actual situation in a ratio close to 1:3

[0087] ⑤ Tank components

[0088] The dimensions of tank components such as the conservator, bushing, and radiator can be adjusted according to the actual situation, and try to ensure a ratio of 1:3 or carry out corresponding counterweight treatment.

[0089] The noise of the transformer is mainly generated by the core, and the selection of the core magnetic density is crucial for the noise of the transformer. Therefore, in addition to the core structure of the scaled-down equivalent model being the same as that of the 110 kV transformer under test, the core magnetic density of the scaled-down equivalent model should also be the same as that of the 110 kV transformer under test. For this reason, the MagNet electromagnetic simulation software was used to simulate and analyze the no-load core magnetic field of the scaled-down model and the 110 kV transformer under test, and the average magnetic density of the core was investigated. Figure 2 and Figure 3 The core surface magnetic field distribution and the magnetic density distribution along the axial section at the center of the core of the scaled-down equivalent model and the 110 kV transformer under test at rated voltage are respectively given. The following table gives the comparison values of the average magnetic density of the core columns of the scaled-down equivalent model and the 110 kV transformer under test.

[0090] Comparison values of the average magnetic density of the core between the scaled equivalent model and the 50MVA / 110kV transformer under test

[0091] Model Average magnetic density of core column (T) Average magnetic density of yoke (T) Scaled-down model 1.745 1.751 110 kV product 1.741 1.748 Error 0.23％ 0.17％

[0092] The general structure of the scaled equivalent model is as Figure 4 shown

[0093] Considering that the winding noise in the actual 50MVA / 110kV transformer under test is not obvious, the winding of the scaled equivalent model is simplified in the design. That is, the winding is electrically designed according to the size, capacity, voltage level, etc. of the core of the scaled equivalent model, rather than designed according to the ratio and structure. The finally prepared scaled equivalent model is a product with a capacity of 10kV 800kVA

[0094] (2) Determine the amplification ratios of the noise level and vibration level of the transformer under test compared with the equivalent model

[0095] Establish a multi-physics coupling simulation model of the cores of the scaled equivalent model and the transformer under test. Under the same core magnetic flux density, calculate and obtain the amplification ratios of the noise level and vibration level of the transformer under test compared with the equivalent model respectively

[0096] Using finite element simulation software, first establish the geometric models of the scaled equivalent model and the transformer under test according to parameters such as the core size. Subsequently, according to the parameters such as the H-B curve, Young's modulus, Poisson's ratio, density, relative permittivity, etc. of the silicon steel sheet obtained by query, define the material properties of the model, and set fixed constraint boundary conditions for the core pad positions. At the same time, use the multi-physics coupling module of circuit-magnetic field-solid mechanics-acoustics to define the core and air domain. Set the rated voltage condition on the winding. After completing the mesh division, perform structural mechanics and acoustic calculations to obtain the simulation analysis results of the vibration field and sound field of the scaled equivalent model and the transformer under test, as Figures 6 - 9 shown. According to the simulation results in the figure, the vibration acceleration ratio of the transformer under test model to the scaled equivalent model is 1.7; taking the noise measurement point at 0.3m, the sound pressure level ratio of the transformer under test model to the scaled equivalent model is 1.18

[0097] (3) Obtain the vibration level and noise level at different positions of the core of the equivalent model

[0098] On the premise of not installing the oil tank and injecting oil, apply voltage or current excitation to the scaled equivalent model, and use an accelerometer to measure the vibration level at different positions, and use a sound level meter to measure the core noise level

[0099] According to Figure 4In the installation plan, eight fiber optic acceleration sensors are respectively fixed on the yoke and the core column by tying, and insulating cardboard is laid between the sensors and the yoke and the core column. At the same time, the binding straps are retracted to ensure that the sensors are in close contact with the insulating cardboard. Apply the rated working condition to the core model, and use a sound level meter to measure the noise at the envelope surface 0.3 m away from the model surface, as Figure 10 shown. The final test results are shown in the following table.

[0100] Table 2 Core surface vibration test results

[0101] Measuring point number Position <![CDATA[Measured value (m / s 2 )]]> 1 Left side of upper part of iron core 0.45 2 Middle of upper part of iron core 0.32 3 Right side of upper part of iron core 0.58 4 Left side of middle part of iron core 0.37 5 Middle of middle part of iron core 0.27 6 Right side of middle part of iron core 0.36 7 Left side of bottom part of iron core 0.17 8 Middle of bottom part of iron core 0.21 9 Right side of bottom part of iron core 0.23

[0102] Table 3 Core noise test results

[0103] Measuring point number Measured value (dB) 1 50 2 49 3 51 4 49

[0104] (3) Based on the noise level amplification ratio, vibration level amplification ratio, vibration level and noise level, determine the acoustic-vibration level of the core of the transformer to be tested.

[0105] Multiply the noise level by the noise level amplification ratio to obtain the noise level of the core of the transformer to be tested. Multiply the vibration level by the vibration level amplification ratio to obtain the vibration level of the core of the transformer to be tested, which is the acoustic-vibration level of the transformer to be tested.

[0106] Multiply the data in Table 2 by the vibration level amplification ratio of 1.7, and multiply the data in Table 3 by the noise level amplification ratio of 1.18 to obtain the noise and vibration data of the core of the actual transformer.

[0107] Example 2

[0108] A 220 kV 50 MVA transformer product produced by a certain equipment factory is about to be put into operation. Take this actual transformer as the transformer to be tested. To understand its core noise and vibration characteristics, the following scheme is adopted for testing:

[0109] (1) Based on the preset standard, obtain the equivalent model of the transformer to be tested.

[0110] For the material and structural characteristics of the transformer core and winding, adopt the principles of magnetic field equivalence, structural equivalence and material equivalence to design and manufacture a transformer equivalent model

[0111] After comprehensively considering the noise level and test capacity limitations of the equivalent model, this project chooses to scale down by a ratio of 1:5, that is, reduce the size of the scaled-down transformer model to 1 / 5 of the original product size. The specific design parameters of the scaled-down equivalent model are as follows:

[0112] ① Capacity, voltage and connection group

[0113] Phase number: 3-phase

[0114] Rated capacity: 3150 kVA

[0115] Rated voltage: 35 kV

[0116] Connection group: YNd11

[0117] ② Core material and structure

[0118] Grade of silicon steel sheet: B30P105

[0119] Core type: Three-phase three-column with inclined joints

[0120] Core magnetic density: 1.7832 T

[0121] ③ Winding structure

[0122] Designed according to capacity and voltage level, no need to scale down proportionally.

[0123] ④ Tank structure

[0124] Tank type: Bell type

[0125] Overall dimensions of the tank: Scaled down proportionally

[0126] Tank thickness: Selected according to the actual situation in a ratio close to 1:5

[0127] ⑤ Tank components

[0128] The dimensions of tank components such as the conservator, bushings, and radiator fins can be adjusted according to the actual situation, and try to ensure a ratio of 1:5 or perform corresponding weight balancing.

[0129] To ensure that the magnetic density of the transformer equivalent model is consistent with that of the transformer product, the coil winding dimensions and current magnitude of the model are set so that its average magnetic flux density is about 1.78 T. Finally, the rated current is set to 70 A, the height is 350 mm, the inner diameter of the coil is 370 mm, and the outer diameter is 450 mm. The number of turns of the high-voltage winding is 440, and the number of turns of the low-voltage winding is 30.

[0130] (2) Determine the amplification ratios of the noise level and vibration level of the transformer under test compared to the equivalent model.

[0131] Establish the multi-physics coupling simulation models of the scaled-down equivalent model and the transformer under test for the core. Under the same core magnetic flux density, calculate the amplification ratios of the noise and vibration levels of the transformer under test compared to the equivalent model respectively.

[0132] Using finite element simulation software, first, according to parameters such as the core size, a scaled-down equivalent model and the geometric model of the transformer under test are established. Subsequently, based on parameters such as the H-B curve, Young's modulus, Poisson's ratio, density, and relative permittivity of the silicon steel sheet obtained through queries, the material properties of the model are defined, and fixed constraint boundary conditions are set for the core pad positions. At the same time, a multi-physics coupling module of circuit-magnetic field-solid mechanics-acoustics is used to define the core and the air domain. A rated voltage condition is set on the winding. After mesh generation, structural mechanics and acoustic calculations are performed to obtain the vibration field and sound field simulation analysis results of the scaled-down equivalent model and the transformer under test. According to the simulation results in the figure, the vibration acceleration ratio of the transformer under test model to the scaled-down equivalent model is 1.4; taking the noise measurement point at 0.3 m, the sound pressure level ratio of the transformer under test model to the scaled-down equivalent model is 1.2.

[0133] (3) Obtain the vibration levels and noise levels at different positions of the core of the equivalent model.

[0134] On the premise of not installing the fuel tank and filling with oil, voltage or current excitation is applied to the scaled-down equivalent model. The vibration levels at different positions are obtained by using an accelerometer for testing, and the core noise level is obtained by using a sound level meter for testing. The noise level is multiplied by the noise level amplification ratio, and the vibration level is multiplied by the vibration level amplification ratio, which is the vibration and sound level of the actual product.

[0135] Using a laser vibrometer, the vibrations of different parts of the core are tested, and the measuring point positions are the Figure 4 installation positions of the fiber optic sensors in. Among them, due to the sleeved winding at the middle position of the core, the laser signal cannot directly enter the core measuring point position. Therefore, the laser needs to be incident on the core part from the top at an angle of 30° to 60°. At the same time, to enhance the reflection effect of the laser signal, a reflector is pasted on the middle polyester tape of the core, and its inclination angle matches the laser incident angle to ensure total reflection of the laser signal. Apply the rated condition to the core model, and use a sound level meter to measure the noise on the envelope surface 0.3 m away from the model surface, as Figure 10 shown. The final test results are shown in the following table.

[0136] Table 4 Vibration test results of the core surface

[0137] Measuring point number Position <![CDATA[Measured value (m / s 2 )]]> 1 Left side of upper part of iron core 0.52 2 Middle of upper part of iron core 0.37 3 Right side of upper part of iron core 0.69 4 Left side of middle part of iron core 0.42 5 Middle of middle part of iron core 0.37 6 Right side of middle part of iron core 0.52 7 Left side of bottom part of iron core 0.23 8 Middle of bottom part of iron core 0.32 9 Right side of bottom part of iron core 0.31

[0138] Table 5 Noise test results of the core

[0139] Measuring point number Measured value (dB) 1 54 2 52 3 55 4 53

[0140] (3) Based on the noise level amplification ratio, vibration level amplification ratio, vibration level, and noise level, determine the vibration and sound level of the core of the transformer under test.

[0141] Multiply the noise level by the noise level amplification ratio to obtain the noise level of the iron core of the transformer to be measured. Multiply the vibration level by the vibration level amplification ratio to obtain the vibration level of the iron core of the transformer to be measured, which is the acoustic-vibration level of the transformer to be measured.

[0142] Multiply the data in Table 4 by the vibration level amplification ratio of 1.4, and multiply the data in Table 5 by the noise level amplification ratio of 1.2, which are the noise-vibration data of the iron core of the actual transformer.

[0143] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art:

[0144] (1) According to the principles of magnetic field, structure and material equivalence, the present invention designs a reduced-scale equivalent model of the transformer to be measured. This model can effectively reflect the noise-vibration data of the actual transformer product, and is convenient for assembly and disassembly, with a low voltage level. The iron core of the reduced-scale equivalent model of the transformer to be measured can be directly loaded with test conditions without oil injection, which is convenient for directly testing the noise and vibration of the iron core.

[0145] (2) The present invention adopts simulation analysis technology to calculate the acoustic-vibration level proportionality coefficient between the equivalent model and the transformer to be measured under the same proportional working conditions. Then, through proportional conversion, the acoustic-vibration test results of the equivalent model are converted into the acoustic-vibration data of the transformer to be measured, avoiding risks such as insulation safety caused by arranging sensors in the fuel tank of the transformer to be measured.

[0146] (3) Vibration tests are carried out by using an optically fiber accelerometer or a non-contact laser vibrometer after insulation treatment, ensuring the electrical safety of the measuring equipment.

[0147] The above is the embodiment of the method for testing the acoustic-vibration level of the iron core of the transformer provided by the present application. The following will introduce other embodiments of the method for testing the acoustic-vibration level of the iron core of a transformer provided by the present application. For details, please refer to the following.

[0148] Figure 11 The following is a schematic structural diagram of a device for testing the acoustic-vibration level of the iron core of a transformer provided by an embodiment of the present invention. The device includes: an equivalent model module 1101, an amplification ratio module 1102, an acquisition module 1103, and an acoustic-vibration level module 1104.

[0149] The equivalent model module 1101 is used to obtain the equivalent model of the transformer to be measured based on a preset standard.

[0150] The amplification ratio module 1102 is used to determine the noise level amplification ratio and the vibration level amplification ratio of the transformer to be measured compared with the equivalent model.

[0151] The acquisition module 1103 is used to acquire the vibration level and the noise level at different positions of the iron core of the equivalent model.

[0152] The acoustic-vibration level module 1104 is configured to determine the acoustic-vibration level of the iron core of the transformer under test based on the noise level amplification ratio, vibration level amplification ratio, vibration level, and noise level.

[0153] The equivalent model module 1101 is specifically configured to obtain an equivalent model of the transformer under test based on the principles of magnetic field equivalence, material equivalence, and structural equivalence for the iron core material, winding material, and structural characteristics of the transformer under test.

[0154] The amplification ratio module 1102 is specifically configured to establish a multi-physical field coupling simulation model of the equivalent model and the iron core of the transformer under test, and respectively obtain the noise level amplification ratio and vibration level amplification ratio of the transformer under test compared to the equivalent model under the same iron core magnetic flux density.

[0155] The acquisition module 1103 is specifically configured to apply a voltage or current excitation to the equivalent model without installing the fuel tank and filling with oil, and use an accelerometer to measure the vibration levels at different positions and a sound level meter to measure the noise level of the iron core.

[0156] The acoustic-vibration level module 1104 is specifically configured to multiply the noise level by the noise level amplification ratio to obtain the noise level of the iron core of the transformer under test; multiply the vibration level by the vibration level amplification ratio to obtain the vibration level of the iron core of the transformer under test.

[0157] The functions performed by each component in the acoustic-vibration level testing device for the iron core of the transformer provided in the embodiments of the present invention have been described in detail in any of the above method embodiments, so they will not be repeated here.

[0158] As Figure 12 shown, an embodiment of the present application provides an electronic device. The electronic device carries a resource scheduling system as mentioned in any of the above embodiments, including a processor 111, a communication interface 112, a memory 113, and a communication bus 114. Among them, the processor 111, the communication interface 112, and the memory 113 communicate with each other through the communication bus 114.

[0159] The memory 113 is used to store a computer program;

[0160] In an embodiment of the present application, when the processor 111 is configured to execute the program stored on the memory 113, it implements the acoustic-vibration level testing method for the iron core of the transformer provided in any of the foregoing method embodiments, including:

[0161] Obtaining an equivalent model of the transformer under test based on a preset standard;

[0162] Obtaining the noise level amplification ratio and vibration level amplification ratio of the transformer under test compared to the equivalent model;

[0163] Obtain the vibration levels and noise levels at different positions of the iron core of the equivalent model;

[0164] Based on the noise level amplification ratio, vibration level amplification ratio, vibration level, and noise level, determine the acoustic-vibration level of the iron core of the transformer under test.

[0165] In one example, based on a preset standard, obtain an equivalent model of the transformer under test, specifically:

[0166] For the iron core material, winding material, and structural characteristics of the transformer under test, based on the principles of magnetic field equivalence, material equivalence, and structural equivalence, obtain an equivalent model of the transformer under test.

[0167] In one example, the iron core material and winding material of the equivalent model are the same as those of the iron core of the transformer under test.

[0168] In one example, the iron core size of the equivalent model is designed with a scale ratio of 1:3 to 1:5 of the iron core size of the transformer under test.

[0169] In one example, obtain the noise level amplification ratio and vibration level amplification ratio of the transformer under test compared to the equivalent model, specifically including:

[0170] Establish a multi-physics field coupling simulation model of the iron cores of the equivalent model and the transformer under test. Under the same iron core magnetic flux density, obtain the noise level amplification ratio and vibration level amplification ratio of the transformer under test compared to the equivalent model respectively.

[0171] In one example, obtain the vibration levels and noise levels at different positions of the iron core of the equivalent model, specifically:

[0172] On the premise of not installing the oil tank and injecting oil, apply voltage or current excitation to the equivalent model, use an accelerometer to test and obtain the vibration levels at different positions, and use a sound level meter to test and obtain the noise level of the iron core.

[0173] In one example, based on the noise level amplification ratio, vibration level amplification ratio, vibration level, and noise level, determine the acoustic-vibration level of the iron core of the transformer under test, specifically including:

[0174] Multiply the noise level by the noise level amplification ratio to obtain the noise level of the iron core of the transformer under test;

[0175] Multiply the vibration level by the vibration level amplification ratio to obtain the vibration level of the iron core of the transformer under test. The embodiments of the present application also provide a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for testing the acoustic-vibration level of the iron core of a transformer provided in any one of the foregoing method embodiments are implemented.

[0176] Those skilled in the art should also be able to further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the present invention.

[0177] The steps of the methods or algorithms described in combination with the embodiments disclosed herein can be implemented by hardware, software modules executed by a processor, or a combination of the two. The software modules can be placed in a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium well-known in the technical field.

[0178] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for testing the acoustic and vibration level of a transformer core, characterized in that, The method includes: Based on a preset standard, obtaining an equivalent model of the transformer under test; Obtaining the noise level amplification ratio and vibration level amplification ratio of the transformer under test compared to the equivalent model; Obtaining the vibration levels and noise levels at different positions of the iron core of the equivalent model; Based on the noise level amplification ratio, the vibration level amplification ratio, the vibration level, and the noise level, determining the acoustic-vibration level of the iron core of the transformer under test; The obtaining of the equivalent model of the transformer under test based on a preset standard is specifically: For the iron core material, winding material, and structural characteristics of the transformer under test, based on the principles of magnetic field equivalence, material equivalence, and structural equivalence, obtaining the equivalent model of the transformer under test; The obtaining of the noise level amplification ratio and vibration level amplification ratio of the transformer under test compared to the equivalent model specifically includes: Establishing a multi-physics field coupling simulation model of the equivalent model and the iron core of the transformer under test, and respectively obtaining the noise level amplification ratio and vibration level amplification ratio of the transformer under test compared to the equivalent model under the same iron core magnetic flux density; The obtaining of the vibration levels and noise levels at different positions of the iron core of the equivalent model is specifically: On the premise of not installing the fuel tank and filling with oil, applying a voltage or current excitation to the equivalent model, using an accelerometer to test and obtain the vibration levels at different positions, and using a sound level meter to test and obtain the noise level of the iron core; The determining of the acoustic-vibration level of the iron core of the transformer under test based on the noise level amplification ratio, the vibration level amplification ratio, the vibration level, and the noise level specifically includes: Multiplying the noise level by the noise level amplification ratio to obtain the noise level of the iron core of the transformer under test; Multiplying the vibration level by the vibration level amplification ratio to obtain the vibration level of the iron core of the transformer under test.

2. The method according to claim 1, characterized in that, The iron core material and winding material of the equivalent model are the same as those of the iron core of the transformer under test.

3. The method according to claim 1, characterized in that, The iron core size of the equivalent model is designed with a scale ratio of 1:3 to 1:5 of the iron core size of the transformer under test.

4. A device for testing the acoustic and vibration level of a transformer core, characterized in that, The device includes: An equivalent model module for obtaining an equivalent model of the transformer under test based on a preset standard; An amplification ratio module for obtaining the noise level amplification ratio and vibration level amplification ratio of the transformer under test compared to the equivalent model; An obtaining module for obtaining the vibration levels and noise levels at different positions of the iron core of the equivalent model; An acoustic-vibration level module for determining the acoustic-vibration level of the iron core of the transformer under test based on the noise level amplification ratio, the vibration level amplification ratio, the vibration level, and the noise level; The obtaining of the equivalent model of the transformer under test based on a preset standard is specifically: For the iron core material, winding material, and structural characteristics of the transformer under test, based on the principles of magnetic field equivalence, material equivalence, and structural equivalence, obtaining the equivalent model of the transformer under test; The obtaining of the noise level amplification ratio and vibration level amplification ratio of the transformer under test compared to the equivalent model specifically includes: Establish a multi-physics field coupling simulation model of the core of the equivalent model and the transformer under test. Under the same core magnetic flux density, respectively obtain the noise level amplification ratio and vibration level amplification ratio of the transformer under test compared with the equivalent model; The obtaining of the vibration level and noise level at different positions of the core of the equivalent model is specifically as follows: On the premise of not installing the fuel tank and filling with oil, apply voltage or current excitation to the equivalent model, use an accelerometer to test and obtain the vibration levels at different positions, and use a sound level meter to test and obtain the noise level of the core; Based on the noise level amplification ratio, the vibration level amplification ratio, the vibration level and the noise level, determine the acoustic-vibration level of the core of the transformer under test, specifically including: Multiply the noise level by the noise level amplification ratio to obtain the noise level of the core of the transformer under test; Multiply the vibration level by the vibration level amplification ratio to obtain the vibration level of the core of the transformer under test.

5. An electronic device, characterized in that, The electronic device carries an acoustic-vibration level test device for the core of a transformer, including a processor, a communication interface, a memory, and a communication bus. Among them, the processor, the communication interface, and the memory complete communication with each other through the communication bus; The memory is used to store computer programs; The processor, when executing the program stored on the memory, implements the steps of the acoustic-vibration level test method for the core of the transformer described in any one of claims 1-3.

6. A computer-readable storage medium, on which a computer program is stored, characterized in that,When the computer program is executed by the processor, it implements the steps of the acoustic-vibration level test method for the core of the transformer described in any one of claims 1-3.

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