Epoxy insulating material aging state evaluation method, system, medium and equipment

Abstract

The embodiment of the invention discloses a method, a system, a medium and equipment for evaluating the aging state of an epoxy insulating material. The method comprises the following steps: applying test conditions to the epoxy insulating material to obtain epoxy insulating material samples with different aging durations; measuring glass transition temperatures and tensile strengths of the epoxy insulating material samples with different aging durations; the surfaces of the epoxy insulating material samples with different aging durations are covered with fiber bragg gratings, optical signals are emitted to the fiber bragg gratings, and wavelength offset is determined according to spectral information of the optical signals reflected by the fiber bragg gratings; ultrasonic waves are emitted to the epoxy insulating material samples with different aging durations, and acoustic impedance is determined according to the time difference of the ultrasonic waves reflected by the material samples and the material density; carrying out linear fitting on the tensile strength and the ultrasonic acoustic impedance and carrying out linear fitting on the wavelength offset and the glass transition temperature, and constructing an aging evaluation model of the epoxy insulating material; the thermal performance and the mechanical performance of the epoxy insulating material in the aging state can be rapidly and conveniently evaluated through the model.

Description

Technical Field

[0001] The present invention relates to the technical field of epoxy insulation dry-type transformer detection and analysis, and particularly to a method, system, medium and device for evaluating the aging state of epoxy insulation materials. Background Art

[0002] In high-voltage equipment, especially dry-type transformers, epoxy resin insulation materials play a crucial role. These materials are continuously affected by electricity, heat, chemistry and mechanical forces during operation, resulting in a continuous increase in temperature, which causes the decomposition and carbonization of epoxy resin, and ultimately loses its original insulation performance. Traditional monitoring and fault prediction methods have many limitations. For example, although partial discharge detection and X-ray detection methods can identify some defects, they rely on complex operating environments and high detection costs, cannot be efficiently carried out under complex working conditions, are difficult to identify internal micro-defects, and have certain safety hazards.

[0003] In actual operation, effectively detecting epoxy insulation materials usually faces two major challenges: one is the high detection cost; the other is the low efficiency of detection methods, making it difficult to identify potential problems in a timely manner. In addition, existing methods have limited ability to identify internal micro-defects, and this problem is particularly prominent in high-voltage equipment such as dry-type transformers because of the limited internal space of these devices and the difficulty of detection. Summary of the Invention

[0004] Based on this, it is necessary to propose a method, system, medium and device for evaluating the aging state of epoxy insulation materials in view of the above problems.

[0005] A method for evaluating the aging state of epoxy insulation materials, the method includes:

[0006] Applying test conditions to the epoxy insulation materials to obtain epoxy insulation material specimens with different aging durations;

[0007] Measuring the glass transition temperature and tensile strength of the epoxy insulation material specimens with different aging durations;

[0008] Optical fiber gratings are coated on the surfaces of the epoxy insulation material specimens with different aging durations, an optical signal is emitted to the optical fiber gratings, and the wavelength shift is determined according to the spectral information of the grating reflected optical signal;

[0009] Emitting ultrasonic waves to the epoxy insulation material specimens with different aging durations, and determining the acoustic impedance according to the time difference of the ultrasonic waves reflected by the material specimens and the material density;

[0010] Perform linear fitting on the tensile strength and ultrasonic acoustic impedance of the epoxy insulation materials with different aging durations, and perform linear fitting on the wavelength shift and glass transition temperature to construct an aging evaluation model for the epoxy insulation materials;

[0011] Evaluate the thermal properties and mechanical properties of the epoxy insulation materials in the aging state through the aging evaluation model of the epoxy insulation materials.

[0012] Among them, the surfaces of the epoxy insulation material specimens with different aging durations are covered with fiber Bragg gratings. A light signal is emitted to the fiber Bragg gratings, and the wavelength shift is determined according to the spectral information of the light signal reflected by the gratings. Specifically, it includes:

[0013] The surfaces of the epoxy insulation material specimens with different aging durations are covered with fiber Bragg gratings;

[0014] At a preset temperature, a light signal is emitted to the fiber Bragg gratings, and the reflected spectral information of the light signal reflected by the gratings is collected;

[0015] According to the reflected spectral information, the initial central wavelength data of each specimen is obtained;

[0016] The wavelength shift is determined according to the initial central wavelength data and material density of the epoxy insulation material specimens with different aging durations.

[0017] Among them, ultrasonic waves are emitted to the epoxy insulation material specimens with different aging durations, and the acoustic impedance is determined according to the time difference of the ultrasonic waves reflected by the material specimens and the material density. Specifically, it includes:

[0018] Ultrasonic waves are emitted to the epoxy insulation material specimens with different aging durations;

[0019] According to the time of emitting the ultrasonic waves and the time of the ultrasonic waves reflected by the material specimens, the round-trip time difference of the ultrasonic waves is determined;

[0020] According to the round-trip time difference of the ultrasonic waves and the specimen thickness, the ultrasonic wave propagation speed is determined;

[0021] The acoustic impedance is determined according to the material density and ultrasonic wave propagation speed of the epoxy insulation material specimens with different aging durations.

[0022] Among them, the specific method for determining the wavelength shift according to the initial central wavelength data and material density of the epoxy insulation material specimens with different aging durations includes:

[0023] According to Determine the wavelength shift, where Δλ is the wavelength shift, λ B is the initial central wavelength data, η eff is the effective refractive index, A is the grating period, P 11and P 12 is the photoelastic coefficient, υ is the Poisson's ratio, Δ ρ is the density change, and ρ is the initial material density.

[0024] Among them, determining the acoustic impedance according to the material density and the ultrasonic propagation velocity of the epoxy insulation material specimens with different aging durations specifically includes:

[0025] Determining the acoustic impedance according to z s = ρc, where z s is the acoustic impedance, ρ is the material density, and c is the ultrasonic propagation velocity.

[0026] Among them, the epoxy insulation material aging evaluation model includes the thermal performance model and the mechanical performance model of the epoxy insulation material. Linear fitting of the tensile strength and acoustic impedance of the epoxy insulation material with different aging durations, and linear fitting of the wavelength shift and glass transition temperature to construct the epoxy insulation material aging evaluation model specifically includes:

[0027] Performing linear fitting on the tensile strength and acoustic impedance to construct the mechanical performance model of the epoxy insulation material. The mechanical performance model of the epoxy insulation material is Z s = k1E + b, where z s is the acoustic impedance, k1 is the first correlation coefficient, E is the tensile strength, and b is the initial tensile strength of the material;

[0028] Performing linear fitting on the tensile strength and ultrasonic acoustic impedance of the epoxy insulation material with different aging durations to construct the thermal performance model of the epoxy insulation material. The thermal performance model of the epoxy insulation material is: T g = T g0 + k2Δλ, where T g0 is the initial glass transition temperature, Δλ is the wavelength shift, and k2 is the second correlation coefficient.

[0029] Among them, applying test conditions to the epoxy insulation material to obtain epoxy insulation material specimens with different aging durations specifically includes:

[0030] At a constant temperature, thermally aging the epoxy insulation material specimens to obtain thermally aged specimens of the epoxy insulation material with different aging durations;

[0031] At a fixed frequency, electrically aging the epoxy insulation material specimens to obtain electrically aged specimens of the epoxy insulation material with different aging durations.

[0032] An epoxy insulation material aging state evaluation system, the system includes:

[0033] The epoxy insulation material sample acquisition module is used to apply test conditions to the epoxy insulation material and obtain epoxy insulation material samples with different aging durations;

[0034] The measurement module is used to measure the glass transition temperature and tensile strength of the epoxy insulation material samples with different aging durations;

[0035] The wavelength shift determination module is used to cover an optical fiber grating on the surface of the epoxy insulation material samples with different aging durations, emit an optical signal to the optical fiber grating, and determine the wavelength shift according to the spectral information of the optical signal reflected by the grating;

[0036] The acoustic impedance determination module is used to emit ultrasonic waves to the epoxy insulation material samples with different aging durations, and determine the acoustic impedance according to the time difference of the ultrasonic waves reflected by the material samples and the material density;

[0037] The epoxy insulation material aging evaluation model construction module is used to perform linear fitting on the tensile strength and ultrasonic acoustic impedance of the epoxy insulation material with different aging durations, and perform linear fitting on the wavelength shift and glass transition temperature, and construct an epoxy insulation material aging evaluation model;

[0038] The thermal property and mechanical property evaluation module is used to evaluate the thermal properties and mechanical properties of the epoxy insulation material in the aging state through the epoxy insulation material aging evaluation model.

[0039] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the processor is caused to execute the steps of the method described above.

[0040] A computer device includes a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, the processor is caused to execute the steps of the method described above.

[0041] Adopting the embodiments of the present invention has the following beneficial effects:

[0042] The present invention first applies test conditions to obtain specimens with different aging durations, and measures the glass transition temperature and tensile strength of epoxy insulation material specimens with different aging durations. Further, optical fiber gratings are coated on the surfaces of the epoxy insulation material specimens with different aging durations, an optical signal is emitted to the optical fiber gratings, and the wavelength shift is determined according to the spectral information of the grating reflected optical signal. Ultrasonic waves are emitted to the epoxy insulation material specimens with different aging durations, and the acoustic impedance is determined according to the time difference of the ultrasonic waves reflected by the material specimens and the material density. Secondly, an aging evaluation model for epoxy insulation materials is established based on the tensile strength, acoustic impedance, wavelength shift, and glass transition temperature. Finally, according to the aging evaluation model of the epoxy insulation material, the changes in the thermal and mechanical properties of the material in different aging states are evaluated. Specifically, the temperature change of the material is reflected through the wavelength shift on the material surface to evaluate the thermal properties of the material, and the internal stress state of the material is reflected through the acoustic impedance to evaluate the mechanical properties of the material. Therefore, through this model, the aging state of the epoxy insulation material can be evaluated quickly and conveniently, which can not only reduce the detection cost, but also improve the detection efficiency, help to discover and predict potential problems in advance, and thus ensure the safe and stable operation of the equipment. Description of the Drawings

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0044] Among them:

[0045] Figure 1 It is a schematic flowchart of an embodiment of a method for evaluating the aging state of an epoxy insulation material;

[0046] Figure 2 It is a schematic flowchart of another embodiment of a method for evaluating the aging state of an epoxy insulation material;

[0047] Figure 3 It is a schematic structural diagram of an embodiment of an aging state evaluation system for an epoxy insulation material provided by the present invention;

[0048] Figure 4 It is a schematic structural diagram of an embodiment of the equipment provided by the present invention;

[0049] Figure 5 It is a schematic structural diagram of an embodiment of the medium provided by the present invention. Detailed Embodiments

[0050] 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. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. 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.

[0051] As Figure 1 shown, Figure 1 FIG. 1 is a schematic flowchart of an embodiment of a method for evaluating the aging state of an epoxy insulating material. A method for evaluating the aging state of an epoxy insulating material includes:

[0052] S101: Apply test conditions to the epoxy insulating material to obtain epoxy insulating material specimens with different aging durations.

[0053] Exemplarily, set the aging durations to be 7d, 14d, 21d, 28d, and 35d respectively, and conduct thermal aging on the epoxy insulating material specimens at a temperature of 120°C to obtain thermal aging specimens of the epoxy insulating material with different aging durations.

[0054] Set the aging durations to be 24h, 48h, 72h, 96h, and 128h respectively, and conduct electrical aging on the epoxy insulating material specimens under the condition of 12 kV voltage (frequency of 50 Hz) to obtain electrical aging specimens of the epoxy insulating material with different aging durations.

[0055] S102: Measure the glass transition temperature and tensile strength of the epoxy insulating material specimens with different aging durations.

[0056] Exemplarily, conduct thermal property tests and mechanical property tests on the epoxy material specimens with different aging durations. Specifically, measure the heat change of the material by differential scanning calorimetry to determine the glass transition temperature of the thermal properties; clamp the epoxy material specimens with a fixture and measure the tensile strength of the material specimens with an extensometer.

[0057] S103: Fiber Bragg gratings are coated on the surfaces of the epoxy insulating material specimens with different aging durations. An optical signal is emitted to the fiber Bragg gratings, and the wavelength shift is determined according to the spectral information of the grating reflected optical signal.

[0058] Exemplarily, fiber Bragg gratings are coated on the surfaces of the epoxy insulating material specimens with different aging durations. At a preset temperature, an optical signal is emitted to the fiber Bragg gratings, and the reflected spectral information of the grating reflected optical signal is collected. According to the reflected spectral information, the initial central wavelength data of each specimen is obtained. The wavelength shift is determined according to the initial central wavelength data and the material density of the epoxy insulating material specimens with different aging durations. The wavelength shift is determined by the following formula:

[0059]

[0060] wherein, Δλ is the wavelength offset, and λ B is the initial central wavelength data, η eff is the effective refractive index, A is the grating period, P 11 and P 12 are the photoelastic coefficients, υ is the Poisson's ratio, Δ ρ is the density change, and ρ is the initial material density.

[0061] S104: Transmit ultrasonic waves to epoxy insulation material specimens with different aging durations, and determine the acoustic impedance according to the time difference of the reflected ultrasonic waves of the material specimens and the material density.

[0062] Exemplarily, transmit ultrasonic waves to epoxy insulation material specimens with different aging durations, determine the round-trip time difference of the ultrasonic waves according to the time of transmitting the ultrasonic waves and the time of the material specimens reflecting the ultrasonic waves, determine the ultrasonic wave propagation speed according to the round-trip time difference of the ultrasonic waves and the specimen thickness, determine the acoustic impedance according to the material density and the ultrasonic wave propagation speed of the epoxy insulation material specimens with different aging durations, and the acoustic impedance is determined according to the formula shown below:

[0063] z s = ρc;

[0064] wherein, z s is the acoustic impedance, ρ is the material density, and c is the ultrasonic wave propagation speed.

[0065] S105: Perform linear fitting on the tensile strength and acoustic impedance of epoxy insulation materials with different aging durations, and perform linear fitting on the wavelength offset and glass transition temperature to construct an aging evaluation model for epoxy insulation materials.

[0066] Exemplarily, perform linear fitting on the tensile strength and acoustic impedance to construct a mechanical property model for epoxy insulation materials to effectively characterize the mechanical properties. The mechanical property model of the epoxy insulation material is shown in the following formula:

[0067] z s = k1E + b;

[0068] wherein, z s is the acoustic impedance, k1 is the first correlation coefficient, E is the tensile strength, and b is the initial tensile strength of the material;

[0069] Perform linear fitting on the tensile strength and ultrasonic acoustic impedance of epoxy insulation materials with different aging durations to construct a thermal property model for epoxy insulation materials to effectively characterize the thermal properties. The thermal property model of the epoxy insulation material is shown in the following formula:

[0070] T g = T g0 + k2Δλ;

[0071] wherein, T g0 is the initial glass transition temperature, Δλ is the wavelength shift, and k2 is the second correlation coefficient.

[0072] S106: Evaluate the thermal properties and mechanical properties of the epoxy insulation material in the aged state through the epoxy insulation material aging evaluation model.

[0073] Exemplarily, evaluate the mechanical properties of the epoxy insulation material in the aged state through the epoxy insulation material mechanical property model. Specifically, the acoustic impedance is related to the sound velocity, and the sound velocity reflects the elastic properties of the material and is related to the elastic modulus of the material. Materials with a high elastic modulus usually have a high tensile strength. Therefore, there is a positive correlation between the acoustic impedance and the tensile strength. By obtaining the acoustic impedance of the epoxy insulation material, the mechanical properties of the epoxy insulation material in the aged state can be evaluated. The higher the acoustic impedance, the higher the elastic properties.

[0074] Evaluate the thermal properties of the epoxy insulation material in the aged state through the epoxy insulation material thermal property model. Specifically, after the epoxy resin is aged for different durations, the molecular chains decompose, the density decreases, and the glass transition temperature drops. When the material density changes, the period and refractive index of the fiber grating will change, resulting in a wavelength shift. Therefore, there is a positive correlation between the glass transition temperature and the wavelength shift. By obtaining the wavelength shift of the epoxy insulation material, the thermal properties of the epoxy insulation material in the aged state can be evaluated. The larger the wavelength shift, the higher the thermal properties.

[0075] From the above description, it can be seen that the present invention first applies test conditions to obtain specimens with different aging durations, and measures the glass transition temperature and tensile strength of the epoxy insulation material specimens with different aging durations. Further, the surfaces of the epoxy insulation material specimens with different aging durations are coated with fiber Bragg gratings. An optical signal is emitted to the fiber Bragg gratings, and the wavelength shift is determined according to the spectral information of the reflected optical signal of the grating. An ultrasonic wave is emitted to the epoxy insulation material specimens with different aging durations, and the acoustic impedance is determined according to the time difference of the reflected ultrasonic wave of the material specimen and the material density. Secondly, an epoxy insulation material aging evaluation model is established based on the tensile strength, acoustic impedance, wavelength shift, and glass transition temperature. Finally, according to the epoxy insulation material aging evaluation model, evaluate the changes in the thermal and mechanical properties of the material in different aging states. Specifically, the temperature change of the material is reflected by the wavelength shift on the surface of the material to evaluate the thermal properties of the material, and the internal stress state of the material is reflected by the acoustic impedance to evaluate the mechanical properties of the material. Therefore, through this model, the aging state of the epoxy insulation material can be evaluated quickly and conveniently, which can not only reduce the detection cost, but also improve the detection efficiency, help to discover and predict potential problems in advance, and thus ensure the safe and stable operation of the equipment.

[0076] Such asFigure 2 As shown Figure 2 It is a schematic flowchart of another embodiment of a method for evaluating the aging state of an epoxy insulating material. A method for evaluating the aging state of an epoxy insulating material, the method includes:

[0077] S201: Apply test conditions to the epoxy insulating material to obtain epoxy insulating material specimens with different aging durations.

[0078] Exemplarily, under a constant temperature, perform thermal aging on the epoxy insulating material specimen to obtain thermal aging specimens of the epoxy insulating material with different aging durations; under a fixed frequency, perform electrical aging on the epoxy insulating material specimen to obtain electrical aging specimens of the epoxy insulating material with different aging durations.

[0079] S202: Measure the glass transition temperature and tensile strength of the epoxy insulating material specimens with different aging durations.

[0080] It should be noted that step S201 has been discussed in detail in the Figure 1 shown implementation scenario and will not be specifically limited here.

[0081] S203: Fiber Bragg gratings are coated on the surfaces of the epoxy insulating material specimens with different aging durations.

[0082] Exemplarily, build an ultrasonic acoustic impedance and fiber Bragg grating detection experimental platform, including a test chamber, an ultrasonic pulse generator, an oscilloscope, an ultrasonic probe, a fiber Bragg grating demodulator, and a fiber Bragg grating. Fiber Bragg gratings are coated on the surfaces of the epoxy insulating material specimens with different aging durations, and the fiber Bragg gratings are led out of the test chamber and connected to the fiber Bragg grating demodulator.

[0083] S204: At a preset temperature, emit an optical signal to the fiber Bragg grating and collect the reflection spectrum information of the grating reflected optical signal.

[0084] S205: According to the reflection spectrum information, obtain the initial central wavelength data of each specimen.

[0085] Exemplarily, adjust the temperature of the test chamber to the preset temperature respectively, and record the fiber Bragg grating central wavelength data at the temperature. According to the reflection spectrum information, obtain the initial central wavelength data of each specimen.

[0086] S206: Determine the wavelength shift according to the initial central wavelength data and material density of the epoxy insulating material specimens with different aging durations.

[0087] Exemplarily, the wavelength shift is determined by the following formula:

[0088]

[0089] where, Δλ is the wavelength shift, λ Bis the initial central wavelength data, η eff is the effective refractive index, A is the grating period, P 11 and P 12 are the photoelastic coefficients, υ is the Poisson's ratio, Δ ρ is the density change, ρ is the initial material density.

[0090] S207: Ultrasonic waves are emitted to epoxy insulation material specimens with different aging durations.

[0091] S208: Determine the round-trip time difference of ultrasonic waves according to the time when ultrasonic waves are emitted and the time when the material specimens reflect ultrasonic waves.

[0092] Exemplarily, place epoxy insulation material specimens with different aging durations under the ultrasonic probe to ensure close contact between the ultrasonic probe and the specimens, and emit ultrasonic waves to the epoxy insulation material specimens with different aging durations. Record the time when ultrasonic waves are emitted and the time when the material specimens reflect ultrasonic waves through an oscilloscope. Determine the round-trip time difference of ultrasonic waves according to the time when ultrasonic waves are emitted and the time when the material specimens reflect ultrasonic waves.

[0093] S209: Determine the ultrasonic wave propagation speed according to the round-trip time difference of ultrasonic waves and the specimen thickness.

[0094] Exemplarily, the ultrasonic wave propagation speed is determined according to the following formula:

[0095] c = 2d / Δt;

[0096] where c is the propagation speed of ultrasonic waves in the material, d is the specimen thickness, and Δt is the round-trip time difference of ultrasonic waves.

[0097] S210: Determine the acoustic impedance according to the material density and ultrasonic wave propagation speed of epoxy insulation material specimens with different aging durations.

[0098] Exemplarily, the acoustic impedance is determined according to the following formula:

[0099] z s = ρc;

[0100] where z s is the acoustic impedance, ρ is the material density, and c is the ultrasonic wave propagation speed.

[0101] S211: Perform linear fitting on the tensile strength and ultrasonic acoustic impedance of epoxy insulation materials with different aging durations, and perform linear fitting on the wavelength shift and glass transition temperature to construct an aging evaluation model for epoxy insulation materials.

[0102] S212: Evaluate the thermal properties and mechanical properties of epoxy insulation materials in the aging state through the aging evaluation model of epoxy insulation materials.

[0103] It should be noted that steps S211 - S212 have been discussed in detail in the Figure 1 illustrated implementation scenario and will not be specifically limited here.

[0104] As Figure 3 shown, Figure 3 is a schematic structural diagram of an embodiment of an epoxy insulation material aging state evaluation system provided by the present invention. An epoxy insulation material aging state evaluation system, the system includes:

[0105] An epoxy insulation material specimen acquisition module 11, configured to apply test conditions to the epoxy insulation material to obtain epoxy insulation material specimens with different aging durations.

[0106] A measurement module 12, configured to measure the glass transition temperature and tensile strength of the epoxy insulation material specimens with different aging durations.

[0107] A wavelength shift determination module 13, for which the surfaces of the epoxy insulation material specimens with different aging durations are coated with fiber Bragg gratings, emitting optical signals to the fiber Bragg gratings, and determining the wavelength shift according to the spectral information of the grating reflected optical signals.

[0108] An acoustic impedance determination module 14, configured to emit ultrasonic waves to the epoxy insulation material specimens with different aging durations, and determine the acoustic impedance according to the time difference of the ultrasonic waves reflected by the material specimens and the material density.

[0109] An epoxy insulation material aging evaluation model construction module 15, configured to perform linear fitting on the tensile strength and ultrasonic acoustic impedance of the epoxy insulation material with different aging durations, and perform linear fitting on the wavelength shift and the glass transition temperature, to construct an epoxy insulation material aging evaluation model.

[0110] A thermal performance and mechanical performance evaluation module 16, configured to evaluate the thermal performance and mechanical performance of the epoxy insulation material in the aging state through the epoxy insulation material aging evaluation model.

[0111] Exemplarily, in the epoxy insulation material sample acquisition module 11, at a constant temperature, the epoxy insulation material sample is thermally aged to obtain thermally aged samples of the epoxy insulation material with different aging durations; at a fixed frequency, the epoxy insulation material sample is electrically aged to obtain electrically aged samples of the epoxy insulation material with different aging durations. In the measurement module 12, the glass transition temperature and tensile strength of the epoxy insulation material samples with different aging durations are measured. In the wavelength shift determination module 13, the surface of the epoxy insulation material samples with different aging durations is coated with fiber Bragg gratings; at a preset temperature, an optical signal is emitted to the fiber Bragg gratings, and the reflection spectrum information of the grating reflected optical signal is collected; according to the reflection spectrum information, the initial central wavelength data of each sample is obtained; according to the initial central wavelength data and material density of the epoxy insulation material samples with different aging durations, the wavelength shift is determined. In the acoustic impedance determination module 14, ultrasonic waves are emitted to the epoxy insulation material samples with different aging durations; according to the time when the ultrasonic waves are emitted and the time when the material samples reflect the ultrasonic waves, the round-trip time difference of the ultrasonic waves is determined; according to the round-trip time difference of the ultrasonic waves and the sample thickness, the ultrasonic wave propagation speed is determined; according to the material density and ultrasonic wave propagation speed of the epoxy insulation material samples with different aging durations, the acoustic impedance is determined. In the epoxy insulation material aging evaluation model construction module 15, a linear fitting is performed on the tensile strength and ultrasonic acoustic impedance of the epoxy insulation material with different aging durations, and a linear fitting is performed on the wavelength shift and glass transition temperature, to construct an epoxy insulation material aging evaluation model. In the thermal and mechanical property evaluation module 16, the thermal and mechanical properties of the epoxy insulation material in the aging state are evaluated through the epoxy insulation material aging evaluation model.

[0112] As Figure 4 shown, Figure 4 is a schematic structural diagram of an embodiment of the device provided by the present invention. The device 20 includes a memory 21 and a processor 22. The memory 21 stores a computer program, and the processor 22 executes the computer program during operation to implement as Figure 1 and Figure 2 shown in the method.

[0113] Regarding the specific technical details of a method for evaluating the aging state of an epoxy insulation material implemented when the above device 20 executes the computer program, they have been elaborated in detail in the foregoing method steps, so no further description will be given here.

[0114] As Figure 5 shown, Figure 5 is a schematic structural diagram of an embodiment of the medium provided by the present invention. The medium 30 stores at least one computer program 31, and the computer program 31 is executed by the processor 22 to implement as Figure 1 and Figure 2For the method shown above, for the detailed method, reference may be made to the above, and details will not be repeated here. In one embodiment, the medium 30 may be a storage chip, a hard disk, a mobile hard disk, a USB flash drive, an optical disc, or other writable and readable storage tools, or may also be a server, etc.

[0115] The above describes specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve the desired result. Additionally, the processes depicted in the figures do not necessarily have to be performed in the particular order shown or in a sequential order to achieve the desired result. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0116] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the embodiments of the device, equipment, and non - volatile computer - readable storage medium, since they are basically similar to the method embodiments, the description is relatively simple, and for the relevant parts, reference can be made to the partial description of the method embodiments.

[0117] The device, equipment, and non - volatile computer - readable storage medium provided in the embodiments of this specification correspond to the method. Therefore, the device, equipment, and non - volatile computer storage medium also have beneficial technical effects similar to the corresponding method. Since the beneficial technical effects of the method have been described in detail above, the beneficial technical effects of the corresponding device, equipment, and non - volatile computer storage medium will not be repeated here.

[0118] The system, device, module, or unit illustrated in the above embodiments can be specifically implemented by a computer chip or entity, or by a product with certain functions. A typical implementation device is a computer. Specifically, the computer can be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or any combination of these devices.

[0119] For the convenience of description, when describing the above device, various units are described separately according to their functions. Of course, when implementing this specification, the functions of each unit can be implemented in the same or multiple software and / or hardware. Those skilled in the art should understand that the embodiments of this specification can be provided as a method, a system, or a computer program product. Therefore, the embodiments of this specification can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the embodiments of this specification can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory, CD-ROM, optical memory, etc.) containing computer-usable program code.

[0120] This specification is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of this specification. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one or more of the processes Figure 1 or a plurality of processes and / or blocks

[0121] These computer program instructions can 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 generate a manufactured article including an instruction device, and the instruction device implements the functions specified in Figure 1 one or more of the processes Figure 1 or a plurality of processes and / or blocks

[0122] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one or more of the processes Figure 1 or a plurality of processes and / or blocks

[0123] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and a memory.

[0124] Memory may include non-permanent memory in the form of computer-readable media, random access memory (RAM) and / or non-volatile memory such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0125] Computer-readable media includes both permanent and non-permanent, removable and non-removable media implemented by any method or technology for information storage. 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 technologies, compact disc read-only memory (CD-ROM), digital versatile discs (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transitory media that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media such as modulated data signals and carrier waves.

Claims

1. A method for evaluating the aging state of an epoxy insulating material, characterized in that The method includes: Applying test conditions to the epoxy insulation material to obtain epoxy insulation material specimens with different aging durations; Measuring the glass transition temperature and tensile strength of the epoxy insulation material specimens with different aging durations; Optical fiber gratings are coated on the surfaces of the epoxy insulation material specimens with different aging durations. An optical signal is emitted to the optical fiber gratings, and the wavelength shift is determined according to the spectral information of the reflected optical signal of the gratings; An ultrasonic wave is emitted to the epoxy insulation material specimens with different aging durations, and the acoustic impedance is determined according to the time difference of the reflected ultrasonic wave of the material specimens and the material density; Performing linear fitting on the tensile strength and ultrasonic acoustic impedance of the epoxy insulation material with different aging durations, and performing linear fitting on the wavelength shift and glass transition temperature, to construct an aging evaluation model for the epoxy insulation material; Evaluating the thermal properties and mechanical properties of the epoxy insulation material in the aging state through the aging evaluation model of the epoxy insulation material.

2. The aging state evaluation method of an epoxy insulation material according to claim 1, wherein Optical fiber gratings are coated on the surfaces of the epoxy insulation material specimens with different aging durations. An optical signal is emitted to the optical fiber gratings, and the wavelength shift is determined according to the spectral information of the reflected optical signal of the gratings. Specifically, it includes: Optical fiber gratings are coated on the surfaces of the epoxy insulation material specimens with different aging durations; At a preset temperature, an optical signal is emitted to the optical fiber gratings, and the reflected spectral information of the reflected optical signal of the gratings is collected; According to the reflected spectral information, the initial central wavelength data of each specimen is obtained; The wavelength shift is determined according to the initial central wavelength data and material density of the epoxy insulation material specimens with different aging durations.

3. The aging state evaluation method of an epoxy insulating material according to claim 1, characterized in that, An ultrasonic wave is emitted to the epoxy insulation material specimens with different aging durations, and the acoustic impedance is determined according to the time difference of the reflected ultrasonic wave of the material specimens and the material density. Specifically, it includes: An ultrasonic wave is emitted to the epoxy insulation material specimens with different aging durations; According to the time of emitting the ultrasonic wave and the time of the reflected ultrasonic wave of the material specimens, the round-trip time difference of the ultrasonic wave is determined; According to the round-trip time difference of the ultrasonic wave and the specimen thickness, the ultrasonic wave propagation speed is determined; The acoustic impedance is determined according to the material density and ultrasonic wave propagation speed of the epoxy insulation material specimens with different aging durations.

4. The aging state evaluation method of an epoxy insulating material according to claim 2, wherein, The determination of the wavelength shift according to the initial central wavelength data and material density of the epoxy insulation material specimens with different aging durations specifically includes: According to determine the wavelength offset, where Δλ is the wavelength offset, and λ B is the initial center wavelength data, η eff is the effective refractive index, A is the grating period, P 11 and P 12 are the elasto-optic coefficients, υ is the Poisson's ratio, Δ ρ is the density change, and ρ is the initial material density.

5. The aging state evaluation method of an epoxy insulating material according to claim 3, characterized in that, The determination of the acoustic impedance according to the material density and ultrasonic wave propagation speed of the epoxy insulation material specimens with different aging durations specifically includes: According to z s = ρc to determine the acoustic impedance, where z s is the acoustic impedance, ρ is the material density, and c is the ultrasonic propagation velocity.

6. A method for evaluating the aging state of an epoxy insulating material according to any one of claims 1-5, characterized in that, The aging evaluation model of the epoxy insulation material includes a thermal property model of the epoxy insulation material and a mechanical property model of the epoxy insulation material. The linear fitting of the tensile strength and acoustic impedance of the epoxy insulation material with different aging durations, and the linear fitting of the wavelength shift and glass transition temperature, to construct an aging evaluation model of the epoxy insulation material. Specifically, it includes: Perform a linear fitting on the tensile strength and acoustic impedance to construct a mechanical property model of the epoxy insulating material. The mechanical property model of the epoxy insulating material is z s = k1E + b, where z s is the acoustic impedance, k1 is the first correlation coefficient, E is the tensile strength, and b is the initial tensile strength of the material; Construct a thermal property model of epoxy insulation materials by linearly fitting the tensile strength and ultrasonic acoustic impedance of the epoxy insulation materials with different aging durations. The thermal property model of the epoxy insulation materials is: T g = T g0 + k2Δλ, where T g0 is the initial glass transition temperature, Δλ is the wavelength offset, and k2 is the second correlation coefficient.

7. The aging state evaluation method of an epoxy insulating material according to claim 1, characterized in that The application of test conditions to the epoxy insulation material to obtain epoxy insulation material specimens with different aging durations specifically includes: At a constant temperature, the epoxy insulation material specimens are thermally aged to obtain thermally aged specimens of the epoxy insulation material with different aging durations; At a fixed frequency, the epoxy insulation material specimen is subjected to electrical aging to obtain electrical aging specimens of the epoxy insulation material with different aging durations.

8. An epoxy insulation material aging state evaluation system, characterized in that, The system includes: An epoxy insulation material specimen acquisition module for applying test conditions to the epoxy insulation material to obtain specimens of the epoxy insulation material with different aging durations; A measurement module for measuring the glass transition temperature and tensile strength of the epoxy insulation material specimens with different aging durations; A wavelength shift determination module for coating the surface of the epoxy insulation material specimens with different aging durations with fiber Bragg gratings, emitting optical signals to the fiber Bragg gratings, and determining the wavelength shift according to the spectral information of the optical signals reflected by the gratings; An acoustic impedance determination module for emitting ultrasonic waves to the epoxy insulation material specimens with different aging durations and determining the acoustic impedance according to the time difference of the ultrasonic waves reflected by the material specimens and the material density; An epoxy insulation material aging evaluation model construction module for linearly fitting the tensile strength and ultrasonic acoustic impedance of the epoxy insulation material with different aging durations, and linearly fitting the wavelength shift and the glass transition temperature to construct an epoxy insulation material aging evaluation model; A thermal property and mechanical property evaluation module for evaluating the thermal properties and mechanical properties of the epoxy insulation material in the aging state through the epoxy insulation material aging evaluation model.

9. A computer-readable storage medium storing a computer program, which when executed by a processor causes the processor to execute the steps of the method according to any one of claims 1 to 7.

10. A computer device including a memory and a processor, the memory storing a computer program, which when executed by the processor causes the processor to execute the steps of the method according to any one of claims 1 to 7.

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