Sleeve silicone rubber electrical aging state evaluation method, system, equipment and medium

Abstract

The invention discloses a sleeve silicone rubber electrical aging state evaluation method, system and device and a medium. The evaluation method comprises the following steps: constructing a microcosmic molecular model of the sleeve silicone rubber; applying an external electric field on the microscopic molecular model; calculating electrical characteristic parameters and infrared spectrums of the sleeve silicone rubber under different external electric field intensities; based on the electrical characteristic parameters and the infrared spectrum, establishing an evaluation model of correlation between the sleeve silicone rubber microstructure change and the infrared spectrum; and according to the evaluation model, predicting the electrical aging state of the sleeve silicone rubber through the change trend of the infrared spectrum. The evaluation method based on microstructure change is provided for macroscopic performance prediction of the sleeve silicone rubber under the action of an electric field, nondestructive testing and evaluation can be carried out on the electrical aging state of the sleeve silicone rubber, the experiment cost is remarkably reduced, the experiment time is remarkably shortened, and the evaluation accuracy and convenience are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of quantum chemical calculation and infrared spectroscopy, and in particular relates to a method, system, equipment and medium for evaluating the electrical aging state of casing silicone rubber. Background Art

[0002] With the rapid development of science and technology, the application value of rubber materials in various fields is constantly increasing. As a polymer material that can be synthesized without relying on fossil energy and has many excellent properties, casing silicone rubber has been widely used in the power field. Due to its excellent physical and chemical properties, casing silicone rubber is used in the manufacture of high-voltage equipment in the power system, such as power switchgear, insulators, etc. Its excellent high temperature resistance, aging resistance, arc resistance and UV resistance enable it to maintain good insulation in harsh environments, thereby ensuring the stable operation of power equipment.

[0003] In high-voltage power transmission systems, factors such as line faults inside power equipment or equipment switching may cause operating impulse voltages. In addition, the electromagnetic energy conversion process may also cause line system oscillations, generating high-frequency and high-amplitude impulse voltages. In this case, the insulating material may age and be damaged due to repeated impulse overvoltages, affecting the insulation state of the equipment. The discharge phenomenon caused by electrical faults will trigger a pyrolysis reaction inside the insulating material, which will lead to material degradation and may cause molecular chain breakage, ultimately causing material degradation. Therefore, it is necessary to conduct further research on the electrical aging state of casing silicone rubber.

[0004] At present, in the field of research on the electrical aging state of insulating materials, existing technologies mainly rely on macroscopic experiments and conventional electrical parameter measurements to evaluate the performance and aging state of insulating materials. These methods simulate the aging process of materials by exposing them to high voltage or high frequency environments for a long time, and detect changes in parameters such as electrical strength, breakdown voltage, and dielectric loss of insulating materials to determine their insulation performance. Although these methods can reveal the aging characteristics of insulating materials under the action of electric fields to some extent, they also have some obvious shortcomings. Macroscopic experimental methods are time-consuming and usually take months to years to observe the aging phenomenon of insulating materials, which not only increases the experimental cost, but also prolongs the research cycle.

[0005] The microstructural changes inside the insulating material can accurately and directly reflect the electrical aging state of the casing silicone rubber. However, the above macroscopic experiments can only provide the changes in the overall performance of the material, and cannot deeply reveal the microscopic aging mechanism inside the material. Existing research relies on the measurement of macroscopic performance, such as evaluating the aging state of the material by measuring electrical parameters (such as insulation resistance, dielectric constant, etc.). However, these methods cannot directly observe and analyze the microstructural changes of the material under the action of the electric field and its relationship with the aging phenomenon. Microscopic mechanisms such as molecular chain breakage, chemical bond changes and molecular rearrangement inside the material are difficult to be accurately observed in macroscopic experiments. Summary of the invention

[0006] In order to overcome the above-mentioned defects, the present invention aims to provide a method, system, equipment and medium for evaluating the electrical aging state of casing silicone rubber.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A method for evaluating the electrical aging state of sleeve silicone rubber comprises the following steps:

[0009] S1. Constructing a microscopic molecular model of casing silicone rubber;

[0010] S2, applying an external electric field to the microscopic molecular model;

[0011] S3. Calculate the electrical characteristic parameters and infrared spectrum of the casing silicone rubber under different external electric field strengths;

[0012] S4. Based on the electrical characteristic parameters and the infrared spectrum, an evaluation model for the correlation between the microstructure change of the sleeve silicone rubber and the infrared spectrum is established;

[0013] S5. According to the evaluation model, predict the electrical aging state of the sleeve silicone rubber through the change trend of the infrared spectrum.

[0014] Preferably, the construction of the microscopic molecular model of the sleeve silicone rubber in step S1 includes:

[0015] According to the chemical formula of silicone rubber, the initial molecular model was established using Gaussian software, and the geometric structure of the constructed initial molecular model was optimized to obtain an optimized microscopic molecular model.

[0016] Preferably, the geometry optimization method is a semi-empirical method.

[0017] Preferably, the application of the external electric field in step S2 is carried out along the main direction of the sleeve silicone rubber molecular chain, and the electric field strength is gradually increased from 0, and the voltage is step-by-step increased in steps of 0.0001 au according to the changes in the internal structure of the molecular model until significant changes or signs of damage appear inside the molecule.

[0018] Preferably, the electrical characteristic parameters in step S3 include dipole moment, polarizability, Hamiltonian, molecular orbital energy level, energy gap and state density.

[0019] Preferably, the calculation formula of the Hamiltonian is:

[0020] H=H 0 +H int ,

[0021] Where H represents the Hamiltonian; H 0 It represents the Hamiltonian of the molecular system when there is no external electric field; H int It represents the additional Hamiltonian introduced by the external electric field. The additional Hamiltonian is expressed as H int =-μ·F, μ represents the dipole moment of the molecule, and F represents the strength of the external electric field.

[0022] Preferably, the calculation method of the molecular orbital energy level, energy gap and state density is:

[0023] Gaussian software was used to calculate the energy level distribution and energy gap of molecular orbitals, the energy levels of the highest occupied molecular orbitals and the lowest unoccupied molecular orbitals of sleeve silicone rubber under different external electric fields were calculated, and then the state density was calculated using Multiwfn software.

[0024] A casing silicone rubber electrical aging state assessment system, comprising:

[0025] Molecular simulation module, used to construct a microscopic molecular model of casing silicone rubber;

[0026] An electric field applying module, used for applying an external electric field on the microscopic molecular model;

[0027] A calculation module is used to calculate the electrical characteristic parameters and infrared spectrum of the casing silicone rubber under different external electric field strengths;

[0028] An evaluation model building module is used to establish an evaluation model for associating the microstructure change of the sleeve silicone rubber with the infrared spectrum based on the electrical characteristic parameters and the infrared spectrum;

[0029] The data analysis module is used to predict the electrical aging state of the sleeve silicone rubber through the change trend of the infrared spectrum according to the evaluation model.

[0030] An electronic device comprises a processor and a memory, wherein the processor is used to execute a computer program stored in the memory to implement the method for evaluating the electrical aging state of sleeve silicone rubber.

[0031] A computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the method for evaluating the electrical aging state of sleeve silicone rubber.

[0032] Positive and beneficial effects of the present invention

[0033] 1. Infrared spectroscopy is closely related to the molecular structure inside the material. The present invention uses infrared spectroscopy to detect changes in the chemical structure and functional groups of material molecules, thereby revealing changes in the microstructure of the material during the aging process. In addition, infrared spectroscopy technology is more convenient and faster than previous testing methods. The present invention proposes an infrared model for predicting the electrical aging state of casing silicone rubber. Through quantum chemical calculation and molecular simulation technology, a microscopic molecular model of casing silicone rubber is constructed, and under the action of a gradually increasing electric field, changes in its dipole moment, polarizability, Hamiltonian, molecular orbital energy level, energy gap and state density are analyzed. By simulating and calculating the infrared spectrum of the casing silicone rubber before and after breakdown under the action of the electric field, a relationship between microscopic structural changes in the electrical aging process of the casing silicone rubber and macroscopic features observed by infrared spectra is established, and a macro-micro correlation model of the casing silicone rubber is formed. The model provides an evaluation method based on microscopic structural changes for macroscopic performance prediction of casing silicone rubber under the action of an electric field by linking molecular structural changes with infrared spectral features, and can perform non-destructive detection and evaluation on the electrical aging state of the casing silicone rubber, significantly reducing experimental cost and time, improving the accuracy and convenience of evaluation, and providing a theoretical basis and data support for the modification of casing silicone rubber materials and the optimization of insulation performance of power equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Molecular model of casing silicone rubber.

[0035] Figure 2 Dynamic changes of the molecular chains of the silicone rubber casing.

[0036] Figure 3 The bond length of the silicone rubber molecules in the casing changes.

[0037] Figure 4 is the change of molecular dipole moment of silicone rubber in sleeve.

[0038] Figure 5 is the change of polarizability of casing silicone rubber molecules.

[0039] Figure 6 is the change of total energy of casing silicone rubber molecules.

[0040] Figure 7 The frontier orbital energy level changes of casing silicone rubber molecules under different electric fields.

[0041] Figure 8The energy gap change of casing silicone rubber molecules under different electric fields.

[0042] Fig. 9 The state density of the silicone rubber molecules in the sleeve when the voltage is 0V / nm.

[0043] Fig.10 The state density of the silicone rubber molecules in the sleeve when the voltage is 5.142 V / nm.

[0044] Fig.11 The state density of the silicone rubber molecules in the sleeve when the voltage is 10.284V / nm.

[0045] Fig.12 The state density of the silicone rubber molecules in the sleeve at 12.7 V / nm.

[0046] Fig.13 This is the infrared spectrum of the casing silicone rubber molecule. DETAILED DESCRIPTION

[0047] The embodiments of the present invention will be described in detail below with reference to examples.

[0048] Example 1

[0049] A method for evaluating the electrical aging state of sleeve silicone rubber comprises the following steps:

[0050] S1. Based on Gaussian software and the chemical formula of silicone rubber, the initial molecular model of casing silicone rubber is established. The PM3 semi-empirical method is used to optimize the geometric structure of the constructed initial molecular model to obtain the molecular configuration with the minimum energy and the most stable, that is, to obtain the optimized microscopic molecular model, to ensure that the simulated molecular structure can truly reflect the microscopic structure of casing silicone rubber in its natural state, thus laying the foundation for the subsequent simulation under the action of electric field;

[0051] S2, gradually applying an external electric field to the microscopic molecular model optimized in step S1, wherein the application of the external electric field is carried out along the main direction of the sleeve silicone rubber molecular chain, gradually increasing the electric field strength from 0, and stepping up the voltage in steps of 0.0001 au according to the changes in the internal structure of the molecular model until significant changes or signs of damage appear inside the molecule;

[0052] S3. Under the action of an external electric field, a semi-empirical method is used to analyze the microscopic electrical properties of the casing silicone rubber molecules, and the dipole moment, polarizability, Hamiltonian, molecular orbital energy level, energy gap and state density of the casing silicone rubber under different external electric field strengths are calculated. The response characteristics of the molecules under the action of the electric field are deeply analyzed. These parameters are obtained through the built-in calculation commands of the software, which reflect the charge distribution of the casing silicone rubber molecules under the electric field and their response ability to the external electric field, providing key data for predicting the performance of the material under the actual electric field;

[0053] In S3, according to the dipole approximation, when there is no external electric field, the Hamiltonian of the molecular system is expressed as H 0 ; After applying an external electric field, the Hamiltonian H of the molecular system is expressed as H = H 0 +H int , where H int It represents the additional Hamiltonian introduced by the external electric field. When the external electric field interacts with the molecular system, this additional Hamiltonian can be further expressed as H int =-μ·F, μ represents the dipole moment of the molecule, and F represents the strength of the external electric field;

[0054] In S3, Gaussian software is used to calculate the energy level distribution and energy gap of molecular orbitals, the energy levels of the highest occupied molecular orbitals and the lowest unoccupied molecular orbitals of sleeve silicone rubber under different external electric fields are calculated, and the state density of sleeve silicone rubber is calculated by Multiwfn software;

[0055] The molecular orbital characteristics of the casing silicone rubber were further analyzed, and the infrared spectra of the casing silicone rubber under different electric field intensities were calculated using Gaussian software in combination with the molecular structure changes before and after breakdown.

[0056] S4. Based on the electrical characteristic parameters and infrared spectrum, a relationship between the microstructure changes of the casing silicone rubber during electrical aging and the macroscopic features observed by infrared spectrum is established to form a macro-micro correlation model of the casing silicone rubber, i.e., an evaluation model;

[0057] S5. According to the evaluation model, predict the electrical aging state of the sleeve silicone rubber through the change trend of the infrared spectrum.

[0058] Application test

[0059] Firstly, the geometric structure of the sleeve silicone rubber molecular model was optimized using the PM3 semi-empirical method to obtain the molecular stable configuration with the lowest energy.

[0060] like Figure 1 As shown in the figure, in the optimized microscopic molecular model, gray-blue represents silicon atoms Si, red represents oxygen atoms O, black represents carbon atoms C, and white represents hydrogen atoms H. The optimization results show that the total energy reaches the minimum, no imaginary frequency appears, and various criteria such as maximum force, root mean square force, maximum displacement and root mean square displacement all meet the convergence standard.

[0061] The geometrical structural parameters, single point energy, dipole moment, polarizability, molecular orbital energy level, energy gap, state density and infrared spectrum of casing silicone rubber are calculated and predicted.

[0062] The calculation results show that under the action of an external electric field, the lengths of some chemical bonds in the sleeve silicone rubber molecules will change. These changes reflect the adjustment of the molecular geometric structure caused by the electric field, such as Figure 2 As shown in Figure 2, as the electric field strength increases, the geometric stability of the silicone rubber molecules in the sleeve decreases, which may lead to significant elongation of the molecular chain and weakening of the insulation performance. Figure 3 As shown in Figure 1, when the electric field strength reaches a critical value, the molecular chain elongates significantly and the insulating properties decrease rapidly.

[0063] like Figure 4 and 5 As shown in the figure, the electrons migrate in the direction of the electric field, which increases the charge on each atom in the direction of the electric field, thereby enhancing the dipole moment and polarizability of the sleeve silicone rubber molecules. Figure 6 As shown in the figure, by calculating the dipole moment and polarizability, it is found that with the increase of electric field strength, the total energy of the sleeve silicone rubber molecules tends to decrease. Figure 4-6 When the electric field strength reaches 12.75216V / nm, imaginary frequency appears in the molecular structure, which means that the molecular structure has been destroyed. Under the long-term influence of the external electric field, the stability of the internal molecular chain system of the sleeve silicone rubber material will gradually weaken. Under the action of the electric field, electrons migrate, resulting in an increase in atomic charge, thereby increasing the dipole moment and polarizability.

[0064] Gaussian software is used to calculate the orbital energy level and energy gap Eg of the sleeve silicone rubber molecule to show its electronic behavior under different electric fields. The electric field reduces the LUMO energy level and increases the HOMO energy level, resulting in changes in the reactivity of the sleeve silicone rubber molecule. As the HOMO and LUMO energy levels approach, the Eg value decreases, such as Figure 7 and Figure 8 As shown, this transition of electrons between the valence band and the conduction band increases the conductivity, thereby reducing the insulating properties.

[0065] Then use Multiwfn software to calculate the state density. The HOMO energy level corresponds to the highest energy of the valence band, and the LUMO energy level corresponds to the lowest energy of the conduction band. Under the action of the electric field, the state density diagram shows the distribution of trap energy levels at different depths, such as Fig. 9 and Fig.10 As the electric field strength increases, the captured energy density increases, the HOMO energy level moves toward higher energy, and the LUMO energy level moves toward lower energy, resulting in an increase in the number of hole and electron traps, as shown in Fig.11 and Fig.12 These trapping effects enhance the ability to capture free electrons and weaken the insulating properties of the silicone rubber casing.

[0066] The calculation results were further processed using Multiwfn software to obtain infrared spectral data when the external electric field strength was 0 V / nm, 5.14 V / nm, 10.284 V / nm and 12.7 V / nm, and these results are displayed in Fig.13 The inflection point of the change in the molecular structure of the casing silicone rubber material marks the beginning of the electrical tree aging of the insulating material. This process will destroy the internal molecular structure of the casing silicone rubber and produce free radicals, which is consistent with the geometric structure analysis. The changes in the infrared spectrum before and after breakdown can be used as an effective reference for evaluating the aging state of the casing silicone rubber.

[0067] Example 2

[0068] A casing silicone rubber electrical aging state assessment system, comprising:

[0069] Molecular simulation module, used to construct a microscopic molecular model of casing silicone rubber;

[0070] An electric field applying module, used for applying an external electric field on the microscopic molecular model;

[0071] A calculation module is used to calculate the electrical characteristic parameters and infrared spectrum of the casing silicone rubber under different external electric field strengths;

[0072] An evaluation model building module is used to establish an evaluation model for associating the microstructure change of the sleeve silicone rubber with the infrared spectrum based on the electrical characteristic parameters and the infrared spectrum;

[0073] The data analysis module is used to predict the electrical aging state of the sleeve silicone rubber through the change trend of the infrared spectrum according to the evaluation model.

[0074] Based on similar inventive concepts, an embodiment of the present invention further provides an electronic device, including a processor and a memory, wherein the processor is used to execute a computer program stored in the memory to implement the method for evaluating the electrical aging state of sleeve silicone rubber.

[0075] The processor and the memory may be connected via a bus or other means.

[0076] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely disposed relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0077] Based on similar inventive concepts, an embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the method for evaluating the electrical aging state of sleeve silicone rubber.

[0078] It will be appreciated by those skilled in the art that all or some of the steps and systems in the disclosed method above may be implemented as software, firmware, hardware and appropriate combinations thereof. Some physical components or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor or a microprocessor, or may be implemented as hardware, or may be implemented as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or a non-transitory medium) and a communication medium (or a temporary medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that may be used to store desired information and may be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in the field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for evaluating the electrical aging state of casing silicone rubber, characterized in that: The following steps are involved: S1. Constructing the microscopic molecular model of casing silicone rubber; S2, applying an external electric field to the microscopic molecular model; S3. Calculate the electrical characteristic parameters and infrared spectrum of the casing silicone rubber under different external electric field strengths; S4. Based on the electrical characteristic parameters and the infrared spectrum, an evaluation model for the correlation between the microstructure change of the sleeve silicone rubber and the infrared spectrum is established; S5. According to the evaluation model, predict the electrical aging state of the sleeve silicone rubber through the change trend of the infrared spectrum.

2. The method for evaluating the electrical aging state of sleeve silicone rubber according to claim 1, characterized in that: The construction of the microscopic molecular model of the sleeve silicone rubber in step S1 includes: According to the chemical formula of silicone rubber, the initial molecular model was established using Gaussian software, and the geometric structure of the constructed initial molecular model was optimized to obtain an optimized microscopic molecular model.

3. The method for evaluating the electrical aging state of sleeve silicone rubber according to claim 2, characterized in that: The geometry optimization method is a semi-empirical method.

4. The method for evaluating the electrical aging state of sleeve silicone rubber according to claim 1, characterized in that: The application of the external electric field in step S2 is carried out along the main direction of the sleeve silicone rubber molecular chain, and the electric field strength is gradually increased from 0, and the voltage is stepped up in steps of 0.0001 au according to the changes in the internal structure of the molecular model until significant changes or signs of damage appear inside the molecule.

5. The method for evaluating the electrical aging state of sleeve silicone rubber according to claim 1, characterized in that: The electrical characteristic parameters in step S3 include dipole moment, polarizability, Hamiltonian, molecular orbital energy level, energy gap and state density.

6. The method for evaluating the electrical aging state of sleeve silicone rubber according to claim 5, characterized in that: The calculation formula of the Hamiltonian is: H=H0+H int , Where H represents the Hamiltonian; H0 represents the Hamiltonian of the molecular system when there is no external electric field; H int It represents the additional Hamiltonian introduced by the external electric field. The additional Hamiltonian is expressed as H int =-μ·F, μ represents the dipole moment of the molecule, and F represents the strength of the external electric field.

7. The method for evaluating the electrical aging state of sleeve silicone rubber according to claim 5, characterized in that: The calculation method of the molecular orbital energy level, energy gap and state density is: Gaussian software was used to calculate the energy level distribution and energy gap of molecular orbitals, the energy levels of the highest occupied molecular orbitals and the lowest unoccupied molecular orbitals of sleeve silicone rubber under different external electric fields were calculated, and then the state density was calculated using Multiwfn software.

8. A casing silicone rubber electrical aging status assessment system, characterized in that: include: Molecular simulation module, used to construct a microscopic molecular model of casing silicone rubber; An electric field applying module, used for applying an external electric field on the microscopic molecular model; A calculation module is used to calculate the electrical characteristic parameters and infrared spectrum of the casing silicone rubber under different external electric field strengths; An evaluation model building module is used to establish an evaluation model for associating the microstructure change of the sleeve silicone rubber with the infrared spectrum based on the electrical characteristic parameters and the infrared spectrum; The data analysis module is used to predict the electrical aging state of the sleeve silicone rubber through the change trend of the infrared spectrum according to the evaluation model.

9. An electronic device comprising a processor and a memory, characterized in that: The processor is used to execute the computer program stored in the memory to implement the bushing silicone rubber electrical aging state assessment method.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the method for evaluating the electrical aging state of sleeve silicone rubber.

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