Method and device for determining insulation aging state of insulating oil, equipment and medium

Abstract

The invention relates to an insulating oil insulation aging state determination method and device, computer equipment, a computer readable storage medium and a computer program product. The method comprises the following steps: constructing a single-molecule model corresponding to a target molecule in composition molecules of the insulating oil by utilizing a molecular simulation tool; acquiring the corresponding extreme electric field intensity when the single-molecule model is damaged, and determining a test electric field intensity interval according to the extreme electric field intensity; obtaining the dipole moment, polarizability, orbital energy level and state density of the single molecule model corresponding to different test electric field intensities in the test electric field intensity interval; according to the dipole moment, the polarizability, the orbital energy level and the state density, determining a reaction site of the single molecule model under the extreme electric field intensity; obtaining target infrared spectrum information of the single molecule model corresponding to the reaction site; the target infrared spectrum information is used for matching and comparing with the infrared spectrum information of the to-be-evaluated insulating oil to obtain the insulation aging state of the to-be-evaluated insulating oil. The method can improve the evaluation efficiency.

Description

Technical Field

[0001] The present application relates to the field of quantum chemical calculation and infrared spectroscopy technology, and in particular to a method, device, computer equipment, computer-readable storage medium and computer program product for determining the insulation aging state of insulating oil. Background Art

[0002] At present, power capacitors are widely used in power grid systems. The insulation performance of power capacitors is the key to ensuring the stable operation of power capacitors. Therefore, the insulation performance of the liquid dielectric material (such as insulating oil) of power capacitors is crucial to the stable operation of the power grid.

[0003] The aging of power capacitors is related to many complex factors of the power grid. At present, there are great difficulties in the accurate fault diagnosis of the aging status of the insulating oil of power capacitors. Complex tests are required to obtain its aging status, resulting in low efficiency in the assessment of the insulation aging status of the insulating oil of power capacitors. Summary of the invention

[0004] Based on this, it is necessary to provide a method, device, computer equipment, computer-readable storage medium and computer program product for determining the insulation aging state of insulating oil, which can efficiently evaluate the insulation aging state of insulating oil, in order to address the above technical problems.

[0005] In a first aspect, the present application provides a method for determining the insulation aging state of insulating oil, comprising:

[0006] Using a molecular simulation tool to construct a single molecule model corresponding to a target molecule in the constituent molecules of insulating oil; the insulating oil includes at least one type of constituent molecules;

[0007] Obtaining the extreme electric field strength corresponding to the destruction of the single molecule model, and determining the test electric field strength interval according to the extreme electric field strength;

[0008] Obtaining the dipole moment, polarizability, orbital energy level and state density of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval;

[0009] Determining the reaction site of the single molecule model under the extreme electric field strength according to the dipole moment, the polarizability, the orbital energy level and the density of states;

[0010] The target infrared spectrum information of the single molecule model corresponding to the reaction site is obtained; the target infrared spectrum information is used to match and compare with the infrared spectrum information of the insulating oil to be evaluated, so as to obtain the insulation aging state of the insulating oil to be evaluated.

[0011] In one embodiment, the use of a molecular simulation tool to construct a single molecule model corresponding to a target molecule in the constituent molecules of insulating oil includes:

[0012] Use molecular simulation tools to construct an initial single-molecule model corresponding to the target molecule in the constituent molecules of insulating oil;

[0013] The initial single-molecule model is structurally optimized at the basis set level of PM3 to obtain a single-molecule stable structure when the molecular energy is the lowest;

[0014] The single molecule model corresponding to the single molecule stable structure is determined as the single molecule model corresponding to the target molecule.

[0015] In one embodiment, obtaining the extreme electric field strength corresponding to the destruction of the single molecule model includes:

[0016] An electric field in the direction of the molecular chain is applied to the single molecule model by the molecular simulation tool, and the electric field strength of the electric field is gradually increased according to a preset electric field strength increment until the single molecule model is destroyed, thereby obtaining the extreme electric field strength corresponding to the destruction of the single molecule model.

[0017] In one embodiment, the step of obtaining the dipole moment, polarizability, orbital energy level and state density of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval includes:

[0018] Using quantum chemical methods, the single molecule model is molecularly simulated in the test electric field strength interval corresponding to different test electric field strengths to obtain the dipole moment of the single molecule model corresponding to different test electric field strengths during the molecular simulation process; and the polarizability corresponding to the single molecule model is obtained by analyzing the dipole moment;

[0019] Utilizing the frontier orbital theory, the orbital energy levels of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval are obtained through a tool; the state density of the single molecule model is obtained according to the orbital energy levels; wherein the orbital energy levels include the energy level of the highest occupied molecular orbital and the energy level of the lowest unoccupied molecular orbital.

[0020] In one embodiment, the method of using quantum chemistry to perform molecular simulation on the single molecule model in the test electric field strength interval corresponding to different test electric field strengths to obtain the dipole moment of the single molecule model corresponding to different test electric field strengths during the molecular simulation process includes:

[0021] Using a quantum chemical method to obtain a first Hamiltonian of the single molecule model when no electric field is applied, and to obtain a second Hamiltonian of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval;

[0022] According to the first Hamiltonian, the second Hamiltonian and the test electric field strength corresponding to the second Hamiltonian, the dipole moment corresponding to the single molecule model under the test electric field strength is obtained.

[0023] In one embodiment, obtaining the density of states of the single molecule model according to the orbital energy level comprises:

[0024] Obtaining an energy gap corresponding to the single molecule model in the test electric field strength interval according to the energy level of the highest occupied molecular orbital and the energy level of the lowest unoccupied molecular orbital;

[0025] The state density of the single molecule model is obtained according to the orbital energy level and the energy gap.

[0026] In a second aspect, the present application also provides a device for determining the insulation aging state of insulating oil, comprising:

[0027] A molecular model building module, used to build a single molecule model corresponding to a target molecule in the constituent molecules of insulating oil using a molecular simulation tool; the insulating oil includes at least one type of constituent molecules;

[0028] A model data acquisition module, used to obtain the extreme electric field strength corresponding to the destruction of the single molecule model, and determine the test electric field strength interval according to the extreme electric field strength; and also used to obtain the dipole moment, polarizability, orbital energy level and state density of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval;

[0029] A reaction site determination module, used to determine the reaction site of the single molecule model under the extreme electric field strength according to the dipole moment, the polarizability, the orbital energy level and the state density;

[0030] The infrared spectrum acquisition module is used to obtain the target infrared spectrum information of the single molecule model corresponding to the reaction site; the target infrared spectrum information is used to match and compare with the infrared spectrum information of the insulating oil to be evaluated to obtain the insulation aging state of the insulating oil to be evaluated.

[0031] In a third aspect, the present application further provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method described in the first aspect when executing the computer program.

[0032] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method described in the first aspect.

[0033] In a fifth aspect, the present application further provides a computer program product, comprising a computer program, which implements the steps of the method described in the first aspect when executed by a processor.

[0034] The above-mentioned method, device, computer equipment, computer-readable storage medium and computer program product for determining the insulation aging state of insulating oil use molecular simulation tools to construct a single molecule model corresponding to a target molecule among the constituent molecules of the insulating oil; the insulating oil includes at least one type of constituent molecules; then the extreme electric field strength corresponding to the destruction of the single molecule model is obtained, and the test electric field strength interval is determined according to the extreme electric field strength; then the dipole moment, polarizability, orbital energy level and state density of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval are obtained; then the reaction site of the single molecule model under the extreme electric field strength is determined according to the dipole moment, polarizability, orbital energy level and state density; finally, the target infrared spectrum information corresponding to the reaction site of the single molecule model is obtained; the target infrared spectrum information is matched and compared with the infrared spectrum information of the insulating oil to be evaluated to obtain the insulation aging state of the insulating oil to be evaluated. The present application constructs a single-molecule model, and obtains the electric field response characteristics of the single-molecule model through molecular simulation, that is, the response changes of dipole moment, polarizability, orbital energy level and state density, and associates the electric field response characteristics with the infrared spectrum of the reaction site of the single-molecule model. Finally, the infrared spectrum information of the reaction site is matched and compared with the infrared spectrum information of the insulating oil to be evaluated, so as to evaluate the degree of change of the reaction site in the insulating oil to be evaluated, and then obtain the insulation aging state of the insulating oil to be evaluated. Therefore, only the infrared spectrum information of the insulating oil to be evaluated and the target infrared spectrum information of the reaction site are needed to obtain the insulation aging state, which improves the efficiency of obtaining the insulation aging state. Compared with the traditional complex testing process, the insulation aging state acquisition process is simplified, which can reduce resource loss. At the same time, the insulation aging state of the insulating oil is determined according to the characteristics of the reaction site at the microscopic molecular level, which can improve the accuracy of the insulation aging state evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments of the present application or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0036] FIG1 is a schematic flow chart of a method for determining insulation aging status of insulating oil in one embodiment;

[0037] FIG2 is a schematic diagram of a process of using a molecular simulation tool to construct a single molecule model corresponding to a target molecule in the constituent molecules of insulating oil in one embodiment;

[0038] FIG3 is a schematic structural diagram of a molecular model of MBT in one embodiment;

[0039] FIG4 is a schematic structural diagram of a molecular model of DBT in one embodiment;

[0040] FIG5 is a schematic diagram of a curve showing the change in bond length of MBT (a) and DBT (b) molecules in one embodiment;

[0041] FIG6 is a schematic structural diagram of the molecular bond breaking change of MBT molecules in one embodiment;

[0042] FIG7 is a schematic structural diagram of the molecular bond breaking change of DBT molecules in one embodiment;

[0043] FIG8 is a schematic diagram of a curve showing changes in total energy, dipole moment and polarizability of MBT molecules in one embodiment;

[0044] FIG9 is a schematic diagram of a curve showing changes in the total energy, dipole moment and polarizability of a DBT molecule in one embodiment;

[0045] FIG10 is a schematic diagram of curves showing changes in orbital energy levels of MBT (a) and DBT (b) under different electric fields in one embodiment;

[0046] FIG11 is a schematic diagram of a curve showing the energy gap change of MBT (a) and DBT (b) under different electric fields in one embodiment;

[0047] FIG12 is a schematic diagram of a curve of the density of states of MBT at 0 V / nm in one embodiment;

[0048] FIG13 is a schematic diagram of a curve of DBT state density at 0 V / nm in one embodiment;

[0049] FIG. 14 is a schematic diagram of a curve of the density of states of MBT at 20.41374 V / nm in one embodiment;

[0050] FIG15 is a schematic diagram of a curve of DBT state density at 13.57488 V / nm in one embodiment;

[0051] FIG16 is a spectrum diagram of an infrared spectrum of MBT at 0 V / nm in one embodiment;

[0052] FIG17 is a schematic diagram of the infrared spectrum of DBT at 0 V / nm in one embodiment;

[0053] FIG18 is a spectrum diagram of an infrared spectrum of MBT at 20.41374 V / nm in one embodiment;

[0054] FIG19 is a spectrum diagram of an infrared spectrum of DBT at 13.57488 V / nm in one embodiment;

[0055] FIG20 is a structural block diagram of a device for determining insulation aging status of insulating oil in one embodiment;

[0056] FIG. 21 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0058] In one embodiment, as shown in FIG1 , a method for determining the insulation aging state of insulating oil is provided. This embodiment is illustrated by applying the method to a terminal. It is understandable that the method can also be applied to a server, and can also be applied to a system including a terminal and a server, and is implemented through the interaction between the terminal and the server. In this embodiment, the method includes the following steps:

[0059] Step S202: constructing a single molecule model corresponding to a target molecule among the constituent molecules of the insulating oil using a molecular simulation tool.

[0060] The insulating oil may refer to a liquid dielectric material in a power capacitor, or may refer to an insulating medium in other devices or components; the insulating oil includes at least one type of component molecules. For example, the insulating oil may include two types of component molecules: monobenzyltoluene (C14H14) and dibenzyltoluene (C21H20).

[0061] Exemplarily, the terminal may utilize a molecular simulation tool deployed in the terminal to determine a target molecule in at least one type of constituent molecules of the insulating oil, and construct a single molecule model corresponding to the target molecule.

[0062] Step S204, obtaining the extreme electric field strength corresponding to the destruction of the single molecule model, and determining the test electric field strength interval according to the extreme electric field strength.

[0063] The extreme electric field strength may refer to the electric field strength applied to the single molecule model when the single molecule model is destroyed. The electric field strength interval may refer to the interval from zero electric field strength or from a preset electric field strength less than the extreme electric field strength to the extreme electric field strength.

[0064] Exemplarily, the terminal simulates the test through a molecular simulation tool to obtain the extreme electric field strength corresponding to the destruction of the single molecule model, and then determines the test electric field strength interval according to the extreme electric field strength.

[0065] Step S206, obtaining the dipole moment, polarizability, orbital energy level and state density of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval.

[0066] Among them, the dipole moment can be a physical quantity used to describe the distribution of positive and negative charges in a molecule, characterizing the degree of polarization of the molecule in an electric field. Polarizability can refer to the ratio of the electric dipole moment generated by a substance under the action of an external electric field to the applied electric field strength, which can reflect the sensitivity of the molecular polarization behavior. Orbital energy level can be used to describe the discrete state of electron energy in a molecule, and each molecular orbital has a specific energy value. The state density can be used to describe the number of quantum states available in a certain energy range, which is usually closely related to the distribution and energy state of electrons.

[0067] Step S208, determining the reaction site of the single molecule model under extreme electric field strength according to the dipole moment, polarizability, orbital energy level and state density.

[0068] The reaction site may refer to a specific position in the target molecule that interacts with the external electric field, for example, it may be a specific chemical bond among multiple chemical bonds in the target molecule.

[0069] Step S210, obtaining target infrared spectrum information corresponding to the reaction site of the single molecule model.

[0070] The target infrared spectrum information is used to match and compare with the infrared spectrum information of the insulating oil to be evaluated, so as to obtain the insulation aging state of the insulating oil to be evaluated.

[0071] The target infrared spectrum information can be the infrared spectrum information corresponding to the reaction site contained in the infrared spectrum information obtained by calculating the single molecule model through a preset software tool. The infrared spectrum information of the insulating oil can be measured by an infrared spectrometer to obtain a spectrum diagram in the infrared band.

[0072] Specifically, the terminal obtains the target infrared spectrum information of the single-molecule model corresponding to the reaction site. The absorption peak of the reaction site in the infrared spectrum and the different frequencies of the absorption peak of the reaction site under different electric field strengths can be determined through the target infrared spectrum information. The terminal then obtains the infrared spectrum information of the insulating oil to be evaluated, and matches and searches for the absorption peak that matches the absorption peak of the reaction site in the infrared spectrum information. The frequency corresponding to the absorption peak can be matched and compared in the target infrared spectrum information to obtain the corresponding test electric field strength in the molecular simulation process. The dipole moment, polarizability, orbital energy level and state density corresponding to the single-molecule model under the test electric field strength are used as the performance parameters of the target molecule of the insulating oil to be evaluated, and the insulation aging state of the insulating oil to be evaluated is evaluated based on the performance parameters.

[0073] In the above-mentioned method for determining the insulation aging state of insulating oil, the terminal uses a molecular simulation tool to construct a single molecule model corresponding to a target molecule among the constituent molecules of the insulating oil; the insulating oil includes at least one type of constituent molecules; then the terminal obtains the extreme electric field strength corresponding to the destruction of the single molecule model, and determines the test electric field strength interval according to the extreme electric field strength; then the terminal obtains the dipole moment, polarizability, orbital energy level and state density of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval; then the terminal determines the reaction site of the single molecule model under the extreme electric field strength according to the dipole moment, polarizability, orbital energy level and state density; finally, the terminal obtains the target infrared spectrum information corresponding to the reaction site of the single molecule model; the terminal matches and compares the target infrared spectrum information with the infrared spectrum information of the insulating oil to be evaluated to obtain the insulation aging state of the insulating oil to be evaluated. The present application constructs a single-molecule model, and obtains the electric field response characteristics of the single-molecule model through molecular simulation, that is, the response changes of dipole moment, polarizability, orbital energy level and state density, and associates the electric field response characteristics with the infrared spectrum of the reaction site of the single-molecule model. Finally, the infrared spectrum information of the reaction site is matched and compared with the infrared spectrum information of the insulating oil to be evaluated, so as to evaluate the degree of change of the reaction site in the insulating oil to be evaluated, and then obtain the insulation aging state of the insulating oil to be evaluated. Therefore, only the infrared spectrum information of the insulating oil to be evaluated and the target infrared spectrum information of the reaction site are needed to obtain the insulation aging state, which improves the efficiency of obtaining the insulation aging state. Compared with the traditional complex testing process, the insulation aging state acquisition process is simplified, which can reduce resource loss. At the same time, the insulation aging state of the insulating oil is determined according to the characteristics of the reaction site at the microscopic molecular level, which can improve the accuracy of the insulation aging state evaluation.

[0074] In an exemplary embodiment, as shown in FIG2 , the above step S202 includes:

[0075] Step S302: construct an initial single molecule model corresponding to the target molecule in the constituent molecules of the insulating oil using a molecular simulation tool.

[0076] Step S304, optimizing the structure of the initial single molecule model at the basis set level of PM3 to obtain a single molecule stable structure when the molecular energy is the lowest.

[0077] Step S306: determine the single molecule model corresponding to the single molecule stable structure as the single molecule model corresponding to the target molecule.

[0078] Among them, molecular simulation tools can refer to computational chemistry software used to simulate the structure and behavior of molecules. Common molecular simulation tools include Gaussian, VASP, LAMMPS and other tools, which can predict the properties of molecules in different environments through physical and chemical principles. PM3 (Parameterized Model 3) is a semi-empirical quantum chemistry method used to calculate the electronic structure of molecular systems. Structural optimization can refer to the process of finding the lowest energy point by changing the molecular structure.

[0079] Exemplarily, the terminal uses a molecular simulation tool to input the atomic type and connection information corresponding to the target molecule in the constituent molecules of the insulating oil to construct an initial single-molecule model. The terminal sets the calculation parameters and optimizes the structure of the initial single-molecule model at the basis set level of PM3 to obtain a single-molecule stable structure when the molecular energy is lowest. The terminal determines the single-molecule model corresponding to the single-molecule stable structure as the single-molecule model corresponding to the target molecule.

[0080] In this embodiment, by performing structural optimization on the constructed initial single-molecule model at the basis set level of PM3, a single-molecule model corresponding to the single-molecule stable structure when the molecular energy is lowest is obtained, which can effectively establish and optimize the single-molecule model and provide reliable structural data support for the subsequent use of the single-molecule model.

[0081] In an exemplary embodiment, in the above step S204, the extreme electric field strength corresponding to the destruction of the single molecule model is obtained, including: applying an electric field in the direction of the molecular chain to the single molecule model through a molecular simulation tool, and gradually increasing the electric field strength of the electric field according to a preset electric field strength increment until the single molecule model is destroyed, and obtaining the extreme electric field strength corresponding to the destruction of the single molecule model.

[0082] The electric field applied in the direction of the molecular chain may refer to the direction of the electric field application being consistent with the main direction of the molecular chain. The direction of the molecular chain generally refers to the orientation of the long chain structure in the molecule, which can more realistically simulate the effect of the electric field on the target molecule. The preset electric field strength increment may refer to the gradual increase in the electric field strength.

[0083] Exemplarily, the terminal applies an electric field in the direction of the molecular chain to the single molecule model through a molecular simulation tool, and gradually increases the electric field strength of the electric field according to a preset electric field strength increment until the single molecule model is destroyed, thereby obtaining the extreme electric field strength corresponding to the destruction of the single molecule model.

[0084] In this embodiment, by applying a gradually increasing electric field strength in the molecular chain direction of the single molecule model, the corresponding extreme electric field strength is obtained when the single molecule model is destroyed. The extreme electric field strength corresponding to the destruction of the single molecule model can be effectively obtained, thereby improving the reliability of the extreme electric field strength data.

[0085] In an exemplary embodiment, the above step S206 may include the following steps:

[0086] Step S61, using quantum chemical methods to perform molecular simulation on the single molecule model in the test electric field strength interval corresponding to different test electric field strengths, to obtain the dipole moment of the single molecule model corresponding to different test electric field strengths during the molecular simulation process; and to obtain the polarizability corresponding to the single molecule model based on the dipole moment.

[0087] Step S62, using the frontier orbital theory, the orbital energy levels of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval are obtained through tools; and the state density of the single molecule model is obtained according to the orbital energy levels.

[0088] The orbital energy levels include the highest occupied molecular orbital energy level and the lowest unoccupied molecular orbital energy level. Quantum chemistry methods can refer to a series of theoretical and computational tools used to calculate and predict molecular behavior.

[0089] Exemplarily, the terminal uses computing software to cyclically apply electric field strength to cover a preset test electric field strength range, and then uses quantum chemical methods to perform molecular simulation on the single molecule model in the test electric field strength range corresponding to different test electric field strengths, and obtains the dipole moment of the single molecule model corresponding to different test electric field strengths during the molecular simulation process; then, the polarizability corresponding to the single molecule model is obtained by analysis and calculation based on the dipole moment; the terminal then uses frontier orbital theory to calculate the electronic state of the single molecule model under different test electric field strengths through tools, and records the energy level values ​​of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO); then, based on the obtained orbital energy levels, the terminal can obtain the state density of the single molecule model using the state density formula.

[0090] In this embodiment, by obtaining the dipole moment and polarizability, the electrical performance of the target molecule in the electric field can be deeply understood; by obtaining the polarizability and its relationship with the electric field strength, the electrical characteristics of the target molecule under actual operating conditions can be evaluated; the calculation of orbital energy levels and state density makes it possible to accurately predict the energy gap and electron transfer properties. Through the above steps, the changes in the physical and chemical properties of the insulating oil under different electric field strengths can be more accurately understood, thereby more accurately evaluating the insulation aging state of the insulating oil.

[0091] In an exemplary embodiment, the above-mentioned step S61 may specifically include the steps of: using a quantum chemical method to obtain a first Hamiltonian of the single molecule model when no electric field is applied, and obtaining a second Hamiltonian of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval; according to the first Hamiltonian, the second Hamiltonian and the test electric field strength corresponding to the second Hamiltonian, obtaining the dipole moment corresponding to the single molecule model under the test electric field strength.

[0092] Among them, Hamiltonian can refer to the operator that describes the energy of the system in quantum mechanics, including the kinetic energy and potential energy terms of the system.

[0093] Exemplarily, the terminal uses a quantum chemical method to obtain the first Hamiltonian of the single molecule model when no electric field is applied, and obtains the second Hamiltonian of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval; according to the first Hamiltonian, the second Hamiltonian and the test electric field strength corresponding to the second Hamiltonian, the dipole moment corresponding to the single molecule model under the test electric field strength is obtained. The dipole moment can be obtained according to the formula H int =-µ×F to get, H int represents the effect of electric field strength on the single-molecule model, that is, represents the Hamiltonian (second Hamiltonian) when an external electric field is applied to the single-molecule model, µ represents the dipole moment of the single-molecule model, and F represents the magnitude of the test electric field strength (the test electric field strength corresponding to the second Hamiltonian); the Hamiltonian H of the single-molecule model can be expressed by H=H0+H int Indicates that H0 represents the Hamiltonian (first Hamiltonian) corresponding to the single-molecule model when there is no external electric field.

[0094] In this embodiment, quantum chemical methods can be used to accurately simulate the behavior of a single molecule model under different electric field strengths. Molecular simulation at the molecular level can more accurately evaluate the aging state of insulating oil under different electric field strengths. Compared with actual experimental tests, molecular simulation can save a lot of time and material resource consumption, and reduce the resource loss of evaluation.

[0095] In an exemplary embodiment, in the above step S62, the state density of the single molecule model is obtained according to the orbital energy level, including the steps of: obtaining the energy gap corresponding to the single molecule model in the test electric field strength range according to the energy level of the highest occupied molecular orbital and the energy level of the lowest unoccupied molecular orbital; and obtaining the state density of the single molecule model according to the orbital energy level and the energy gap.

[0096] Among them, by understanding the state density and energy gap, we can have a deep understanding of the electronic structure of molecules, electron transfer ability and interaction with external electric fields.

[0097] Exemplarily, all molecular orbital energy levels of the molecular model are obtained through quantum chemical calculations (such as DFT or HF methods), including the energy level of the highest occupied molecular orbital (HOMO) and the energy level of the lowest unoccupied molecular orbital (LUMO). From the obtained orbital energy levels, the energy values ​​of HOMO and LUMO are extracted, and the difference is calculated to obtain the energy gap; the state density is constructed using the orbital energy level information and the energy gap. The state density can usually be obtained by: visualizing the molecular orbital energy level distribution to detect the state density within a specific energy range. The state density distribution in different energy regions is estimated by numerical methods (such as Gaussian smoothing). Repeat the above steps under different test electric field strengths to count the state density under different conditions.

[0098] In this embodiment, by understanding the state density and energy gap, we can deeply understand the electronic structure of the molecule, the electron transfer ability and the interaction with the external electric field. By accurately calculating the orbital energy level and state density, we can more accurately evaluate the aging state of the insulating oil under different electric field strengths, thereby improving the accuracy of the evaluation.

[0099] In another exemplary embodiment, a method for determining the insulation aging state of insulating oil is provided, which specifically includes:

[0100] Step S1, constructing a single molecule model, using molecular simulation software to construct a single molecule model of benzyltoluene (C14H14, MBT) and dibenzyltoluene (C21H20, DBT); wherein the target molecules of insulating oil can be benzyltoluene (C14H14, MBT) and dibenzyltoluene (C21H20, DBT). In step S1, the single molecule model is structurally optimized at the basis set level of PM3 to obtain a stable structure when the molecular energy is the lowest.

[0101] Step S2, establishing an external electric field and gradually increasing the strength of the external electric field in the molecular model until the molecular model is destroyed.

[0102] Step S3, calculation of dipole moment and polarizability, using quantum chemical methods to perform molecular simulation of capacitor insulating oil under different external electric field strengths, and calculating the microstructural characteristics of the molecular model through the built-in commands of the software to obtain the dipole moment and polarizability under different external electric field strengths. In step S3, according to the dipole approximation, when there is no external electric field, the corresponding Hamiltonian is recorded as H0. Subsequently, after the electric field is applied, the Hamiltonian H of the molecular system can be represented by H=H0+Hint. The Hint term represents the Hamiltonian when an external electric field is applied to the molecular system. When interacting with the molecular system, Hint=-µ×F represents the effect of the electric field strength on it, where µ represents the electric dipole moment of the molecule, and F represents the magnitude of the electric field, and the dipole moment and polarizability under different external electric field strengths are calculated.

[0103] Step S4, molecular orbital analysis, uses software to calculate the characteristics of orbital energy levels and state density under different external electric field strengths, and combines the dipole moment and polarizability parameters of step S3 to predict the reaction sites of capacitor insulating oil under extreme electric field strengths.

[0104] Step S5, establish a macro-micro correlation model, calculate the infrared spectrum of the capacitor insulating oil before and after the breakdown of the external electric field through software, and establish a state assessment model of the electrical aging of the capacitor insulating oil through the difference of the infrared spectrum before and after the breakdown. In step S5, the infrared spectrum of the capacitor insulating oil under different external electric fields is calculated to complete the establishment of the correlation between the electrical aging state of the capacitor insulating oil and the infrared spectrum.

[0105] Specifically, the geometric configuration of the capacitor insulating oil molecular model is first optimized using the PM3 basis set based on the semi-empirical method to obtain the lowest energy molecular stable conformation. The optimized molecular model is shown in Figures 3 and 4, where Figure 3 is a schematic diagram of the molecular model of MBT and Figure 4 is a schematic diagram of the molecular model of DBT, where gray represents carbon atoms C and white represents hydrogen atoms h. The total energy is the lowest, there is no imaginary frequency, and the criteria Maximum Force, RMS Force, Maximum Displacement, and RMS Displacement are all converged.

[0106] The same method and bases are used to apply electric dipole fields in the X direction of the molecular chain and optimize the geometric structure. The geometric structure parameters, single point energy, dipole moment, polarizability, molecular orbital energy level gap, state density and infrared spectrum of the insulating material are predicted.

[0107] The calculation shows that the length of the chemical bond in the molecule will change accordingly under the action of the external electric field. As shown in Figure 5, a curve diagram of the bond length change of MBT (a) and DBT (b) molecules is provided, thereby characterizing the change in molecular geometry caused by the electric field. In the molecular system, the positive and negative charges are affected by the external electric field, resulting in a mutual transfer effect, which causes the insulating oil molecules to be elongated to a certain extent, reducing the stability of its internal geometric structure. When the external electric field strength reaches a certain threshold, the insulating oil molecules are significantly elongated due to the action of the external electric field, resulting in a rapid deterioration of the insulation performance, approaching the critical level, and about to break down. Combining Figure 3 with Figure 6, it can be seen that the structure contained in the red circle in the MBT molecular model in Figure 6 is significantly elongated, and a molecular bond breaking change has occurred; combining Figure 4 with Figure 7, it can be seen that the structure contained in the red circle in the DBT molecular model in Figure 7 is significantly elongated, and a molecular bond breaking change has occurred.

[0108] Calculate the molecular dipole moment and polarizability under the action of an external electric field. As the external electric field intensity (Electric Field Intensity) gradually increases, the total energy of the MBT / DBT molecule shows a downward trend, as shown in Figures 8 and 9, where Total Energy represents the total energy of the molecule, Dipole Moment represents the dipole moment, and Polarizability represents the polarizability. Under the influence of the electric field, electrons migrate in its direction, resulting in an increase in the charge on each atom, while increasing the dipole moment and polarizability within the MBT / DBT molecule. When the critical value is reached, both the dipole moment and the polarizability increase sharply, indicating that the structural state is highly unstable. The stability of the internal molecular system of MBT / DBT insulating oil gradually weakens after long-term exposure to an external electric field. When the upper limit of the dipole moment is exceeded, it exceeds the critical value, causing free electrons to escape from the nucleus.

[0109] The orbital energy level and energy gap (Eg) of MBT / DBT molecules were calculated by Gaussian software to reflect the electronic motion characteristics of MBT / DBT molecules under different external electric fields. The external electric field gradually reduces the LUMO energy level of MBT / DBT molecules and gradually increases the HOMO energy level, thereby changing the reactivity characteristics of MBT / DBT molecules. At the same time, the HOMO and LUMO orbital energy levels of the two molecules are relatively close, the Eg value of MBT molecules is 3.28eV, and the Eg value of DBT molecules is 1.33eV, as shown in Figures 10 and 11, where the horizontal axis is the electric field intensity (Electric Field Intensity) in units of (V / nm). As electrons shuttle freely between the valence band and the conduction band, MBT / DBT molecules break down, thereby generating current and destroying the insulating properties of MBT / DBT insulating oil.

[0110] The density of states is calculated by Multiwfn software. The HOMO orbital energy corresponds to the highest level of the valence band, while the LUMO orbital energy corresponds to the lowest energy level of the conduction band. Under an external electric field, the density of states diagram predicts that the deep trap energy level distribution appears near the upper edge of the valence band, while the shallow trap energy level distribution appears near the lower edge of the conduction band, as shown in Figures 12 and 13, where Density of State represents the density of states and Energy Level represents the energy level, with the unit of eV (electron volt). With the application of an external electric field, the capture energy density of the molecular orbital gradually increases. The energy distribution of the highest occupied molecular orbital (HOMO) moves to a higher position, resulting in an increase in the number of hole traps near the valence band. On the contrary, the energy distribution of the lowest unoccupied molecular orbital (LUMO) moves to a lower position, resulting in an increase in the number of electron traps near the conduction band. Finally, there is a significant difference between the number of electron and hole traps, as shown in Figure 14 and Figure 15, where Figure 14 is a curve diagram of the density of states of MBT at 20.41374 V / nm and Figure 15 is a curve diagram of the density of states of DBT at 13.57488 V / nm. This difference makes it easier for MBT / DBT materials to capture free electrons or inject charges.

[0111] The calculation results were further processed using Multiwfn software to obtain infrared spectral data under zero external electric field strength and breakdown field strength, as shown in Figures 16, 17, 18, and 19, where the molar absorption coefficient (Molar Absorption Coefficient), usually represented by the symbol ε, is a physical quantity used to describe the absorption capacity of a substance to light at a specific wavelength; Frequency (cm-1) represents frequency. As the external electric field increases, the absorption peaks of MBT and DBT molecules above 3000cm-1 red-shift, and the bond energy decreases due to the increase in bond length. As the external electric field increases, the peak value also increases. The C25-H28, C11-C13, C11-H14 bonds of MBT molecules and the C38-H41 bonds of DBT molecules show obvious red-shifts, indicating that they are very unstable before the chemical bonds break, which is consistent with the geometric structure analysis. Therefore, the changes in infrared spectra before and after breakdown can provide a feasible reference for detecting the aging state of MBT / DBT insulating oil.

[0112] In the present embodiment, computer molecular simulation experiments are utilized to simulate and predict the electrical properties of capacitor insulating oil from a microscopic scale. This model is not subject to the constraints of instrument accuracy and the influence of human factors, and can simulate physical and chemical and electrical properties such as molecular structure changes, dipole moment, polarizability, molecular orbital energy level, energy gap, density of states, infrared spectrum, etc. The predicted infrared spectrum and the breakdown of insulating materials have reliability. The main feature is that this model effectively links microstructural changes with infrared spectrum. The internal weak molecular chemical bonds of capacitor insulating oil under extreme electric fields can be predicted, providing site references for capacitor insulating oil material modification. Meanwhile, the changing trend of infrared spectrum can be used as a theoretical basis for insulating state assessment.

[0113] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0114] Based on the same inventive concept, the embodiment of the present application also provides an insulating oil insulation aging state determination device for implementing the above-mentioned insulating oil insulation aging state determination method. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above-mentioned method, so the specific limitations in one or more embodiments of the insulating oil insulation aging state determination device provided below can refer to the limitations of the insulating oil insulation aging state determination method above, and will not be repeated here.

[0115] In an exemplary embodiment, as shown in FIG. 20 , an insulating oil insulation aging state determination device 900 is provided, comprising: a molecular model building module 901, a model data acquisition module 902, a reaction site determination module 903 and an infrared spectrum acquisition module 904, wherein:

[0116] The molecular model building module 901 is used to build a single molecule model corresponding to a target molecule in the constituent molecules of the insulating oil using a molecular simulation tool; the insulating oil includes at least one type of constituent molecules;

[0117] Model data acquisition module 902, used to obtain the extreme electric field strength corresponding to the destruction of the single molecule model, determine the test electric field strength interval according to the extreme electric field strength; and also used to obtain the dipole moment, polarizability, orbital energy level and state density of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval;

[0118] A reaction site determination module 903 is used to determine the reaction site of the single molecule model under extreme electric field strength according to the dipole moment, polarizability, orbital energy level and state density;

[0119] The infrared spectrum acquisition module 904 is used to obtain the target infrared spectrum information corresponding to the reaction site of the single molecule model; the target infrared spectrum information is used to match and compare with the infrared spectrum information of the insulating oil to be evaluated to obtain the insulation aging state of the insulating oil to be evaluated.

[0120] In an exemplary embodiment, the above-mentioned molecular model construction module 901 is also used to use molecular simulation tools to construct an initial single-molecule model corresponding to the target molecule among the constituent molecules of the insulating oil; the initial single-molecule model is structurally optimized at the basis set level of PM3 to obtain a single-molecule stable structure when the molecular energy is lowest; and the single-molecule model corresponding to the single-molecule stable structure is determined as the single-molecule model corresponding to the target molecule.

[0121] In an exemplary embodiment, the above-mentioned model data acquisition module 902 is also used to apply an electric field in the direction of the molecular chain to the single molecule model through a molecular simulation tool, and gradually increase the electric field strength of the electric field according to a preset electric field strength increment until the single molecule model is destroyed, and obtain the extreme electric field strength corresponding to the destruction of the single molecule model.

[0122] In an exemplary embodiment, the above-mentioned model data acquisition module 902 is also used to use quantum chemical methods to perform molecular simulation on the single molecule model in the test electric field strength interval corresponding to different test electric field strengths, and obtain the dipole moment of the single molecule model corresponding to different test electric field strengths during the molecular simulation process; analyze according to the dipole moment to obtain the polarizability corresponding to the single molecule model; use the frontier orbital theory to obtain the orbital energy level of the single molecule model in the test electric field strength interval corresponding to different test electric field strengths through tools; obtain the state density of the single molecule model according to the orbital energy level; wherein the orbital energy level includes the energy level of the highest occupied molecular orbital and the energy level of the lowest unoccupied molecular orbital.

[0123] In an exemplary embodiment, the above-mentioned model data acquisition module 902 is also used to obtain the first Hamiltonian of the single molecule model when no electric field is applied using a quantum chemical method, and to obtain the second Hamiltonian of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval; according to the first Hamiltonian, the second Hamiltonian and the test electric field strength corresponding to the second Hamiltonian, the dipole moment corresponding to the single molecule model under the test electric field strength is obtained.

[0124] In an exemplary embodiment, the above-mentioned model data acquisition module 902 is also used to obtain the energy gap corresponding to the single molecule model in the test electric field strength range according to the energy level of the highest occupied molecular orbital and the energy level of the lowest unoccupied molecular orbital; and obtain the state density of the single molecule model according to the orbital energy level and the energy gap.

[0125] Each module in the insulating oil insulation aging state determination device can be implemented in whole or in part by software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each module.

[0126] In an exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be shown in FIG21. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit, and an input device. The processor, the memory, and the input / output interface are connected via a system bus, and the communication interface, the display unit, and the input device are connected to the system bus via the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner may be implemented through WIFI, a mobile cellular network, near field communication (NFC) or other technologies. When the computer program is executed by the processor, a method for determining the insulation aging state of insulating oil is implemented. The display unit of the computer device is used to form a visually visible picture, which may be a display screen, a projection device, or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the computer device shell, or an external keyboard, touchpad or mouse.

[0127] Those skilled in the art will understand that the structure shown in FIG. 21 is merely a block diagram of a partial structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0128] In one embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiments when executing the computer program.

[0129] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0130] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0131] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0132] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0133] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for determining the insulation aging state of insulating oil, characterized in that: The method comprises: Using a molecular simulation tool to construct a single molecule model corresponding to a target molecule in the constituent molecules of insulating oil; the insulating oil includes at least one type of constituent molecules; Obtaining the extreme electric field strength corresponding to the destruction of the single molecule model, and determining the test electric field strength interval according to the extreme electric field strength; Obtaining the dipole moment, polarizability, orbital energy level and state density of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval; Determining the reaction site of the single molecule model under the extreme electric field strength according to the dipole moment, the polarizability, the orbital energy level and the density of states; The target infrared spectrum information of the single molecule model corresponding to the reaction site is obtained; the target infrared spectrum information is used to match and compare with the infrared spectrum information of the insulating oil to be evaluated, so as to obtain the insulation aging state of the insulating oil to be evaluated.

2. The method according to claim 1, characterized in that The method of using a molecular simulation tool to construct a single molecule model corresponding to a target molecule in the constituent molecules of insulating oil includes: Use molecular simulation tools to construct an initial single-molecule model corresponding to the target molecule in the constituent molecules of insulating oil; The initial single-molecule model is structurally optimized at the basis set level of PM3 to obtain a single-molecule stable structure when the molecular energy is the lowest; The single molecule model corresponding to the single molecule stable structure is determined as the single molecule model corresponding to the target molecule.

3. The method according to claim 2, characterized in that The obtaining of the extreme electric field strength corresponding to the destruction of the single molecule model comprises: An electric field in the direction of the molecular chain is applied to the single molecule model by the molecular simulation tool, and the electric field strength of the electric field is gradually increased according to a preset electric field strength increment until the single molecule model is destroyed, thereby obtaining the extreme electric field strength corresponding to the destruction of the single molecule model.

4. The method according to claim 1, characterized in that: The obtaining of the dipole moment, polarizability, orbital energy level and state density of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval includes: Using quantum chemical methods, the single molecule model is molecularly simulated in the test electric field strength interval corresponding to different test electric field strengths to obtain the dipole moment of the single molecule model corresponding to different test electric field strengths during the molecular simulation process; and the polarizability corresponding to the single molecule model is obtained by analyzing the dipole moment; Utilizing the frontier orbital theory, the orbital energy levels of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval are obtained through a tool; the state density of the single molecule model is obtained according to the orbital energy levels; wherein the orbital energy levels include the energy level of the highest occupied molecular orbital and the energy level of the lowest unoccupied molecular orbital.

5. The method according to claim 4, characterized in that The method of using a quantum chemical method to perform molecular simulation on the single molecule model in the test electric field strength interval corresponding to different test electric field strengths to obtain the dipole moment of the single molecule model corresponding to different test electric field strengths during the molecular simulation process includes: Using a quantum chemical method to obtain a first Hamiltonian of the single molecule model when no electric field is applied, and to obtain a second Hamiltonian of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval; According to the first Hamiltonian, the second Hamiltonian and the test electric field strength corresponding to the second Hamiltonian, the dipole moment corresponding to the single molecule model under the test electric field strength is obtained.

6. The method according to claim 4, characterized in that The step of obtaining the density of states of the single molecule model according to the orbital energy level comprises: Obtaining an energy gap corresponding to the single molecule model in the test electric field strength interval according to the energy level of the highest occupied molecular orbital and the energy level of the lowest unoccupied molecular orbital; The state density of the single molecule model is obtained according to the orbital energy level and the energy gap.

7. A device for determining insulation aging status of insulating oil, characterized in that: The device comprises: A molecular model building module, used to build a single molecule model corresponding to a target molecule in the constituent molecules of insulating oil using a molecular simulation tool; the insulating oil includes at least one type of constituent molecules; A model data acquisition module, used to obtain the extreme electric field strength corresponding to the destruction of the single molecule model, and determine the test electric field strength interval according to the extreme electric field strength; and also used to obtain the dipole moment, polarizability, orbital energy level and state density of the single molecule model corresponding to different test electric field strengths in the test electric field strength interval; A reaction site determination module, used to determine the reaction site of the single molecule model under the extreme electric field strength according to the dipole moment, the polarizability, the orbital energy level and the state density; The infrared spectrum acquisition module is used to obtain the target infrared spectrum information of the single molecule model corresponding to the reaction site; the target infrared spectrum information is used to match and compare with the infrared spectrum information of the insulating oil to be evaluated to obtain the insulation aging state of the insulating oil to be evaluated.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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