Insulating oil electrothermal aging process simulation method based on de novo molecular dynamics

Abstract

The invention discloses an insulating oil electrothermal aging process simulation method based on de novo molecular dynamics, and belongs to the field of quantum calculation and liquid insulation, and the method comprises the following steps: 1, constructing an insulating oil system molecular model, and optimizing the system; 2, simulating an electric heating aging process of the insulating oil based on de novo molecular dynamics; and step 3, monitoring the system state at each moment in the electrothermal aging process, counting electrothermal aging products, and drawing an insulating oil electrothermal aging reaction path. The long electrothermal aging process of the insulating oil is simulated through quantum calculation, the experiment cost is saved, the simulation precision is improved, a scientific basis can be provided for electrothermal aging of the insulating oil in the transformer, and theoretical guidance is provided for fault diagnosis of the oil-immersed transformer.

Description

Technical Field

[0001] The present invention relates to the fields of quantum computing and liquid insulation, and more specifically, to a method for simulating the electrothermal aging process of insulating oil based on ab initio molecular dynamics. Background Art

[0002] As an important device for regulating voltage and realizing energy transfer and utilization in the power system, the safe and stable operation of oil-immersed transformers is crucial for the reliability of the power grid. Among them, insulation is a key performance of oil-immersed transformers. However, factors such as long-term operation and human errors will inevitably lead to the aging of insulating oil, resulting in a decline in the insulation performance of the transformer and affecting the stable operation of the oil-immersed transformer. In order to judge the insulation performance of oil-immersed transformers, researchers have begun to focus on the research of the aging mechanism of insulating oil during operation. However, due to the long aging process, diverse aging pathways, rapid cracking process, and high experimental costs, it is difficult to quickly and accurately observe the aging process of insulating oil from the perspective of macroscopic experiments. Therefore, many researchers have focused on starting from the microscopic perspective and simulating the aging process of insulating oil under the combined action of electrothermal based on the ReaxFF-MD of the first principles.

[0003] However, the simulation method of ReaxFF-MD is limited by the empirical force field and strong subjectivity of humans, and the parameters of the ReaxFF force field cannot cover all element types. For high-precision calculations of complex systems, the accuracy of ReaxFF-MD is insufficient and it is difficult to be applied to actual engineering predictions. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a method for simulating the electrothermal aging process of insulating oil based on ab initio molecular dynamics, which improves the accuracy of simulating the electrothermal aging of insulating oil by calculating the interaction between electrons and atomic nuclei through quantum mechanics.

[0005] To achieve the above object, a method for simulating the electrothermal aging process of insulating oil based on ab initio molecular dynamics includes the following steps:

[0006] Step 1, constructing a molecular model of the insulating oil system and optimizing the system;

[0007] Step 2, simulating the electrothermal aging process of insulating oil based on ab initio molecular dynamics;

[0008] Step 3, monitoring the system state at each moment of the electrothermal aging process, counting the electrothermal aging products, and drawing the reaction path of the electrothermal aging of insulating oil.

[0009] Preferably, in the step 1, a molecular model of the insulating oil system is constructed in the molecular simulation software Materials Studio, the geometric optimization simulation parameters are set by using the Multiwfn software, and then the molecular model of the insulating oil system is optimized by cp2k.

[0010] Preferably, in the step 2, the ab initio molecular dynamics simulation of the electrothermal aging process of the insulating oil includes: inputting the optimized molecular model of the insulating oil system into Multiwfn, setting the calculation parameters of the ab initio molecular dynamics, and then simulating the electrothermal aging process of the insulating oil by using cp2k.

[0011] More preferably, the calculation parameters of the ab initio molecular dynamics include functional, basis set and pseudopotential, temperature control method, dispersion correction, cutoff radius, electric field strength and electric field direction.

[0012] Preferably, in the step 3, monitoring the system state at each moment of the electrothermal aging process, counting the electrothermal aging products, and drawing the reaction path of the electrothermal aging of the insulating oil are realized by visualizing the results of the molecular dynamics simulation by using the VMD software after the cp2k simulation of the electrothermal aging of the insulating oil.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The present invention provides a method for simulating the electrothermal aging process of insulating oil based on ab initio molecular dynamics. This method realizes self-consistent calculation of the electronic structure by introducing quantum mechanics to calculate the interaction between electrons and atomic nuclei, making up for the deficiency of ReaxFF-MD in ignoring the electron motion; ab initio molecular dynamics does not require the introduction of empirical force fields, reducing the influence of human subjectivity and improving the accuracy of the simulation of the electrothermal aging of insulating oil. The present invention provides technical support for accurately predicting the electrothermal aging process of insulating oil; at the same time, it can also provide reference for related research on other molecular simulation calculations. Description of the Drawings

[0015] Figure 1 is a flowchart of simulating the electrothermal aging process of insulating oil based on ab initio molecular dynamics.

[0016] Figure 2 is the optimized molecular model of the insulating oil system.

[0017] Figure 3 is the cracking path of methyl laurate. Detailed Embodiments

[0018] Combined with the accompanying drawings in the embodiments of the present invention, the technical solutions in the present invention are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0019] The present invention proposes a simulation method for the electrothermal aging process of insulating oil based on ab initio molecular dynamics, including the following steps:

[0020] Step 1, construct a molecular model of the insulating oil system and optimize the system;

[0021] Step 2, simulate the electrothermal aging process of insulating oil based on ab initio molecular dynamics;

[0022] Step 3, monitor the system state at each moment of the electrothermal aging process, count the electrothermal aging products, and draw the reaction path of the electrothermal aging of insulating oil.

[0023] Embodiment 1

[0024] Construct a molecular model of the insulating oil system and optimize the system.

[0025] Specifically, when implementing, construct a molecular model of the insulating oil system in the molecular simulation software Materials Studio and export it as a pdb file that can be recognized by the Multiwfn software; use the Multiwfn software to open the pdb file and set the geometric optimization simulation parameters, including the functional, basis set and pseudopotential, dispersion correction, cutoff radius, electric field strength and electric field direction, to obtain an inp file that can be recognized by cp2k; then use cp2k to run the inp file to optimize the molecular model of the insulating oil system and obtain the optimized molecular model of the insulating oil system, as Figure 2 shown.

[0026] Embodiment 2

[0027] Simulate the electrothermal aging process of insulating oil based on ab initio molecular dynamics.

[0028] Specifically, when implementing, use the optimized molecular model of the insulating oil system as the initial guess for the aging simulation. Use the Multiwfn software to open the optimized molecular model file of the insulating oil system and set the calculation parameters of ab initio molecular dynamics, including the functional, basis set and pseudopotential, temperature control method, dispersion correction, cutoff radius, electric field strength and electric field direction. Then use cp2k to perform electrothermal aging simulation on the molecular model of the insulating oil system with the calculation parameters set.

[0029] More specifically, among the calculation parameters of ab initio molecular dynamics, the settings of the functional, basis set, pseudopotential, dispersion correction, cutoff radius, electric field strength, and electric field direction need to be consistent with the parameter settings in the geometric optimization.

[0030] Example 3

[0031] Monitor the system state at each moment during the electrothermal aging process, count the electrothermal aging products, and draw the reaction path of the electrothermal aging of insulating oil.

[0032] Specifically, after the electrothermal aging simulation of the insulating oil is completed, use the VMD software to visualize the electrothermal aging simulation process, observe the atomic bond breaking and bond formation at each moment during the electrothermal aging process, count the electrothermal aging products, and then draw the reaction path of the electrothermal aging of insulating oil, as Figure 3 shown.

[0033] The above content is only an explanation of the structure of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific structure. As long as they do not deviate from the structure of the invention or exceed the scope defined by this claim book, they should fall within the protection scope of the present invention.

Claims

1. A method for simulating the electrothermal aging process of insulating oil based on ab initio molecular dynamics, characterized in that: The following steps are involved: Step 1, constructing a molecular model of the insulating oil system and optimizing the system; Step 2, simulating the electrothermal aging process of insulating oil based on ab initio molecular dynamics; Step 3: monitor the system status at each moment of the electrothermal aging process, count the electrothermal aging products, and draw the electrothermal aging reaction path of the insulating oil.

2. The method according to claim 1, characterized in that: In the step 1, a molecular model of the insulating oil system is constructed in the molecular simulation software Materials Studio, and the geometric optimization simulation parameters are set using the Multiwfn software, and then the molecular model of the insulating oil system is optimized using cp2k.

3. The method according to claim 1, characterized in that: In the step 2, the ab initio molecular dynamics simulation of the electrothermal aging process of the insulating oil includes: inputting the optimized insulating oil system molecular model into Multiwfn, setting the calculation parameters of the ab initio molecular dynamics, and then using cp2k to simulate the electrothermal aging process of the insulating oil.

4. The method according to claim 3, characterized in that: The calculation parameters of the ab initio molecular dynamics include: functional, basis set and pseudopotential, temperature control method, dispersion correction, cutoff radius, electric field strength and electric field direction.

5. The method according to claim 1, characterized in that: In the step 3, monitoring the system status at each moment of the electrothermal aging process, counting the electrothermal aging products, and drawing the electrothermal aging reaction path of the insulating oil are achieved by visualizing the molecular dynamics simulation results using VMD software after cp2k simulates the electrothermal aging of the insulating oil.

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