Oil-immersed CT reignition arc modeling method, device and equipment and storage medium

Abstract

The invention relates to an oil-immersed CT reignition arc modeling method, device and equipment and a storage medium, and belongs to the technical field of arc modeling, and the method comprises the steps: taking instantaneous input power, arc loss power and arcing time as input to determine a differential equation of an arc universal model; establishing a differential equation of a first electric arc model based on a hypothesis condition of a Cassie model and the differential equation of the electric arc general model; establishing a differential equation of a second electric arc model based on a Schwarz model and the differential equation of the electric arc general model; and setting a transition function, and obtaining a reignition arc model according to the differential equation of the first arc model, the differential equation of the second arc model, the differential equation of the arc general model and the transition function. According to the method, accurate expression of the arc combustion process is realized through differential equations of a plurality of models.

Description

Technical Field

[0001] The present invention relates to the field of arc modeling technology, and in particular to an oil-immersed CT restrike arc modeling method, device, equipment and storage medium. Background Art

[0002] The internal arc in an oil-immersed CT can be described in four stages. The first stage is the generation of the discharge source. The source of the arc discharge is usually a defect inside the equipment, dielectric breakdown, or incomplete equipment structure. When the voltage increases or the dielectric insulation strength decreases, the possibility of arc discharge increases. The second stage is arc formation. When there is a high voltage inside the equipment, if the dielectric insulation breaks down, the current will form an arc through the breakdown point. In an oil-immersed voltage transformer, oil is used as an insulating medium. If the insulation breaks down due to local defects or external factors, an arc may form. The third stage is arc continuation. Once the arc is formed, it may persist because the presence of the arc causes the current to continue to flow. The duration of the arc discharge depends on the arc energy and environmental conditions. The fourth stage is energy release. Arc discharge releases a large amount of energy, resulting in local temperature increase, which may lead to serious consequences such as equipment damage, dielectric breakdown, and even fire.

[0003] When an arc fault occurs in an oil-immersed CT, the internal voltage and current may change dramatically. Arc discharge causes a sudden increase in voltage and current in a local area, forming high-energy, high-frequency fluctuations. This fluctuation may cause serious damage to the transformer insulation system and also affect the stability and reliability of the power system. Since arc discharge releases a large amount of energy, it may cause a temporary increase in current, accompanied by abnormal voltage fluctuations. These changes may affect the normal operation of other equipment and systems in the power grid, and even cause system failures or power outages. Therefore, regular inspection, maintenance and care of oil-immersed voltage transformers are essential to promptly detect and deal with potential fault hazards and ensure the safe and stable operation of the power system.

[0004] Arc faults in oil-immersed CTs are the main problem faced by most transformers at this stage. In particular, most arc faults do not end at once, but are often accompanied by arc reignition, resulting in arc burning phenomena multiple times over a period of time. Therefore, it is necessary to study the arc modeling method of oil-immersed CTs and understand the intermittent restrike arc. Summary of the invention

[0005] In view of this, it is necessary to provide an oil-immersed CT reignition arc modeling method, device, equipment and storage medium to solve the problem that arc faults in oil-immersed CTs will cause arc burning phenomena multiple times within a period of time, making it difficult for existing technologies to accurately express the arc burning process.

[0006] In order to solve the above problems, the present invention provides an oil-immersed CT restrike arc modeling method, comprising: Determine the differential equation of the general arc model with instantaneous input power, arc dissipation power, and arcing time as input; The differential equation of the first arc model is established based on the assumptions of the Cassie model and the differential equation of the general arc model; The differential equation of the second arc model is established based on the differential equation of the Schwarz model and the general arc model; A transition function is set, and a restrike arc model is obtained according to the differential equation of the first arc model, the differential equation of the second arc model, the differential equation of the arc universal model and the transition function.

[0007] In a possible implementation, the differential equation of the arc general model is determined with instantaneous input power, arc dissipation power, and arcing time as inputs, including: A general arc model is established based on instantaneous input power, arc dissipation power, and arcing time; Determine the dynamic arc model differential equation based on the general arc model, the arc instantaneous conductance and the rate of change of the arc accumulated energy with time; The differential equation of the general arc model is established according to the arc conductance, arc input expression and dynamic arc model differential equation.

[0008] In a possible implementation, a dynamic arc model differential equation is determined according to a general arc model, an arc instantaneous conductance, and a rate of change of arc accumulated energy over time, including: Analyze the instantaneous conductance of the arc and determine the expression of the instantaneous conductance of the arc; The rate of change of the arc accumulated energy with time is obtained by taking the derivative of the arc accumulated energy with respect to time.

[0009] In a possible implementation, the differential equation of the first arc model is: ; in, is the arc conductance of the first arc model, is the arc burning time, is the arc time constant, is the arc voltage constant, Indicates the current arc voltage value.

[0010] In a possible implementation, the differential equation of the second arc model is: ; in, , is the power dissipation coefficient (abbreviated as dissipation coefficient), is the time constant (referred to as time coefficient), α and β The time constants are and power dissipation The exponential component of represents the arc conductance of the second arc model, is the arc model conductance based on the transition function, Indicates the current arc voltage value.

[0011] In a possible implementation, the transition function is a Fermi distribution function, and the specific expression is: ; in, is the threshold set in the continuous transition function, represents the arc current, γ is the proportional parameter of the distribution function, Indicates the current arc voltage value, Represents a transition function.

[0012] In a possible implementation, the restrike arc model is obtained according to the differential equation of the first arc model, the differential equation of the second arc model, the differential equation of the arc general model and the transition function, including: Determine the weight of the first arc model and the weight of the second arc model respectively according to the transition function; calculating an assigned arc resistance based on a weight of the first arc model and a weight of the second arc model; Substituting the assigned arc resistance into the differential equation of the general arc model, the reignition arc model is obtained.

[0013] The present invention also provides an oil-immersed CT restrike arc modeling device, comprising: A general modeling module for determining the differential equation of the general arc model with instantaneous input power, arc dissipation power, and arcing time as input; A first modeling module, used for establishing a differential equation of a first arc model based on the assumptions of the Cassie model and the differential equation of the arc general model; A second modeling module is used to establish a differential equation of a second arc model based on the differential equation of the Schwarz model and the general arc model; The restrike arc modeling module is used to set a transition function and obtain a restrike arc model according to the differential equation of the first arc model, the differential equation of the second arc model, the differential equation of the arc general model and the transition function.

[0014] In a third aspect, the present invention further provides an oil-immersed CT restrike arc modeling device, comprising a memory and a processor, wherein: Memory, used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the lithium-ion battery health status prediction method in any of the above implementations.

[0015] In a fourth aspect, the present invention further provides a computer-readable storage medium for storing computer-readable programs or instructions, which, when executed by a processor, can implement the steps in the lithium-ion battery health status prediction method in any of the above-mentioned implementation modes.

[0016] The beneficial effects of the present invention are as follows: the present invention first establishes the differential equation of the general arc model, and then allocates the proportion of the differential equation of the first arc model and the differential equation of the second arc model through a transition function to determine the accurate expression of some parameters of the differential equation of the general arc model, and finally determines the reignition arc model by combining the differential equation of the general arc model, which can accurately express the arc burning process generated multiple times by arc faults in an oil-immersed CT within a period of time. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic flow chart of an embodiment of a method for modeling an oil-immersed CT restrike arc provided by the present invention; Figure 2 The present invention provides Figure 1 A schematic flow chart of an embodiment of step S101; Figure 3 A schematic diagram of a flow chart of an embodiment of obtaining a reignition arc model provided by the present invention; Figure 4 A schematic structural diagram of an embodiment of an oil-immersed CT restrike arc modeling device provided by the present invention; Figure 5 A schematic diagram of the structure of an oil-immersed CT restrike arc modeling device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0019] See also Figure 1 , Figure 1 A flowchart of an embodiment of a method for modeling an oil-immersed CT restrike arc provided by the present invention is provided. A specific embodiment of the present invention discloses a method for modeling an oil-immersed CT restrike arc, comprising: S101, determining a differential equation of a general arc model with instantaneous input power, arc dissipation power, and arcing time as input; S102, establishing a differential equation of a first arc model based on the assumptions of the Cassie model and the differential equation of the general arc model; S103, establishing a differential equation of a second arc model based on the differential equations of the Schwarz model and the general arc model; S104, setting a transition function, and obtaining a restrike arc model according to the differential equation of the first arc model, the differential equation of the second arc model, the differential equation of the general arc model, and the transition function.

[0020] In the above embodiment, the arc releases energy to the surrounding medium through convection effect, heat conduction and radiation. The input energy, dissipated energy and arc burning time of the arc all have an important influence on the arc resistance. Therefore, the general formula for establishing the arc mathematical model is based on instantaneous input power, arc dissipated power and arc burning time as input.

[0021] The differential equation of the first arc model is based on the Cassie model. The Cassie model is often used in the case of large current and small resistance, and can accurately reflect the process before the current in the arc passes through zero. However, due to the deviation between the assumptions of the Cassie model and the actual situation, there is a certain deviation between the calculated results and the measured results, and it is not applicable in the low current stage.

[0022] For low current, the Schwarz model optimized based on the Mayr model is adopted, so the differential equation of the second arc model is established based on the optimized Schwarz model. It should be noted that high current and low current can be distinguished according to actual conditions, and the present invention does not make further restrictions on this.

[0023] The combined model proposed in the present invention is derived from the expressions of the Schwarz model and the Cassie model and the advantages and disadvantages of their respective modeling, which can make up for the deficiencies of each model in different current stages and make the restrike arc model conform to the current and voltage change characteristics when an arc fault occurs to the greatest extent.

[0024] Compared with the prior art, the embodiment of the present invention first establishes the differential equation of the general arc model, and then allocates the proportion of the differential equation of the first arc model and the differential equation of the second arc model through a transition function to determine the accurate expression of some parameters of the differential equation of the general arc model, and finally determines the reignition arc model by combining the differential equation of the general arc model, which can accurately express the arc burning process generated multiple times by arc faults in an oil-immersed CT within a period of time.

[0025] See also Figure 2 , Figure 2 The present invention provides Figure 1In some embodiments of the present invention, the differential equation of the arc general model is determined by taking the instantaneous input power, the arc dissipation power and the arc burning time as inputs, including: S201, establishing a general arc model according to instantaneous input power, arc dissipation power, and arcing time; S202, determining a dynamic arc model differential equation according to a general arc model, the instantaneous conductance of the arc, and the rate of change of the accumulated energy of the arc over time; S203. Establishing a differential equation of a general arc model according to arc conductance, arc input expression and dynamic arc model differential equation.

[0026] In some embodiments of the present invention, the dynamic arc model differential equation is determined according to the general arc model, the instantaneous arc conductance and the rate of change of the arc accumulated energy over time, including: Analyze the instantaneous conductance of the arc and determine the expression of the instantaneous conductance of the arc; The rate of change of the arc accumulated energy with time is obtained by taking the derivative of the arc accumulated energy with respect to time.

[0027] In the above embodiment, the general arc model is as follows: (1); in, is the instantaneous value of arc current, is the instantaneous value of the voltage gradient of the arc column, is the instantaneous value of arc resistance per unit arc length, is the instantaneous input power per unit length of arc, is the arc power dissipated per unit length, is the arc burning time, It is related to instantaneous input power, arc dissipation power and time, and is a function used to represent the arc mathematical model.

[0028] Arc conductance is a function of the energy in the arc gap. The instantaneous arc conductance is defined as: (2); The relationship between the energy Q accumulated in the arc and time is: (3); By taking the derivative of equation (2) and substituting equation (3) into it, we can obtain the differential equation of the dynamic arc model: (4); Will Substituting into equation (4) we get the differential equation of the general arc model: (5); From formula (5), we can see that in order to determine the specific form of the differential equation, we must know and The specific expression of and The expression relies on certain assumptions.

[0029] In some embodiments of the present invention, the differential equation of the first arc model is: (6); in, is the arc conductance of the first arc model, is the arc burning time, is the arc time constant, is the arc voltage constant, Indicates the current arc voltage value.

[0030] In the above embodiment, it can be seen from equation (5) that in order to determine the specific form of the differential equation, it is necessary to know and The specific expression of and The expression depends on certain assumptions. The differential equation of the first arc model is derived using equation (5) based on the assumptions of the Cassie model.

[0031] In some embodiments of the present invention, the differential equation of the second arc model is: (7); in, (8); in, is the power dissipation coefficient (abbreviated as dissipation coefficient), is the time constant (referred to as time coefficient), α and β The time constants are and power dissipation The exponential component of represents the arc conductance of the second arc model, is the arc model conductance based on the transition function, Indicates the current arc voltage value.

[0032] In the above embodiment, because the arc burning is unstable, the arc time constant and power dissipation The Schwarz model regards conductivity as a function of time constant and dissipated power, which describes the changes in the arcing process very well.

[0033] In some embodiments of the present invention, the transition function is a Fermi distribution function, and the specific expression is: (9); in, is the threshold set in the continuous transition function, represents the arc current, γ is the proportional parameter of the distribution function, Indicates the current arc voltage value, Represents a transition function.

[0034] In the above embodiment, there are three most common continuous transition functions, namely, Sigmoid function, Fermi distribution function and exponential function variants. Compared with other continuous transition functions, Fermi distribution function has a smoother S-shaped curve, which can make the transition of Cassie-Schwarz combined arc model smoother, which is more consistent with the actual situation that the arc current changes smoothly during the burning process. Therefore, the Fermi distribution function is used as the continuous transition function of the combined arc model in the present invention. It is specifically shown in formula (9).

[0035] See also Figure 3 , Figure 3 A flow chart of an embodiment of obtaining a reignited arc model provided by the present invention. In some embodiments of the present invention, the reignited arc model is obtained according to the differential equation of the first arc model, the differential equation of the second arc model, the differential equation of the arc general model and the transition function, including: S301, determining a weight of a first arc model and a weight of a second arc model respectively according to a transition function; S302, calculating the allocated arc resistance according to the weight of the first arc model and the weight of the second arc model; S303, substituting the allocated arc resistance into the differential equation of the general arc model to obtain a reignition arc model.

[0036] In the above embodiments, in general, the arc current zero crossing point is used to determine the high current and low current periods to select different models, but the arc current zero crossing and the low arc current are not the same thing, and it is too simple to use the arc current zero crossing as a basis for judgment. Therefore, an arc current zero crossing is introduced in the present invention. Function As a transition function, it represents the weight ratio of the two models. The specific expression is as follows: (10); To analyze the transition function The present invention selects a continuous transition function as the transition mode to affect the arc characteristics. About is a monotonically increasing function, as The change of continuously changes the proportion of Schwarz and Cassie models, and finally the restrike arc model is obtained.

[0037] In the Cassie arc model, the arc voltage constant is E 0 and arc dissipation power P loss The relationship is shown in formula (11): (11); It can be seen from formula (11) that the two are positively correlated. The black box arc model mainly describes the change of arc resistance. The change law of arc resistance depends on the relationship between arc energy input and dissipation. In the joint arc model, the arc current changes from high current to low current smoothly during the transition period. The two models should have the same arc characteristics, that is, the arc voltage, arc current and arc resistance are the same, that is, the arc energy input and dissipated power are consistent.

[0038] It should be noted that the present invention can also effectively avoid the oscillation problem caused by the discontinuous transition function during the model step conversion.

[0039] Fermi function value The weight of the joint model is assigned between 0 and 1. After the assignment is completed, the arc resistance is obtained by weighted addition of the arc resistance of the Schwarz model and the arc resistance of the Cassie model. The Fermi function value is used to assign weights to the Cassie-Schwarz joint model to achieve a continuous and smooth transition of the arc model in the transition section, avoiding the oscillation problem caused by the step-by-step conversion between the two models.

[0040] (12); in, It represents the arc resistance after the transition function is introduced for proportional distribution; is the arc resistance of the Schwarz model; is the arc resistance of the Cassie model; Transition function , used to adjust the proportion of the two models.

[0041] Different from the discontinuous function type, the whole process of arc discharge in the continuous function type is represented by the Cassie model and the Schwarz model, and the contribution ratio of the two is determined by the threshold I 0 and the scale parameter γ.

[0042] I The value of 0 will directly affect the weight of the single arc model. IIf the value is too large, the Cassie model will fail and the full arc waveform will be controlled by the Schwarz model; if the value is too small, the switching frequency of the model transition section will be too high and the fault harmonics will be too large, resulting in waveform oscillation. I The value 0 is crucial.

[0043] Obviously, the continuous transition function describes the discharge process of the oil-immersed CT more accurately. The present invention uses the continuous Fermi distribution function as the transition function to avoid the oscillation phenomenon caused by model mutation in the discontinuous transition function.

[0044] The arc fault in the oil-immersed CT is a kind of fault that has a great impact on the normal operation of the oil-immersed CT. It is caused by the breakdown of the weak insulation points in the cabinet under the action of instantaneous or long-term overvoltage. Some arcs gradually disappear after one or several cycles, which is called instantaneous arc fault; some fault arcs will reignite, which is called intermittent restrike arc fault. Intermittent restrike arc causes strong oscillation and accumulation of arc energy, large overvoltage amplitude, and long duration, which is extremely harmful to the oil-immersed CT and even the entire power system related to it. Therefore, it is necessary to understand the characteristics and judgment basis of intermittent restrike arc, and prevent and deal with it in time.

[0045] According to the power frequency arc extinction theory, the maximum arc-to-ground voltage can be reached when the fault arc starts, extinguishes, and reignites at the following three moments (T is the power frequency period): (1) Arcing time: Assuming that the arcing occurs when the fault voltage is at its maximum value, this time is recorded as .

[0046] (2) Arc extinction moment: the arc will continue to burn for half a power frequency cycle until the power frequency current component passes through zero ( ) is off.

[0047] (3) Restirritation time: after the arc is extinguished for an integer half cycle, that is, When the fault arc reignites.

[0048] After the arc is extinguished, it takes a while for each electrical quantity to return to normal. Considering the maximum overvoltage, it is believed that after 0.5nT, the critical breakdown voltage is greater than the dielectric recovery voltage, and the arc reignites.

[0049] In order to better implement the oil-immersed CT restrike arc modeling method in the embodiment of the present invention, based on the oil-immersed CT restrike arc modeling method, correspondingly, please refer to Figure 4 , Figure 4 The present invention provides an oil-immersed CT restrike arc modeling device 400, which includes: A general modeling module 401, for determining a differential equation of a general arc model with instantaneous input power, arc dissipation power, and arcing time as inputs; A first modeling module 402, for establishing a differential equation of a first arc model based on the assumptions of the Cassie model and the differential equation of the arc general model; A second modeling module 403, used to establish a differential equation of a second arc model based on the differential equation of the Schwarz model and the general arc model; The restrike arc modeling module 404 is used to set a transition function and obtain a restrike arc model according to the differential equation of the first arc model, the differential equation of the second arc model, the differential equation of the arc general model and the transition function.

[0050] It should be noted here that: the device 400 provided in the above embodiment can implement the technical solutions described in the above method embodiments. The specific implementation principles of the above modules or units can refer to the corresponding contents in the above method embodiments, which will not be repeated here.

[0051] See also Figure 5 , Figure 5 A schematic diagram of the structure of an oil-immersed CT reignited arc modeling device provided in an embodiment of the present invention. Based on the above oil-immersed CT reignited arc modeling method, the present invention also provides an oil-immersed CT reignited arc modeling device, which can be a computing device such as a mobile terminal, a desktop computer, a notebook, a palm computer, and a server. The oil-immersed CT reignited arc modeling device 500 includes a processor 501, a memory 502, and a display 503. Figure 5 Only some of the components of the oil-immersed CT restrike arc modeling apparatus are shown, but it should be understood that it is not required to implement all of the components shown, and more or fewer components may be implemented instead.

[0052] In some embodiments, the memory 502 may be an internal storage unit of the oil-immersed CT restrike arc modeling device 500, such as a hard disk or memory of the oil-immersed CT restrike arc modeling device 500. In other embodiments, the memory 502 may also be an external storage device of the oil-immersed CT restrike arc modeling device 500, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the oil-immersed CT restrike arc modeling device 500. Further, the memory 502 may also include both an internal storage unit and an external storage device of the oil-immersed CT restrike arc modeling device 500. The memory 502 is used to store application software and various data installed in the oil-immersed CT restrike arc modeling device 500, such as a program code for installing the oil-immersed CT restrike arc modeling device 500. The memory 502 may also be used to temporarily store data that has been output or is to be output. In one embodiment, the memory 502 stores an oil-immersed CT restrike arc modeling program, which can be executed by the processor 501 to implement the oil-immersed CT restrike arc modeling method of each embodiment of the present application.

[0053] In some embodiments, the processor 501 may be a central processing unit (CPU), a microprocessor or other data processing chip, and is used to run program codes or process data stored in the memory 502, such as executing an oil-immersed CT reignition arc modeling method.

[0054] In some embodiments, the display 503 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, an OLED (Organic Light-Emitting Diode) touch device, etc. The display 503 is used to display information on the oil-immersed CT restrike arc modeling device 500 and to display a visual user interface. The components 501-503 of the oil-immersed CT restrike arc modeling device 500 communicate with each other via a system bus.

[0055] In one embodiment, when the processor 501 executes the oil-immersed CT restrike arc modeling program in the memory 502 , the steps in the above oil-immersed CT restrike arc modeling method are implemented.

[0056] This embodiment further provides a computer-readable storage medium on which an oil-immersed CT restrike arc modeling program is stored. When the oil-immersed CT restrike arc modeling program is executed by a processor, the following steps are implemented: Determine the differential equation of the general arc model with instantaneous input power, arc dissipation power, and arcing time as input; The differential equation of the first arc model is established based on the assumptions of the Cassie model and the differential equation of the general arc model; The differential equation of the second arc model is established based on the differential equation of the Schwarz model and the general arc model; A transition function is set, and a restrike arc model is obtained according to the differential equation of the first arc model, the differential equation of the second arc model, the differential equation of the arc universal model and the transition function.

[0057] In summary, the oil-immersed CT reignition arc modeling method, device, equipment and storage medium provided in this embodiment belong to the field of arc modeling technology. The present invention first establishes the differential equation of the general arc model, and then allocates the proportion of the differential equation of the first arc model and the differential equation of the second arc model through a transition function to determine the accurate expression of some parameters of the differential equation of the general arc model, and finally determines the reignition arc model by combining the differential equation of the general arc model, which can accurately express the arc burning process generated multiple times by arc faults in the oil-immersed CT within a period of time.

[0058] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0059] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for modeling an oil-immersed CT restrike arc, characterized in that: include: Determine the differential equation of the general arc model with instantaneous input power, arc dissipation power, and arcing time as input; Establishing a differential equation of a first arc model based on the assumptions of the Cassie model and the differential equation of the arc general model; Establishing a differential equation of a second arc model based on the Schwarz model and the differential equation of the arc general model; A transition function is set, and a restrike arc model is obtained according to the differential equation of the first arc model, the differential equation of the second arc model, the differential equation of the arc general model and the transition function.

2. The oil-immersed CT restrike arc modeling method according to claim 1, characterized in that: The differential equation for determining the general arc model using instantaneous input power, arc dissipation power, and arcing time as inputs includes: A general arc model is established based on instantaneous input power, arc dissipation power, and arcing time; Determining a dynamic arc model differential equation according to the general arc model, the instantaneous arc conductance and the rate of change of the arc accumulated energy over time; A differential equation of a general arc model is established according to the arc conductance, the arc input expression and the dynamic arc model differential equation.

3. The oil-immersed CT restrike arc modeling method according to claim 2, characterized in that: Determining the dynamic arc model differential equation according to the universal arc model, the instantaneous arc conductance and the rate of change of the arc accumulated energy over time includes: Analyzing the instantaneous conductance of the arc to determine an expression for the instantaneous conductance of the arc; The arc accumulated energy is derived with respect to time to obtain the rate of change of the arc accumulated energy with time.

4. The oil-immersed CT restrike arc modeling method according to claim 1, characterized in that: The differential equation of the first arc model is: ； in, is the arc conductance of the first arc model, is the arc burning time, is the arc time constant, is the arc voltage constant, Indicates the current arc voltage value.

5. The oil-immersed CT restrike arc modeling method according to claim 1, characterized in that: The differential equation of the second arc model is: ； in, , is the power dissipation coefficient (abbreviated as dissipation coefficient), is the time constant (referred to as time coefficient), α and β The time constants are and power dissipation The exponential component of represents the arc conductance of the second arc model, is the arc model conductance based on the transition function, Indicates the current arc voltage value.

6. The oil-immersed CT restrike arc modeling method according to claim 1, characterized in that: The transition function is the Fermi distribution function, and the specific expression is: ； in, is the threshold set in the continuous transition function, represents the arc current, γ is the proportional parameter of the distribution function, Indicates the current arc voltage value, Represents a transition function.

7. The oil-immersed CT restrike arc modeling method according to claim 1, characterized in that: The restrike arc model is obtained according to the differential equation of the first arc model, the differential equation of the second arc model, the differential equation of the arc general model and the transition function, comprising: Determining the weight of the first arc model and the weight of the second arc model respectively according to the transition function; calculating an allocated arc resistance based on a weight of the first arc model and a weight of the second arc model; Substituting the distributed arc resistance into the differential equation of the general arc model obtains the reignition arc model.

8. An oil-immersed CT restrike arc modeling device, characterized in that: include: A general modeling module for determining the differential equation of the general arc model with instantaneous input power, arc dissipation power, and arcing time as input; A first modeling module, used for establishing a differential equation of a first arc model based on the assumptions of the Cassie model and the differential equation of the arc general model; A second modeling module, used for establishing a differential equation of a second arc model based on the Schwarz model and the differential equation of the arc general model; The reignite arc modeling module is used to set a transition function and obtain a reignite arc model according to the differential equation of the first arc model, the differential equation of the second arc model, the differential equation of the general arc model and the transition function.

9. An oil-immersed CT restrike arc modeling device, characterized in that: comprising a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the oil-immersed CT restrike arc modeling method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: Used to store computer-readable programs or instructions, which, when executed by a processor, can implement the steps in the oil-immersed CT restrike arc modeling method as described in any one of claims 1 to 7.

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