Time step size matching method and system for large-current switching-on and switching-off arc simulation solution

Abstract

The invention relates to the technical field of energy-saving and emission-reducing power generation equipment, in particular to a time step size matching method for large-current breaking arc simulation solution, which comprises the following steps of: determining an initial turbulence coefficient, determining an initial time step size, calculating a current turbulence coefficient, calculating a current time step size and iteratively calculating a next time step size. The time step length is dynamically adjusted according to the current current and the turbulence intensity, so that when the turbulence intensity is high or the current changes drastically, the time step length is shortened, the calculation precision is improved, the influence of a large-gradient flow field is reduced, and the convergence is improved. The method for iteratively solving the time step length is introduced, the smaller time step length is calculated according to the turbulence intensity, the flow field characteristics are captured more accurately, and a solution with higher precision is provided. The finer time step length can better capture the nonlinear characteristics of the electric arc, reduces the numerical error caused by the nonlinear effect, reduces the truncation error, enables the solution to be closer to the real solution, and achieves the more accurate simulation, better design optimization and performance evaluation.

Description

Technical Field

[0001] The invention relates to the technical field of finite element calculation of circuit breakers, and in particular to a time step coordination method for solving large current arc breaking simulation. Background Art

[0002] In the arc simulation of large-capacity circuit breakers, turbulence is an important issue to consider. Turbulence is a more complex flow of fluid. As the flow rate of the fluid increases, laminar flow may turn into turbulent flow, and the movement of the fluid becomes complex and chaotic. Turbulent flow is crucial to the study of circuit breaker arc breaking. The various vortices formed by turbulence can make the arc unstable and change the arc shape, and also affect the energy transmission of the arc.

[0003] Although turbulence itself is complex, in the study of the calculation methods of turbulence models, it can be found that turbulence also follows some basic quantitative characteristics. At present, there are mainly direct and indirect numerical simulation methods in the methods of solving turbulence models. The direct numerical simulation method can capture subtle turbulent structures in the research, does not rely on other turbulence models and empirical formulas, reduces model errors and is suitable for in-depth analysis. However, its computational cost is very high, and the requirements for computer memory, storage and computing speed are extremely high, which is limited in practical applications. Therefore, indirect numerical simulation methods are still widely used in engineering research, mainly including two common models: Reynolds-averaged Navier-Stokes (RANS) model and large eddy simulation (LES) method. The large eddy simulation method separates large-scale vortices and small-scale vortices in time and space. The large-scale vortex is directly simulated by the NS equations, while the small-scale turbulence is approximated by the subgrid scale model (SGS). Although the large eddy simulation method has lower computational requirements than direct numerical simulation in the solution process, it still requires high-performance computing resources to meet the requirements for processing power, memory, storage and network. The RANS method has low requirements for computing resources and has achieved good results in practical engineering applications. The standard Ke two-equation model is the most commonly used turbulence model. However, the Ke model requires solving two partial differential equations at the same time, and has poor convergence and calculation accuracy for flow fields with extremely large gradients.

[0004] Therefore, in order to improve the design accuracy and performance of the circuit breaker, the present invention proposes a multi-physics field solution time step coordination method for finite element simulation. This method takes into account the turbulence that occurs during arc burning. For this phenomenon, the solution time step needs to be determined based on the current size and turbulence intensity. Through this comprehensive simulation, the performance and safety of the circuit breaker can be evaluated more accurately. Summary of the invention

[0005] In view of the above problems existing in the prior art, the present invention is proposed.

[0006] To solve the above technical problems, the present invention provides the following technical solutions, which are a time step coordination method for solving large current arc breaking simulation problems, including: establishing an arc magnetofluid calculation model for the circuit breaker breaking process; obtaining characteristic values ​​of the arc and flow field after the first simulation step, and obtaining the average width and the widest size of the arc according to the arc temperature; calculating the first turbulence coefficient according to the average width of the arc and the widest size of the arc; calculating the first time step according to the obtained first turbulence coefficient; setting the time step to the first time step, and setting the iteration step to 1 to start the next simulation step, obtaining the characteristic values ​​of the arc and flow field in the first iteration step after the current moment, and obtaining the average width and the widest size of the arc according to the arc temperature; defining the average width of the arc and the widest size of the arc in the first iteration step after the current moment, and calculating the second end flow coefficient; calculating the second time step according to the obtained second end flow coefficient; calculating the final required time step setting value at the current moment according to the first time step and the second time step. The obtained value is set as the time step, and the iterative step takes a reasonable value for simulation. The subsequent steps are the same. After each time step is calculated, the next time step is calculated to set the simulation.

[0007] As a preferred solution of the time step coordination method for solving the large current arc breaking simulation of the present invention, the arc magnetic fluid calculation model includes: performing a pre-simulation model setting process to complete the setting of various boundary conditions before the arc simulation;

[0008] Set the initial time step to be less than or equal to 5×10 -6 s starts the simulation.

[0009] As a preferred solution of the time step coordination method for solving the large current arc breaking simulation of the present invention, wherein: the calculation of the first turbulence coefficient is expressed as,

[0010]

[0011] Among them, k t Expressed as the first end flow coefficient, d max,n,t Expressed as the arc's widest dimension, d average,n,t Expressed as the average arc width.

[0012] As a preferred solution of the time step coordination method for solving the large current arc breaking simulation described in the present invention, wherein: the calculation of the first time step is expressed as,

[0013]

[0014] Among them, T Step,prediction Represents the first time step.

[0015] As a preferred solution of the time step coordination method for solving the large current arc breaking simulation described in the present invention, wherein: the second end current coefficient obtained by calculation is expressed as,

[0016]

[0017] Among them, k t+1 Expressed as the second end flow coefficient, d max,1,t+1 It is expressed as the average arc width of the first iteration step after the current moment, d average,1,t+1 It is expressed as the maximum size of the arc at the first iteration step after the current moment.

[0018] As a preferred solution of the time step coordination method for solving the large current arc breaking simulation of the present invention, wherein: the calculation of the second time step is expressed as,

[0019]

[0020] Among them, T Step,prediction Represents the second time step.

[0021] As a preferred solution of the time step coordination method for solving the large current arc breaking simulation of the present invention, the time step setting value finally required at the current moment is expressed as:

[0022] T Step,t+1 =T Step,prior +0.2×(T Step,prior -T Step,prediction )

[0023] Among them, T Step,t+1 Indicates the final time step setting value required at the current moment.

[0024] Another object of the present invention is to provide a time step coordination system for solving the simulation of large current breaking arcs. The arc model construction module provides an accurate mathematical model for the circuit breaker breaking process, which helps to deeply understand the physical characteristics of the arc and provide theoretical support for design optimization, ensuring the reliability and practicality of the simulation results. The characteristic value extraction module quickly and accurately identifies the key parameters of the arc and flow field, improving the interpretability and comparability of the simulation results. The initial turbulence coefficient calculation module provides a quantitative index of the initial turbulence characteristics for the simulation, enhances the model's ability to describe actual turbulence phenomena, and improves the accuracy of flow field calculation. The initial step calculation module ensures the stability and convergence of the simulation in the initial stage and avoids calculation divergence. The iterative simulation startup module realizes the automation of the simulation process, gradually approaches the real behavior of the arc through iterative calculation, and improves the accuracy. The iterative feature analysis module monitors the changes in arc characteristics in real time, provides feedback for simulation parameter adjustment, and helps to identify the dynamic changes in arc behavior. The flow coefficient update module improves the dynamic response capability of the simulation by capturing flow field changes. The time step optimization module dynamically adjusts the time step, balances computational efficiency and accuracy, reduces resource consumption, ensures the stability and accuracy of simulation results, and improves the flexibility and adaptability of the simulation process.

[0025] As a preferred solution of the time step coordination system for large current arc breaking simulation solution described in the present invention, it includes an arc model construction module, a characteristic value extraction module, an initial end flow coefficient calculation module, an initial step calculation module, an iterative simulation startup module, an iterative characteristic analysis module, a flow coefficient update module, and a time step optimization module.

[0026] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, the steps of any one of the time step coordination methods for solving large current arc breaking simulation are implemented.

[0027] 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 any one of the time step coordination methods for solving large current arc breaking simulation are implemented.

[0028] Through the above formulas and derivations, the iterative calculation method of the present invention takes into account the influence of the arc generated by the large current and the turbulence intensity on the arc when the large-capacity circuit breaker breaks the current. In the finite element simulation solution of the circuit breaker breaking current under the action of multiple physical fields, the influence of the appearance of eddy currents is taken into account, and it is necessary to further calculate a more accurate time step to cooperate with the simulation solution. This technical solution improves the convergence and accuracy of the turbulence model. As the number of iterations increases, the calculation results will tend to the true solution. At the same time, with the cooperation of the present invention, the turbulence model can more accurately describe the random and complex movement of the fluid, which is very important for the analysis of arc behavior, and the converged turbulence model can be effectively coupled with other physical field models to provide reliable comprehensive analysis and prediction capabilities, which is of great significance to the overall design, optimization and engineering application of circuit breakers.

[0029] Beneficial effects of the present invention:

[0030] 1) Improve the convergence of the model: This method dynamically adjusts the time step according to the current current and turbulence intensity, so that when the turbulence intensity is high or the current changes dramatically, the time step is reduced, the calculation accuracy is increased, and the influence of the large gradient flow field is reduced, thereby improving the convergence. The current is obtained by combining the current waveform expression given in the simulation with the current time; the turbulence intensity is characterized by the turbulence coefficient in this patent, and the larger the turbulence coefficient, the greater the turbulence intensity. According to the calculation formula on the left, the more drastic the current change, the larger the turbulence coefficient. Substituting the larger turbulence coefficient into the time step calculation formula will result in a smaller time step.

[0031] 2) Improve model accuracy: This method introduces an iterative solution time step method, which calculates a smaller time step according to the turbulence intensity, thereby capturing the flow field characteristics more accurately and providing a more accurate solution. The time step is calculated according to the turbulence coefficient, that is, the time step size is adjusted by the turbulence intensity. Since the flow field changes dramatically under turbulence, a smaller time step, that is, a higher sampling rate, can obtain more accurate simulation results.

[0032] 3) Better handling of nonlinear problems: A finer time step can better capture the nonlinear characteristics of the arc, reduce the numerical error caused by nonlinear effects, reduce the truncation error, and make the solution closer to the true solution. The arc characteristic values ​​calculated under a smaller time step, such as temperature and conductivity, are more precise, reducing the possibility of inaccurate calculation results due to ignoring drastic changes, and the corresponding error is smaller.

[0033] 4) It is conducive to improving design and performance evaluation: through more accurate simulation, engineers can make better design optimization and performance evaluation. This helps to improve the reliability, safety and efficiency of high-voltage switch systems. Evaluation calculation refers to the more accurate simulation results obtained by optimizing the time step setting of arc simulation through this technology: such as more accurate zero-pre-conductance and post-arc voltage characteristics, etc. These results can help circuit breaker optimization and design. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0035] Figure 1 A schematic flow chart of a time step coordination method for solving large current arc breaking simulation provided by an embodiment of the present invention.

[0036] Figure 2 An arc temperature cloud diagram calculated by using a time step dynamic adjustment technology in a time step coordination method for solving a large current arc breaking simulation provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0038] Example 1, reference Figure 1 , which is the first embodiment of the present invention, provides a time step coordination method for solving large current arc breaking simulation, including:

[0039] S1. Establish an arc magnetic fluid calculation model for the circuit breaker breaking process.

[0040] The arc magnetic fluid calculation model includes performing a pre-simulation model setting process to complete the setting of various boundary conditions before arc simulation;

[0041] Set the initial time step to be less than or equal to 5×10 -6 s starts the simulation.

[0042] S2. After the first step of simulation, the characteristic values ​​of the arc and flow field are obtained, and the average width and the widest size of the arc are obtained according to the arc temperature.

[0043] S3. Calculate the first turbulence coefficient based on the average arc width and the size of the arc at its widest point.

[0044] Determine the initial turbulence coefficient

[0045] Define the average arc width of the last iteration step n at the current moment, d average,t ; The maximum arc size d at the last iteration step n at the current moment max,t ; then the turbulence coefficient at the current moment, κ t The expression of is,

[0046]

[0047] κ t The value range is 0.69-2.65, that is, the iterative method is valid only when the maximum width of the arc is within 2.65 times the average width of the arc.

[0048] S4. Calculate a first time step according to the obtained first turbulence coefficient.

[0049] Determine the initial time step

[0050] Initial time step value, T Step,prior The expression of is,

[0051]

[0052] S5. Set the time step to the first time step, and set the iteration step to 1 to start the next simulation, obtain the arc and smoothness characteristic values ​​of the first iteration step after the current moment, and determine the average width and the widest size of the arc based on the arc temperature.

[0053] S6. Define the average arc width of the first iteration step after the current moment, the size of the arc at its widest point, and calculate the second end current coefficient.

[0054] Calculate the current turbulence coefficient

[0055] Define the average arc width of the first iteration step at the current moment, d average,1,t+1 ; The maximum arc size d of the first iteration step at the current moment max,1,t+1 ; Turbulence coefficient at the current moment, κ t+1 The expression of is,

[0056]

[0057] S7. Calculate the second time step according to the obtained second end flow coefficient.

[0058] Calculate the current time step

[0059] Calculate the current time step T by the current turbulence coefficient Step,prediction , T Step,prediction The expression of is,

[0060]

[0061] S8. Calculate the final time step setting value required at the current moment according to the first time step and the second time step. Set the obtained value as the time step, take a reasonable value for the iteration step to perform simulation, and the subsequent steps are the same. After each time step is calculated, the next time step is calculated to set the simulation.

[0062] Iterate and calculate the next time step

[0063] Calculate the next time step based on the current time step, calculate an iteration, and use the following time step calculation:

[0064] T Step,t+1 =T Step,prior +0.2×(T Step,prior -T Step,prediction )

[0065] Through the above formulas and derivations, the iterative calculation method of the present invention takes into account the arc generated by the large current and the influence of the turbulence intensity on the arc when the large-capacity circuit breaker breaks the current. In the finite element simulation solution of the circuit breaker breaking current under the action of multiple physical fields, the influence of the appearance of eddy currents is taken into account, and it is necessary to further calculate a more accurate time step to cooperate with the simulation solution. The scheme improves the convergence and accuracy of the turbulence model. As the number of iterations increases, the calculation results will tend to the true solution. At the same time, with the cooperation of the present invention, the turbulence model can more accurately describe the random and complex movement of the fluid, which is very important for the analysis of arc behavior, and the converged turbulence model can be effectively coupled with other physical field models to provide reliable comprehensive analysis and prediction capabilities, which is of great significance to the overall design, optimization and engineering application of circuit breakers.

[0066] In the finite element simulation of the arc breaking of a large-capacity circuit breaker, the influence of turbulence on the arc is considered. Among the calculation methods of many turbulence models, the k-ε model is a mathematical model for turbulent flow simulation. Due to its relative simplicity and high computational efficiency, it is widely used in turbulence research. However, the k-ε model has low prediction accuracy for complex flow conditions such as strong gradient flow and separation flow, and its description ability is relatively weak for transient flow or rapidly changing flow conditions. This leads to inaccuracy in the simulation results and reduces the reliability of circuit breaker design.

[0067] Therefore, in order to solve this problem, the present invention proposes a time step coordination method for multi-physics field solution of finite element simulation. The method comprehensively considers the influence of turbulence on the arc during arc burning, and solves the turbulence coefficient adapted to the flow field characteristics according to the current turbulence intensity. A smaller time step is solved through an iterative algorithm. This can avoid numerical instability and oscillation when dealing with complex turbulence phenomena, help to improve the accuracy and convergence of the turbulence model, and help to improve the accuracy, stability and authenticity of the simulation, thereby playing an important role in the design and performance analysis of circuit breakers.

[0068] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

[0069] Circuit breaker: A circuit breaker is a switching device used to automatically cut off a circuit to protect electrical equipment and lines from damage caused by overload, short circuit, and other faults. It is commonly used in power systems to close, carry, and disconnect currents under normal or abnormal circuit conditions.

[0070] Finite element calculation: Finite element calculation is a method of completing numerical calculations based on finite element models. It is used to solve complex mathematical problems and complex engineering problems such as electromagnetic fields, fluid mechanics, and heat conduction. Finite element calculation is a method of completing numerical calculations based on finite element models. Its tasks include the formation of unit and overall matrices, the processing of boundary conditions, and the solution of characteristic equations. This method divides complex continua (such as solids, fluids, etc.) into finite small units (finite elements), performs numerical analysis on each unit, and finally summarizes the results to obtain the behavior of the entire system.

[0071] Turbulence: Turbulence is a complex flow state of fluid. Compared with laminar flow, turbulence has higher momentum, energy and material transfer efficiency. The formation of turbulence is usually related to the velocity, viscosity and characteristic scale of the fluid. When the flow rate of the fluid exceeds a certain critical value (usually related to the Reynolds number), laminar flow may turn into turbulent flow. There are many small vortices in the flow field that interact, merge and split in the flow. The speed and pressure of turbulence are highly random and volatile in space and time. Due to its strong stirring effect, the substances in the fluid can mix and spread quickly.

[0072] Time step: The time step refers to the discrete unit used to represent time in the computational model. In many scientific and engineering fields, such as the finite element calculation field involved in the present invention, the dynamic changes of the system are usually continuous, but computers can only process discrete data. Therefore, continuous time is divided into discrete time points for numerical calculations. If the time step is too large, important dynamic features may be ignored, thereby reducing the accuracy of the model and may even cause numerical instability. In order to improve the accuracy of the model, a smaller time step is required to cooperate with the solution. Of course, this will increase the amount of calculation and extend the calculation time.

[0073] Example 2, reference Figure 2 The second embodiment of the present invention provides a time step coordination method for solving large current arc breaking simulation;

[0074] The technical solution of the invention focuses on the convergence and accuracy of the turbulence model in the simulation of the breaking current of a large-capacity circuit breaker, so as to more accurately simulate the influence of turbulence on the arc during the operation of the circuit breaker breaking the current. The main key points are:

[0075] 1. Time step for solving the turbulence model for circuit breaker breaking current simulation: The core of the present invention is to propose a unique iterative algorithm, which can simultaneously consider the current current size and turbulence intensity to solve a smaller time step to ensure the physical consistency of the model and improve the credibility of the simulation.

[0076] 2. Enhance the coupling between electromagnetic field and fluid field: The present invention introduces an iterative calculation method to obtain a smaller time step and enhance the coupling between electromagnetic field and fluid field. The combination of this method and the finite element method plays a key role in the simulation and provides an effective tool for more accurate simulation of turbulence effects.

[0077] 3. Improve stability and convergence: The present invention introduces a method for solving smaller time steps to deal with the instability of the numerical solution that may be caused by turbulent changes in the process of circuit breaker breaking current, reduce numerical oscillations, and make the simulation process more stable and convergent better.

[0078] 4. Turbulence coefficient adapted to flow field to optimize the selection of time step: The present invention proposes a turbulence coefficient adapted to flow field characteristics, which can more accurately describe the intensity of turbulence in the flow field, thereby dynamically adjusting the time step to capture the changing characteristics of the flow field, which helps to improve the accuracy and stability of the model.

[0079] The method of the present invention helps to improve the design of large-capacity circuit breakers and increases the accuracy of their performance evaluation, which is crucial to ensuring the reliability and safety of power systems.

[0080] Embodiment 3, the third embodiment of the present invention, is different from the first two embodiments in that:

[0081] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0082] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0083] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0084] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0085] Embodiment 4, this embodiment provides a time step coordination system for solving large current breaking arc simulation, characterized in that it includes: an arc model construction module, a characteristic value extraction module, an initial end flow coefficient calculation module, an initial step calculation module, an iterative simulation startup module, an iterative characteristic analysis module, a flow coefficient update module, and a time step optimization module.

[0086] Arc model building module: Establish arc magnetic fluid calculation model of circuit breaker breaking process.

[0087] Characteristic value extraction module: After the first step of simulation, the characteristic values ​​of the arc and flow field are obtained, and the average width and the widest size of the arc are obtained based on the arc temperature.

[0088] Initial turbulence coefficient calculation module: calculates the first turbulence coefficient based on the average arc width and the size of the widest part of the arc.

[0089] Initial step calculation module: calculates the first time step according to the obtained first turbulence coefficient.

[0090] Iterative simulation startup module: Set the time step to the first time step and set the iteration step to 1 to start the next simulation.

[0091] Iterative feature analysis module: obtains the characteristic values ​​of the arc and flow field in the first iteration step after the current moment, and obtains the average width and the widest size of the arc based on the arc temperature.

[0092] Flow coefficient update module: defines the average arc width of the first iteration step after the current moment, the size of the arc at its widest point, and calculates the flow coefficient of the second end.

[0093] Time step optimization module: calculates the second time step according to the obtained second end flow coefficient, and calculates the final time step setting value required at the current moment according to the first time step and the second time step.

[0094] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A time step coordination method for solving large current arc breaking simulation, characterized in that: include, Establish arc magnetic fluid calculation model of circuit breaker breaking process; After the first step of simulation, the characteristic values ​​of the arc and flow field are obtained, and the average width and the widest size of the arc are obtained according to the arc temperature; Calculate the first turbulence coefficient based on the average arc width and the size of the arc at its widest point; Calculate a first time step according to the obtained first turbulence coefficient; Set the time step to the first time step and set the iteration step to 1 to start the next simulation. Get the arc and smoothness characteristic values ​​of the first iteration step after the current moment. Get the average width and the widest size of the arc based on the arc temperature. Define the average arc width of the first iteration step after the current moment, the size of the arc at its widest point, and calculate the second end current coefficient; Calculate a second time step according to the obtained second end flow coefficient; The final time step setting value required for calculating the current moment is calculated based on the first time step and the second time step.

2. The time step coordination method for solving large current arc breaking simulation according to claim 1 is characterized in that: The arc magnetic fluid calculation model includes performing a pre-simulation model setting process to complete the setting of various boundary conditions before arc simulation; Set the initial time step to be less than or equal to 5×10 -6 s starts the simulation.

3. The time step coordination method for solving large current arc breaking simulation as claimed in claim 2 is characterized in that: The calculation of the first turbulence coefficient is expressed as, Among them, κ t Expressed as the first end flow coefficient, d max,n,t Expressed as the arc's widest dimension, d average,n,t Expressed as the average arc width.

4. The time step coordination method for solving large current arc breaking simulation according to claim 1 is characterized in that: The calculation of the first time step is expressed as, Among them, T Step,prediction Represents the first time step.

5. The time step coordination method for solving large current arc breaking simulation as claimed in claim 4 is characterized in that: The calculated second end flow coefficient is expressed as: Among them, κ t+1 Expressed as the second end flow coefficient, d max,1,t+1 It is expressed as the average arc width of the first iteration step after the current moment, d average,1,t+1 It is expressed as the maximum size of the arc at the first iteration step after the current moment.

6. The time step coordination method for large current arc breaking simulation solution according to claim 1, characterized in that: The calculation of the second time step is expressed as, Among them, T Step,prediction Represents the second time step.

7. The time step coordination method for large current arc breaking simulation solution according to claim 1 is characterized in that: The final time step setting value required at the current moment is expressed as: T Step,t+1 =T Step,prior +0.2×(T Step,prior -T Step,prediction ) Among them, T Step,t+1 Indicates the final time step setting value required at the current moment.

8. The time step coordination method for solving large current arc breaking simulation according to claim 1 is characterized in that: It includes an arc model building module, a characteristic value extraction module, an initial end flow coefficient calculation module, an initial step calculation module, an iterative simulation startup module, an iterative characteristic analysis module, a flow coefficient update module, and a time step optimization module.

9. 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 7 are implemented.

10. 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 7 are implemented.

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