A boundary condition setting method for enhancing initial stability of simulation and related device

Abstract

The application discloses a boundary condition setting method for enhancing initial stability of simulation and a related device, and comprises the following steps: when the actual arc starting current is less than 4kA, a transition current is not added, and the arc starting is performed through the actual current, so that the stability of initial solving can be ensured; and when the arc starting current is 4kA or above, since the initial current area is wide in the model, the problems of numerical instability or non-convergence are prone to occur when the parameters in the calculation model are calculated, therefore, a transition small current is added before the actual current is introduced. The application designs to increase the transition time according to different arc starting current conditions, so as to ensure the stability of simulation calculation. At the same time, the application also ensures the consistency with the actual arc combustion law in the circuit breaker. The application provides an effective mathematical simulation model for improving the performance of the high-voltage circuit breaker, and provides a strong support for improving the reliability of the power system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-voltage circuit breakers, and in particular to a boundary condition setting method for enhancing initial stability of simulation and related devices. BACKGROUND

[0002] In power systems, high-voltage circuit breakers are often used to handle circuit protection in high-current and high-load situations. In recent years, with the continuous progress of research and development technology, high-voltage circuit breakers have gradually possessed stronger breaking capacity and higher reliability. Modern high-voltage circuit breakers adopt advanced arc extinguishing technologies such as gas-insulated circuit breakers and vacuum circuit breakers, which enable the circuit breaker to rapidly and effectively cut off the current at a higher current level, thereby protecting the power system from overload and short-circuit faults. With the expansion of the scale of the power system and the increasing demand for safety and stability, the design and manufacturing technology of high-voltage circuit breakers at 80kA current level and above are also continuously upgraded to ensure stable operation and reliable protection under various harsh conditions.

[0003] Finite element simulation calculation plays a key role in improving the performance of high-voltage circuit breakers. In research, the electromagnetic, thermal and mechanical properties of the circuit breaker are modeled and analyzed in detail through finite element simulation, thereby providing ideas for optimizing the structure of the circuit breaker. Type tests of the circuit breaker are carried out under three working conditions of short arc, medium arc and long arc, so the arc burning trend under these three working conditions also needs to be simulated during simulation. The treatment of the three working conditions is different in simulation: for short arc and long arc working conditions, the arc is generally initiated at the minimum current; while for medium arc working conditions, the arc is usually initiated near the peak value.

[0004] Currently, there are still some shortcomings in finite element simulation calculation for medium arc working conditions above 80kA current level. For example, the behavior of the arc under high current is very complex, making it difficult to establish a very accurate physical model; the accuracy and stability of the calculation results of the model depend on the initial data and boundary conditions, and if the initial solution result is unstable, it will hinder the smooth progress of the simulation. In some working conditions, if the arc initiation current is too large, the initial current set in the circuit breaker is large, which will result in poor initial solution stability, thereby reducing the efficiency and accuracy of the simulation solution. Therefore, in order to enhance the stability of the simulation of breaking arc plasma under medium arc working conditions above 80kA current level, it is urgent to design a boundary condition setting method for enhancing the initial stability of simulation. SUMMARY

[0005] The present application provides a boundary condition setting method for enhancing the initial stability of simulation and related devices, which is used to enhance the stability of the simulation of breaking arc plasma under medium arc working conditions above 80kA current level.

[0006] Therefore, the first aspect of the present application provides a boundary condition setting method for enhancing initial stability of simulation, which comprises:

[0007] According to the size of the starting arc current, the situation of applying small current is divided into several cases, including: when the absolute value of the starting arc current is less than 4kA, and when the absolute value of the starting arc current is greater than 4kA;

[0008] When the absolute value of the starting arc current is less than 4kA, the starting arc is performed by the actual current without applying a transition small current;

[0009] When the absolute value of the starting arc current is greater than 4kA, the current level is determined to determine the value of the applied current and the corresponding transition time.

[0010] Optionally, when the absolute value of the starting arc current is greater than 4kA, the current level is determined to determine the value of the applied current and the corresponding transition time, comprising:

[0011] When the absolute value of the starting arc current is greater than 4kA and the starting arc is after the peak, the empirical data of the transition time under multiple current levels is obtained, and the empirical data is fitted to derive a first fitting formula, and the value of the transition time from small current to large current under different current levels is obtained by the first fitting formula;

[0012] When the absolute value of the starting arc current is greater than 4kA and the starting arc is after the peak, the empirical data of the transition time under multiple current levels is obtained, and the empirical data is fitted to derive a second fitting formula, and the value of the transition time from small current to large current under different current levels is obtained by the second fitting formula.

[0013] Optionally, the first fitting formula is:

[0014] ;

[0015] In the formula, is the transition time, is the size of the starting arc current.

[0016] Optionally, the second fitting formula is:

[0017] ;

[0018] In the formula, is the transition time, is the size of the starting arc current.

[0019] The second aspect of the present application provides a boundary condition setting system for enhancing initial stability of simulation, which comprises:

[0020] The dividing unit is configured to divide the small current application situation into several cases according to the arc starting current, including: when the absolute value of the arc starting current is less than 4 kA, and when the absolute value of the arc starting current is greater than 4 kA.

[0021] The first setting unit is configured to start the arc by the actual current and not apply the transition small current when the absolute value of the arc starting current is less than 4 kA.

[0022] The second setting unit is configured to determine the current value and the corresponding transition time value according to the current level when the absolute value of the arc starting current is greater than 4 kA.

[0023] Optionally, the second setting unit comprises:

[0024] The first setting subunit is configured to obtain the empirical data of the transition time under multiple current levels when the absolute value of the arc starting current is greater than 4 kA and the arc is started after the peak, and fit the empirical data to derive a first fitting formula, so as to obtain the transition time value from small current to large current under different current levels by the first fitting formula.

[0025] The second setting subunit is configured to obtain the empirical data of the transition time under multiple current levels when the absolute value of the arc starting current is greater than 4 kA and the arc is started after the peak, and fit the empirical data to derive a second fitting formula, so as to obtain the transition time value from small current to large current under different current levels by the second fitting formula.

[0026] Optionally, the first fitting formula is:

[0027] ;

[0028] In the formula, t is the transition time, and I is the arc starting current.

[0029] Optionally, the second fitting formula is:

[0030] ;

[0031] In the formula, t is the transition time, and I is the arc starting current.

[0032] The third aspect of the present application provides a boundary condition setting device for enhancing the initial stability of simulation, which comprises a processor and a memory:

[0033] The memory is configured to store program code and transmit the program code to the processor.

[0034] ​​​​The processor is configured to execute the steps of the method for setting boundary conditions to enhance initial stability of simulation according to the instructions in the program code.

[0035] The fourth aspect of the present application provides a computer readable storage medium for storing program code, the program code being used to execute the method for setting boundary conditions to enhance initial stability of simulation according to the first aspect.

[0036] From the above technical solutions, the present application has the following advantages:

[0037] The method for setting boundary conditions to enhance initial stability of simulation provided by the present application increases the transition time according to different arc current conditions, thereby ensuring the stability of simulation calculation. At the same time, it also ensures the consistency with the actual arc burning law in the circuit breaker. The present application provides an effective mathematical simulation model for improving the performance of high-voltage circuit breakers, and provides strong support for improving the reliability of power systems. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 A flowchart of the method for setting boundary conditions to enhance initial stability of simulation provided in the embodiments of the present application is shown;

[0039] Figure 2 A structural diagram of the system for setting boundary conditions to enhance initial stability of simulation provided in the embodiments of the present application is shown. DETAILED DESCRIPTION

[0040] In order to enable persons skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative work fall within the scope of protection of the present application.

[0041] TERMS EXPLANATION:

[0042] Circuit breaker: The circuit breaker refers to a switching device capable of closing, carrying and opening the current under normal loop conditions and capable of closing, carrying and opening the current under abnormal loop conditions within a specified time. Circuit breakers are divided into high-voltage circuit breakers and low-voltage circuit breakers according to their use.

[0043] Medium arc burning condition: The medium arc burning time refers to the arc burning duration of the circuit breaker under medium load or medium fault condition. Usually, this time is determined by the shortest arc burning time of the circuit breaker, and is between the short arc burning time and the long arc burning time. This time length has an important influence on the performance of the circuit breaker and the ability of the protection circuit.

[0044] Arc: Arc is a kind of gas discharge phenomenon, the instantaneous spark generated by the current through some insulating medium (such as air). When breaking the circuit in the atmosphere, as long as the voltage exceeds 12-20V, the current to be broken exceeds 0.25-1A, a group of extremely high temperature, strong light and conductive approximately cylindrical gas is usually generated in the contact gap (also known as arc gap), which is the arc. Arc is a kind of gas discharge phenomenon, also a kind of plasma.

[0045] Plasma: Plasma is the fourth state of matter, which is parallel to solid, liquid and gas. With 50000K as the boundary, plasma can be divided into two categories: high temperature plasma and low temperature plasma, and arc belongs to the latter.

[0046] Finite element simulation calculation: Finite element simulation calculation refers to a method of simplifying complex problems into simpler problems and then solving them. It regards the solution area as composed of many interconnected small sub-regions called finite elements. For each finite element, a suitable approximate solution is assumed, and then the solution that satisfies the conditions of the whole region is derived.

[0047] Initial solution stability: Initial solution stability refers to the stability of the initial solution of a problem in the field of mathematical optimization, computational science or control system. It usually involves the following aspects: stability of initial solution, numerical stability and algorithm convergence. Initial solution stability is an important indicator to evaluate the robustness and reliability of the initial solution, and to ensure that the system can effectively cope with the initial conditions and disturbances in the calculation or control process.

[0048] Arcing current: Arcing current refers to the current at the point when the contacts and contact fingers are just separated during the breaking process of the circuit breaker.

[0049] See Figure 1 , the boundary condition setting method for enhancing the initial stability of simulation provided in the embodiments of the present application comprises:

[0050] Step 101: According to the size of the arcing current, the situation of applying small current is divided into several cases, including: when the absolute value of the arcing current is less than 4kA, and when the absolute value of the arcing current is greater than 4kA.

[0051] It should be noted that according to the size of the arcing current, the situation of applying small current is divided into when the absolute value of the arcing current is less than 4kA, and when the absolute value of the arcing current is greater than 4kA.

[0052] Further, in an embodiment, when the absolute value of the arcing current is greater than 4kA, it further includes: when the absolute value of the arcing current is greater than 4kA, and the arcing occurs after the peak, and when the absolute value of the arcing current is greater than 4kA, and the arcing occurs before the peak.

[0053] Step 102, when the absolute value of the arcing current is less than 4kA, arcing is performed by the actual current and no small transition current is applied.

[0054] It should be noted that when the absolute value of the arcing current is less than 4kA, the arcing current in the circuit breaker is small at this time, and when using the finite element method for simulation, the current region set initially is relatively narrow, and the stability state can be reached relatively quickly during calculation and iteration, and is consistent with the actual working condition of the arc. Therefore, when the absolute value of the arcing current is below 4kA, arcing is directly performed by the actual current, and no transition small current needs to be added, so as to meet the stability and accuracy required for simulation.

[0055] Step 103, when the absolute value of the arcing current is greater than 4kA, the current value and the corresponding transition time value are determined according to the current level.

[0056] It should be noted that when the arcing current is 4kA and above, the initial current region in the model is relatively wide, and the problem of numerical instability or non-convergence is prone to occur when calculating the parameters in the model. Therefore, a transition small current is added before the actual current is introduced. See the following description for details.

[0057] In one embodiment, step 103 includes:

[0058] Step 1031, when the absolute value of the arcing current is greater than 4kA and arcing is performed after the peak value, the empirical data of the transition time under multiple current levels is obtained, and the empirical data is fitted to derive a first fitting formula. Through the first fitting formula, the transition time values from small current to large current under different current levels are obtained.

[0059] The first fitting formula is:

[0060] ;

[0061] In the formula, is the transition time, is the arcing current.

[0062] It should be noted that when the absolute value of the arcing current is above 4kA, the current region in the initial model is relatively wide, and if arcing is directly started from the original current size, it is difficult to ensure the stability of the initial solution during simulation calculation. At this time, a transition current needs to be set to gradually increase the current to the arcing current value within a certain transition time. The working conditions targeted by the present application are all working currents with a frequency of 50Hz.

[0063] The application summarizes the influence law of different arc starting current on the stability solving, and fits the obtained empirical data, so as to derive the corresponding fitting formula. The fitting formula can obtain the numerical value of the transition time from small current to large current under different current levels. The formula of the relationship between the transition time (unit: millisecond) and the arc starting current size (unit: kiloampere) is as follows: t = 0.000 1I 2+ 0.000 2I + 0.000 3.

[0064] Through the analysis of the first fitting formula, the following conclusions can be drawn: in the mapping relationship involved in the application, the increase of the arc starting current does not cause the monotonic increase of the transition time, but presents a nonlinear trend with the change of the current level. Specifically, in the current level range of 50-100 kA, the transition time is prolonged with the increase of the current; however, when the current level reaches 100-150 kA, the transition time is shortened instead; when the current level exceeds 150 kA, the transition time is significantly increased. This law is consistent with the calculation stability requirement in the simulation process, indicating that in the case of the increase of the arc starting current level, the transition time needs to be appropriately prolonged or reduced, so as to ensure the smooth progress of the iteration process and the accuracy of the simulation result.

[0065] In step 1032, when the absolute value of the arc starting current is greater than 4 kA and the arc starting is after the peak value, the empirical data of the transition time under multiple current levels are obtained, and the empirical data are fitted, so as to derive the second fitting formula. Through the second fitting formula, the numerical value of the transition time from small current to large current under different current levels is obtained.

[0066] The second fitting formula is as follows:

[0067] ;

[0068] In the formula, t is the transition time, is the transition time, is the arc starting current size.

[0069] It should be noted that this case (when the absolute value of the arc starting current is greater than 4 kA and the arc starting is after the peak value) is similar to the above case (when the absolute value of the arc starting current is greater than 4 kA and the arc starting is after the peak value). Due to the large actual arc starting current and the gradual increase of the current value after the arc starting, the actual current cannot be directly used for arc starting in the simulation, and small current transition is adopted. Similar to the method of the above case, the empirical data of the transition time under multiple current levels are first adopted, and then the data are fitted, so as to obtain the fitting formula as the above second fitting formula.

[0070] It can be seen from the above second fitting formula that when the arc starting current level is below 250 kA, the transition time is prolonged with the increase of the arc starting current.

[0071] In summary, when the absolute value of the actual arcing current is less than 4kA, the stability in the simulation calculation process is good due to the narrow initial arcing area, and therefore the transition current does not need to be set. However, when the absolute value of the actual arcing current reaches or exceeds 4kA, directly setting a wide initial arcing area may cause a large residual error in the initial calculation iteration process, thereby affecting the feasibility of the calculation. At this time, a certain transition time needs to be set to gradually transition the current from small to large, so as to ensure that the simulation process can proceed smoothly, while maintaining a high consistency with the actual arc plasma combustion condition. The method provided in the application can obtain a fitting curve through fitting of the empirical data under multiple known current levels, thereby providing a reliable reference for researchers to reasonably set the transition time under different current levels.

[0072] The boundary condition setting method for enhancing the initial stability of simulation provided in the application mainly focuses on how to apply a small current under different situations in the simulation process, and determines the transition time from small current to large current according to the size of the arcing current, the current frequency and the arcing time. The selection of the transition time needs to meet the stability of the initial solution in the simulation, and also needs to comply with the actual arcing process rule. The application specifically includes accurately determining the transition time according to the parameters such as the size of the arcing current, the current frequency and the arcing time under different situations, so as to ensure the rationality and accuracy of the current transition in the simulation process, and maintain a high consistency between the simulation condition and the actual working condition.

[0073] The above is a boundary condition setting method for enhancing the initial stability of simulation provided in the embodiments of the application, and the following is a boundary condition setting system for enhancing the initial stability of simulation provided in the embodiments of the application.

[0074] Please refer to Figure 2 The boundary condition setting system for enhancing the initial stability of simulation provided in the embodiments of the application includes:

[0075] The dividing unit 201 is configured to divide the situation of applying a small current into several situations according to the size of the arcing current, including when the absolute value of the arcing current is less than 4kA, and when the absolute value of the arcing current is greater than 4kA.

[0076] The first setting unit 202 is configured to, when the absolute value of the arcing current is less than 4kA, arc by the actual current and not apply a transition small current.

[0077] The second setting unit 203 is configured to, when the absolute value of the arcing current is greater than 4kA, determine the value of the applied current and the corresponding transition time according to the current level.

[0078] In one embodiment, the second setting unit 203 includes:

[0079] The first setting subunit 2031 is used to obtain empirical data on the transition time at multiple current levels when the absolute value of the arc-starting current is greater than 4kA and the arc starts after the peak value, and to fit the empirical data to derive the first fitting formula. Through the first fitting formula, the numerical value of the transition time from small current to large current at different current levels is obtained.

[0080] The first fitting formula is:

[0081] ;

[0082] In the formula, For the transition period, This represents the magnitude of the arc-starting current.

[0083] The second setting subunit 2032 is used to obtain empirical data on the transition time at multiple current levels when the absolute value of the arc-starting current is greater than 4kA and the arc starts after the peak value. The empirical data is then fitted to derive a second fitting formula. Through the second fitting formula, the values ​​of the transition time from small current to large current at different current levels are obtained.

[0084] The second fitting formula is:

[0085] ;

[0086] In the formula, For the transition period, This represents the magnitude of the arc-starting current.

[0087] Furthermore, this application embodiment also provides a boundary condition setting device to enhance the initial stability of simulation, the device including a processor and a memory:

[0088] The memory is used to store program code and transmit the program code to the processor;

[0089] The processor is used to execute the steps of the boundary condition setting method for enhancing the initial stability of simulation as described in the above method embodiments, according to the instructions in the program code.

[0090] Furthermore, this application embodiment also provides a computer-readable storage medium for storing program code, which is used to execute the boundary condition setting method for enhancing the initial stability of simulation as described in the above method embodiment.

[0091] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0092] The terms "first", "second", "third", "fourth", and the like in the description and in the claims of this application, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the use of the terms so termed is interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of accomplishing functionalities that are either the same or similar to that of other embodiments of the application. Moreover, the terms "include", "have", and the like, are used in the detailed description and in the claims of this application essentially open- ended and are intended to encompass the items listed thereafter, equivalents thereof, as well as additional items not listed after the comma. Finally, terms of degree such as "substantially", "approximately", and the like, are used to describe and account for subjective measurements that are inherently imprecise.

[0093] It should be understood that, in the application, "at least one" means one or more, and "multiple" means two or more. "And / or", used to describe the relationship between associated objects, means that there can be three relationships, for example, "A and / or B" can mean: only A, only B, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects. "At least one of the following" or the like means any combination of these items, including single or multiple items. For example, at least one of a, b or c, can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be singular or plural.

[0094] In several embodiments provided in the application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the above-described device embodiments are only illustrative, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed objects can be indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0095] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, i.e. they can be located in one place or distributed on multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0096] In addition, each of the functional units in the various embodiments of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0097] The integrated unit, if realized in the form of a software functional unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application, essentially or in part, or all or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods according to the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (English full name: Read-Only Memory, English abbreviation: ROM), a random access memory (English full name: Random Access Memory, English abbreviation: RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0098] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A boundary condition setting method for enhancing initial stability of simulation, characterized by, The method comprises the following steps: According to the size of the arc current, the situation of applying small current is divided into several cases, including: when the absolute value of the arc current is less than 4kA, and when the absolute value of the arc current is greater than 4kA; When the absolute value of the arc current is less than 4kA, the actual current is used for arc starting and no transition small current is applied; When the absolute value of the arc current is greater than 4kA, the current level is used to determine the applied current value and the corresponding transition time value; Wherein, when the absolute value of the arc current is greater than 4kA, the current level is used to determine the applied current value and the corresponding transition time value, which comprises: When the absolute value of the arc current is greater than 4kA and the arc is started after the peak, the empirical data of transition time under multiple current levels is obtained, and the empirical data is fitted to derive a first fitting formula, and the transition time value from small current to large current under different current levels is obtained through the first fitting formula; When the absolute value of the arc current is greater than 4kA and the arc is started after the peak, the empirical data of transition time under multiple current levels is obtained, and the empirical data is fitted to derive a second fitting formula, and the transition time value from small current to large current under different current levels is obtained through the second fitting formula; The first fitting formula is: ； In the formula, is the transition time, is the arc current magnitude.

2. The boundary condition setting method for enhancing initial stability of simulation according to claim 1, wherein, The second fitting formula is: ； In the formula, is the transition time, is the arc current magnitude.

3. A boundary condition setting system for enhancing initial stability of simulation, characterized by, The method comprises the following steps: The dividing unit is used to divide the situation of applying small current into several cases according to the size of the arc current, including: when the absolute value of the arc current is less than 4kA, and when the absolute value of the arc current is greater than 4kA; The first setting unit is used to start the arc by the actual current and not to apply the transition small current when the absolute value of the arc current is less than 4kA; The second setting unit is used to determine the applied current value and the corresponding transition time value according to the current level when the absolute value of the arc current is greater than 4kA; Wherein, the second setting unit comprises: The first setting subunit is used to obtain the empirical data of transition time under multiple current levels when the absolute value of the arc current is greater than 4kA and the arc is started after the peak, and the empirical data is fitted to derive a first fitting formula, and the transition time value from small current to large current under different current levels is obtained through the first fitting formula; The second setting subunit is used to obtain the empirical data of transition time under multiple current levels when the absolute value of the arc current is greater than 4kA and the arc is started after the peak, and the empirical data is fitted to derive a second fitting formula, and the transition time value from small current to large current under different current levels is obtained through the second fitting formula; The first fitting formula is: ； In the formula, is the transition time, is the arc current magnitude.

4. The system for setting a boundary condition for enhancing initial stability of simulation according to claim 3, wherein The second fitting formula is: ； In the formula, is the transition time, is the arc current magnitude.

5. An apparatus for setting a boundary condition to enhance initial stability of simulation, characterized by, The device comprises a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the boundary condition setting method for enhancing the simulation of initial stability according to the instructions in the program code.

6. A computer-readable storage medium, characterized in that, The computer readable storage medium is configured to store program codes for performing the method of setting boundary conditions for enhancing initial stability of simulation according to any one of claims 1-2.

Images