Method for calculating transient electric force of gas insulated transmission line, medium and electronic equipment

Abstract

The application discloses a kind of gas insulated transmission line transient electromotive force calculation method, medium and electronic equipment, the method includes: establishing magnetic field control model, and according to magnetic field control model definition gas insulated transmission line three-phase current excitation;According to three-phase current excitation, field-circuit coupling control model is established, and with magnetic vector potential variable in magnetic field control model and the three-phase current variable of gas insulated transmission line as unknown variable, combination field-circuit coupling control model establishes assembly matrix;To the assembly matrix is solved and obtains the magnetic flux density and current density of gas insulated transmission line, and in finite element calculation domain, the magnetic flux density and current density are integrated, so as to obtain the transient electromotive force of gas insulated transmission line.The application can accurately and quickly obtain the transient electromotive force distribution of gas insulated transmission line under given voltage excitation condition.

Description

Technical Field

[0001] This invention relates to the field of gas-insulated transmission line technology, and in particular to a method for calculating transient electrodynamic forces in gas-insulated transmission lines, as well as a dielectric and electronic device. Background Technology

[0002] Gas-insulated transmission lines (GILs) offer advantages such as high transmission capacity, low loss, and minimal electromagnetic interference, making them widely used in urban utility tunnels and power transmission systems. However, under short-circuit faults, GILs generate extremely high magnetic flux density and transient electrodynamic forces. High magnetic flux density affects the detection and normal operation of communication equipment installed in GIL tunnels, while high transient electrodynamic forces can cause the electrical connection structure to separate from the current-carrying conductor and deform rigid structures such as conductors, casings, and post insulators. Therefore, calculating transient electromagnetic fields is crucial for the optimized design and operation and maintenance monitoring of GILs.

[0003] Gas-insulated transmission lines are typically tens of kilometers long. When using the finite element method (FEM) to calculate the induced voltage and electromotive force of such lines, a 3D (three-dimensional) gas-insulated transmission line of tens of meters would generate tens or even hundreds of millions of meshes. This massive mesh count makes calculating the electromotive force of a full-scale 3D gas-insulated transmission line under short-circuit conditions impractical, and further increases model complexity when considering structures like short-circuit busbars. Furthermore, 3D simulation is extremely costly in terms of time and computational resources, limiting its application to localized analyses of short-distance gas-insulated transmission lines. Additionally, most existing research on transient voltage calculations relies on solving for the eddy current field of a given short-circuit current to assess the transient electromotive force, or on equivalent circuit models, neglecting the eddy current effect and the electromagnetic field-circuit coupling effect, respectively.

[0004] Gas-insulated transmission lines, as transmission equipment whose external excitation is the external port voltage or constrained by an external power network, have unknown time-varying currents. Their transient electrodynamic forces are essentially the result of electromagnetic field-circuit coupling, i.e., field-circuit coupling. Therefore, there is a lack of a method for calculating the transient electrodynamic forces of gas-insulated transmission lines based on field-circuit coupling. Summary of the Invention

[0005] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the first objective of this invention is to provide a method for calculating the transient electrodynamics of gas-insulated transmission lines, which can accurately and quickly obtain the transient electrodynamic distribution of gas-insulated transmission lines under given voltage excitation conditions.

[0006] A second objective of this invention is to provide a computer-readable storage medium.

[0007] A third objective of this invention is to provide an electronic device.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0009] A method for calculating transient electrodynamic forces in a gas-insulated transmission line includes:

[0010] Step S1: Establish a magnetic field control model and define the three-phase current excitation of the gas-insulated transmission line according to the magnetic field control model;

[0011] Step S2: Establish a field-circuit coupling control model based on the three-phase current excitation, and use the magnetic vector potential variable in the magnetic field control model and the three-phase current variable of the gas-insulated transmission line as unknown variables, and establish an assembly matrix in combination with the field-circuit coupling control model;

[0012] Step S3: Solve the assembly matrix to obtain the magnetic flux density and current density of the gas-insulated transmission line, and integrate the magnetic flux density and current density in the finite element calculation domain to obtain the transient electrodynamic force of the gas-insulated transmission line.

[0013] Preferably, in step S1, the step of establishing the magnetic field control model includes: determining the form of the excitation source of the gas-insulated transmission line so as to establish the magnetic field control model based on the determined form of the excitation source.

[0014] Preferably, when the excitation source is a power frequency current excitation, a frequency domain magnetic field control model is established; when the excitation source is a transient voltage excitation, a time domain magnetic field control model is established; wherein,

[0015] The frequency domain magnetic field control model is expressed by the following formula:

[0016]

[0017]

[0018] in, Let μ represent the Hamiltonian operator, A represent the magnetic vector potential, ω represent the angular frequency, and σ represent the electrical conductivity. J represents the scalar potential. s This represents the source current density of the conductor rod in a gas-insulated transmission line;

[0019] The time-domain magnetic field control model is expressed by the following formula:

[0020]

[0021]

[0022] Where I represents the phase current flowing tangentially along the axial direction of the straight conductor in the gas-insulated transmission line, S represents the cross-sectional area of ​​the conductor, and t represents time. This indicates the direction of current flow in the conductor.

[0023] Preferably, the three-phase current of the gas-insulated transmission line is expressed by the following formula:

[0024]

[0025] Among them, I a (t), I b (t) and I c (t) represent the currents in phases a, b, and c, respectively. and S represents the scalar potential of phases a, b, and c. a S b and S c Let these represent the cross-sectional areas of the phase a guide rod, phase b guide rod, and phase c guide rod, respectively. The cross-sectional area variable represents the integration process.

[0026] Preferably, the field-circuit coupling control model is expressed by the following formula:

[0027]

[0028] Among them, u a (t), u b (t) and u c (t) represent the three-phase external voltage source excitation of the gas-insulated transmission line, R ta R tb and R tc R represents the external resistance of each phase of a gas-insulated transmission line. la R lb and R lc L represents the load resistance of each phase of the gas-insulated transmission line. ta L tb and L tc Let θ represent the external inductance of each phase of the gas-insulated transmission line, U be the effective value of the external voltage source excitation, and θ be the phase delay.

[0029] Preferably, the assembly matrix is ​​represented by the following formula:

[0030]

[0031] Among them, T, M and N TLet represent the stiffness matrix, K represent the load matrix for conduction current, R represent the resistance matrix of the external circuit, L represent the inductance matrix of the external circuit, and U represent the port voltage matrix of the external circuit.

[0032] Preferably, in step S3, the step of solving the assembly matrix to obtain the magnetic flux density and current density of the gas-insulated transmission line includes:

[0033] The simulation duration and simulation step size of the magnetic field control model are determined, and at each time step, the assembly matrix is ​​solved to obtain the magnetic flux density and current density at each time step. The simulation duration is determined based on the short-circuit fault type and fault duration of the gas-insulated transmission line.

[0034] To achieve the above objectives, a second aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, it implements the above-described method for calculating transient electrodynamic forces of gas-insulated transmission lines.

[0035] To achieve the above objectives, a third aspect of the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it implements the aforementioned method for calculating transient electrodynamic forces of gas-insulated transmission lines.

[0036] This invention has at least the following technical effects:

[0037] This invention determines the magnetic field control model based on the excitation source form of the gas-insulated transmission line, then defines the three-phase current excitation of the gas-insulated transmission line based on the determined magnetic field control model, and establishes an electromagnetic field-circuit coupled control model based on the defined three-phase current excitation. Using the magnetic vector potential variable in the magnetic field control model and the three-phase current variable of the gas-insulated transmission line as unknown variables, an assembly matrix is ​​established in conjunction with the electromagnetic field-circuit coupled control model. The simulation duration and simulation step size of the magnetic field control model are then determined, and the assembly matrix is ​​solved at each time step to obtain the magnetic flux density and current density of the gas-insulated transmission line at each time step. Finally, the magnetic flux density and current density of the gas-insulated transmission line at each time step are integrated in the finite element computation domain, thereby obtaining the transient electrodynamic distribution of the gas-insulated transmission line under a given voltage excitation condition. This transient electrodynamic calculation method is characterized by its simplicity, high accuracy, and high efficiency.

[0038] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0039] Figure 1 This is a flowchart of the transient electrodynamic calculation method for gas-insulated transmission lines according to an embodiment of the present invention.

[0040] Figure 2 This is a schematic diagram of the 2D electromagnetic field-circuit coupling control model according to an embodiment of the present invention.

[0041] Figure 3 This is a schematic diagram of the physical structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0042] The following describes this embodiment in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0043] The following description, with reference to the accompanying drawings, illustrates a method for calculating transient electrodynamic forces in a gas-insulated transmission line, as well as the medium and electronic equipment described herein.

[0044] Figure 1 This is a flowchart illustrating the transient electrodynamic calculation method for gas-insulated transmission lines according to an embodiment of the present invention. Figure 1 As shown, the method includes:

[0045] Step S1: Establish a magnetic field control model and define the three-phase current excitation of the gas-insulated transmission line based on the magnetic field control model.

[0046] The steps for establishing the magnetic field control model include determining the form of the excitation source for the gas-insulated transmission line, so as to establish the magnetic field control model based on the determined excitation source form. When the excitation source is power frequency current excitation, a frequency domain magnetic field control model can be established; when the excitation source is transient voltage excitation, a time domain magnetic field control model can be established.

[0047] In this embodiment, the frequency domain magnetic field control model is expressed by the following formula:

[0048]

[0049]

[0050] in, Let μ represent the Hamiltonian operator, A represent the magnetic vector potential, ω represent the angular frequency, and σ represent the electrical conductivity. J represents the scalar potential. s This represents the source current density of the conductor in a gas-insulated transmission line.

[0051] In this embodiment, the time-domain magnetic field control model is expressed by the following formula:

[0052]

[0053]

[0054] Where I represents the phase current flowing tangentially along the axial direction of the straight conductor in the gas-insulated transmission line, S represents the cross-sectional area of ​​the conductor, and t represents time. This indicates the direction of current flow in the conductor.

[0055] Specifically, when the steady-state excitation current at a given power frequency, i.e., the given power frequency current excitation, is used, the frequency domain magnetic field control model can be solved using the finite element method to obtain the electromagnetic field distribution. Since high permeability ferromagnetic materials are not used in gas-insulated transmission lines, the eddy current field can be solved using the nodal element method, which is convenient for applying voltage sources and coupling with external circuit excitation. The frequency domain magnetic field control model or frequency domain magnetic field control equation established using this method is shown in formulas (1) and (2) above.

[0056] When the excitation is a transient voltage under short-circuit conditions, i.e., transient voltage excitation, it is necessary to solve the transient magnetic field control model in the time domain. The transient magnetic field control model is the time domain magnetic field control model as shown in formulas (3) and (4) above.

[0057] Furthermore, the three-phase current of a gas-insulated transmission line, as defined by the magnetic field control model, can be expressed by the following formula:

[0058]

[0059] Among them, I a (t), I b (t) and I c (t) represent the currents in phases a, b, and c, respectively. and S represents the scalar potential of phases a, b, and c. a S b and S c Let these represent the cross-sectional areas of the phase a guide rod, phase b guide rod, and phase c guide rod, respectively. The cross-sectional area variable represents the integration process.

[0060] Specifically, the phase current I flowing along the axial tangential direction of the straight conductor in a gas-insulated transmission line, i.e. the unknown current, can be defined by introducing an additional unknown voltage, as shown in equation (5) above.

[0061] Step S2: Establish a field-circuit coupling control model based on the three-phase current excitation, and use the magnetic vector potential variable in the magnetic field control model and the three-phase current variable of the gas-insulated transmission line as unknown variables, and establish an assembly matrix in combination with the field-circuit coupling control model.

[0062] The field-circuit coupling control model, i.e., the electromagnetic field-circuit coupling control model, is expressed by the following formula:

[0063]

[0064] Among them, u a (t), u b (t) and u c (t) represent the three-phase external voltage source excitation of the gas-insulated transmission line, R ta R tb and R tc R represents the external resistance of each phase of a gas-insulated transmission line. la R lb and R lc L represents the load resistance of each phase of the gas-insulated transmission line. ta L tb and L tc Let θ represent the external inductance of each phase of the gas-insulated transmission line, U be the effective value of the external voltage source excitation, and θ be the phase delay.

[0065] Specifically, the external power supply excitation, transmission line impedance, load impedance, and other system parameters of the gas-insulated transmission line will all affect the current in the conductive region, and the current in the conductor determines the transient electrodynamic force in the conductor and the shell. It should be noted that the field-circuit coupling control model in this embodiment is a 2D simulation model. However, in the 2D simulation process, it is necessary to introduce voltage degrees of freedom for each phase conductor of the gas-insulated transmission line. In order to make the field-circuit coupling control model uniquely solvable, the voltage balance equation of each phase conductor needs to be solved simultaneously. Since the voltage source, transmission line impedance, and load impedance form the first loop, the magnetic field degree of freedom and the circuit degree of freedom are coupled in the conductor port, so the field-circuit coupling control model composed of the voltage balance equation of each phase conductor is as shown in the above equation (6).

[0066] The circuit structure corresponding to the 2D field-path coupling control model in this embodiment is as follows: Figure 2 As shown. Where, u a u b and u c To L ta L tb and L tc The circuit is the external circuit section, R s1n+1 L s1n+1 R s2n+1 L s2n+1 R sgn+1 and L sgn+1 These are the grounding resistance and grounding inductance of each corresponding conductor or rod in a gas-insulated transmission line.

[0067] In this embodiment, the geometric model and quantity of the magnetic field region in the field-circuit coupling model can be determined according to the geometric structure, number of standard sections and equipment length of the gas-insulated transmission line. Then, the external circuit power supply excitation, transmission line impedance (such as external impedance and external inductive reactance), load impedance and other system parameters are determined simultaneously. The 2D field-circuit coupling control model is then established according to the determined geometric model and quantity and system parameters. The corresponding field-circuit coupling control equation is shown in the above equation (6).

[0068] Furthermore, the magnetic vector potential variable in the magnetic field control model and the three-phase current variable of the gas-insulated transmission line can be taken as unknown variables. Combined with the field-circuit coupling control model, a spatial discretization equation, i.e., an assembly matrix, for the transient electromagnetic field and external circuit variables can be established. The assembly matrix is ​​expressed by the following formula:

[0069]

[0070] Among them, T, M and N T Let M and N represent the stiffness matrix, K represent the load matrix for conducting current, R represent the resistance matrix of the external circuit, L represent the inductance matrix of the external circuit, U represent the port voltage matrix of the external circuit, and M and N represent the resistance matrix of the external circuit. T It depends on the geometry and material properties of the conductors in the circuit.

[0071] Step S3: Solve the assembly matrix to obtain the magnetic flux density and current density of the gas-insulated transmission line, and integrate the magnetic flux density and current density in the finite element calculation domain to obtain the transient electrodynamic force of the gas-insulated transmission line.

[0072] In this embodiment, the steps of solving the assembly matrix to obtain the magnetic flux density and current density of the gas-insulated transmission line include determining the simulation duration and simulation step size of the magnetic field control model, and solving the assembly matrix at each time step to obtain the magnetic flux density and current density at each time step. The magnetic field control model is a transient magnetic field control model, i.e., a time domain magnetic field control model.

[0073] In this embodiment, the simulation duration can be determined based on the short-circuit fault type and duration of the gas-insulated transmission line. For example, the duration of three power frequency cycles, such as 60ms, can be selected as the simulation duration. Simulation experience shows that selecting a simulation step size of 1% of the power frequency cycles, such as 0.2ms, provides sufficient accuracy for tracking transient voltage and current trajectories.

[0074] Furthermore, the magnetic flux density and current density flowing through the conductive region of the gas-insulated transmission line can be integrated in the finite element calculation domain to obtain the transient electrodynamic force of the gas-insulated transmission line, which is expressed by the following formula:

[0075] F=∫S J×BdS (8)

[0076] Where F represents the transient electrodynamic force of the conductor and shell during a short-circuit fault in a gas-insulated transmission line, J represents the current density, and B represents the magnetic flux density.

[0077] It should be noted that this method for calculating the transient electrodynamics of gas-insulated transmission lines can also obtain the induced voltage of the gas-insulated transmission line under a given voltage excitation condition, i.e., the aforementioned scalar potential.

[0078] Furthermore, the present invention also provides a method for verifying the correctness and feasibility of the 2D field-path coupling model.

[0079] To verify the correctness and feasibility of the 2D field-circuit coupling model, this invention compares the eddy current field solution results of the 3D model of a gas-insulated transmission line with two standard sections with the eddy current field solution results of the corresponding 2D field-circuit coupling model.

[0080] First, ensure that the dimensions of the guide rod and the shell in the 2D field-path coupling model are consistent with the dimensions of the 3D geometric model, including the outer diameter and thickness of the guide rod and the outer diameter and thickness of the shell. Specifically, the outer diameter of the guide rod is 120mm and the thickness is 15mm, and the outer diameter of the shell is 321.6mm and the thickness is 8mm.

[0081] Secondly, the excitation sources of the 3D geometric model and the 2D field-circuit coupling model are kept consistent, and the line materials and shorting block parameters are the same. In this embodiment, the excitation source of both the 3D geometric model and the 2D field-circuit coupling model is a voltage with an effective value of 220kV. The length of the conductor rod and the shell is 4.32 meters, both made of aluminum alloy. Table 1 shows the impedance values ​​of the shorting block, which are obtained by solving the eddy current field. The impedance values ​​of the external transmission line and the load are shown in Table 1.

[0082] Table 1 Impedance Parameters of Circuit Section

[0083] part Resistance (Ω) Inductance (H) Shorting pin <![CDATA[2.66×10 -6 ]]> <![CDATA[1.85×10 -9 ]]> power transmission lines <![CDATA[1×10 -6 ]]> <![CDATA[1×10 -9 ]]> load 55 0

[0084] Then, the magnetic flux density distribution of the three axial sections is obtained from the solution results of the eddy current field of the 3D geometric model. The highest value is compared with the highest value of the magnetic flux density of the field-circuit coupling model. At the same time, the magnetic flux density distribution of the axial direction of the 3D model is examined to verify whether the electromagnetic field distribution has good uniformity.

[0085] In this embodiment, the magnetic flux density distribution of the three axial sections was obtained from the solution results of the eddy current field of the 3D geometric model. The highest value of the a-phase was 19.07 mT, and the highest magnetic flux density of the 2D field-circuit coupling model was 18.93 mT, with a maximum deviation of 0.73%. In addition, the axial magnetic flux density distribution of the 2D field-circuit coupling model and the 3D geometric model is basically consistent, that is, the electromagnetic field distribution has good uniformity.

[0086] Furthermore, it is possible to extract whether the magnetic flux density along the axial direction of the 3D geometric model remains stable on the straight line 2mm inside (Bein) and outside (Beout) of the outer surface of the shell, and to extract the current in the shell and the conductor current, and compare their magnitude and direction.

[0087] Experiments show that the magnetic flux density remains stable along the axial direction on a straight line 2 mm from the inner (Bein) and outer (Beout) sides of the outer surface of the 3D geometric model shell, except for a spike at the flange location. The three-phase shell current values ​​of a, b, and c are (-3.968, 2.189, 1.779) kA, which are basically consistent with the three-phase currents in the conductor rod (-3.999, 1.999, 1.999) kA, proving that the flow direction of the induced current in the shell is opposite to the flow direction of the current in the corresponding conductor rod. However, due to the influence of the shorting bar, the magnitude of the current in each phase of the shell is not completely equal to the current in the conductor rod.

[0088] Furthermore, the measured shell potential value at the experimental site can be compared with the shell induced voltage value obtained from the post-processing of the solution results from the field-circuit coupling model, in order to further verify the feasibility of using the field-circuit coupling model to calculate magnetic induction intensity and induced voltage.

[0089] Furthermore, the computational efficiency of solving 3D geometric models and 2D field-circuit coupling models under the same computer configuration can be examined to verify whether the field-circuit coupling method can greatly save computational resources and time, thereby facilitating the rapid optimization design of gas-insulated transmission lines.

[0090] Regarding computational efficiency, the computer configuration used was as follows: CPU: Intel Core i5-9500 processor, RAM: 64GB. Solving the eddy current field of a 3D geometric model with approximately 832,000 meshes required 53.28 minutes of computation time, while solving the 2D field-circuit coupled model only took 15 seconds. The results show that the field-circuit coupled method can significantly save computational resources and time, which is beneficial for the rapid optimization design of gas-insulated transmission lines.

[0091] Therefore, based on the large aspect ratio structure characteristics of gas-insulated transmission lines, a 2D electromagnetic field-circuit coupling model is established. Compared with 3D simulation and equivalent circuit methods, the 2D field-circuit coupling method is feasible for calculating the induced voltage and electrodynamic force of long-distance gas-insulated transmission lines, while ensuring high calculation accuracy and efficiency, and can be better applied to engineering practice.

[0092] In summary, this invention determines the magnetic field control model based on the excitation source form of the gas-insulated transmission line, then defines the three-phase current excitation of the gas-insulated transmission line based on the determined magnetic field control model, and establishes an electromagnetic field-circuit coupled control model based on the defined three-phase current excitation. Using the magnetic vector potential variable and the three-phase current variable of the gas-insulated transmission line in the magnetic field control model as unknown variables, an assembly matrix is ​​established in conjunction with the field-circuit coupled control model. The simulation duration and simulation step size of the magnetic field control model are then determined, and the assembly matrix is ​​solved at each time step to obtain the magnetic flux density and current density of the gas-insulated transmission line at each time step. Finally, the magnetic flux density and current density of the gas-insulated transmission line at each time step are integrated in the finite element computational domain, thereby obtaining the transient electrodynamic distribution of the gas-insulated transmission line under a given voltage excitation condition. This transient electrodynamic calculation method is characterized by its simplicity, high accuracy, and high efficiency.

[0093] Furthermore, a second aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, can realize the above-described method for calculating transient electrodynamic forces of gas-insulated transmission lines.

[0094] Figure 3 An example is a schematic diagram of the physical structure of an electronic device. For example... Figure 3 As shown, the electronic device may include a processor 210, a communication interface 220, a memory 230, and a communication bus 240, wherein the processor 210, the communication interface 220, and the memory 230 communicate with each other via the communication bus 240. The processor 210 can call logic instructions in the memory 230 to execute the aforementioned transient electrodynamic calculation method for gas-insulated transmission lines.

[0095] Furthermore, the logical instructions in the aforementioned memory 230 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0096] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0097] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions 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 invention.

Claims

1. A method for calculating transient electrodynamic forces in a gas-insulated transmission line, characterized in that, include: Step S1: Establish a magnetic field control model and define the three-phase current excitation of the gas-insulated transmission line according to the magnetic field control model; Step S2: Establish a field-circuit coupling control model based on the three-phase current excitation, and use the magnetic vector potential variable in the magnetic field control model and the three-phase current variable of the gas-insulated transmission line as unknown variables, and establish an assembly matrix in combination with the field-circuit coupling control model; Step S3: Solve the assembly matrix to obtain the magnetic flux density and current density of the gas-insulated transmission line, and integrate the magnetic flux density and current density in the finite element calculation domain to obtain the transient electrodynamic force of the gas-insulated transmission line; In step S1, the step of establishing the magnetic field control model includes: determining the form of the excitation source of the gas-insulated transmission line so as to establish the magnetic field control model based on the determined form of the excitation source; When the excitation source is power frequency current excitation, a frequency domain magnetic field control model is established; when the excitation source is transient voltage excitation, a time domain magnetic field control model is established; wherein, The frequency domain magnetic field control model is expressed by the following formula: in, Represents the Hamiltonian operator. Indicates magnetic permeability, Represents the magnetic vector potential. Represents angular frequency. Indicates electrical conductivity. Represents scalar potential. This represents the source current density of the conductor rod in a gas-insulated transmission line; The time-domain magnetic field control model is expressed by the following formula: in, This refers to the phase current flowing tangentially along the axial direction of the straight conductor in a gas-insulated transmission line. Indicates the cross-sectional area of ​​the guide rod. t Indicates time, Indicates the direction of current flow in the conductor; The three-phase current of the gas-insulated transmission line is expressed by the following formula: in, , and These represent the currents in phases a, b, and c, respectively. , and Represents the scalar potentials of phases a, b, and c. , and They represent a Phase guide rod cross-sectional area, b Phase guide rod cross-sectional area, c Phase guide cross-sectional area, The cross-sectional area variable represents the integration process; The field-circuit coupling control model is expressed by the following formula: in, , and These represent the three-phase external voltage source excitation of the gas-insulated transmission line. , and These represent the external resistances of each phase of a gas-insulated transmission line. , and These represent the load resistances of each phase of a gas-insulated transmission line. , and These represent the external inductance of each phase of a gas-insulated transmission line. This is the effective value of the external voltage source excitation. For delayed phase; The assembly matrix is ​​represented by the following formula: in, , and Represents the stiffness matrix. The load matrix representing the conduction current. Represents the resistance matrix of the external circuit. Represents the inductance matrix of the external circuit. This represents the port voltage matrix of the external circuit.

2. The method for calculating transient electrodynamic forces of gas-insulated transmission lines as described in claim 1, characterized in that, In step S3, the step of solving the assembly matrix to obtain the magnetic flux density and current density of the gas-insulated transmission line includes: The simulation duration and simulation step size of the magnetic field control model are determined, and at each time step, the assembly matrix is ​​solved to obtain the magnetic flux density and current density at each time step. The simulation duration is determined based on the short-circuit fault type and fault duration of the gas-insulated transmission line.

3. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the transient electrodynamic calculation method for gas-insulated transmission lines as described in any one of claims 1-2.

4. An electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the transient electrodynamic calculation method for gas-insulated transmission lines as described in any one of claims 1-2.

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