Lightning arrester transient electrothermal response characteristic solving method, system, medium and equipment

Abstract

The invention discloses a lightning arrester transient electrothermal response characteristic solving method, system, medium and equipment, and the method comprises the steps: building a finite element equivalent model of a lightning arrester according to the size of the lightning arrester, and solving the stray capacitance Cij of each resistor disc in the lightning arrester through the simulation of an electrostatic module; building a lightning arrester equivalent loop in electromagnetic transient simulation software, applying lightning arrester action voltage recording U0 (t) to the lightning arrester equivalent loop, and calculating lightning arrester through-current I (t); judging whether the similarity S0 between the lightning arrester through-current I (t) and the actually measured recording data I0 (t) meets s0gt or not; s1; calculating internal electric field distribution and thermal field distribution, and outputting an overall energy curve Q (t) of the lightning arrester; and judging whether heat source input and heat loss in simulation meet an energy balance equation or not, and if an energy error is within a threshold range, outputting internal electric field distribution and temperature rise distribution of the lightning arrester.

Description

Technical Field

[0001] The present invention relates to the technical field of lightning arrester monitoring, and in particular to a method, system, medium and equipment for solving transient electrothermal response characteristics of a lightning arrester. Background Art

[0002] Lightning arresters are critical components in power systems used to limit overvoltage and protect electrical equipment. They withstand strong surge currents under transient conditions such as lightning strikes and switching overvoltages, dissipating the overvoltage energy through nonlinear resistors to protect the system. However, the electrothermal characteristics of lightning arresters under transient surges are very complex, making it difficult to accurately analyze their internal electric field distribution, temperature rise effects, and internal losses using a single simulation method.

[0003] Currently, electromagnetic transient simulation software (such as ATP-EMTP) is widely used to calculate the current flow response and electrical performance of lightning arresters under transient overvoltages. However, this type of simulation method is based on an equivalent circuit model and cannot accurately describe the electric field distortion, local power loss, and heat conduction process within the lightning arrester, thus failing to meet the needs of internal state monitoring and optimization design of the lightning arrester. On the other hand, the finite element analysis method (FEM) has high accuracy in calculating electric field distribution and thermal fields, but the direct solution of the lightning arrester transient response is computationally intensive and difficult to handle the complex electromagnetic-thermal multi-physics field coupling problem. In addition, due to the complex structure of the multi-column parallel structure lightning arrester, the stray parameters of the internal resistors have a significant impact on the electric field and thermal distribution, further increasing the difficulty of simulation.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the Invention

[0005] The present invention provides a method, system, medium, and device for solving the transient electrothermal response characteristics of a lightning arrester. This method uses electromagnetic transient simulation to obtain the arrester's current flow response and incorporates its voltage, current, and power loss information into a finite element model to more accurately solve the arrester's transient electric and thermal field distributions, thereby enabling precise analysis of the arrester's internal electrothermal response characteristics. This method improves simulation efficiency while ensuring computational accuracy, avoiding the excessive computational effort required when directly solving transient problems using finite element methods.

[0006] A method for solving transient electrothermal response characteristics of a lightning arrester includes:

[0007] Step 1: Build a finite element equivalent model of the arrester according to its size, and solve the stray capacitance C of each resistor inside the arrester through electrostatic simulation. ij ;

[0008] Step 2: Build an arrester equivalent circuit in the electromagnetic transient simulation software, apply the arrester action voltage U0(t) to the arrester equivalent circuit, and calculate the arrester current I(t);

[0009] Step 3: Determine whether the similarity s0 between the arrester current I(t) and the measured waveform data I0(t) satisfies s0>s1. If so, output the potentials of each resistor inside the arrester u1(t), u2(t)...u n (t) and power loss P1(t), P2(t)...P n (t); if not, return to step 2 and debug the arrester equivalent circuit in the electromagnetic transient simulation software and recalculate the arrester current I(t) until s0>s1 is satisfied;

[0010] Step 4: Define the potentials of each resistor inside the arrester u1(t), u2(t)...u in the finite element equivalent model. n (t) and power loss P1(t), P2(t)...P n (t), calculate its internal electric field distribution and thermal field distribution, and output the arrester overall energy curve Q(t);

[0011] Step 5: Determine whether the heat source input and heat loss in the simulation satisfy the energy balance equation. If the energy error is within the threshold range, output the electric field distribution and temperature rise distribution inside the arrester. If the energy error exceeds the threshold range, return to step 1 to adjust the mesh division of the finite element equivalent model, update its boundary conditions, and then execute steps 1 to 5 until the energy error is within the threshold range, and output the electric field distribution and temperature rise distribution inside the arrester.

[0012] In the method for solving the transient electrothermal response characteristics of a lightning arrester, the stray capacitance C of each resistor inside the lightning arrester is solved by electrostatic module simulation. ij include,

[0013] Based on electrostatics theory, a mutual capacitance calculation model is established in finite element software. Its basic control equations satisfy Gauss's law, the relationship between electric field and electric potential, and the law of conservation of charge:

[0014] (1)

[0015] (2)

[0016] Where, is the electric potential; D is the displacement vector of the electrons on the resistor; n is the normal vector on the resistor surface; ρ is the volume free charge density; Q is the total charge stored in the arrester; C is the capacitance value of the arrester; V is the potential difference between the two ends of the arrester; Q i is the total charge of the i-th resistor; C ijV represents the mutual capacitance between the i-th resistor and the j-th resistor, that is, the stray capacitance; j is the potential of the jth resistor, ε0 is the dielectric constant of vacuum, ε ro is the relative dielectric constant of the resistor. Without considering the free charge accumulation inside the material, ρ=0. The simultaneous equations are solved to obtain the mutual capacitance and self-capacitance between the resistors inside the arrester, and the stray capacitance matrix is ​​obtained.

[0017] In the method for solving the transient electrothermal response characteristics of a lightning arrester, the electric field distribution is (3)

[0018] Where ε0 is the dielectric constant of vacuum; ε ro is the relative dielectric constant of the resistor; E is the electric field intensity in space; is the electric potential; J is the total current density in the arrester; σ is the conductivity of the resistor.

[0019] In the method for solving the transient electrothermal response characteristics of a lightning arrester, the control equation of the solid heat transfer module of the thermal field distribution is:

[0020] (4)

[0021] Where t is time; ρ T C is the density of the internal material of the arrester at temperature T; p is the constant pressure specific heat capacity of the internal material of the arrester; T Q is the thermal conductivity of the internal material of the arrester at temperature T; E is a Joule heat source. The first term on the left side of the equal sign represents the change of temperature with time, and the second term represents the heat conduction inside the material. The Joule heat source on the right side of the equal sign is:

[0022] (5)

[0023] Where, P E is the heat consumption rate of the resistor, and the temperature field equation is:

[0024] (6)

[0025] Where θ(x,y,z) is the distribution function of the initial temperature of the object; β f is the convection heat transfer coefficient of the solid to the cooling fluid on the third type boundary surface S3; v is the emissivity of the arrester resistor surface; T ∞ is the ambient temperature; a represents the normal vector of the boundary surface. The simultaneous equations (4), (5) and (6) describe the spatial distribution of heat during the heat conduction process and the dynamic process of its change with time, thereby realizing the simulation of the thermal field distribution under the action of transient overvoltage.

[0026] In the method for solving the transient electrothermal response characteristics of a lightning arrester, after the lightning arrester absorbs transient energy, the resistor generates heat, which is dissipated axially by heat conduction through the upper and lower flanges, and radially mainly by the filling gas to the inner surface of the shell.

[0027] In the method for solving the transient electrothermal response characteristics of a lightning arrester, the heat in the lightning arrester casing is transferred by heat conduction, and the outer surface of the jacket and flange dissipates heat to the external air by heat convection and heat radiation, and finally dissipates into the external atmosphere.

[0028] In the method for solving the transient electrothermal response characteristics of a lightning arrester, the lightning arrester is a multi-column core parallel structure lightning arrester.

[0029] An identification system for implementing the method includes:

[0030] Finite element unit, which is used to build its finite element equivalent model according to the size of the arrester, and solve the stray capacitance C of each resistor inside the arrester through electrostatic module simulation ij ;

[0031] Electromagnetic transient simulation software, which is used to build an arrester equivalent circuit in the electromagnetic transient simulation software, apply the arrester action voltage U0(t) to the arrester equivalent circuit, and calculate the arrester current I(t);

[0032] The similarity unit is used to determine whether the similarity s0 between the arrester current I(t) and the measured waveform data I0(t) satisfies s0>s1. If so, the potentials of the resistors inside the arrester u1(t), u2(t)...u n (t) and power loss P1(t), P2(t)...P n (t); If not, debug the arrester equivalent circuit in the electromagnetic transient simulation software and recalculate the arrester current I(t) until s0>s1 is satisfied;

[0033] Calculation unit, which is used to define the potential of each resistor inside the arrester u1(t),u2(t)...u in the finite element equivalent model n (t) and power loss P1(t), P2(t)...P n (t), calculate its internal electric field distribution and thermal field distribution, and output the arrester overall energy curve Q(t);

[0034] The judgment unit is used to judge whether the heat source input and heat loss in the simulation satisfy the energy balance equation. If the energy error is within the threshold range, the electric field distribution and temperature rise distribution inside the lightning arrester are output; if the energy error exceeds the threshold range, return to step 1 to adjust the mesh division of the finite element equivalent model, update its boundary conditions and rerun until the energy error is within the threshold range, and output the electric field distribution and temperature rise distribution inside the lightning arrester.

[0035] A computer storage medium includes computer instructions, which, when executed on a computer, cause the computer to execute the method described above.

[0036] An electronic device, comprising:

[0037] A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein:

[0038] When the processor executes the program, the method described is implemented.

[0039] Compared with the existing technology, the present invention has the following advantages: the present invention obtains the arrester current, potential distribution and power loss through electromagnetic transient simulation, and introduces it into finite element simulation to accurately solve the problems of electric field distortion and local overheating inside the arrester, providing data support for optimizing the arrester structure. On the other hand, the energy balance equation is used to verify the simulation results to ensure the calculation accuracy and reduce the problems of large calculation amount and poor convergence of traditional finite element methods. This method is suitable for the optimization design, insulation improvement and fault diagnosis of arresters, can improve the reliability of arresters under transient impact conditions, provide technical support for ultra-high / ultra-high voltage transmission systems, and has broad engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Various other advantages and benefits of the present invention will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are intended only to illustrate preferred embodiments and are not to be construed as limiting the present invention. It should be understood that the drawings described below are merely examples of the present invention, and that those skilled in the art will be able to derive other drawings from these drawings without inventive effort. Throughout the drawings, identical reference numerals are used to denote identical components.

[0041] In the attached figure:

[0042] Figure 1 is a flow chart of the method of the present invention;

[0043] Figure 2 It is a schematic diagram of the electromagnetic transient-circuit equivalent model of the lightning arrester;

[0044] Figure 3 It is a schematic diagram of transient overvoltage waveform recording;

[0045] Figure 4 This is a schematic diagram of the simulation results using the method for solving the transient electrothermal response characteristics of the arrester based on electromagnetic transient and finite element analysis in the method of the present invention. Figure 4 (a) is a schematic diagram of the electric field distribution. Figure 4 (b) is a schematic diagram of temperature rise distribution.

[0046] The present invention will be further explained below with reference to the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0047] Specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although specific embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0048] It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. This specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of the components as the criterion for distinction. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, so it should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the invention. The scope of protection of the present invention shall be as defined in the attached claims.

[0049] To facilitate understanding of the embodiments of the present invention, further explanation will be given below using specific embodiments as examples in conjunction with the accompanying drawings, and the accompanying drawings do not constitute a limitation on the embodiments of the present invention.

[0050] like Figures 1 to 4 As shown in Figure 2, the method for solving the transient electrothermal response characteristics of the arrester includes the following steps:

[0051] Step 1: Build a finite element equivalent model of the arrester according to its size, and solve the stray capacitance C of each resistor inside the arrester through electrostatic simulation. ij ;

[0052] Step 2: Build an arrester equivalent circuit in the electromagnetic transient simulation software, apply the arrester action voltage U0(t) to the arrester equivalent circuit, and calculate the arrester current I(t);

[0053] Step 3: Determine whether the similarity s0 between the arrester current I(t) and the measured waveform data I0(t) satisfies s0>s1. If so, output the potentials of each resistor inside the arrester u1(t), u2(t)...u n (t) and power loss P1(t), P2(t)...P n (t); if not, return to step 2 and debug the equivalent circuit of the lightning arrester in the electromagnetic transient simulation software and recalculate the lightning arrester current I(t) until s0>s1 is satisfied; further, pressurize the lightning arrester and measure the current data obtained under the action of the corresponding voltage to obtain the measured recorded data I0(t).

[0054] Step 4: Define the potentials of each resistor inside the arrester u1(t), u2(t)...u in the finite element equivalent model. n (t) and power loss P1(t), P2(t)...P n (t), calculate its internal electric field distribution and thermal field distribution, and output the arrester overall energy curve Q(t);

[0055] In step 5, determine whether the heat source input and heat loss in the simulation satisfy the energy balance equation. If the energy error is within the threshold range of 2%, output the internal electric field distribution and temperature rise distribution of the lightning arrester; if the energy error exceeds the threshold range, return to step 1 to adjust the mesh division of the finite element equivalent model, update its boundary conditions, and then execute steps 1 to 5 until the energy error is within the threshold range, and output the internal electric field distribution and temperature rise distribution of the lightning arrester.

[0056] In a preferred embodiment of the method for solving the transient electrothermal response characteristics of a lightning arrester, the stray capacitance C of each resistor in the lightning arrester is solved by electrostatic module simulation. ij include,

[0057] Based on electrostatics theory, a mutual capacitance calculation model is established in finite element software. Its basic control equations satisfy Gauss's law, the relationship between electric field and electric potential, and the law of conservation of charge:

[0058] (1)

[0059] (2)

[0060] Where D is the displacement vector of the electrons on the resistor; n is the normal vector on the resistor surface; ρ is the volume free charge density; Q is the total charge stored in the arrester; C is the capacitance of the arrester; V is the potential difference between the two ends of the arrester; Q i is the total charge of the i-th resistor; C ij V represents the mutual capacitance between the i-th resistor and the j-th resistor, that is, the stray capacitance; jis the potential of the jth resistor, ε0 is the dielectric constant of vacuum, ε ro is the relative dielectric constant of the resistor. Without considering the accumulation of free charge inside the material, ρ=0. The simultaneous equations are used to solve the mutual capacitance and self-capacitance between the resistors inside the arrester to obtain the corresponding capacitance matrix.

[0061] In a preferred embodiment of the method for solving the transient electrothermal response characteristics of a lightning arrester, the electric field distribution is (3)

[0062] Where ε0 is the dielectric constant of vacuum; ε ro is the relative dielectric constant of the resistor; E is the electric field intensity in space; is the electric potential; J is the total current density in the arrester; σ is the conductivity of the resistor.

[0063] In a preferred embodiment of the method for solving the transient electrothermal response characteristics of a lightning arrester, the control equation of the solid heat transfer module of the thermal field distribution is:

[0064] (4)

[0065] Where t is time; ρ T C is the density of the internal material of the arrester at temperature T; p is the constant pressure specific heat capacity of the internal material of the arrester; T Q is the thermal conductivity of the internal material of the arrester at temperature T; E is a Joule heat source. The first term on the left side of the equal sign represents the change of temperature with time, and the second term represents the heat conduction inside the material. The Joule heat source on the right side of the equal sign is:

[0066] (5)

[0067] Where, P E is the heat consumption rate of the resistor, and the temperature field equation is:

[0068] (6)

[0069] Where θ(x,y,z) is the distribution function of the initial temperature of the object; β f is the convection heat transfer coefficient of the solid to the cooling fluid on the third type boundary surface S3; v is the emissivity of the arrester resistor surface; T ∞ is the ambient temperature; a represents the normal vector of the boundary surface. The simultaneous equations (4), (5) and (6) describe the spatial distribution of heat during the heat conduction process and the dynamic process of its change with time, thereby realizing the simulation of the thermal field distribution under the action of transient overvoltage.

[0070] In a preferred embodiment of the method for solving the transient electrothermal response characteristics of a lightning arrester, after the lightning arrester absorbs transient energy, the resistor plate generates heat, which is dissipated axially by heat conduction through the upper and lower flanges, and radially mainly by filling gas to the inner surface of the shell.

[0071] In a preferred embodiment of the method for solving the transient electrothermal response characteristics of a lightning arrester, the heat in the lightning arrester housing is transferred by heat conduction, and the outer surface of the jacket and flange dissipates heat to the external air by heat convection and heat radiation, and finally dissipates into the external atmosphere.

[0072] In a preferred embodiment of the method for solving the transient electrothermal response characteristics of a lightning arrester, the lightning arrester is a multi-column core parallel structure lightning arrester.

[0073] An identification system for implementing the method includes:

[0074] Finite element unit, which is used to build its finite element equivalent model according to the size of the arrester, and solve the stray capacitance C of each resistor inside the arrester through electrostatic module simulation ij ;

[0075] Electromagnetic transient simulation software, which is used to build an arrester equivalent circuit in the electromagnetic transient simulation software, apply the arrester action voltage U0(t) to the arrester equivalent circuit, and calculate the arrester current I(t);

[0076] The similarity unit is used to determine whether the similarity s0 between the arrester current I(t) and the measured waveform data I0(t) satisfies s0>s1. If so, the potentials of the resistors inside the arrester u1(t), u2(t)...u n (t) and power loss P1(t), P2(t)...P n (t); If not, debug the arrester equivalent circuit in the electromagnetic transient simulation software and recalculate the arrester current I(t) until s0>s1 is satisfied;

[0077] Calculation unit, which is used to define the potential of each resistor inside the arrester u1(t),u2(t)...u in the finite element equivalent model n (t) and power loss P1(t), P2(t)...P n (t), calculate its internal electric field distribution and thermal field distribution, and output the arrester overall energy curve Q(t);

[0078] The judgment unit is used to judge whether the heat source input and heat loss in the simulation satisfy the energy balance equation. If the energy error is within the threshold range, the electric field distribution and temperature rise distribution inside the lightning arrester are output; if the energy error exceeds the threshold range, return to step 1 to adjust the mesh division of the finite element equivalent model, update its boundary conditions and rerun until the energy error is within the threshold range, and output the electric field distribution and temperature rise distribution inside the lightning arrester.

[0079] A computer storage medium includes computer instructions, which, when executed on a computer, cause the computer to execute the method described above.

[0080] An electronic device, comprising:

[0081] A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein:

[0082] When the processor executes the program, the method described is implemented.

[0083] In one embodiment, the threshold range is 2%.

[0084] In one embodiment, the method includes,

[0085] Step 1: Build a finite element equivalent model of the arrester based on its size, and solve the stray capacitance of each resistor inside the arrester through electrostatic simulation;

[0086] Step 2: Build an arrester equivalent circuit in the electromagnetic transient simulation software, apply the arrester action voltage U0(t) to the arrester equivalent circuit, and calculate the arrester current I(t);

[0087] Step 3: determine whether the similarity s0 between the arrester current I(t) and the measured recorded data I0(t) satisfies s0>s1. If so, proceed to step 4; otherwise, return to step 2.

[0088] Step 4: Define the potential and power loss of each resistor in the arrester in the finite element equivalent model, calculate its internal electric field distribution and thermal field distribution, and output the overall energy curve Q(t) of the arrester;

[0089] Step 5: Determine whether the heat source input and heat loss in the simulation satisfy the energy balance equation. If the energy error is within the threshold range of 2%, proceed to step 6; otherwise, return to step 1.

[0090] Step 6: Output the electric field distribution and temperature rise distribution inside the arrester.

[0091] Example

[0092] The feasibility of this solution is illustrated by taking the internal electric field distribution and temperature rise of an EM arrester in a ±800kV converter station under a typical transient overvoltage shock as an example. In this embodiment, the arrester equivalent circuit model is as follows: Figure 2 As shown, Figure 2 The equivalent circuit of the EM lightning arrester is built using electromagnetic transient simulation software. The nonlinear resistance setting is based on the actual parameters of the lightning arrester, the stray capacitance setting is calculated by finite element software simulation, and the power supply is set to a programmable power supply.

[0093] Transient overvoltage waveform is as follows Figure 3 As shown, Figure 3 The waveform recording of the typical operating voltage of a lightning arrester applied to a circuit using a programmable power supply shows that the negative overvoltage process of the impulse voltage lasts about 20ms, with a peak value of 385.58kV; the positive overvoltage process lasts about 30ms, with a peak value of 382.42kV, and a wave head time of 5ms. Under the transient overvoltage impact, the maximum electric field strength of the internal resistor of the lightning arrester occurs at the peak of the transient overvoltage impact, and the peak voltage is 385.58kV. Based on the same inventive concept, the embodiment of the present invention also provides a lightning arrester internal electric field and temperature rise state detection module, including:

[0094] Electric field strength detection module: determines that the corresponding electric field strength at the maximum electric field strength point inside the lightning arrester exceeds its critical value, and then issues an alarm;

[0095] Arrester internal temperature rise detection module: determines the temperature rise status of each part of the arrester under the current flow state. If the temperature rise is too high, an alarm will be issued;

[0096] The calculation results of the internal electric field distribution and temperature rise distribution of a multi-column parallel structure arrester under rated working conditions are as follows: Figure 4 shown. Figure 4 (a) shows the internal electric field distribution of the arrester under the transient overvoltage peak of 385.58 kV. The average electric field strength of the internal resistor is 257.15 kV / m, and the maximum electric field occurs at the edge of the top resistor, where the maximum electric field is 342.24 kV / m. Figure 4 (b) is the final temperature rise distribution of the arrester under the action of the transient voltage wave. The highest temperature rise inside the arrester appears in the middle area of ​​the resistor, reaching 14.27°C. Figure 4 It can be seen that the accuracy of solving the internal electric field distribution and temperature rise distribution of the lightning arrester under the action of transient overvoltage can reach 100%. Therefore, the identification method of the present invention can effectively identify the internal electric field distribution and temperature rise distribution of the lightning arrester under the action of transient voltage impulse, which is of great significance for its structural optimization and fault warning.

[0097] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk drives, CD-ROMs, optical storage devices, etc.) containing computer-usable program code. The solutions in the embodiments of the present invention may be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0098] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0099] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0100] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0101] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments and application fields. The above-mentioned specific embodiments are merely illustrative and instructive, and are not restrictive. A person skilled in the art, guided by this specification and without departing from the scope of protection of the claims of the present invention, may also devise various forms, all of which fall within the scope of protection of the present invention.

Claims

1. A method for solving the transient electrothermal response characteristics of a lightning arrester, characterized in that: The steps include: Step 1: Build a finite element equivalent model of the arrester according to its size, and solve the stray capacitance C of each resistor inside the arrester through electrostatic simulation. ij ; Step 2: Build an arrester equivalent circuit in the electromagnetic transient simulation software, apply the arrester action voltage U0(t) to the arrester equivalent circuit, and calculate the arrester current I(t); Step 3: Determine whether the similarity s0 between the arrester current I(t) and the measured waveform data I0(t) satisfies s0>s1. If so, output the potentials of each resistor inside the arrester u1(t), u2(t)...u n (t) and power loss P1(t), P2(t)...P n (t); if not, return to step 2 and debug the arrester equivalent circuit in the electromagnetic transient simulation software and recalculate the arrester current I(t) until s0>s1 is satisfied; Step 4: Define the potentials of each resistor inside the arrester u1(t), u2(t)...u in the finite element equivalent model. n (t) and power loss P1(t), P2(t)...P n (t), calculate its internal electric field distribution and thermal field distribution, and output the arrester overall energy curve Q(t); Step 5: Determine whether the heat source input and heat loss in the simulation satisfy the energy balance equation. If the energy error is within the threshold range, output the electric field distribution and temperature rise distribution inside the arrester. If the energy error exceeds the threshold range, return to step 1 to adjust the mesh division of the finite element equivalent model, update its boundary conditions, and then execute steps 1 to 5 until the energy error is within the threshold range, and output the electric field distribution and temperature rise distribution inside the lightning arrester.

2. A method for solving transient electrothermal response characteristics of a lightning arrester according to claim 1, characterized in that: Preferably, the stray capacitance C of each resistor inside the arrester is solved by electrostatic module simulation ij include, Based on electrostatics theory, a mutual capacitance calculation model is established in finite element software. Its basic control equations satisfy Gauss's law, the relationship between electric field and electric potential, and the law of conservation of charge: (1)； (2)； Where, is the electric potential; D is the displacement vector of the electrons on the resistor; n is the normal vector on the resistor surface; ρ is the volume free charge density; Q is the total charge stored in the arrester; C is the capacitance value of the arrester; V is the potential difference between the two ends of the arrester; Q i is the total charge of the i-th resistor; C ij V represents the mutual capacitance between the i-th resistor and the j-th resistor, that is, the stray capacitance; j is the potential of the jth resistor, ε0 is the dielectric constant of vacuum, ε ro is the relative dielectric constant of the resistor. Without considering the free charge accumulation inside the material, ρ=0. The simultaneous equations are solved to obtain the mutual capacitance and self-capacitance between the resistors inside the arrester, and the stray capacitance matrix is ​​obtained.

3. The method for solving the transient electrothermal response characteristics of a lightning arrester according to claim 1, characterized in that: The electric field distribution is (3); Where ε0 is the dielectric constant of vacuum; ε ro is the relative dielectric constant of the resistor; E is the electric field intensity in space; is the electric potential; J is the total current density in the arrester; σ is the conductivity of the resistor.

4. The method for solving the transient electrothermal response characteristics of a lightning arrester according to claim 1, characterized in that: The governing equation of the solid heat transfer module for thermal field distribution is: (4)； Where t is time; ρ T C is the density of the internal material of the arrester at temperature T; p is the constant pressure specific heat capacity of the internal material of the arrester; T Q is the thermal conductivity of the internal material of the arrester at temperature T; E is a Joule heat source. The first term on the left side of the equal sign represents the change of temperature with time, and the second term represents the heat conduction inside the material. The Joule heat source on the right side of the equal sign is: (5)； Where, P E is the heat consumption rate of the resistor, and the temperature field equation is: (6)； Where θ(x,y,z) is the distribution function of the initial temperature of the object; β f is the convection heat transfer coefficient of the solid to the cooling fluid on the third type boundary surface S3; v is the emissivity of the arrester resistor surface; T ∞ is the ambient temperature; a represents the normal vector of the boundary surface. The simultaneous equations (4), (5) and (6) describe the spatial distribution of heat during the heat conduction process and the dynamic process of its change with time, thereby realizing the simulation of the thermal field distribution under the action of transient overvoltage.

5. A method for solving transient electrothermal response characteristics of a lightning arrester according to claim 4, characterized in that: After the arrester absorbs transient energy, the resistor plate heats up and dissipates heat through the upper and lower flanges in the axial direction by heat conduction, and mainly dissipates heat to the inner surface of the shell in the radial direction through the filling gas.

6. A method for solving transient electrothermal response characteristics of a lightning arrester according to claim 5, characterized in that: The heat in the arrester casing is transferred by heat conduction, and the outer surface of the jacket and flange dissipates heat to the external air by heat convection and heat radiation, and finally dissipates into the external atmosphere.

7. A method for solving transient electrothermal response characteristics of a lightning arrester according to claim 1, characterized in that: The arrester is a multi-column core parallel structure arrester.

8. An identification system for implementing the method according to any one of claims 1 to 7, characterized in that: It includes: Finite element unit, which is used to build its finite element equivalent model according to the size of the arrester, and solve the stray capacitance C of each resistor inside the arrester through electrostatic module simulation ij ; Electromagnetic transient simulation software, which is used to build an arrester equivalent circuit in the electromagnetic transient simulation software, apply the arrester action voltage U0(t) to the arrester equivalent circuit, and calculate the arrester current I(t); The similarity unit is used to determine whether the similarity s0 between the arrester current I(t) and the measured waveform data I0(t) satisfies s0>s1. If so, the potentials of the resistors inside the arrester u1(t), u2(t)...u n (t) and power loss P1(t), P2(t)...P n (t); If not, debug the arrester equivalent circuit in the electromagnetic transient simulation software and recalculate the arrester current I(t) until s0>s1 is satisfied; Calculation unit, which is used to define the potential of each resistor inside the arrester u1(t),u2(t)...u in the finite element equivalent model n (t) and power loss P1(t), P2(t)...P n (t), calculate its internal electric field distribution and thermal field distribution, and output the arrester overall energy curve Q(t); A judgment unit is used to judge whether the heat source input and heat loss in the simulation satisfy the energy balance equation. If the energy error is within the threshold range, the electric field distribution and temperature rise distribution inside the arrester are output; If the energy error exceeds the threshold range, return to step 1 to adjust the mesh division of the finite element equivalent model, update its boundary conditions and rerun until the energy error is within the threshold range, and output the electric field distribution and temperature rise distribution inside the lightning arrester.

9. A computer storage medium, characterized in that The storage medium includes computer instructions, which, when executed on a computer, enable the computer to perform the method according to any one of claims 1 to 7.

10. An electronic device, characterized in that: The electronic device comprises: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the method according to any one of claims 1 to 7 is implemented.

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