Temperature field distribution calculation method for high-voltage bushing under current-carrying defect and related product

Abstract

The invention relates to the technical field of high voltage and insulation, in particular to a temperature field distribution calculation method for a high-voltage bushing under a current-carrying defect and a related product, and the method comprises the steps: building a three-dimensional geometric model of the high-voltage bushing, and setting geometric parameters of the model; describing a control equation of high-voltage bushing temperature field distribution; setting boundary conditions and basic assumption of the high-voltage bushing according to the control equation; setting material parameters for the three-dimensional geometric model of the high-voltage bushing, defining a physical field, dividing grids and setting solver parameters; simulation calculation of steady-state temperature field distribution is carried out through finite element simulation calculation software, and temperature field distribution characteristics of the high-voltage bushing under the current-carrying defect are obtained; according to the method, the overall space geometric model of the high-voltage bushing is established, electromagnetic field and heat transfer field control equations are considered, corresponding physical field setting is reasonably selected, mesh generation and solver setting are carried out, and the three-dimensional temperature field distribution characteristics of the high-voltage bushing under the current-carrying defect are obtained through simulation calculation.

Description

Technical Field

[0001] The present invention relates to the field of high voltage and insulation technology, and in particular to a method for calculating the temperature field distribution of a high voltage bushing under current-carrying defects and related products. Background Art

[0002] Ultra-high voltage direct current transmission technology has become an important way to achieve cross-regional power grid interconnection, optimal resource allocation, clean energy transmission and consumption, and energy transformation in my country. The high-voltage bushing bears the role of lead insulation and mechanical support, and its good service performance is directly related to the safe and reliable operation of ultra-high voltage direct current transmission projects. However, with the substantial increase in my country's voltage level and transmission capacity, the long-term operation of high-voltage bushings under extremely complex working conditions such as high voltage, high current and strong mechanical loads can easily lead to overheating problems inside, especially in the current-carrying connection parts of the high-voltage bushings. Bushing overheating failures caused by current-carrying defects often occur, which seriously threatens the long-term service performance of the high-voltage bushings.

[0003] However, at present, domestic and foreign scholars have conducted relevant research on the thermal characteristics and temperature field of high-voltage bushings under normal operating conditions through large current tests and numerical simulations. There are fewer studies on the temperature field distribution of high-voltage bushings under current-carrying defects. Therefore, it is necessary to accurately calculate the temperature field distribution inside the high-voltage bushing under current-carrying defects and obtain the law of temperature field distribution, which is of great significance for preventing high-voltage bushing overheating failures and ensuring ultra-high voltage direct current transmission projects. Summary of the invention

[0004] The purpose of the present invention is to provide a method for calculating the temperature field distribution of a high-voltage bushing under a current-carrying defect and related products, so as to accurately obtain the internal temperature field distribution characteristics of the high-voltage bushing under a current-carrying defect.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for calculating the temperature field distribution of a high-voltage bushing under current-carrying defects, comprising:

[0007] Establish a three-dimensional geometric model of the high-voltage bushing based on the finite element method and set the geometric parameters of the model;

[0008] The governing equations describing the temperature field distribution of the high-voltage bushing, including the electromagnetic field governing equations and the heat transfer equations;

[0009] Set the boundary conditions and basic assumptions of the high-voltage bushing according to the governing equations;

[0010] Set material parameters for the 3D geometric model of the high-voltage bushing, define the physical field, divide the mesh and set the solver parameters;

[0011] The steady-state temperature field distribution is simulated and calculated by finite element simulation software to obtain the temperature field distribution characteristics of the high-voltage bushing under current-carrying defects.

[0012] Specifically, the electromagnetic field governing equations are described by Maxwell's equations as: Where, σ is the conductivity, J s is the current density, μ is the magnetic permeability, and A is the magnetic vector potential;

[0013] The heat transfer equation is described as: Among them, Q v The units of heat source are mentioned, T is temperature, and λ is thermal conductivity.

[0014] Specifically, the boundary conditions and basic assumptions of the high-voltage bushing are set according to the control equations, including:

[0015] Set the potential distribution boundary conditions of the high-voltage bushing, including reference potential and operating voltage;

[0016] Set the current boundary conditions of the high-voltage bushing, including the input value of the carrying current;

[0017] Set the thermal boundary conditions of the external environment of the high-voltage bushing, including the ambient temperature, heat transfer coefficient and thermal conductivity of the relevant area.

[0018] Optionally, boundary conditions and basic assumptions of the high voltage bushing are set according to the control equations including:

[0019] The bottom of the high-voltage bushing oil tank is set to zero reference potential, i.e. φ0 = 0;

[0020] The potential of the central conductive tube of the high-voltage bushing is set to the operating voltage, i.e. φ1 = 400 kV;

[0021] Set the current terminal of the high-voltage bushing to I0=5000A;

[0022] According to the actual operating conditions, the external air temperature of the high-voltage bushing is set to 50°C and the transformer tank temperature is set to 90°C;

[0023] Set the air heat transfer coefficient to 8 W·m -1 K -1 , and adopt convection-enhanced thermal conductivity for the air, transformer oil and SF6 gas areas inside the bushing.

[0024] Specifically, setting material parameters, defining physical fields, dividing grids and setting solution parameters for the three-dimensional geometric model of the high-voltage bushing include:

[0025] Set material properties for each region of the high-voltage bushing model, including electromagnetic parameters and thermophysical parameters;

[0026] Define multi-physics computational interfaces, including the coupling relationship between electromagnetic fields and heat transfer fields;

[0027] Mesh the model and set the appropriate mesh type and density;

[0028] Set the solver parameters.

[0029] Optionally, the areas that need to set parameters include: the central current-carrying conductor of the high-voltage bushing, the epoxy impregnated paper capacitor core, the silicone rubber outer insulation sheath, the flange, the transformer oil tank and the SF6 gas area; the set material parameters include: relative dielectric constant, electrical conductivity, thermal conductivity, specific heat capacity, density and contact resistance in the copper-aluminum transition zone;

[0030] The defined physics fields include: Electric Current Physics Interface and Solid Heat Transfer Physics Interface, and the electromagnetic heating multiphysics interface is used to set simulation parameters.

[0031] Use free triangle mesh to mesh the 3D geometric model and adjust the mesh density according to the calculation accuracy;

[0032] Set the solver parameters, including the fully coupled solution for steady-state calculations of the electromagnetic-thermal coupled fields and the parametric sweep of the contact resistance.

[0033] Specifically, the method for performing simulation calculation includes:

[0034] Setting the heat source distribution and parameters related to the electromagnetic thermal coupling field in the simulation model;

[0035] Parameterize key parameters, including contact resistance, current carrying and thermal conductivity;

[0036] Simulate and calculate the temperature field distribution of high-voltage bushing;

[0037] Obtain steady-state temperature field distribution characteristics, including temperature field distribution images and key data.

[0038] Optionally, the method for performing simulation calculation includes:

[0039] The current-carrying conductor at the center of the high-voltage bushing is taken as the only heat source, and the heat source distribution is calculated based on its current density and conductivity;

[0040] Perform parameterized scans of different contact resistance values ​​in the electromagnetic thermal coupling field and set the contact resistance value R c =800μΩ;

[0041] The overall temperature field distribution of the high-voltage bushing under high current load is calculated by using a steady-state solution method based on electromagnetic thermal coupling field simulation;

[0042] Output the temperature field distribution characteristics of the high-voltage bushing under current-carrying defects, including temperature distribution cloud diagram and key point data of the temperature field.

[0043] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for calculating the temperature field distribution of a high-voltage bushing under a current-carrying defect as described above is implemented.

[0044] A computer program product includes a computer program / instruction, which, when executed by a processor, implements the above-mentioned method for calculating the temperature field distribution of a high-voltage bushing under a current-carrying defect.

[0045] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0046] The present invention simulates and calculates the three-dimensional temperature field distribution of the high-voltage bushing under current-carrying defects based on the finite element method. Through reasonable assumptions, the overall spatial geometric model of the high-voltage bushing is established, the electromagnetic field and heat transfer field control equations are considered, the corresponding physical field settings are reasonably selected, the mesh generation and the solver settings are performed, and the three-dimensional temperature field distribution characteristics of the high-voltage bushing under current-carrying defects are obtained through simulation calculation. According to the provided method, the temperature field distribution of each part of the high-voltage bushing under different current-carrying defects can be accurately known, which has important engineering significance for the optimization design of the insulation structure of the high-voltage bushing and the overheating fault analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings illustrate exemplary embodiments of the present invention and, together with the description thereof, are used to explain the principles of the present invention. These drawings are included to provide a further understanding of the present invention, and the accompanying drawings are included in and constitute a part of this specification and do not constitute a limitation of the embodiments of the present invention.

[0048] Figure 1 It is a flow chart of a method for calculating the temperature field distribution of a high-voltage bushing under a current-carrying defect according to the present invention.

[0049] Figure 2 It is a schematic diagram of a three-dimensional geometric model of a high voltage bushing according to the present invention.

[0050] Figure 3 It is a schematic diagram of the temperature field distribution of the high-voltage bushing under the current-carrying defect according to the present invention. DETAILED DESCRIPTION

[0051] To make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and implementation methods. It is understood that the specific implementation methods described herein are only used to explain the relevant content, rather than to limit the present invention.

[0052] It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the drawings.

[0053] In the absence of conflict, the embodiments and features of the embodiments of the present invention may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0054] Embodiment 1

[0055] like Figure 1 As shown, a method for calculating the temperature field distribution of a high-voltage bushing under a current-carrying defect is provided, comprising:

[0056] Based on the finite element method, a three-dimensional geometric model of the high-voltage bushing is established, and the geometric parameters of the model are set; the finite element method is used to construct a three-dimensional geometric model of the high-voltage bushing, which includes the main structure of the high-voltage bushing, including the center conductor, capacitor core, outer insulation sheath, transformer tank, etc. The geometric parameters of the model are determined according to the dimensional data of the actual high-voltage bushing, such as conductor diameter, bushing length and flange thickness.

[0057] The control equations describing the temperature field distribution of the high-voltage bushing include the electromagnetic field control equation and the heat transfer equation; the electromagnetic field control equation is determined based on the Maxwell equations, and the heat transfer equation needs to consider both the heat conduction of the conductor and the convective heat transfer with the air.

[0058] To simplify the calculation, the boundary conditions and basic assumptions of the high-voltage bushing are set according to the control equations;

[0059] The material parameters of the three-dimensional geometric model of the high-voltage bushing are set, the physical field is defined, the mesh is divided and the solver parameters are set; the accuracy and efficiency of the calculation process are ensured through the detailed setting of material parameters, physical field and mesh division.

[0060] The steady-state temperature field distribution is simulated and calculated by finite element simulation software to obtain the temperature field distribution characteristics of the high-voltage bushing under current-carrying defects. The above modeling and parameters are input and calculated using finite element simulation software to obtain the following results: temperature field distribution cloud map and key point temperature data. The temperature field distribution cloud map can intuitively display the temperature distribution characteristics inside the high-voltage bushing and identify areas with higher temperature rise. The key point temperature data can quantify the temperature rise values ​​of each area and provide data support for overheating risk assessment.

[0061] Embodiment 2

[0062] This embodiment provides a specific method.

[0063] S1. Perform three-dimensional geometric modeling of the high-voltage bushing in actual operation based on the finite element method to determine the geometric parameters of each part of the high-voltage bushing; Figure 2It is a schematic diagram of the established three-dimensional high-voltage bushing geometric model; the three-dimensional high-voltage bushing geometric model consists of a central current-carrying conductor, an epoxy impregnated paper capacitor core, a silicone rubber outer insulating sheath, a flange, a transformer oil tank, etc.

[0064] S2. Provide a basic description of the control equation for solving the temperature field distribution of the high-voltage bushing;

[0065] The governing equations of the electromagnetic field are described by Maxwell's equations: Where, σ is the conductivity, J s is the current density, μ is the magnetic permeability, and A is the magnetic vector potential;

[0066] Considering both the heat conduction of the conductor and the convection heat transfer with the air, the heat transfer equation is described as: Among them, Q v The units of heat source are mentioned, T is temperature, and λ is thermal conductivity.

[0067] S3. The control equations for calculating the temperature field and electric field of the high-voltage bushing described in step S2 are nonlinear differential equations. When using the finite element method to calculate the temperature field distribution, it is necessary to make reasonable assumptions about the boundary conditions of the three-dimensional geometric space model of the high-voltage bushing.

[0068] Boundary conditions and basic assumptions include:

[0069] Set the potential distribution boundary conditions of the high-voltage bushing, including reference potential and operating voltage;

[0070] Set the current boundary conditions of the high-voltage bushing, including the input value of the carrying current;

[0071] Set the thermal boundary conditions of the external environment of the high-voltage bushing, including the ambient temperature, heat transfer coefficient and thermal conductivity of the relevant area.

[0072] Specific bits:

[0073] The bottom of the high-voltage bushing oil tank is set to zero reference potential, i.e. φ0 = 0;

[0074] The potential of the central conductive tube of the high-voltage bushing is set to the operating voltage, i.e. φ1 = 400 kV;

[0075] Set the current terminal of the high-voltage bushing to I0=5000A;

[0076] According to the actual operating conditions, the external air temperature of the high-voltage bushing is set to 50°C and the transformer tank temperature is set to 90°C;

[0077] Set the air heat transfer coefficient to 8 W·m -1 K -1 , and adopt convection-enhanced thermal conductivity for the air, transformer oil and SF6 gas areas inside the bushing.

[0078] S4. Setting material parameters, defining physical fields, dividing grids and setting solution parameters for the three-dimensional geometric model of the high-voltage bushing include:

[0079] Set material properties for each region of the high-voltage bushing model, including electromagnetic parameters and thermophysical parameters;

[0080] Define multi-physics computational interfaces, including the coupling relationship between electromagnetic fields and heat transfer fields;

[0081] Mesh the model and set the appropriate mesh type and density;

[0082] Set the solver parameters.

[0083] Specifically include:

[0084] The areas that need to set parameters include: the central current-carrying conductor of the high-voltage bushing, the epoxy impregnated paper capacitor core, the silicone rubber outer insulation sheath, the flange, the transformer oil tank and the SF6 gas area; the material parameters to be set include: relative dielectric constant, conductivity, thermal conductivity, specific heat capacity, density and contact resistance in the copper-aluminum transition zone;

[0085] The defined physics fields include: Electric Current Physics Interface and Solid Heat Transfer Physics Interface, and the electromagnetic heating multiphysics interface is used to set simulation parameters.

[0086] Use free triangle mesh to mesh the 3D geometric model and adjust the mesh density according to the calculation accuracy;

[0087] Set the solver parameters, including the fully coupled solution for steady-state calculations of the electromagnetic-thermal coupled fields and the parametric sweep of the contact resistance.

[0088] S5. Perform simulation calculation according to the settings in S4, obtain the steady-state temperature field distribution law of the high-voltage bushing through finite element simulation calculation software, and accurately know the overall temperature field distribution characteristics of the high-voltage bushing under a large current load; the method for performing simulation calculation includes:

[0089] Setting the heat source distribution and parameters related to the electromagnetic thermal coupling field in the simulation model;

[0090] Parameterize key parameters, including contact resistance, current carrying and thermal conductivity;

[0091] Simulate and calculate the temperature field distribution of high-voltage bushing;

[0092] Obtain steady-state temperature field distribution characteristics, including temperature field distribution images and key data.

[0093] Assuming that the central current-carrying conduit of the high-voltage bushing is the only heat source, the material is copper alloy, the electrical conductivity is 5.99×107, and the thermal conductivity is 400, specifically:

[0094] The current-carrying conductor at the center of the high-voltage bushing is taken as the only heat source, and the heat source distribution is calculated based on its current density and conductivity;

[0095] Perform parameterized scans of different contact resistance values ​​in the electromagnetic thermal coupling field and set the contact resistance value R c =800μΩ;

[0096] The overall temperature field distribution of the high-voltage bushing under high current load is calculated by using a steady-state solution method based on electromagnetic thermal coupling field simulation;

[0097] The temperature field distribution characteristics of the high-voltage bushing under output current defects, such as Figure 3 As shown, it includes temperature distribution cloud diagram and key point data of temperature field.

[0098] Embodiment 3

[0099] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for calculating the temperature field distribution of a high-voltage bushing under a current-carrying defect as described above is implemented.

[0100] Without loss of generality, computer readable media may include computer storage media and communication media. Computer storage media include volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information such as computer readable instruction data structures, program modules or other data. Computer storage media include RAM, ROM, EPROM, EEPROM, flash memory or other solid-state storage technology, CD-ROM, DVD or other optical storage, cassettes, magnetic tapes, disk storage or other magnetic storage devices. Of course, those skilled in the art will appreciate that computer storage media are not limited to the above. The above-mentioned system memory and mass storage devices can be collectively referred to as memory.

[0101] A computer program product includes a computer program / instruction, which, when executed by a processor, implements the above-mentioned method for calculating the temperature field distribution of a high-voltage bushing under a current-carrying defect.

[0102] A computer program product includes a computer program or set of instructions for performing specific tasks or achieving specific functions. These programs or instructions are designed to be executed by a processor to implement a series of predefined steps or operations. The program product may be stored in various forms of computer storage media, such as memory, hard disk, solid-state drive, optical disk or other forms of digital storage devices. It may exist in the form of compiled binary code or in the form of scripts or bytecodes that can be executed by an interpreter. The program product uses carefully designed algorithms and logical instructions to enable the processor to process data in a specific order and manner to complete various functions such as data analysis, user interaction, device control, etc.

[0103] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments / methods or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments / methods or examples described in this specification and the features of the different embodiments / methods or examples, unless they are contradictory.

[0104] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0105] It should be understood by those skilled in the art that the above embodiments are only for the purpose of clearly illustrating the present invention, and are not intended to limit the scope of the present invention. For those skilled in the art, other changes or modifications may be made based on the above invention, and these changes or modifications are still within the scope of the present invention.

Claims

1. A method for calculating the temperature field distribution of a high voltage bushing under current-carrying defects, characterized in that: include: Establish a three-dimensional geometric model of the high-voltage bushing based on the finite element method and set the geometric parameters of the model; The governing equations describing the temperature field distribution of the high-voltage bushing, including the electromagnetic field governing equations and the heat transfer equations; Set the boundary conditions and basic assumptions of the high-voltage bushing according to the governing equations; Set material parameters for the 3D geometric model of the high-voltage bushing, define the physical field, divide the mesh and set the solver parameters; The steady-state temperature field distribution is simulated and calculated by finite element simulation software to obtain the temperature field distribution characteristics of the high-voltage bushing under current-carrying defects.

2. The method for calculating the temperature field distribution of a high-voltage bushing under current-carrying defects according to claim 1 is characterized in that: The governing equations of the electromagnetic field are described by Maxwell's equations: Where, σ is the conductivity, J s is the current density, μ is the magnetic permeability, and A is the magnetic vector potential; The heat transfer equation is described as: Among them, Q v The units of heat source are mentioned, T is temperature, and λ is thermal conductivity.

3. The method for calculating the temperature field distribution of a high-voltage bushing under current-carrying defects according to claim 2 is characterized in that: The boundary conditions and basic assumptions for setting the high-voltage bushing according to the control equations include: Set the potential distribution boundary conditions of the high-voltage bushing, including reference potential and operating voltage; Set the current boundary conditions of the high-voltage bushing, including the input value of the carrying current; Set the thermal boundary conditions of the external environment of the high-voltage bushing, including the ambient temperature, heat transfer coefficient and thermal conductivity of the relevant area.

4. The method for calculating the temperature field distribution of a high-voltage bushing under current-carrying defects according to claim 3 is characterized in that: The boundary conditions and basic assumptions for setting the high-voltage bushing according to the control equations include: The bottom of the high-voltage bushing oil tank is set to zero reference potential, i.e. φ0 = 0; The potential of the central conductive tube of the high-voltage bushing is set to the operating voltage, i.e. φ1 = 400 kV; Set the current terminal of the high-voltage bushing to I0=5000A; According to the actual operating conditions, the external air temperature of the high-voltage bushing is set to 50°C and the transformer tank temperature is set to 90°C; Set the air heat transfer coefficient to 8 W·m -1 K -1 , and adopt convection-enhanced thermal conductivity for the air, transformer oil and SF6 gas areas inside the bushing.

5. The method for calculating the temperature field distribution of a high voltage bushing under current-carrying defects according to claim 1 is characterized in that: The material parameters of the three-dimensional geometric model of the high-voltage bushing are set, the physical field is defined, the mesh is divided, and the solution parameters are set, including: Set material properties for each region of the high-voltage bushing model, including electromagnetic parameters and thermophysical parameters; Define multi-physics computational interfaces, including the coupling relationship between electromagnetic fields and heat transfer fields; Mesh the model and set the appropriate mesh type and density; Set the solver parameters.

6. The method for calculating the temperature field distribution of a high voltage bushing under current-carrying defects according to claim 5, The areas that require parameter setting include: The central current-carrying conductor of the high-voltage bushing, the epoxy-impregnated paper capacitor core, the silicone rubber outer insulation sheath, the flange, the transformer tank and the SF6 gas area; The set material parameters include: relative dielectric constant, electrical conductivity, thermal conductivity, specific heat capacity, density and contact resistance of copper-aluminum transition zone; The defined physics fields include: Electric Current Physics Interface and Solid Heat Transfer Physics Interface, and the electromagnetic heating multiphysics interface is used to set simulation parameters. Use free triangle mesh to mesh the 3D geometric model and adjust the mesh density according to the calculation accuracy; Set the solver parameters, including the fully coupled solution for steady-state calculations of the electromagnetic-thermal coupled fields and the parametric sweep of the contact resistance.

7. The method for calculating the temperature field distribution of a high voltage bushing under current-carrying defects according to claim 1 is characterized in that: The methods for performing simulation calculations include: Setting the heat source distribution and parameters related to the electromagnetic thermal coupling field in the simulation model; Parameterize key parameters, including contact resistance, current carrying and thermal conductivity; Simulate and calculate the temperature field distribution of high-voltage bushings; Obtain steady-state temperature field distribution characteristics, including temperature field distribution images and key data.

8. The method for calculating the temperature field distribution of a high voltage bushing under current-carrying defects according to claim 7 is characterized in that: The methods for performing simulation calculations include: The current-carrying conductor at the center of the high-voltage bushing is taken as the only heat source, and the heat source distribution is calculated based on its current density and conductivity; Perform parameterized scans of different contact resistance values ​​in the electromagnetic thermal coupling field and set the contact resistance value R c =800μΩ; The overall temperature field distribution of the high-voltage bushing under high current load is calculated by using a steady-state solution method based on electromagnetic thermal coupling field simulation; Output the temperature field distribution characteristics of the high-voltage bushing under current-carrying defects, including temperature distribution cloud diagram and key point data of the temperature field.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, a method for calculating the temperature field distribution of a high-voltage bushing under a current-carrying defect is implemented as described in any one of claims 1 to 8.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, a method for calculating the temperature field distribution of a high-voltage bushing under a current-carrying defect as claimed in any one of claims 1 to 8 is implemented.

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