Modeling simulation method for icing stress of distribution line and data query system

Abstract

The invention specifically discloses a modeling simulation method for icing stress of a distribution line and a data query system, and relates to the technical field of power system monitoring and management. According to the method, based on COMSOL Multiphysics software, modeling is carried out on the distribution line according to the section, span and material of the distribution line, self-weight load, wind load, icing load and the like are applied to the distribution line, then grid division and calculation are carried out, research types are determined, and a stress diagram, a deformation diagram and the like are obtained. And then through a software built-in App developer, a distribution line icing stress data query system is made by using a form editor, and by inputting related parameters and corresponding meteorological data of the distribution line, a stress and deformation graph of the distribution line can be calculated and queried. According to the method, the real-time stress condition of the wire can be comprehensively analyzed, the method can be applied to finite element modeling and stress analysis of the distribution wire, meanwhile, a manufactured data query system can help workers to judge whether the distribution wire has potential risks or not, safe operation of the line is guaranteed, and disasters are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of power system monitoring and management, and in particular to a simulation method and a calculation query system for ice-covered stress on distribution lines. Background Art

[0002] Severe weather has become an important factor causing distribution line failures, and icing is a serious natural disaster that affects the safety of the power system and is the most likely type of disaster to cause mass tripping of distribution lines. Large-scale icing disasters may cause accidents such as broken distribution lines, swaying conductors, and collapsed towers, causing huge economic losses. The winter freezing disaster in 2021 caused 2,125 10kV lines of the Southern Power Grid to be iced, 1,349 lines to be shut down, and 39,749 distribution transformers to be shut down, affecting a total of 1.9994 million users, of which about 90% of the accidents were caused by unbalanced tension on both sides of the line due to icing on the distribution lines. Therefore, it is of great significance to study the simulation method of the stress of icing on distribution lines.

[0003] In the existing finite element analysis method of transmission towers, if a simple parameter is often to be modified, the simulation engineer needs to re-modify the simulation, which is not convenient for directly inputting data to obtain the calculation results. The simulation program is not easy to modify, which increases the cumbersome operation process. The present invention studies and develops a data query system using the App developer of COMSOL Multiphysics software, which can enable non-professionals who lack finite element modeling and simulation analysis to obtain calculation results by quickly modifying parameters, and can help staff determine whether there are potential risks in the distribution line, ensure the safe operation of the line, and reduce the occurrence of disasters.

[0004] The disclosure of the above background technology content is only used to assist in understanding the inventive concept and technical solution of the present invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above content has been disclosed on the filing date of this patent application, the above background technology should not be used to evaluate the novelty and creativity of the present application. Summary of the invention

[0005] The purpose of the present invention is to provide a basis for judging whether a distribution line will fail due to icing, and to provide a modeling and simulation method for icing stress on a distribution line and a data query system.

[0006] To achieve the above purpose, the present invention adopts the following technical solution.

[0007] A modeling and simulation method for ice-covered stress on distribution lines and a data query system include the following steps.

[0008] S1 builds the geometric model of the distribution line, configures material properties, adds relevant constraints, and sets self-weight load, wind load, and ice load.

[0009] S2 performs meshing and sets up the solver to perform steady-state and transient calculations and obtain result plots.

[0010] S3 uses the built-in APP developer and form editor to create a distribution line ice stress data query system.

[0011] Furthermore, a geometric model of the distribution line is constructed, and a straight line is drawn in three-dimensional space coordinates to simulate the distribution line using the built-in drawing tools in the COMSOL Multiphysics software.

[0012] Going further, we configure the material properties, add a physical field interface in COMSOL Multiphysics, use the existing "cable" in "structural mechanics" to simulate the distribution line, and configure the material properties and wire cross-sectional area for it.

[0013] Furthermore, relevant constraints are added to set the self-weight load, wind load, and ice load. Specifically, the self-weight load, ice load, and wind load of the distribution line are calculated according to the relevant parameters of the distribution line and the corresponding meteorological data, and applied to the corresponding edges using the "edge load" interface provided by the software. At the same time, the two sides of the straight line are fixed using the "fixed constraint" interface provided by the software.

[0014] As a preferred solution of the modeling and simulation method and data query system for ice-covered distribution line stress described in the present invention, the deadweight load of the distribution line is calculated using the following calculation formula.

[0015]

[0016] Fg is the deadweight load of the distribution line, in N.

[0017] m0 is the mass per unit length of the distribution line, expressed in kg / m.

[0018] L0 is the horizontal span of the distribution line, in meters.

[0019] gb is the local gravitational acceleration, gb=9.80665m / s2.

[0020] As a preferred solution of the modeling and simulation method and data query system for the ice-covered stress of distribution lines described in the present invention, the ice-covered load of the distribution lines is calculated using the following calculation formula.

[0021]

[0022] F b is the conductor ice load, in N.

[0023] δ is the ice density in kg / m3 In general, the ice density is δ=900kg / m 3 .

[0024] b is the ice thickness in meters.

[0025] d is the outer diameter of the wire, in meters.

[0026] As a preferred solution of the modeling and simulation method and data query system for ice-covered distribution line stress described in the present invention, the wind load of the distribution line is calculated using the following calculation formula.

[0027]

[0028] F f It is the horizontal wind load value perpendicular to the conductor direction, in N.

[0029] α is the wind pressure unevenness coefficient, which is generally taken as 1.0.

[0030] μ is the air density, in kg / m 3 In general, the air density is ρ = 1.225 kg / m 3 .

[0031] v is the wind speed in m / s.

[0032] C xc is the drag coefficient, generally taken as 1.0.

[0033] G c It is the combined body coefficient of the conductor. If this coefficient is not taken into consideration, it is generally taken as 1.0.

[0034] G L is the span coefficient, generally taken as 1.0.

[0035] θ is the angle between the wind direction and the conductor direction, which is considered to be equal to 90°, meaning that the wind is perpendicular to the conductor.

[0036] Going further, the mesh is divided and the solver is set up, the research type is determined, and the result drawing is obtained, which is shown below.

[0037] (1) Mesh generation and solver setting: The mesh generation size is set according to the actual situation, and the mesh generation and solver setting are performed on the transmission tower simulation model constructed in step S1 above.

[0038] (2) Calculation and result drawing: Conduct finite element analysis, perform steady-state and transient calculations, and obtain force diagrams, deformation diagrams, etc.

[0039] Furthermore, through the built-in APP developer, the form editor is used to create a distribution line ice stress data query system. The specific performance is as follows: insert objects to create forms and design user interfaces by yourself. The objects can be built-in objects in the software or objects generated by users in the process of modeling transmission towers.

[0040] As a preferred solution of the modeling and simulation method and data query system for ice-covered distribution line stress described in the present invention, the real-time wind speed is calculated, and the harmonic superposition method is used to simulate the pulsating wind. The instantaneous wind speed calculation formula is as follows.

[0041]

[0042] U mean It stands for average wind speed, refers to the stable wind speed based on long-term statistics, and represents the overall trend of the wind.

[0043] u(t) represents the random fluctuation of wind speed based on the average wind speed. Fluctuating wind can be described by a random process, which is usually simulated by a time series.

[0044]

[0045] f k Represents discrete frequencies.

[0046] ϕ k Represents a random phase angle, usually a random number in the range [0, 2π].

[0047] Compared with the prior art, the beneficial technical effects of the present invention are as follows.

[0048] The present invention can be widely used in finite element modeling and force analysis of distribution lines by being able to comprehensively analyze the real-time stress conditions of conductors covered with ice. By studying and applying the App developer of COMSOL Multiphysics software to develop a data query system, non-professionals who lack finite element modeling and simulation analysis can obtain calculation results by quickly modifying parameters, and non-professionals can query the stress or deformation conditions of distribution lines when ice is covered with ice of different thicknesses by inputting relevant data anytime and anywhere, thereby providing a basis for judging whether a distribution line will fail due to the influence of ice covering. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The present invention is a flow chart of a modeling and simulation method for ice-covered distribution lines and a data query system.

[0050] Figure 2 The three-dimensional diagram of displacement at different positions of the distribution line.

[0051] Figure 3 One-dimensional diagram of displacement at different locations of the distribution line.

[0052] Figure 4 It is a one-dimensional diagram of the displacement of the lowest point of the distribution line at different times.

[0053] Figure 5 This is the interface diagram of the data query system. DETAILED DESCRIPTION

[0054] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0055] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "top", "bottom", "top surface", "bottom surface", "inside", "outside", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0056] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If the terms "first", "second", "third" are described, they are only used for the purpose of description and distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0057] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The following is an explanation of the embodiments of the present invention based on its overall structure.

[0058] The purpose of the present invention is to provide a modeling and simulation method for distribution line icing stress and a data query system, so as to provide a basis for judging whether a distribution line will fail due to icing.

[0059] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0060] Figure 1 This is a modeling and simulation method for ice-covered distribution lines and a flow chart of a data query system. Figure 1 As shown, the present invention provides a modeling and simulation method for ice-coated stress on distribution lines and a data query system, and the method includes the following steps.

[0061] S1 builds the geometric model of the distribution line, configures material properties, adds relevant constraints, and sets self-weight load, wind load, and ice load.

[0062] S2 performs meshing and sets up the solver to perform steady-state and transient calculations and obtain result plots.

[0063] S3 uses the built-in APP developer and form editor to create a distribution line ice stress data query system.

[0064] Specifically, in step S1, a geometric model of the distribution line is constructed, and a drawing tool provided in the COMSOL Multiphysics software is used to draw a straight line in three-dimensional space coordinates to simulate the distribution line.

[0065] Specifically, in step S1, material properties are configured, a physical field interface is added in COMSOL Multiphysics, the "cable" in the existing "structural mechanics" is used to simulate the distribution line, and material properties and wire cross-sectional area are configured for it.

[0066] Specifically, add relevant constraints and set the self-weight load, wind load and ice load. Specifically, calculate the self-weight load, ice load and wind load of the distribution line according to the relevant parameters of the distribution line and the corresponding meteorological data, and use the "edge load" interface provided by the software to apply them to the corresponding edges. At the same time, use the "fixed constraint" interface provided by the software to fix the two sides of the straight line.

[0067] Specifically, the step S1 calculates the deadweight load of the distribution line, and the calculation formula is as follows:

[0068] F g It is the deadweight load of the distribution line, in N.

[0069] m0 is the mass per unit length of the distribution line, expressed in kg / m.

[0070] L0 is the horizontal span of the distribution line, in meters.

[0071] g b is the local gravitational acceleration, g b =9.80665m / s 2 .

[0072] Specifically, the step S1 calculates the ice load of the distribution line, and the calculation formula is as follows.

[0073]

[0074] F b is the conductor ice load, in N.

[0075] δ is the ice density in kg / m 3 In general, the ice density is δ=900kg / m 3 .

[0076] b is the ice thickness in meters.

[0077] d is the outer diameter of the wire, in meters.

[0078] Specifically, the step S1 calculates the wind load of the distribution line, and the calculation formula is as follows.

[0079]

[0080] F f It is the horizontal wind load value perpendicular to the conductor direction, in N.

[0081] α is the wind pressure unevenness coefficient, which is generally taken as 1.0.

[0082] μ is the air density, in kg / m 3 In general, the air density is ρ = 1.225 kg / m 3 .

[0083] v is the wind speed in m / s.

[0084] C xc is the drag coefficient, generally taken as 1.0.

[0085] G c It is the combined body coefficient of the conductor. If this coefficient is not taken into consideration, it is generally taken as 1.0.

[0086] G L is the span coefficient, generally taken as 1.0.

[0087] θ is the angle between the wind direction and the conductor direction, which is considered to be equal to 90°, meaning that the wind is perpendicular to the conductor.

[0088] Specifically, the step S2 performs meshing and sets a solver, determines the research type, and obtains a result drawing, which is specifically shown as follows.

[0089] (1) Mesh generation and solver setting: The mesh generation size is set according to the actual situation, and the mesh generation and solver setting are performed on the transmission tower simulation model constructed in step S1 above.

[0090] (2) Calculation and result drawing: Conduct finite element analysis, perform steady-state and transient calculations, and obtain force diagrams, deformation diagrams, etc.

[0091] Specifically, step S3 is to use the built-in APP developer and the form editor to create a distribution line ice stress data query system. The specific performance is as follows: insert objects to create forms and design the user interface by yourself, where the objects can be objects built into the software or objects generated by the user in the process of modeling the transmission tower.

[0092] Specifically, the harmonic superposition method is used to simulate the pulsating wind, and the instantaneous wind speed calculation formula is as follows.

[0093]

[0094] U mean It stands for average wind speed, refers to the stable wind speed based on long-term statistics, and represents the overall trend of the wind.

[0095] u(t) represents the random fluctuation of wind speed based on the average wind speed. Fluctuating wind can be described by a random process, which is usually simulated by a time series.

[0096]

[0097] f k Represents discrete frequencies.

[0098] ϕ k Represents a random phase angle, usually a random number in the range [0, 2π].

[0099] Figure 2 To pass Figure 1 The three-dimensional displacement diagrams at different positions obtained by the modeling and simulation method of ice-covered distribution line stress shown in the figure show that the displacement at both ends of the distribution line is small, while the displacement in the middle is large.

[0100] Figure 3 To pass Figure 1 The one-dimensional displacement diagrams at different positions obtained by the modeling and simulation method of ice-covered distribution lines shown in the figure are consistent with the results Figure 2 Reflects the same, but Figure 3The data results are more intuitive when reflected by specific numerical values.

[0101] Figure 4 To pass Figure 1 The one-dimensional displacement diagram of the lowest point of the distribution line at different times is obtained by the modeling and simulation method of ice-covered distribution line shown in the figure. The displacement size changes with time, reflecting the dancing state of the conductor, and the transient simulation is closer to reality.

[0102] Figure 5 The interface of the data query system can be obtained by inputting relevant parameters of the distribution line, surrounding environment data, etc. to timely obtain relevant information on ice stress and displacement. Non-professionals who lack finite element modeling and simulation analysis can obtain calculation results by quickly modifying parameters, so that non-professionals can query the stress or deformation of the distribution line when ice is covered with different thicknesses by inputting relevant data anytime and anywhere, providing a basis for judging whether the distribution line will fail due to the influence of ice.

[0103] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the examples is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A modeling and simulation method for ice-covered distribution line stress and a data query system, characterized in that: The following steps are involved: S1 builds the geometric model of the distribution line, configures material properties, adds relevant constraints, and sets self-weight load, wind load, and ice load; S2 performs meshing and sets up solvers to perform steady-state and transient calculations and obtain result plots; S3 uses the built-in APP developer and form editor to create a distribution line ice stress data query system.

2. A distribution line icing stress modeling simulation method and data query system according to claim 1, characterized in that: In the step S1, a geometric model of the distribution line is constructed, and a straight line is drawn in three-dimensional space coordinates to simulate the distribution line using the drawing tool provided in the COMSOL Multiphysics software.

3. A distribution line icing stress modeling simulation method and data query system according to claim 1, characterized in that: In the step S1, material properties are configured, a physical field interface is added in COMSOL Multiphysics, and the "cable" in the existing "structural mechanics" is used to simulate the distribution line, and material properties and wire cross-sectional area are configured for it.

4. A distribution line icing stress modeling simulation method and data query system according to claim 1, characterized in that: In the step S1, the self-weight load, wind load and ice load are added, and the specific performance is as follows: according to the relevant parameters of the distribution line and the corresponding meteorological data, the self-weight load, ice load and wind load of the distribution line are calculated, and applied to the corresponding edge using the "edge load" interface provided by the software. At the same time, the two sides of the straight line are fixed using the "fixed constraint" interface provided by the software.

5. A distribution line icing stress modeling simulation method and data query system according to claim 1, characterized in that: The step S1 calculates the deadweight load of the distribution line, and the calculation formula is as follows: Where: F g is the deadweight load of the distribution line, in N; m0 is the mass per unit length of the distribution line, in kg / m; L0 is the horizontal span of the distribution line, in meters; g b is the local gravitational acceleration, g b =9.80665m / s 2 .

6. A distribution line icing stress modeling simulation method and data query system according to claim 1, characterized in that: The step S1 calculates the ice load of the distribution line, and the calculation formula is as follows: Where: F b is the conductor ice load, in N; δ is the ice density in kg / m 3 In general, the ice density is δ=900kg / m 3 ; b is the ice thickness in m; d is the outer diameter of the wire, in meters.

7. A distribution line icing stress modeling simulation method and data query system according to claim 1, characterized in that: The step S1 calculates the wind load of the distribution line, and the calculation formula is as follows: Where: F f It is the horizontal wind load value perpendicular to the conductor direction, in N; α is the wind pressure unevenness coefficient, which is generally taken as 1.0; μ is the air density, in kg / m 3 In general, the air density is ρ = 1.225 kg / m 3 ; v is the wind speed in m / s; C xc is the drag coefficient, which is generally taken as 1.0; G c It is the combined body coefficient of the conductor. This coefficient is not considered and is generally taken as 1.0; G L is the span coefficient, which is generally taken as 1.0; θ is the angle between the wind direction and the conductor direction, which is considered to be equal to 90°, meaning that the wind is perpendicular to the conductor.

8. A distribution line icing stress modeling simulation method and data query system according to claim 1, characterized in that: The step S2 performs meshing and sets the solver, determines the research type, and obtains the result drawing, which is specifically shown as follows: (1) Meshing and solver setting: The mesh size is set according to the actual situation, and the meshing and solver setting are performed on the transmission tower simulation model constructed in step S1 above; (2) Calculation and result drawing: Conduct finite element analysis, perform steady-state and transient calculations, and obtain force diagrams, deformation diagrams, etc.

9. A distribution line icing stress modeling simulation method and data query system according to claim 1, characterized in that: The step S3 is to use the built-in APP developer and the form editor to create a distribution line ice stress data query system. The specific performance is as follows: insert objects to create forms and design the user interface by yourself, where the objects can be objects built into the software or objects generated by the user in the process of modeling the transmission tower.

10. A distribution line icing stress modeling simulation method and data query system according to claim 7, characterized in that: It is necessary to simulate the real-time wind speed and use the harmonic superposition method to simulate the pulsating wind. The instantaneous wind speed calculation formula is as follows: Where: U mean It stands for average wind speed, which refers to the stable wind speed based on long-term statistics and represents the overall trend of the wind. u(t) represents the random fluctuation of wind speed based on the average wind speed. Fluctuating wind can be described by a random process, which is usually simulated by a time series. Where: f k represents discrete frequency; ϕ k Represents a random phase angle, usually a random number in the range [0, 2π].

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