Copper bar thermal calculation method based on virtual structure and discrete equation

Abstract

The invention discloses a copper bar thermal calculation method based on a virtual structure and a discrete equation, a copper bar comprises a bare copper bar, a plastic coating and a plastic coating rib, and the method comprises the following steps: S1, virtualizing the copper bar according to the actual structure and calculation boundary characteristics of the copper bar, and obtaining a virtualized copper bar model; according to the copper bar thermal calculation method based on the virtual structure and the discrete equation, a design engineer does not need to provide geometric modeling, a copper bar structure can be virtualized according to boundary features of a peripheral structure, and the structural features of the copper bar structure are parameterized. Meanwhile, dimension reduction processing is carried out on an actual three-dimensional temperature calculation problem, discretization processing is carried out on the virtualized copper bar structure, a heat balance equation is established for each discretized virtual structure, numerical solution is carried out, and therefore temperature field distribution of the whole copper bar structure is obtained through rapid calculation.

Description

Technical Field

[0001] The invention belongs to the technical field of copper heat removal calculation, and in particular relates to a copper heat removal calculation method based on virtual structure and discrete equation. Background Art

[0002] In the existing automotive electric drive system, the thermal calculation of copper bars in the early stage of design mainly relies on the simulation of commercial software, which can accurately reflect the temperature field of the product. However, the simulation process of commercial computing software takes a long time, and it requires mechanical design engineers to complete the geometric modeling of the copper bars before it can be carried out. In general, the design requires multiple rounds of optimization iterations, resulting in a large workload for design and simulation engineers, as well as an increase in the design cycle, which is not conducive to adapting to the current automotive design and development cycle and causes a shortage of design resources.

[0003] Therefore, further improvements are made to the above problems. Summary of the invention

[0004] The main purpose of the present invention is to provide a copper busbar heat calculation method based on virtual structure and discrete equations. It does not require design engineers to provide geometric modeling. According to the boundary characteristics of the surrounding structure, a copper busbar structure can be virtualized and its structural characteristics can be parameterized. At the same time, the actual three-dimensional temperature calculation problem is reduced in dimension, and then the virtualized copper busbar structure is discretized. For each discrete virtual structure, a heat balance equation is established and numerically solved, so as to obtain the temperature field distribution of the entire copper busbar structure through rapid calculation. The present invention can not only meet the needs of temperature estimation in the early design stage, but also greatly improve the speed of temperature calculation, saving a lot of development time.

[0005] To achieve the above objectives, the present invention provides a copper bar heat calculation method based on virtual structure and discrete equation, wherein the copper bar includes a bare copper bar, a plastic-coated copper bar and a plastic-coated rib, and comprises the following steps:

[0006] Step S1: virtualizing the copper busbar according to its actual structure and calculated boundary features and obtaining a virtualized copper busbar model;

[0007] Step S2: After reducing the dimension and discretizing the virtualized bronze medal model, a discretized calculation model is obtained;

[0008] Step S3: Establish a heat balance equation for each discretized microstructure in the discretized calculation model. The heat balance equation is:

[0009]

[0010] Assuming a symmetric thermal model, the formula is:

[0011] T (m-1)x =T (m+1)x;

[0012] Among them, T m(x-1) , T mx , T m(x+1) , T (m-1)x , T (m+1)x is the temperature of the discretized microstructure; B and H are the width and thickness of the copper bar; λ cu and λ pl are the thermal conductivity of the copper busbar and the plastic-coated material, I is the current, ρ is the resistivity, l is the mx is the length of the copper bar after discreteness, δ pl is the plastic coating thickness;

[0013] Step S4: thermal balance equations are established for all discretized microstructures to form a set of equations. The temperature of each microstructure is quickly solved by calculation, so as to quickly obtain the temperature field distribution of the entire copper busbar structure (since the set of equations is a linear set of equations, the solution speed is fast, which greatly saves the time of temperature calculation and development time).

[0014] As a further preferred technical solution of the above technical solution, step S4 is specifically implemented as follows:

[0015] The equations for bare copper busbars are:

[0016] Discrete structure m1:

[0017]

[0018] Discrete structure mn:

[0019]

[0020] Among them, T m1 , T m2 , T mn , T m(n-1) , T a1 , T b1 ( Figure 6 ) is the temperature of the discretized microstructure; l m1 , l mn is the length of the copper bar after discretization, h is the convection heat transfer coefficient, T amb is the ambient temperature, δ a is the thickness of a boundary copper bar, δ b is the thickness of the other boundary copper bar;

[0021] Equations for overmolding:

[0022] Discrete structure (m-1)1:

[0023]

[0024] h·[l (m-1)1 ·(B+2δ pl )+B·δ pl ]·(T (m-1)1 -T amb );

[0025] Discrete structure (m-1)x:

[0026]

[0027] Discrete structure (m-1)s:

[0028]

[0029] Among them, T (m-1)1 , T mu , T (m-1)2 , T mx , T (m-1)x , T (m-1)(x-1) , T (m-1)(x+1) , T (m-2)x) , T (m-1)(s-1) , T (m-1)s , T mv for( Figure 6 ) The temperature of the discretized microstructure; l (m-1)1 , l mx , l (m-1)x , l (m-1)s is the length of the copper bar after discreteness;

[0030] The system of equations for the boundary:

[0031] Discrete structure a1:

[0032]

[0033] Discrete structure a2:

[0034]

[0035] Discrete structure a3:

[0036]

[0037] Discrete structure b1:

[0038]

[0039] Discrete structure b2:

[0040]

[0041] Discrete structure b3:

[0042]

[0043] Among them, T a1 , T a2 , T a3 , T b1 , T b2 , T b3 for( Figure 6 ) The temperature of the discretized microstructure; l a1 ,l a2 , l a3 , l b1 , l b2 , l b3 is the length of the copper bar at the discrete rear boundary;

[0044] For plastic coated reinforcement:

[0045] Discrete structure (m-2)1:

[0046]

[0047] Discrete structure (m-2)t:

[0048]

[0049] Among them, T (m-1)2 , T (m-2)1 , T (m-2)2 , T (m-2)(t-1) , T (m-2)t , T (m-1)(s-1) for( Figure 6 ) The temperature of the discretized microstructure; l (m-2)1 ,l (m-2)t is the length of the discrete rear boundary copper bar, δ rib is the thickness of plastic coated reinforcement.

[0050] As a further preferred technical solution of the above technical solution, the plastic coating is installed on the bare copper busbar and the plastic coating ribs are installed on the plastic coating.

[0051] As a further preferred technical solution of the above technical solution, the first side and the second side of the bare copper bus are respectively installed with plastic coating, and the side of the plastic coating on the first side away from the bare copper bus is installed with plastic coating ribs, and boundaries are respectively provided on both sides of the second side of the bare copper bus.

[0052] To achieve the above objectives, the present invention provides an electronic device, comprising 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 steps of the copper heat removal calculation method based on virtual structure and discrete equation are implemented.

[0053] To achieve the above objectives, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the copper heat removal calculation method based on virtual structure and discrete equations.

[0054] The beneficial effects of the present invention are:

[0055] 1. The present invention can calculate the precise temperature field distribution rather than a single temperature value, providing more accurate temperature prediction for product design.

[0056] 2. Temperature calculation occurs before formal design. The temperature field of the copper busbar can be predicted earlier in the conceptual design stage before the geometric model is created, which makes up for the defect that commercial software can only perform temperature calculation after the geometric model is created.

[0057] 3. Compared with traditional commercial software calculations, this method is faster and can save development and design cycles.

[0058] 4. The calculation tool created by this method has a simple interface, does not require software training, and does not require the participation of professional simulation engineers, which greatly reduces R&D costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 The invention discloses a flow chart of a copper heat removal calculation method based on a virtual structure and a discrete equation.

[0060] Figure 2 This is a schematic diagram of the structure of a conventional copper busbar.

[0061] Figure 3 It is a schematic diagram of a virtualized copper busbar model of a copper busbar heat calculation method based on a virtual structure and a discrete equation of the present invention.

[0062] Figure 4 It is a schematic diagram of a discretized calculation model of a copper heat removal calculation method based on a virtual structure and a discrete equation of the present invention.

[0063] Figure 5 It is a discretized microstructure schematic diagram of a copper heat removal calculation method based on a virtual structure and a discrete equation of the present invention.

[0064] Figure 6 It is a schematic diagram of a copper heat removal calculation method based on a virtual structure and a discrete equation according to the present invention.

[0065] The reference numerals include: 1. bare copper busbar; 2. plastic coated; 3. plastic coated rib. DETAILED DESCRIPTION

[0066] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0067] In the preferred embodiment of the present invention, those skilled in the art should note that the copper busbars and the like involved in the present invention may be regarded as prior art.

[0068] Preferred embodiments.

[0069] like Figure 1-6 As shown, the present invention discloses a copper bar heat calculation method based on virtual structure and discrete equation, the copper bar comprises a bare copper bar 1, a plastic coating 2 and a plastic coating rib 3, and comprises the following steps:

[0070] Step S1: According to the actual structure of the copper busbar and the calculated boundary features, virtualize it and obtain a virtualized copper busbar model (such as Figure 3 , respectively simplifying the real structures of bare copper busbar, plastic-coated copper bar and plastic-coated copper bar into plane overlapping rectangular structures);

[0071] Step S2: After reducing the dimension and discretizing the virtualized bronze model, a discretized calculation model is obtained (such as Figure 4 ,In order to simplify the calculation, the longitudinal heat transfer path is not considered, and the three-dimensional heat conduction problem is simplified into a plane heat conduction problem; the plane model is cut into infinite rectangular structures of equal size, and the plane model is discretized);

[0072] Step S3: For each discretized microstructure (such as Figure 5 ) Establish a heat balance equation, such as the heat balance equation of the discrete structure mx:

[0073]

[0074] Assuming a symmetric thermal model, the formula is:

[0075] T (m-1)x =T (m+1)x ;

[0076] Among them, T m(x-1) , T mx , T m(x+1) , T (m-1)x , T (m+1)x for( Figure 5 ) is the temperature of the discretized microstructure; B and H are the width and thickness of the copper bar; λ cu and λ plare the thermal conductivity of the copper busbar and the plastic-coated material, I is the current, ρ is the resistivity, l is the mx is the length of the copper bar after discreteness, δ pl is the plastic coating thickness;

[0077] Step S4: thermal balance equations are established for all discretized microstructures to form a set of equations. The temperature of each microstructure is quickly solved by calculation, so as to quickly obtain the temperature field distribution of the entire copper busbar structure (since the set of equations is a linear set of equations, the solution speed is fast, which greatly saves the time of temperature calculation and development time).

[0078] It is worth mentioning that step S4 is specifically implemented as follows:

[0079] The equations for bare copper busbars are:

[0080] Discrete structure m1:

[0081]

[0082] …

[0083] Discrete structure mx: see step S3;

[0084] …

[0085] Discrete structure mn:

[0086]

[0087] Among them, T m1 , T m2 , T mn , T m(n-1) , T a1 , T b1 ( Figure 6 ) is the temperature of the discretized microstructure; l m1 ,l mn is the length of the copper bar after discretization, h is the convection heat transfer coefficient, T amb is the ambient temperature, δ a is the thickness of a boundary copper bar, δ b is the thickness of the other boundary copper bar;

[0088] Equations for overmolding:

[0089] Discrete structure (m-1)1:

[0090]

[0091] …

[0092] Discrete structure (m-1)x:

[0093]

[0094] …

[0095] Discrete structure (m-1)s:

[0096]

[0097] Among them, T (m-1)1 , T mu , T (m-1)2 , T mx , T (m-1)x , T (m-1)(x-1) , T (m-1)(x+1) , T (m-2)x) , T (m-1)(s-1) , T (m-1)s , T mv for( Figure 6 ) The temperature of the discretized microstructure; l (m-1)1 ,l mx , l (m-1)x , l (m-1)s is the length of the copper bar after discreteness;

[0098] The system of equations for the boundary:

[0099] Discrete structure a1:

[0100]

[0101] Discrete structure a2:

[0102]

[0103] Discrete structure a3:

[0104]

[0105] Discrete structure b1:

[0106]

[0107] Discrete structure b2:

[0108]

[0109] Discrete structure b3:

[0110]

[0111] Among them, T a1 , T a2 , T a3 , T b1 , T b2 , T b3 for( Figure 6) The temperature of the discretized microstructure; l a1 ,l a2 , l a3 , l b1 , l n2 , l n3 is the length of the copper bar at the discrete rear boundary;

[0112] For plastic coated reinforcement:

[0113] Discrete structure (m-2)1:

[0114]

[0115] Discrete structure (m-2)t:

[0116]

[0117] Among them, T (m-1)2 , T (m-2)1 , T (m-2)2 , T (m-2)(t-1) , T (m-2)t , T (m-1)(s-1) for( Figure 6 ) The temperature of the discretized microstructure; l (m-2)1 ,l (m-2)t is the length of the discrete rear boundary copper bar, δ rib is the thickness of plastic coated reinforcement.

[0118] Specifically, the plastic coating is installed on the bare copper busbar and the plastic coating ribs are installed on the plastic coating.

[0119] More specifically, the first side and the second side of the bare copper busbar are respectively installed with plastic coating, a side of the plastic coating on the first side away from the bare copper busbar is installed with plastic coating ribs, and both sides of the second side of the bare copper busbar are respectively provided with borders.

[0120] The present invention also discloses an electronic device, comprising 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 steps of the copper heat removal calculation method based on virtual structure and discrete equation are implemented.

[0121] The present invention also discloses a non-transitory computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the copper heat removal calculation method based on virtual structure and discrete equation are implemented.

[0122] It is worth mentioning that the technical features such as copper busbars involved in the patent application of this invention should be regarded as prior art. The specific structure, working principle and possible control method and spatial layout method of these technical features can be selected according to the conventional selection in the field, and should not be regarded as the inventive point of this patent. This patent will not be further elaborated.

[0123] For those skilled in the art, it is still possible to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A copper bar heat calculation method based on virtual structure and discrete equation, the copper bar includes bare copper bar, plastic coated bar and plastic coated bar, characterized in that: The following steps are involved: Step S1: virtualizing the copper busbar according to its actual structure and calculated boundary features and obtaining a virtualized copper busbar model; Step S2: After reducing the dimension and discretizing the virtualized bronze medal model, a discretized calculation model is obtained; Step S3: Establish a heat balance equation for each discretized microstructure in the discretized calculation model. The heat balance equation is: Assuming a symmetric thermal model, the formula is: T (m-1)x =T (m+1)x ; Among them, T m(x-1) , T mx , T m(x+1) , T (m-1)x , T (m+1)x is the temperature of the discretized microstructure; B and H are the width and thickness of the copper bar; λ cu and λ pl are the thermal conductivity of the copper busbar and the plastic-coated material, I is the current, ρ is the resistivity, l is the mx is the length of the copper bar after discreteness, δ pl is the plastic coating thickness; Step S4: thermal balance equations are established for all discretized microstructures to form a set of equations, and the temperature of each microstructure is quickly solved by calculation, so as to quickly obtain the temperature field distribution of the entire copper busbar structure.

2. The copper heat removal calculation method based on virtual structure and discrete equation according to claim 1 is characterized in that: Step S4 is specifically implemented as follows: The equations for bare copper busbars are: Discrete structure m1: Discrete structure mn: Among them, T m1 , T m2 , T mn , T m(n-1) , T a1 , T b1 is the temperature of the discretized microstructure; l m1 ,l mn is the length of the copper bar after discretization, h is the convection heat transfer coefficient, T amb is the ambient temperature, δ a is the thickness of a boundary copper bar, δ b is the thickness of the other boundary copper bar; Equations for overmolding: Discrete structure (m-1)1: Discrete structure (m-1)x: Discrete structure (m-1)s: Among them, T (m-1)1 , T mu , T (m-1)2 , T mx , T (m-1)x , T (m-1)(x-1) , T (m-1)(x+1) , T (m-2)x) , T (m-1)(s-1) , T (m-1)s , T mv is the temperature of the discretized microstructure; l (m-1)1 ,l mx , l (m-1)x , l (m-1)s is the length of the copper bar after discreteness; The system of equations for the boundary: Discrete structure a1: Discrete structure a2: Discrete structure a3: Discrete structure b1: Discrete structure b2: Discrete structure b3: Among them, T a1 , T a2 , T a3 , T b1 , T b2 , T b3 is the temperature of the discretized microstructure; l a1 ,l a2 , l a3 , l a1 , l n2 , l n3 is the length of the copper bar at the discrete rear boundary; For plastic coated reinforcement: Discrete structure (m-2)1: Discrete structure (m-2)t: Among them, T (m-1)2 , T (m-2)1 , T (m-2)2 , T (m-2)(t-1) , T (m-2)t , T (m-1)(s-1) is the temperature of the discretized microstructure; l (m-2)1 ,l (m-2)t is the length of the discrete rear boundary copper bar, δ rib is the thickness of plastic coated reinforcement.

3. The copper heat removal calculation method based on virtual structure and discrete equation according to claim 2 is characterized in that: The plastic coating is installed on the bare copper busbar and the plastic coating ribs are installed on the plastic coating.

4. The copper heat removal calculation method based on virtual structure and discrete equation according to claim 3 is characterized in that: Plastic coating is installed on the first side and the second side of the bare copper busbar respectively, and plastic coating ribs are installed on the side of the plastic coating on the first side away from the bare copper busbar, and borders are arranged on both sides of the second side of the bare copper busbar respectively.

5. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the copper heat removal calculation method based on virtual structure and discrete equations as claimed in any one of claims 1 to 4 are implemented.

6. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the copper heat removal calculation method based on virtual structure and discrete equations as claimed in any one of claims 1 to 4 are implemented.

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