Method and device for determining equivalent young's modulus of secondary transposed litz wire

Abstract

The application provides a kind of equivalent Young's modulus determination method and device of secondary transposition Litz wire, and the method comprises the following steps: constructing the first parallel flexibility model of secondary transposition Litz wire along the length direction, the second series flexibility model and the second parallel flexibility model along the width direction and the third series flexibility model and the third parallel flexibility model along the thickness direction; determine the first equivalent Young's modulus of secondary transposition Litz wire along the length direction based on the first parallel flexibility model; determine the second equivalent Young's modulus of secondary transposition Litz wire along the width direction based on the second series flexibility model and the second parallel flexibility model; determine the third equivalent Young's modulus of secondary transposition Litz wire along the width direction based on the third series flexibility model and the third parallel flexibility model.The common influence of series force transmission and parallel force transmission on Young's modulus is closer to the actual structure, and the accuracy of mechanical simulation of secondary transposition Litz wire is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of temperature field analysis, and particularly relates to a method and device for determining equivalent Young's modulus of a secondary transposed Litz wire. BACKGROUND

[0002] For some special electric machines (high-speed electric machines and high-magnetic-load electric machines, etc.) or power transformers, a coil is wound with a Litz transposed wire, which can significantly reduce coil circulating current and eddy current loss, improve operation reliability and service life. It is usually necessary to predict the carrying capacity and maximum stress, and thus the evaluation of mechanical parameters of the Litz transposed wire is particularly important. The Young's modulus is a key parameter in the evaluation of mechanical properties.

[0003] Many methods are used to estimate the equivalent Young's modulus of the Litz transposed wire, including experimental determination, simulation analysis and equivalent analysis method. The equivalent analysis method can usually evaluate the Young's modulus of the Litz wire in a time- and resource-saving manner, and the disadvantage is that the accuracy of the analysis method for evaluating the equivalent Young's modulus of the Litz transposed wire depends on the simplified model. Most existing physical models are simplified into simple parallel models or series models, and the axial force in the Litz transposed wire exists in two cases of series force transmission and parallel force transmission between different materials. Therefore, the equivalent parameters obtained by using the simple parallel model or series model cannot reflect the actual structure, which affects the accuracy of the simulation analysis results.

[0004] Therefore, it is urgent to provide a method and device for determining the equivalent Young's modulus of a secondary transposed Litz wire, which takes into account the common influence of series and parallel connection on the Young's modulus and improves the simulation accuracy of the mechanical properties of the secondary transposed Litz wire. SUMMARY

[0005] Therefore, it is necessary to provide a method and device for determining the equivalent Young's modulus of a secondary transposed Litz wire, which takes into account the common influence of series and parallel connection on the Young's modulus and improves the simulation accuracy of the mechanical properties of the secondary transposed Litz wire.

[0006] In one aspect, to solve the above technical problems, the present application provides a method for determining the equivalent Young's modulus of a secondary transposed Litz wire, comprising:

[0007] constructing a first parallel compliance model along the length direction, a second series compliance model and a second parallel compliance model along the width direction, and a third series compliance model and a third parallel compliance model along the thickness direction of the secondary transposed Litz wire;

[0008] determining the first equivalent Young's modulus of the secondary transposed Litz wire along the length direction based on the first parallel compliance model;

[0009] determining a second series Young's modulus and a second parallel Young's modulus of the second transposed Litz wire along the width direction based on the second series compliance model and the second parallel compliance model respectively, and taking a weighted sum of the second series Young's modulus and the second parallel Young's modulus as a second equivalent Young's modulus of the second transposed Litz wire along the width direction;

[0010] determining a third series Young's modulus and a third parallel Young's modulus of the second transposed Litz wire along the thickness direction based on the third series compliance model and the third parallel compliance model respectively, and taking a weighted sum of the third series Young's modulus and the third parallel Young's modulus as a third equivalent Young's modulus of the second transposed Litz wire along the thickness direction.

[0011] In a possible implementation, the preparation process of the second transposed Litz wire is as follows:

[0012] insulating the copper round wire with paint film to obtain a lacquered copper round wire;

[0013] transposing the plurality of lacquered copper round wires, vacuum pressure impregnating the transposed plurality of lacquered copper round wires to obtain a first transposed Litz wire, and wrapping a first polyimide film around the first transposed Litz wire;

[0014] transposing the first transposed Litz wire wrapped with the first polyimide film to obtain a second transposed Litz wire, wrapping a second polyimide film around the second transposed Litz wire, and vacuum pressure impregnating the second transposed Litz wire wrapped with the second polyimide film.

[0015] In a possible implementation, the second series compliance model includes a lacquered copper round wire series compliance model of the lacquered copper round wire, a first transposition series compliance model of the first transposed Litz wire, and a second transposition series compliance model of the transposed Litz wire; and determining the second series Young's modulus of the second transposed Litz wire along the width direction based on the second series compliance model includes:

[0016] determining lacquered series compliance of the lacquered copper round wire based on the lacquered copper round wire series compliance model, and determining lacquered copper round wire equivalent series Young's modulus based on the lacquered series compliance and size parameters of the lacquered copper round wire;

[0017] determining first transposition series compliance of the first transposed Litz wire based on the first transposition series compliance model and the lacquered copper round wire equivalent series Young's modulus, and determining first transposition equivalent series Young's modulus based on the first transposition series compliance and size parameters of the first transposed Litz wire;

[0018] determining a secondary transposition series flexibility of the secondary transposition Litz wire based on the secondary transposition series flexibility model and the primary transposition series equivalent Young's modulus, and determining the second series Young's modulus based on the secondary transposition series flexibility and size parameters of the secondary transposition Litz wire.

[0019] In a possible implementation, the second series Young's modulus is:

[0020]

[0021] wherein, E eq2 is a second series Young's modulus; delta eq2 is a secondary transposition series flexibility; w is a width of the primary transposition Litz wire; b is a thickness of the primary transposition Litz wire; t 3 is a double-side thickness of the first polyimide film; t 4 is a double-side thickness of the resin layer in the secondary transposition Litz wire; t 5 is a double-side thickness of the second polyimide film; dl is a length of a single enameled copper round wire along a length direction.

[0022] In a possible implementation, the second parallel flexibility model comprises an enameled copper round wire parallel flexibility model of the enameled copper round wire, a primary transposition parallel flexibility model of the primary transposition Litz wire, and a secondary transposition parallel flexibility model of the transposition Litz wire; and determining the second parallel Young's modulus of the secondary transposition Litz wire along the width direction based on the second parallel flexibility model comprises:

[0023] determining an enameled parallel flexibility of the enameled copper round wire based on the enameled copper round wire parallel flexibility model, and determining an enameled copper round wire equivalent parallel Young's modulus based on the enameled parallel flexibility and size parameters of the enameled copper round wire;

[0024] determining a primary transposition parallel flexibility of the primary transposition Litz wire based on the primary transposition parallel flexibility model and the enameled copper round wire equivalent parallel Young's modulus, and determining a primary transposition equivalent parallel Young's modulus based on the primary transposition parallel flexibility and size parameters of the primary transposition Litz wire;

[0025] determining a secondary transposition parallel flexibility of the secondary transposition Litz wire based on the secondary transposition parallel flexibility model and the primary transposition series equivalent Young's modulus, and determining the second parallel Young's modulus based on the secondary transposition parallel flexibility and size parameters of the secondary transposition Litz wire.

[0026] In a possible implementation, the second parallel Young's modulus is:

[0027]

[0028] wherein, is the second parallel Young's modulus; is the quadratic transposed parallel compliance; w is the width of the linear transposed Litz wire; b is the thickness of the linear transposed Litz wire; t 3 is the double-side thickness of the first polyimide film; t 4 is the double-side thickness of the resin layer in the quadratic transposed Litz wire; t 5 is the double-side thickness of the second polyimide film; dl is the length of a single enameled copper round wire along the length direction.

[0029] In a possible implementation, the method further includes:

[0030] obtaining the diameter of the copper round wire and the paint film thickness of the insulating paint film;

[0031] determining the volume fraction of the copper round wire based on the diameter and the paint film thickness, and determining a first weight of the second serial Young's modulus and a second weight of the third serial Young's modulus based on the volume fraction;

[0032] determining the second equivalent Young's modulus and the third equivalent Young's modulus based on the first weight, the second weight, the second serial Young's modulus, the second parallel Young's modulus, the third serial Young's modulus and the third parallel Young's modulus.

[0033] In a possible implementation, the second equivalent Young's modulus is:

[0034]

[0035]

[0036] wherein, is the second equivalent Young's modulus; is the first weight; V m is the volume fraction of the copper round wire.

[0037] In a possible implementation, the third equivalent Young's modulus is:

[0038]

[0039]

[0040] wherein, is a second equivalent Young's modulus; is a second weight; V m is a volume fraction of the copper round wire.

[0041] In another aspect, the application also provides a device for determining an equivalent Young's modulus of a secondary transposed Litz wire, comprising:

[0042] a series-parallel compliance model construction unit configured to construct a first parallel compliance model along a length direction, a second series compliance model and a second parallel compliance model along a width direction, and a third series compliance model and a third parallel compliance model along a thickness direction of the secondary transposed Litz wire;

[0043] a first equivalent Young's modulus determination unit configured to determine a first equivalent Young's modulus of the secondary transposed Litz wire along the length direction based on the first parallel compliance model;

[0044] a second equivalent Young's modulus determination unit configured to determine a second series Young's modulus and a second parallel Young's modulus of the secondary transposed Litz wire along the width direction based on the second series compliance model and the second parallel compliance model respectively, and to determine a second equivalent Young's modulus of the secondary transposed Litz wire along the width direction as a weighted sum of the second series Young's modulus and the second parallel Young's modulus;

[0045] a third equivalent Young's modulus determination unit configured to determine a third series Young's modulus and a third parallel Young's modulus of the secondary transposed Litz wire along the thickness direction based on the third series compliance model and the third parallel compliance model respectively, and to determine a third equivalent Young's modulus of the secondary transposed Litz wire along the thickness direction as a weighted sum of the third series Young's modulus and the third parallel Young's modulus.

[0046] The application provides a method for determining an equivalent Young's modulus of a secondary transposed Litz wire, which constructs a second series compliance model, a second parallel compliance model, a third series compliance model and a third parallel compliance model along a width direction and a thickness direction of the secondary transposed Litz wire respectively, considers two cases of series force transmission and parallel force transmission of an axial force in the secondary transposed Litz wire between different materials, and takes into account the common influence of the two cases on the Young's modulus, so that the equivalent method is closer to the actual structure, the equivalent precision is higher, and the accuracy of mechanical simulation of the secondary transposed Litz wire is improved. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort based on these drawings.

[0048] Figure 1 An embodiment flowchart of the method for determining the equivalent Young's modulus of the secondary transposition Litz wire provided by the present application is shown in the figure.

[0049] Figure 2 An embodiment structure diagram of the secondary transposition Litz wire provided by the present application is shown in the figure.

[0050] Figure 3 An embodiment three-dimensional structure diagram of the secondary transposition Litz wire provided by the present application is shown in the figure.

[0051] Figure 4 An embodiment flowchart of determining the second serial Young's modulus in step S103 of the present application is shown in the figure.

[0052] Figure 5 (a) An embodiment structure diagram of the enameled copper round wire provided by the present application is shown in the figure.

[0053] Figure 5 (b) An embodiment structure diagram of the enameled copper round wire serial flexibility division model provided by the present application is shown in the figure.

[0054] Figure 5 (c) An embodiment structure diagram of the enameled copper round wire serial flexibility model provided by the present application is shown in the figure.

[0055] Figure 6 (a) An embodiment structure diagram of the primary transposition Litz wire provided by the present application is shown in the figure.

[0056] Figure 6 (b) An embodiment structure diagram of the primary transposition Litz wire serial flexibility division model provided by the present application is shown in the figure.

[0057] Figure 6 (c) An embodiment structure diagram of the primary transposition Litz wire serial flexibility model provided by the present application is shown in the figure.

[0058] Figure 7 An embodiment structure diagram of the secondary transposition Litz wire serial flexibility division model provided by the present application is shown in the figure.

[0059] Figure 8 An embodiment structure diagram of the secondary transposition Litz wire serial flexibility model provided by the present application is shown in the figure.

[0060] Figure 9 An embodiment flow chart for determining the second parallel Young's modulus in step S103 provided by the present application is shown in the figure;

[0061] Figure 10 (a) An embodiment structure diagram of the parallel flexibility division model of the enameled copper round wire provided by the present application is shown in the figure;

[0062] Figure 10 (b) An embodiment structure diagram of the parallel flexibility model of the enameled copper round wire provided by the present application is shown in the figure;

[0063] Figure 11 (a) An embodiment structure diagram of the parallel flexibility division model of the primary transposition Litz wire provided by the present application is shown in the figure;

[0064] Figure 11 (b) An embodiment structure diagram of the parallel flexibility model of the primary transposition Litz wire provided by the present application is shown in the figure;

[0065] Figure 12 An embodiment structure diagram of the parallel flexibility division model of the secondary transposition Litz wire provided by the present application is shown in the figure;

[0066] Figure 13 An embodiment structure diagram of the parallel flexibility model of the secondary transposition Litz wire provided by the present application is shown in the figure;

[0067] Figure 14 An embodiment structure diagram of the determination of the equivalent Young's modulus weighting weight provided by the present application is shown in the figure;

[0068] Figure 15 An embodiment structure diagram of the equivalent Young's modulus determination device of the secondary transposition Litz wire provided by the present application is shown in the figure. DETAILED DESCRIPTION

[0069] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0070] It should be understood that the illustrative drawings are not drawn to scale. The flowcharts used in the present disclosure show the operations implemented according to some embodiments of the present disclosure. It should be understood that the operations of the flowcharts can not be implemented in order, steps without logical context relationship can be reversed in order or implemented simultaneously. In addition, one or more other operations can be added to the flowcharts or one or more operations can be removed from the flowcharts under the guidance of the present disclosure by those skilled in the art. Some block diagrams shown in the drawings are functional entities, which do not necessarily have to correspond to physically or logically independent entities. These functional entities can be implemented in the form of software, or in one or more hardware modules or integrated circuits, or in different network and / or processor systems and / or microcontroller systems.

[0071] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive or alternative embodiments. It is explicitly and implicitly understood that the embodiments described herein can be combined with other embodiments.

[0072] The present disclosure provides a method and device for determining the equivalent Young's modulus of a secondary transposed Litz wire.

[0073] Figure 1 An embodiment flowchart of the method for determining the equivalent Young's modulus of a secondary transposed Litz wire provided by the present disclosure is shown in FIG. 1, which includes the following steps. Figure 1

[0074] S101, constructing a first parallel compliance model along the length direction, a second series compliance model and a second parallel compliance model along the width direction, and a third series compliance model and a third parallel compliance model along the thickness direction of the secondary transposed Litz wire;

[0075] S102, determining the first equivalent Young's modulus of the secondary transposed Litz wire along the length direction based on the first parallel compliance model;

[0076] S103, determining the second series Young's modulus and the second parallel Young's modulus of the secondary transposed Litz wire along the width direction based on the second series compliance model and the second parallel compliance model respectively, and taking the weighted sum of the second series Young's modulus and the second parallel Young's modulus as the second equivalent Young's modulus of the secondary transposed Litz wire along the width direction;

[0077] ​S104, determine the third series Young's modulus and the third parallel Young's modulus of the secondary transposed Litz wire along the thickness direction based on the third series flexibility model and the third parallel flexibility model respectively, and take the weighted sum of the third series Young's modulus and the third parallel Young's modulus as the third equivalent Young's modulus of the secondary transposed Litz wire along the thickness direction.

[0078] In specific embodiments of the present application, as shown in Figure 2 The preparation process of the secondary transposed Litz wire is as follows:

[0079] First, the copper round wire with a diameter of d (radius of r) is subjected to insulating paint film treatment (double-sided thickness of t1 mm) to obtain a enameled copper round wire with a diameter of d1; secondly, n1 enameled copper round wires with a diameter of d1 are transposed and vacuum pressure impregnated to obtain a wmm×bmm primary transposed Litz wire, after vacuum pressure impregnation, the enameled copper round wire is attached with a resin layer with a double-sided thickness of t2 mm; then, the wmm×bmm primary transposed Litz wire is wrapped with a double-sided thickness of t3 mm polyimide film; thirdly, n2 wmm×bmm primary transposed Litz wires are transposed to obtain a Wmm×Bmm secondary transposed Litz wire, the secondary transposed Litz wire includes a resin layer with a double-sided thickness of t4 mm; then the secondary transposed Litz wire is wrapped with a double-sided thickness of t5 mm polyimide film, and finally, the secondary transposed Litz wire is vacuum pressure impregnated as a whole.

[0080] Wherein, the length direction, width direction and thickness direction of the secondary transposed Litz wire are as shown in Figure 3

[0081] It should be noted that: in order to simplify the analysis, the enameled copper round wire is extruded into a square during the preparation of the primary transposed Litz wire, that is, the enameled copper round wire is approximately simplified as a square, and the square length is determined according to the equal area principle. For example: when the radius of the copper round wire is r, the length of the simplified square is .

[0082] Since the secondary transposed Litz wire does not have the influence of axial force between series and parallel along the length direction, the equivalent Young's modulus along the length direction is derived according to the parallel model, which is not described here.

[0083] ​Compared with the prior art, the method for determining the equivalent Young's modulus of the secondary transposed Litz wire provided by the embodiment of the application can construct a second series flexibility model, a second parallel flexibility model, a third series flexibility model and a third parallel flexibility model in the width and thickness directions of the secondary transposed Litz wire, consider the series force transmission and parallel force transmission of the axial force in the secondary transposed Litz wire between different materials, and take into account the common influence of the series force transmission and parallel force transmission on the Young's modulus, so that the equivalent method is closer to the actual structure and has higher equivalent accuracy, and thus the accuracy of the mechanical simulation of the secondary transposed Litz wire can be improved.

[0084] As can be known from the preparation process of the secondary transposed Litz wire, the preparation process is: copper round wire-primary transposed Litz wire-secondary transposed Litz wire, and therefore, in some embodiments of the application, the process for determining the equivalent Young's modulus of the secondary transposed Litz wire is also performed according to this process. Specifically, the second series flexibility model includes a varnished copper round wire series flexibility model of the varnished copper round wire, a primary transposition series flexibility model of the primary transposed Litz wire, and a secondary transposition series flexibility model of the secondary transposed Litz wire, and then, as shown in Figure 4 the second series Young's modulus of the secondary transposed Litz wire along the width direction is determined based on the second series flexibility model in step S103, which includes:

[0085] S401, a varnished series flexibility of the varnished copper round wire is determined based on the varnished copper round wire series flexibility model, and a varnished series equivalent Young's modulus of the varnished copper round wire is determined based on the varnished series flexibility and the size parameters of the varnished copper round wire;

[0086] S402, a primary transposition series flexibility of the primary transposed Litz wire is determined based on the primary transposition series flexibility model and the varnished series equivalent Young's modulus, and a primary transposition equivalent series Young's modulus is determined based on the primary transposition series flexibility and the size parameters of the primary transposed Litz wire;

[0087] S403, a secondary transposition series flexibility of the secondary transposed Litz wire is determined based on the secondary transposition series flexibility model and the primary transposition equivalent series Young's modulus, and a second series Young's modulus is determined based on the secondary transposition series flexibility and the size parameters of the secondary transposed Litz wire.

[0088] In specific embodiments of the application, as shown in Figure 5 (a), a varnished copper round wire series flexibility division network is constructed based on the copper round wire, the insulating varnish film and the resin layer, and since this structure has symmetry, half of it is taken for analysis, and the flexibility division network is as shown in Figure 5 (b), this structure is divided into three regions from left to right along the series direction, the first region includes the resin first flexibility delta 1iFirst flexibility of insulating varnish film delta 1p Copper round wire flexibility delta 1c First flexibility of insulating varnish film delta 1p First flexibility of resin delta 1i The second region includes the second flexibility of the resin from top to bottom. delta 2i Second flexibility of insulating varnish film delta 2p Resin Second Flexibility delta 2i The third region includes the third resin flexibility. delta 3i .

[0089] Based on the above structural flexibility analysis, the following can be obtained: Figure 5 (c) The series flexibility model of enameled copper round wire. Based on Figure 5 (c) The series flexibility model of enameled copper round wire can be used to obtain the series flexibility of enameled copper round wire. for:

[0090]

[0091] Then the equivalent series Young's modulus of the enameled copper round wire for:

[0092]

[0093] In the formula, r is the radius of the round copper wire; t1 is the bilateral thickness of the insulating varnish film; t2 is the bilateral thickness of the resin layer covering the enameled copper round wire. dl It is the length of a single enameled copper round wire along its length direction.

[0094] In a specific embodiment of the present invention, a single-transformed Litz wire is prepared from 23 enameled copper round wires, and the structure of the single-transformed Litz wire is as follows: Figure 6 As shown in (a), similarly, due to its symmetry, a general structure is used for analysis, and its flexibility partitioning network is as follows: Figure 6 As shown in (b), this structure is divided into two regions from left to right along the series direction. The first region includes the fourth flexibility of polyimide from top to bottom. delta 4n Flexibility of enameled copper round wire delta 4c Polyimide fourth flexibility delta 4n The second region includes the fifth flexibility of polyimide. delta 5n .

[0095] Based on the flexibility analysis of the above structure, the following can be obtained Figure 6 The series flexibility model of the first transposition Litz wire of (c) is based on Figure 6 The series flexibility model of the first transposition Litz wire of (c) is based on

[0096]

[0097] The equivalent series Young's modulus of the first transposition Litz wire is lambda q2

[0098]

[0099] In the formula, w is the width of the first transposition Litz wire; t3 is the double-sided thickness of the polyimide film coated on the first transposition Litz wire.

[0100] In the specific embodiments of the present application, Figure 7 The flexibility division network of the second transposition Litz wire is composed of 9 first transposition Litz wires and a coated resin layer, and the flexibility division network is divided into four regions from left to right in the series direction, the first region is the polyimide seventh Young's modulus delta 7n The second region includes the parallel connection of the seventh resin flexibility delta 7p The eighth first transposition series flexibility delta 7c The fourth sixth first transposition series flexibility delta 6c The polyimide eighth flexibility delta 8n The third region includes the parallel connection of the eighth resin flexibility delta 8p The eighth first transposition series flexibility delta 8c The fourth sixth first transposition series flexibility delta 6c The polyimide eighth flexibility delta 8n The fourth region is the polyimide seventh flexibility delta 7n .

[0101] Based on the flexibility division structure, the following can be obtained Figure 8 The series flexibility model of the second transposition Litz wire of (c) is based on Figure 8 The series flexibility model of the second transposition Litz wire of (c) is based on

[0102] ​​​

[0103] The second series Young's modulus is:

[0104]

[0105] wherein, is the second series Young's modulus.

[0106] Similarly, the second parallel flexibility model includes the enameled copper round wire parallel flexibility model of the enameled copper round wire, the primary transposition parallel flexibility model of the primary transposition Litz wire, and the secondary transposition parallel flexibility model of the transposition Litz wire; then as shown in Figure 9 determining the second parallel Young's modulus of the secondary transposition Litz wire along the width direction based on the second parallel flexibility model in step S103, includes:

[0107] S901, determining the enameled copper round wire parallel flexibility of the enameled copper round wire based on the enameled copper round wire parallel flexibility model, and determining the enameled copper round wire equivalent parallel Young's modulus based on the enameled copper round wire parallel flexibility and the size parameters of the enameled copper round wire;

[0108] S902, determining the primary transposition Litz wire primary transposition parallel flexibility based on the primary transposition parallel flexibility model and the enameled copper round wire equivalent parallel Young's modulus, and determining the primary transposition equivalent parallel Young's modulus based on the primary transposition parallel flexibility and the size parameters of the primary transposition Litz wire;

[0109] S903, determining the secondary transposition Litz wire secondary transposition parallel flexibility based on the secondary transposition parallel flexibility model and the primary transposition series equivalent Young's modulus, and determining the second parallel Young's modulus based on the secondary transposition parallel flexibility and the size parameters of the secondary transposition Litz wire.

[0110] In specific embodiments of the present application, the enameled copper round wire parallel flexibility division model is divided into five areas from top to bottom along the parallel direction as shown in Figure 10 (a), the first area is the third parallel resin flexibility , the second area includes the second parallel enamel film flexibility and the second parallel resin flexibility , the third area includes the first parallel copper round wire flexibility , the first parallel enamel film flexibility and the first parallel resin flexibility , the fourth area includes the second parallel enamel film flexibility and the second parallel resin flexibility , and the fifth area is the third parallel resin flexibility .

[0111] Based on the above flexibility analysis, the following can be obtained:Figure 10 The parallel flexibility model of the enameled copper round wire of (b) is based on the parallel flexibility model of the enameled copper round wire, and the parallel flexibility of the enameled copper round wire is :

[0112]

[0113] The equivalent series Young's modulus of the enameled copper round wire is :

[0114]

[0115] In a specific embodiment of the present application, the primary transposed Litz wire is prepared from 23 enameled copper round wires, and the flexibility network thereof is as shown in (a). Figure 11 The structure is divided into three regions from top to bottom in the parallel direction, the first region is the polyimide parallel fourth flexibility , the second region includes the parallel enameled copper round wire flexibility and the polyimide parallel fourth flexibility from left to right in series, and the third region is the polyimide parallel fourth flexibility .

[0116] Based on the flexibility analysis of the above structure, the primary transposed Litz wire series flexibility model as shown in (b) is obtained, and based on the primary transposed series flexibility model of (b), the primary transposed parallel flexibility Figure 11 Figure 11 is obtained.

[0117]

[0118] The primary transposed parallel equivalent Young's modulus is E q2 0

[0119]

[0120] In a specific embodiment of the present application, Figure 12 is the parallel flexibility network of the secondary transposed Litz wire, which is composed of 9 primary transposed Litz wires, and the parallel flexibility network is divided into seven regions from top to bottom in the parallel direction, the first region is the parallel polyimide eighth flexibility , the second region includes the parallel polyimide seventh flexibility , the parallel seventh resin flexibility , the parallel sixth primary transposed series equivalent flexibility , the parallel eighth resin flexibility and the parallel polyimide seventh flexibility ​​​The third region, the fourth region, the fifth region and the sixth region each include a parallel polyimide seventh compliance , two parallel sixth primary transposition series equivalent compliance and the parallel polyimide seventh compliance The seventh region is a parallel polyimide eighth compliance .

[0121] Based on the above compliance network, a primary transposition Litz wire parallel compliance model can be obtained as Figure 13 Based on the secondary transposition parallel compliance model Figure 13 , the secondary transposition parallel compliance is:

[0122]

[0123] The second parallel Young's modulus is:

[0124]

[0125] wherein, The second parallel Young's modulus is:

[0126] It should be understood that the derivation process of the third series Young's modulus and the third parallel Young's modulus is the same as that of the second series Young's modulus and the second parallel Young's modulus, and is not repeated here.

[0127] Since the second equivalent Young's modulus in the embodiment of the application is a weighted sum of the second series Young's modulus and the second parallel Young's modulus, and the third equivalent Young's modulus is a weighted sum of the third series Young's modulus and the third parallel Young's modulus, i.e., the weight distribution is crucial to the accuracy of the equivalent Young's modulus, therefore, in some embodiments of the application, as shown in Figure 14 The equivalent Young's modulus determination method of the secondary transposition Litz wire further includes:

[0128] S1401, obtaining the diameter of the copper round wire and the paint film thickness of the insulating paint film;

[0129] S1402, determining the volume fraction of the copper round wire based on the diameter and the paint film thickness, and determining the first weight of the second series Young's modulus and the second weight of the third series Young's modulus based on the volume fraction;

[0130] S1403, determining the second equivalent Young's modulus and the third equivalent Young's modulus based on the first weight, the second weight, the second series Young's modulus, the second parallel Young's modulus, the third series Young's modulus and the third parallel Young's modulus.

[0131] Specifically, the second equivalent Young's modulus is:

[0132]

[0133]

[0134] wherein, is a second equivalent Young's modulus; is a first weight; V m is a volume fraction of the copper round wire.

[0135] The third equivalent Young's modulus is:

[0136]

[0137]

[0138] wherein, is a second equivalent Young's modulus; is a second weight.

[0139] The embodiment of the present application can further improve the accuracy of the determined equivalent Young's modulus by assigning different series-parallel weights along the width and thickness directions of the secondary transposed Litz wire.

[0140] In order to better implement the equivalent Young's modulus determination method of the secondary transposed Litz wire in the embodiment of the present application, on the basis of the equivalent Young's modulus determination method of the secondary transposed Litz wire, correspondingly, the embodiment of the present application also provides a secondary transposed Litz wire equivalent Young's modulus determination device, as shown in Figure 5 The secondary transposed Litz wire equivalent Young's modulus determination device 1500 comprises:

[0141] A series-parallel compliance model construction unit 1501 is configured to construct a first parallel compliance model along the length direction, a second series compliance model and a second parallel compliance model along the width direction, and a third series compliance model and a third parallel compliance model along the thickness direction of the secondary transposed Litz wire.

[0142] A first equivalent Young's modulus determination unit 1502 is configured to determine a first equivalent Young's modulus along the length direction of the secondary transposed Litz wire based on the first parallel compliance model.

[0143] A second equivalent Young's modulus determination unit 1503 is configured to determine a second series Young's modulus and a second parallel Young's modulus along the width direction of the secondary transposed Litz wire based on the second series compliance model and the second parallel compliance model respectively, and take the weighted sum of the second series Young's modulus and the second parallel Young's modulus as the second equivalent Young's modulus along the width direction of the secondary transposed Litz wire.

[0144] The third equivalent Young's modulus determination unit 1504 is configured to determine a third series Young's modulus and a third parallel Young's modulus of the secondary transposed Litz wire along the thickness direction based on the third series compliance model and the third parallel compliance model respectively, and take a weighted sum of the third series Young's modulus and the third parallel Young's modulus as the third equivalent Young's modulus of the secondary transposed Litz wire along the thickness direction.

[0145] The equivalent Young's modulus determination device 1500 of the secondary transposed Litz wire provided by the above embodiment can implement the technical solutions described in the above equivalent Young's modulus determination method embodiments of the secondary transposed Litz wire, and the principles of the implementation of each module or unit can be referred to the corresponding content in the above equivalent Young's modulus determination method embodiments of the secondary transposed Litz wire, which will not be described here.

[0146] Those skilled in the art can understand that all or part of the processes of the above-mentioned embodiments can be completed by a computer program instructing relevant hardware (such as a processor, a controller, etc.) to complete. The computer program can be stored in a computer readable storage medium. The computer readable storage medium includes a magnetic disk, an optical disk, a read-only memory, a random access memory, etc.

[0147] The above provides a detailed description of the equivalent Young's modulus determination method and device of the secondary transposed Litz wire. The principle and implementation of the application are described by applying specific examples. The above embodiment is only used to help understand the method and its core idea. Meanwhile, for those skilled in the art, the specific implementation and application range will be changed according to the idea of the application. In summary, the content of the specification should not be understood as a limitation of the application.

Claims

1. A method for determining the equivalent Young's modulus of a secondary transposed Litz wire, characterized in that, The method comprises the following steps: constructing a first parallel flexibility model along the length direction, a second series flexibility model and a second parallel flexibility model along the width direction, and a third series flexibility model and a third parallel flexibility model along the thickness direction of the secondary transposed Litz wire; determining a first equivalent Young's modulus of the secondary transposed Litz wire along the length direction based on the first parallel flexibility model; determining a second series Young's modulus and a second parallel Young's modulus of the secondary transposed Litz wire along the width direction based on the second series flexibility model and the second parallel flexibility model respectively, and taking the weighted sum of the second series Young's modulus and the second parallel Young's modulus as a second equivalent Young's modulus of the secondary transposed Litz wire along the width direction; determining a third series Young's modulus and a third parallel Young's modulus of the secondary transposed Litz wire along the thickness direction based on the third series flexibility model and the third parallel flexibility model respectively, and taking the weighted sum of the third series Young's modulus and the third parallel Young's modulus as a third equivalent Young's modulus of the secondary transposed Litz wire along the thickness direction; the preparation process of the secondary transposed Litz wire is as follows: insulating varnish film treatment is performed on the copper round wire to obtain enameled copper round wire; a plurality of enameled copper round wires are transposed, and vacuum pressure impregnation is performed on the transposed plurality of enameled copper round wires to obtain primary transposed Litz wire, and a first polyimide film is wrapped around the primary transposed Litz wire; secondary transposition is performed on the primary transposed Litz wire wrapped with the first polyimide film to obtain secondary transposed Litz wire, a second polyimide film is wrapped around the secondary transposed Litz wire, and vacuum pressure impregnation is performed on the secondary transposed Litz wire wrapped with the second polyimide film; the second series flexibility model comprises an enameled copper round wire series flexibility model of the enameled copper round wire, a primary transposition series flexibility model of the primary transposed Litz wire, and a secondary transposition series flexibility model of the transposed Litz wire; and determining the second series Young's modulus of the secondary transposed Litz wire along the width direction based on the second series flexibility model comprises: determining enameled series flexibility of the enameled copper round wire based on the enameled copper round wire series flexibility model, and determining enameled copper round wire equivalent series Young's modulus based on the enameled series flexibility and size parameters of the enameled copper round wire; determining primary transposition series flexibility of the primary transposed Litz wire based on the primary transposition series flexibility model and the enameled copper round wire equivalent series Young's modulus, and determining primary transposition equivalent series Young's modulus based on the primary transposition series flexibility and size parameters of the primary transposed Litz wire; determining secondary transposition series flexibility of the secondary transposed Litz wire based on the secondary transposition series flexibility model and the primary transposition equivalent series Young's modulus, and determining the second series Young's modulus based on the secondary transposition series flexibility and size parameters of the secondary transposed Litz wire.

2. The method of claim 1, wherein, The second series Young's modulus is: In the formula, E eq2 is the second series Young's modulus; δ eq2 is the quadratic transposed series compliance; w is the width of the primary transposed Litz wire; b is the thickness of the primary transposed Litz wire; t 3 is the double-sided thickness of the first polyimide film; t 4 is the double-sided thickness of the resin layer in the secondary transposed Litz wire; t 5 is the double-sided thickness of the second polyimide film; dl is the length of a single enameled copper round wire along the length direction.

3. The method of claim 2, wherein, The second parallel flexibility model comprises a parallel flexibility model of the enameled copper round wire, a parallel flexibility model of the primary transposed Litz wire, and a parallel flexibility model of the secondary transposed Litz wire; and the second parallel Young's modulus of the secondary transposed Litz wire in the width direction is determined based on the second parallel flexibility model, comprising: determining the parallel flexibility of the enameled copper round wire based on the parallel flexibility model of the enameled copper round wire, and determining the equivalent parallel Young's modulus of the enameled copper round wire based on the parallel flexibility and the size parameters of the enameled copper round wire; determining the parallel flexibility of the primary transposed Litz wire based on the parallel flexibility model of the primary transposed Litz wire and the equivalent parallel Young's modulus of the enameled copper round wire, and determining the equivalent parallel Young's modulus of the primary transposed Litz wire based on the parallel flexibility and the size parameters of the primary transposed Litz wire; determining the parallel flexibility of the secondary transposed Litz wire based on the parallel flexibility model of the secondary transposed Litz wire and the equivalent parallel Young's modulus of the primary transposed Litz wire, and determining the second parallel Young's modulus based on the parallel flexibility and the size parameters of the secondary transposed Litz wire.

4. The method of claim 3, wherein, The second parallel Young's modulus is: In the formula, is the second parallel Young's modulus; is the quadratic transposed parallel compliance; w is the width of the linear transposed Litz wire; b is the thickness of the linear transposed Litz wire; t 3 is the double-side thickness of the first polyimide film; t 4 is the double-side thickness of the resin layer in the quadratic transposed Litz wire; t 5 is the double-side thickness of the second polyimide film; dl is the length of a single enameled copper round wire along the length direction.

5. The method of claim 4, wherein, The method further comprises: obtaining the diameter of the copper round wire and the thickness of the insulating paint film; determining the volume fraction of the copper round wire based on the diameter and the thickness of the paint film, and determining the first weight of the second serial Young's modulus and the second weight of the third serial Young's modulus based on the volume fraction; determining the second equivalent Young's modulus and the third equivalent Young's modulus based on the first weight, the second weight, the second serial Young's modulus, the second parallel Young's modulus, the third serial Young's modulus, and the third parallel Young's modulus.

6. The method for determining the equivalent Young's modulus of a Litz line with secondary transposition according to claim 5, characterized in that, The second equivalent Young's modulus is: wherein C2 is a second weight; and V is a volume fraction of copper round wires. m C2 is a second weight; and V is a volume fraction of copper round wires.

7. The method for determining the equivalent Young's modulus of a Litz line with secondary transposition according to claim 5, characterized in that, The third equivalent Young's modulus is: wherein E2 is the second equivalent Young's modulus; C3 is the second weight; V m is the volume fraction of copper round wires.

8. An apparatus for determining the equivalent Young's modulus of a secondary transposed Litz wire, characterized by The device is suitable for the equivalent Young's modulus determination method of the secondary transposed Litz wire according to any one of claims 1-7, and the device comprises: a series-parallel flexibility model construction unit configured to construct a first parallel flexibility model in the length direction, a second serial flexibility model and a second parallel flexibility model in the width direction, and a third serial flexibility model and a third parallel flexibility model in the thickness direction of the secondary transposed Litz wire; a first equivalent Young's modulus determination unit configured to determine a first equivalent Young's modulus of the secondary transposed Litz wire in the length direction based on the first parallel flexibility model; a second equivalent Young's modulus determination unit configured to determine a second serial Young's modulus and a second parallel Young's modulus of the secondary transposed Litz wire in the width direction based on the second serial flexibility model and the second parallel flexibility model respectively, and to take a weighted sum of the second serial Young's modulus and the second parallel Young's modulus as a second equivalent Young's modulus of the secondary transposed Litz wire in the width direction. A third equivalent Young's modulus determination unit is configured to determine a third series Young's modulus and a third parallel Young's modulus of the secondally displaced Litz wire along the thickness direction based on the third series compliance model and the third parallel compliance model, respectively, and to determine a third equivalent Young's modulus of the secondally displaced Litz wire along the thickness direction as a weighted sum of the third series Young's modulus and the third parallel Young's modulus.

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