Busbar cooling structure

Abstract

The present invention provides a busbar cooling structure that effectively cools a busbar and cools multiple busbars in a well-balanced manner. The busbar cooling structure cools multiple busbars and includes an insulating cooling portion disposed in contact with a portion of each of the multiple busbars. The multiple busbars have different lengths from the starting point to the end point of a current path, and the contact area between each busbar and the cooling portion is set to be proportional to the length of each busbar.

Description

Technical Field

[0001] The present invention relates to a busbar cooling structure. Background Art

[0002] Patent Document 1 discloses a cooling structure that transfers heat generated by semiconductor elements within a semiconductor module to a cooling plate, where the heat is dissipated by the cooling plate. In this cooling structure, a busbar connected to the semiconductor elements extends from the semiconductor module to the outside. A heat transfer plate, which transfers heat from the busbar to the cooling plate, extends from the cooling plate and is attached to the busbar at its tip.

[0003]

Prior art literature

[0004] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-060304 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] As electric power systems increase in current, the self-heating of busbars and the amount of heat received from connected internal electrical components increase. Without proactive busbar cooling, the increased size required to dissipate heat leads to increased busbar size, internal electrical components, and ultimately, a larger unit size. Therefore, effective busbar cooling is desirable.

[0008] Furthermore, when there are multiple busbars, balanced cooling of each is necessary. If cooling performance varies significantly, the busbar with the lowest cooling performance will be oversized to facilitate heat dissipation, leading to an increase in the unit size. This results in the unit size being dominated by the busbar with the lowest cooling performance.

[0009] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a bus bar cooling structure capable of efficiently cooling a bus bar and cooling a plurality of bus bars in a well-balanced manner.

[0010] Means for solving problems

[0011] The present invention is a busbar cooling structure for cooling multiple busbars, characterized in that the busbar cooling structure has an insulating cooling portion arranged in a manner that contacts a portion of each of the multiple busbars, the multiple busbars have different lengths from the starting point to the end point of the current path, and the contact area between each busbar and the cooling portion is set to an area proportional to the length of each busbar.

[0012] This configuration allows the cooling area of ​​each busbar to be proportional to its length, thus minimizing variations in cooling performance when cooling multiple busbars of varying lengths. This allows efficient and balanced cooling of the busbars.

[0013] Furthermore, the cooling portion may be a heat conducting member having higher thermal conductivity than the bus bar, each bus bar may be provided upright from the heat conducting member with the portion embedded in the heat conducting member, and the plurality of bus bars may be stacked in a direction in which they are provided upright from the heat conducting member.

[0014] According to this configuration, by embedding a portion of the bus bar in the heat-conductive member, the cooling performance of the bus bar is improved.

[0015] In addition, the busbar may include: a heat transfer portion, which is embedded in the heat conductive member; a current-carrying portion, which forms a portion extending from the starting point to the end point; and a branch portion, which branches from the current-carrying portion and reaches the heat transfer portion, and the heat transfer portion is not included in the current path.

[0016] According to this configuration, heat can be dissipated using the portion branching from the current path.

[0017] Furthermore, the heat conducting member may be formed in a rectangular parallelepiped shape, and the branch portions of the plurality of bus bars may be provided standing from the heat conducting member with the heat transfer portions arranged in parallel in the longitudinal direction of the heat conducting member, and the conducting portions may be stacked in the standing direction.

[0018] According to this configuration, by stacking a plurality of bus bars in the vertical arrangement direction, space can be effectively utilized, thereby achieving space saving.

[0019] Effects of the Invention

[0020] In the present invention, since the cooling area of ​​each busbar is proportional to its length, variations in cooling performance can be suppressed when cooling multiple busbars of varying lengths. This allows efficient and balanced cooling of the busbars. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a perspective view showing a bus bar cooling structure in the embodiment.

[0022] Figure 2 It shows that Figure 1 A perspective view of the bus bar cooling structure as viewed from the opposite side.

[0023] Figure 3 It shows that Figure 1 A side view of the busbar cooling structure as viewed from the X direction.

[0024] Figure 4 It shows that Figure 1 A top view of the busbar cooling structure as viewed from the Z direction.

[0025] Figure 5 Graph showing the relationship between bus bar length and cooling area.

[0026] Figure 6 It is a graph showing the relationship between bus bar width and current value.

[0027] Figure 7 This is a diagram showing the relationship between the number of bus bars and the current value in a structure in which a plurality of bus bars are stacked in the Z direction.

[0028] Figure 8 It is a perspective view schematically showing a bus bar cooling structure of a comparative example.

[0029] Figure 9 It shows that Figure 8 A perspective view of the bus bar cooling structure as viewed from the opposite side.

[0030] Figure 10 It shows that Figure 8 A side view of the busbar cooling structure as viewed from the X direction.

[0031] Figure 11 It shows that Figure 8 A top view of the busbar cooling structure as viewed from the Z direction.

[0032] Figure 12 This is a side view for comparing and explaining the sizes of the bus bar cooling structure in the Z direction.

[0033] Figure 13 This is a plan view for comparing and explaining the sizes of the bus bar cooling structure in the X direction.

[0034] Description of Reference Numerals

[0035] 1 Busbar cooling structure

[0036] 2 busbars

[0037] 2A Bus Bar 1

[0038] 2B Bus Bar 2

[0039] 2C Bus Bar 3

[0040] 2D Bus Bar 4

[0041] 2E Bus 5

[0042] 2F Bus Bar 6

[0043] 3Heat conduction components

[0044] 21, 21A, 21B, 21C, 21D, 21E, 21F starting point

[0045] 22, 22A, 22B, 22C, 22D, 22E, 22F end points

[0046] 23, 23A, 23B, 23C, 23D, 23E, 23F energized parts

[0047] 24, 24A, 24B, 24C, 24D, 24E, 24F heat transfer section

[0048] 25, 25A, 25B, 25C, 25D, 25E, 25F branches DETAILED DESCRIPTION

[0049] Hereinafter, the bus bar cooling structure in the embodiment of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiment described below.

[0050] Figure 1 It is a diagram schematically showing a bus bar cooling structure in an embodiment. Figure 2 It shows that Figure 1 A perspective view of the bus bar cooling structure as viewed from the opposite side. Figure 3 It shows that Figure 1 A side view of the busbar cooling structure as viewed from the X direction. Figure 4 It shows that Figure 1 The busbar cooling structure is a top view of the busbar cooling structure when viewed from the Z direction. Figures 1 to 4 In the figure, the internal structure is shown in perspective. The X and Y directions are perpendicular to each other. The Z direction is perpendicular to the XY plane.

[0051] A busbar cooling structure 1 cools a plurality of busbars 2. Busbar cooling structure 1 has a structure in which a portion of each busbar 2 is in contact with a heat conducting member 3. In busbar cooling structure 1, heat from busbar 2 is transferred from busbar 2 to heat conducting member 3, thereby cooling busbar 2.

[0052] Busbar 2 is a plate-shaped conductive member. It is formed from a metal material such as aluminum, copper, nickel, or stainless steel. Busbar 2 has an input-side connection portion (starting point) for connecting to input-side electrical components and an output-side connection portion (end point) for connecting to output-side electrical components. Busbar 2 electrically connects the electrical components to one another. The physical connection method (fastening method) between busbar 2 and the electrical components is not particularly limited.

[0053] For example, the busbar 2 is included in an electrical unit in which a plurality of electrical components are unitized, and is housed in a unit housing together with the electrical components to be connected. The unit housing (hereinafter, simply referred to as the housing) is a housing that houses the unitized electrical components. Inside the housing, a certain electrical component and other electrical components are electrically connected by the busbar 2. When power is supplied from a certain electrical component (input side) to other electrical components (output side) via the busbar 2, in order to allow a large current to flow between the certain electrical component and the other electrical components, the current path therebetween is branched through a plurality of busbars 2. That is, the busbar 2 is a busbar for a large current to flow, and a branched current path consisting of a plurality of busbars 2 is formed.

[0054] The plurality of busbars 2 are composed of six busbars 2A, 2B, 2C, 2D, 2E, and 2F of different lengths. This length (busbar length) is the distance from the starting point 21 to the end point 22 of the current path. The starting point 21 is the point where the input side electrical components are connected. The end point 22 is the point where the output side electrical components are connected. Figure 1 As shown, the plurality of bus bars 2 include a first bus bar 2A, a second bus bar 2B, a third bus bar 2C, a fourth bus bar 2D, a fifth bus bar 2E, and a sixth bus bar 2F in descending order of distance from a starting point 21 to an end point 22 of a current path.

[0055] First bus bar 2A has a starting point 21A serving as an input-side connection and an end point 22A serving as an output-side connection, and is formed to maximize the distance from starting point 21A to end point 22A of the current path. First bus bar 2A electrically connects electrical components, forming a current path between these components, extending from starting point 21A to end point 22A.

[0056] Second bus bar 2B has a starting point 21B, which serves as an input-side connection, and an end point 22B, which serves as an output-side connection. It is shaped so that the distance from starting point 21B to end point 22B of the current path is the second longest. Second bus bar 2B electrically connects electrical components, forming a current path between these components, from starting point 21B to end point 22B.

[0057] Third bus bar 2C has a starting point 21C, which serves as an input-side connection, and an end point 22C, which serves as an output-side connection. It is shaped so that the distance from starting point 21C to end point 22C of the current path is the third longest. Third bus bar 2C electrically connects electrical components, forming a current path between these components, extending from starting point 21C to end point 22C.

[0058] Fourth bus bar 2D has a starting point 21D serving as an input-side connection and an end point 22D serving as an output-side connection, and is formed so that the distance from starting point 21D to end point 22D of the current path is the fourth longest. Fourth bus bar 2D electrically connects electrical components, forming a current path between these components, extending from starting point 21D to end point 22D.

[0059] The fifth bus bar 2E has a starting point 21E, which serves as an input-side connection, and an end point 22E, which serves as an output-side connection. The distance from the starting point 21E to the end point 22E of the current path is the fifth longest. The fifth bus bar 2E electrically connects the electrical components, forming a current path between these components, from the starting point 21E to the end point 22E.

[0060] The sixth bus bar 2F has a starting point 21F serving as an input-side connection and an end point 22F serving as an output-side connection. The sixth bus bar 2F is formed to have the sixth longest distance from the starting point 21F to the end point 22F of the current path, i.e., the shortest shape. The sixth bus bar 2F electrically connects the electrical components, forming a current path between these components, extending from the starting point 21F to the end point 22F.

[0061] The 1st to 6th busbars 2A to 2F are all connected to the electrical component on the same input side (the 1st electrical component) and the electrical component on the same output side (the 2nd electrical component). The 1st to 6th busbars 2A to 2F are connected in such a way as to form six current paths between the 1st electrical component and the 2nd electrical component. For example, the busbar cooling structure 1 can be applied to a boost converter, where the reactor provided on the input side and the power module provided on the output side are electrically connected using the 1st to 6th busbars 2A to 2F. In this case, the unit is a boost converter unit (boost DC / DC converter), and the housing is a converter housing that accommodates the boost converter unit. The unit can be mounted on a vehicle.

[0062] Furthermore, each bus bar 2 is provided upright from the heat conduction member 3 in a state where a portion of the bus bar 2 is embedded in the heat conduction member 3 .

[0063] The heat conduction member 3 is a member having high thermal conductivity and high insulation properties. The heat conduction member 3 is an insulating cooling unit formed from a material (high thermal conductivity material) having a higher thermal conductivity than the busbars 2. The heat conduction member 3 functions as a cooling unit that cools each busbar 2 by receiving heat from the busbars 2.

[0064] The heat conduction member 3 is formed in a rectangular parallelepiped shape and extends along the Y direction with the X direction as the short side direction, the Y direction as the long side direction, and the Z direction as the height direction.

[0065] For example, the heat-conducting member 3 is housed within the housing in close contact with the inner surface of the housing. The heat-conducting member 3 forms a thermal path for transferring heat from the busbar 2 from the heat-conducting member 3 to the housing. The housing functions as a heat sink that dissipates heat from the busbar 2. For example, if the busbar 2 is made of copper and the housing is made of aluminum, the heat-conducting member 3 is formed of a material with a higher thermal conductivity than copper. The high insulating properties of the heat-conducting member 3 prevent short circuits between the busbar 2 and the housing.

[0066] Furthermore, the bus bar cooling structure 1 is configured to directly transfer heat from each bus bar 2 to the heat conducting member 3. Each bus bar 2 includes a portion that contacts the heat conducting member 3 and directly transfers heat from the bus bar 2 to the heat conducting member 3.

[0067] Specifically, the bus bar 2 has a starting point 21, an end point 22, a current-carrying portion 23, a heat transfer portion 24, and a branch portion 25. The bus bar 2 is formed of a plate-shaped member having a thickness of 2 mm.

[0068] In this description, when starting points 21A, 21B, 21C, 21D, 21E, and 21F are not particularly distinguished, they are simply referred to as starting point 21 by omitting the designations A to F. Similarly, designations A to F may also be omitted for end point 22, current-carrying portion 23, heat transfer portion 24, and branch portion 25.

[0069] The conducting portion 23 forms the current path of the busbar 2, extending from the starting point 21 to the end point 22 of the current path. The starting point 21, the end point 22, and the conducting portion 23 are positioned higher than the heat conducting member 3 in the Z direction and do not contact the heat conducting member 3. In the Y direction, the starting point 21 is located on one side, and the end point 22 is located on the other side. The conducting portion 23 extends along the Y direction, connecting the starting point 21 and the end point 22. The conducting portion 23 has a thickness of 2 mm and a width of 22 mm.

[0070] In addition, if Figure 2As shown, the conducting portions 23 are stacked in the Z direction. The conducting portions 23 have a first portion located on one side of the Y direction, closer to the starting point 21; a second portion located on the other side of the Y direction, closer to the end point 22; and an intermediate portion extending in the Y direction to connect the first and second portions. In the plurality of bus bars 2, the conducting portions 23 are stacked in the Z direction, with the intermediate portions of the conducting portions 23 stacked in the Z direction. The first and second portions of the conducting portions 23 are stacked in the Y direction.

[0071] The heat transfer portion 24 is a portion that transfers heat from the busbar 2 directly to the heat conducting member 3. The heat transfer portion 24 is embedded in the heat conducting member 3, with its surface in contact with the heat conducting member 3. The surface of the heat transfer portion 24 is in surface contact (close contact) with the surface of the heat conducting member 3. The heat transfer portion 24 is the tip of the branch portion 25 that branches off from the current conducting portion 23 and is therefore not included in the current path. The heat transfer portion 24 is formed to the same thickness of 2 mm as the current conducting portion 23, but its width does not need to be the same width as the current conducting portion 23. The width of the heat transfer portion 24 is set according to the length of each busbar 2.

[0072] The branch portion 25 is a portion that branches from the power supply portion 23 and reaches the heat transfer portion 24. Figure 1 As shown, the branch portion 25 extends upward from the heat conducting member 3 in the Z direction. Since the branch portion 25 branches off from the current conducting portion 23, it is not included in the current path. This branch portion 25 functions as a heat conducting portion that transfers heat from the current conducting portion 23 to the heat transfer portion 24. Heat from the current conducting portion 23 is transferred to the heat transfer portion 24 via the branch portion 25, and then from the heat transfer portion 24 to the heat conducting member 3. The branch portion 25 has the same thickness of 2 mm as the current conducting portion 23 and the same width as each heat transfer portion 24.

[0073] Each bus bar 2 configured in this manner transfers heat from the heat transfer portion 24 to the heat conducting member 3. At this time, heat generated by the bus bar itself when energized, and heat received from the electrical component fastened to the start point 21 or the end point 22, is transferred from each bus bar 2 to the heat conducting member 3. Furthermore, in the bus bar cooling structure 1, the contact area (contact area, cooling area) between the bus bar 2 and the heat conducting member 3 is set according to the length of each bus bar 2 in order to provide balanced cooling for the six bus bars 2A, 2B, 2C, 2D, 2E, and 2F of varying lengths.

[0074] Specifically, in the bus bar 2, the heat generated by the bus bar itself (self-heat) is the loss during power supply, i.e., RI. 2Indicates. R is the resistance value of the busbar 2, and I is the value of the current flowing in the busbar 2. In each busbar 2, when the cross-sectional area of ​​the current path is formed to be the same size, the loss when the current is passed through each busbar 2 is proportional to the length of the current path of each busbar 2 (busbar length ∝ R). The heat dissipation of each busbar 2 is proportional to the contact area with the heat conduction member 3 (heat dissipation ∝ area). Therefore, in the busbar cooling structure 1, as Figure 5 As shown, the cooling area of ​​each bus bar 2 is set to an area proportional to the distance from the starting point 21 to the end point 22 of each bus bar 2 (bus bar length).

[0075] The cooling area of ​​the busbar 2 is the area (contact area) where the heat transfer portion 24 contacts the heat conduction member 3. In the plurality of busbars 2, the branch portions 25 are arranged upright from the heat conduction member 3, with the heat transfer portions 24 arranged side by side in the longitudinal direction (Y direction) of the heat conduction member 3. Each heat transfer portion 24 is arranged at the same position in the transverse direction (X direction) of the heat conduction member 3. Furthermore, the heat transfer portions 24A, 24B, 24C, 24D, 24E, and 24F of each busbar 2 are formed to have the same thickness and are embedded in the heat conduction member 3 at the same depth. In other words, the size of the cooling area of ​​the busbar 2 is determined by the width of the heat transfer portion 24. In the plurality of busbars 2, although the width of each current-carrying portion 23 is formed to be the same, the heat transfer portion 24 is a portion that branches from the current-carrying portion 23. Therefore, the width of the heat transfer portion 24 can be formed to be different from the width of the current-carrying portion 23.

[0076] like Figure 1 and Figure 3 As shown, the cooling area of ​​the first bus bar 2A is the area where the heat transfer portion 24A contacts the heat conduction member 3. The heat transfer portion 24A is formed to have the widest width. The heat transfer portion 24A is formed from two parts. The heat transfer portion 24A includes a first contact portion 241 located on one side in the Y direction, and a second contact portion 242 located on the other side in the Y direction. The cooling area of ​​the first bus bar 2A is the sum of the area where the first contact portion 241 contacts the heat conduction member 3 and the area where the second contact portion 242 contacts the heat conduction member 3.

[0077] like Figure 1 and Figure 3 As shown, the cooling area of ​​the second bus bar 2B is the area where the heat transfer portion 24B is in contact with the heat conduction member 3. The heat transfer portion 24B is formed to have the second widest width.

[0078] like Figure 1 and Figure 3 As shown, the cooling area of ​​the third bus bar 2C is the area where the heat transfer portion 24C is in contact with the heat conduction member 3. The heat transfer portion 24C is formed to have the third widest width.

[0079] like Figure 1 and Figure 3 As shown, the cooling area of ​​the fourth bus bar 2D is the area where the heat transfer portion 24D is in contact with the heat conduction member 3. The heat transfer portion 24D is formed to have the fourth widest width.

[0080] like Figure 1 and Figure 3 As shown, the cooling area of ​​the fifth bus bar 2E is the area where the heat transfer portion 24E is in contact with the heat conduction member 3. The heat transfer portion 24E is formed to have the fifth largest width.

[0081] like Figure 1 and Figure 3 As shown, the cooling area of ​​the sixth bus bar 2F is the area where the heat transfer portion 24F is in contact with the heat conduction member 3. The heat transfer portion 24F is formed to have the sixth widest width, that is, the narrowest width.

[0082] According to the bus bar cooling structure 1 configured in this manner, by setting the cooling area of ​​each bus bar 2 to a size proportional to the length of the current path, variations in cooling performance among the bus bars 2 due to differences in their lengths can be suppressed.

[0083] Figure 6 It is a graph showing the relationship between bus bar width and current value. Figure 7 : is a diagram showing the relationship between the number of bus bars and the current value in a structure in which a plurality of bus bars are stacked in the Z direction. Figure 6 2 shows an example in which the bus bar thickness is fixed at 2 mm and the bus bar width is varied.

[0084] Figure 6 The relationship between the current value and the bus bar width (bus bar cross-sectional area) shown is expressed by the relationship formula of Melson & Booth. Figure 6 The figure shows the busbar width (busbar cross-sectional area) required to support a given current value. In other words, it shows the allowable current value corresponding to the busbar width. For example, a busbar width of 9 mm is required to support a current of 100 A.

[0085] Figure 7 , it is shown that a structure in which a plurality of bus bars are stacked in the Z direction is excellent in compactness. Figure 7 The relationship between the current value and the number of bus bars shown in the figure shows that in a structure in which a plurality of bus bars are stacked in the Z direction, the current value and the number of bus bars increase (the closer to the Z direction). Figure 7 The lower right direction of the graph shown in the figure), the more compact the body. Figure 7As shown, in the structure in which two bus bars are stacked in the Z direction, when the current value is 100A, it is smaller than the structure in which two bus bars are stacked in the X direction or Y direction. Similarly, in the structure in which four bus bars are stacked in the Z direction, when the current value is 100-600A, it is smaller than the structure in which four bus bars are stacked in the X direction or Y direction. Moreover, in the structure in which six bus bars are stacked in the Z direction, when the current value is 100-1000A, it is smaller than the structure in which six bus bars are stacked in the X direction or Y direction. For example, in the case of a current value of 900A, since the current of 900A is branched and flows to the six bus bars 2A, 2B, 2C, 2D, 2E, and 2F, the current value of each bus bar is 150A. If the width of the conducting portion 23 of the bus bar 2 is formed to be 22mm, then as shown in FIG. Figure 6 As shown, it converges to the allowable current value.

[0086] The busbar cooling structure 1 in which six busbars 2A, 2B, 2C, 2D, 2E, and 2F are stacked in the Z direction can be smaller than a busbar cooling structure in which a plurality of busbars are stacked in the X direction or the Y direction. Figures 8 to 11 , a bus bar cooling structure 100 is shown in which a plurality of bus bars are stacked in the X direction.

[0087] like Figures 8 to 11 As shown, a bus bar cooling structure 100 of a comparative example has a structure in which a plurality of bus bars 102 are stacked in the X direction, and each bus bar 102 is cooled by a heat conducting member 103. The plurality of bus bars 102 include, in descending order of distance from a starting point 121 to an end point 122 of a current path, a first bus bar 102A, a second bus bar 102B, a third bus bar 102C, a fourth bus bar 102D, a fifth bus bar 102E, and a sixth bus bar 102F.

[0088] The bus bar 102 has a starting point 121 , an end point 122 , and a conducting portion 123 .

[0089] In this description, when the starting points 121A, 121B, 121C, 121D, 121E, and 121F are not particularly distinguished, the reference numerals A to F are omitted and the starting point 121 is described. Similarly, the reference numerals A to F are sometimes omitted for the end point 122 and the current-carrying portion 123.

[0090] The conducting portion 123 is stacked in the X direction with at least a portion embedded in the heat conducting member 103. That is, the conducting portion 123 is a portion that forms a current path for the bus bar 102 and a portion that directly transfers heat from the bus bar 102 to the heat conducting member 103. Figure 10As shown, each conducting portion 123 is embedded in the heat conducting member 103 at the same depth, so the cooling area of ​​each bus bar 102 is as follows: Figure 11 As shown, the length of the conductive portion 123 embedded in the heat conducting member 103 is determined. Therefore, the cooling area of ​​each bus bar 102 decreases in order from the first bus bar 102A to the sixth bus bar 102F.

[0091] Figure 12 This is a side view for comparing and explaining the sizes of the bus bar cooling structure in the Z direction. Figure 13 This is a plan view for comparing and explaining the sizes of the bus bar cooling structure in the X direction.

[0092] Regarding the size in the Z direction, such as Figure 12 As shown in FIG. 1 , the busbar cooling structure 1 and the busbar cooling structure 100 are of the same size. Figure 13 As shown, busbar cooling structure 1 is smaller than busbar cooling structure 100. Thus, a structure in which multiple busbars 2 are stacked in the Z direction can achieve a more compact X-direction configuration compared to a structure in which multiple busbars 102 are stacked in the X direction. Furthermore, within the housing, the space above the busbars (in the Z direction) is difficult to utilize effectively due to other components. Therefore, by effectively utilizing this space, the overall unit can achieve space savings.

[0093] As described above, according to the embodiment, by embedding the heat transfer portion 24 of the busbar 2 in the heat conduction member 3, cooling performance is improved. Furthermore, the cooling area of ​​each busbar 2 is set to a size corresponding to the busbar length, thereby suppressing variations in cooling performance caused by differences in length among the multiple busbars 2. This allows efficient cooling of multiple busbars 2 of varying lengths, while suppressing variations in cooling performance among the busbars 2. As a result, a structure including multiple busbars 2 can achieve both space savings and reduced variations in cooling performance.

[0094] Furthermore, the busbar cooling structure 1 can cool multiple busbars 2 of different lengths, so there is no particular limitation on the length combination or the number of busbars 2. It suffices that at least two of the multiple busbars 2 have different lengths, and all busbars do not need to have different lengths.

[0095] The thickness of the bus bar 2 is not limited to 2 mm. For example, the bus bar 2 may be formed with a thickness of 2 to 5 mm. Similarly, the width of the conducting portion 23 of the bus bar 2 is not limited to 22 mm.

[0096] Furthermore, an example has been described in which the unit including the bus bar cooling structure 1 is mounted on a vehicle. In this case, the X direction can be the vehicle width direction, the Y direction can be the vehicle front-rear direction, and the Z direction can be the height direction.

[0097] While the busbar cooling structure 1 has been described as being applied to a boost converter, its application is not limited to this example. The busbar cooling structure 1 can be effectively applied to systems where multiple busbars are required due to thermal constraints of the busbars themselves or the electrical components to which they are fastened, as the system increases in output (higher current). In short, the busbar cooling structure 1 is more advantageous as the current increases and the number of busbars increases.

[0098] The bus bar 2 is not limited to being formed of a single plate-shaped member, but may be formed by joining a plurality of plate-shaped members. For example, the conducting portion 23 may be formed by joining two plate-shaped members.

Claims

1. A busbar cooling structure for cooling a plurality of busbars, characterized in that: The bus bar cooling structure includes an insulating cooling portion provided so as to be in contact with a portion of each of the plurality of bus bars. The lengths of the plurality of bus bars from the starting point to the end point of the current path are different. The contact area between each bus bar and the cooling portion is set to an area proportional to the length of each bus bar. The cooling unit is a heat-conducting member having a higher heat conductivity than the bus bar. Each bus bar is provided upright from the heat conducting member in a state where the portion thereof is embedded in the heat conducting member. The plurality of bus bars are stacked in a direction in which the bus bars are arranged upright from the heat conducting member.

2. The busbar cooling structure according to claim 1, wherein: The bus bar has: a heat transfer portion embedded in the heat conducting member; a conducting portion, the conducting portion forming a portion extending from the starting point to the end point; and a branch portion that branches from the power-carrying portion and reaches the heat transfer portion, The heat transfer portion is not included in the current path.

3. The busbar cooling structure according to claim 2, wherein: The heat conducting member is formed in a rectangular parallelepiped shape, In the plurality of bus bars, the branch portions are provided upright from the heat conduction member in a state in which the heat transfer portions are arranged in parallel in the longitudinal direction of the heat conduction member, and the current conducting portions are stacked in the upright direction.

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