Power conversion device and motor integrated power conversion device

Abstract

In the past, the heat transferred from the semiconductor module to the capacitor via the busbar module was not considered. In the power conversion device of the present invention, the heat generated in the semiconductor module (1) is transferred to the busbar module (3) via the DC terminal (1A) of the semiconductor module (1). Moreover, as shown in Figure 4(B), the heat transferred to the busbar module (3) is transferred to the pressing member (5) via the annular conductor (8) and the bolt (5A). Since the pressing member (5) is in close contact with the second cooler (2B), the heat transferred to the pressing member (5) is cooled by the second cooler (2B). On the other hand, the heat transferred to the protrusion (6A) of the housing (6) is transferred to the first cooler (2A) via the housing (6) and cooled. Thus, in a structure in which the capacitor (4) is connected to the semiconductor module (1) via the busbar module (3), the heat transferred from the semiconductor module (1) to the capacitor (4) can be suppressed.

Description

Technical Field

[0001] The present invention relates to a power conversion device and a motor-integrated power conversion device. Background Art

[0002] Power conversion devices such as inverters and converters perform power conversion between direct current and alternating current by switching multiple semiconductor elements. In such power conversion devices, capacitors for filtering the current supplied from a direct current power supply to the semiconductor module are electrically connected to the semiconductor module via a busbar module. Due to the miniaturization of the power conversion device, the semiconductor module and the capacitor are close to each other, and heat is conducted from the semiconductor module to the capacitor via the busbar.

[0003] Patent Document 1 discloses a power conversion device in which semiconductor terminals of a semiconductor module and capacitor terminals of a capacitor are in direct contact with each other and in thermal contact with a cooler.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2010-252460 Summary of the invention

[0007] Technical problem to be solved by the invention

[0008] In the device described in Patent Document 1, heat transferred from the semiconductor module to the capacitor via the bus bar module is not considered.

[0009] Technical solutions adopted to solve technical problems

[0010] The power conversion device involved in the present invention includes: a semiconductor module, which has a built-in semiconductor element; a cooler, which is used to cool the semiconductor module; a pressing member, which presses the cooler onto the semiconductor module; a bus bar module, which uses an insulating member to seal the bus bar used to electrically connect the semiconductor module and the capacitor; and a shell, which is used to accommodate the semiconductor module, the cooler, and the bus bar module, and a portion of the bus bar module is in contact with a portion of the shell and the pressing member.

[0011] Effects of the Invention

[0012] According to the present invention, it is possible to suppress the amount of heat transferred from the semiconductor module to the capacitor via the bus bar module. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is an exploded perspective view of the power conversion device according to the first embodiment.

[0014] Figure 2 This is a perspective view of the power conversion device according to the first embodiment.

[0015] Figure 3 It is a top view of the power conversion device according to Embodiment 1.

[0016] Figure 4 (A) Figure 4 (B) is a cross-sectional view of the power conversion device according to the first embodiment.

[0017] Figure 5 It is a top view of the power conversion device according to the second embodiment.

[0018] Figure 6 (A) Figure 6 (B) is a cross-sectional view of the power conversion device according to the second embodiment.

[0019] Figure 7 It is a cross-sectional view of a power conversion device according to Embodiment 3.

[0020] Figure 8 It is a cross-sectional view of a motor-integrated power conversion device according to a fourth embodiment.

[0021] Fig. 9 It is a cross-sectional view of a motor-integrated power conversion device according to a fifth embodiment. DETAILED DESCRIPTION

[0022] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following description and drawings are examples for illustrating the present invention, and are appropriately omitted and simplified for clarity of description. The present invention may also be implemented in various other forms. Unless otherwise specified, each constituent element may be singular or plural.

[0023] In order to facilitate understanding of the present invention, the positions, sizes, shapes, ranges, etc. of the components shown in the drawings may not represent actual positions, sizes, shapes, ranges, etc. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, ranges, etc. disclosed in the drawings.

[0024] [Implementation Method 1] Figures 1 to 4 The power conversion device 100 according to the first embodiment will be described.

[0025] Figure 1 FIG. 1 is an exploded perspective view of the power conversion device 100 according to the present embodiment. Figure 1As shown, the first cooler 2A is in contact with one surface of the semiconductor module 1, and the second cooler 2B is in contact with the other surface of the semiconductor module 1. The semiconductor module 1 is built with semiconductor elements such as IGBT using silicon (Si) as a base material and MOSFET using SiC (silicon carbide) as a base material. The first cooler 2A and the second cooler 2B have a path for the flow of a cooling fluid (long-life coolant, etc.) formed therein, and are made of aluminum and resin. The semiconductor module 1 that generates heat due to the switching action of the semiconductor element is cooled by the first cooler 2A and the second cooler 2B arranged on the two surfaces of the semiconductor module 1.

[0026] The terminals of the semiconductor module 1 are connected to the terminals of the busbars in the busbar module 3. The busbar module 3 is a module in which the busbars are sealed with an insulating member.

[0027] The bus bar is a plate-shaped conductor used for electrical wiring, and copper or aluminum is used. This embodiment is used for electrical connection between the semiconductor module 1 and the capacitor 4. The insulating member is a member such as resin for insulating between bus bars having different potentials.

[0028] The capacitor 4 is adjacent to the semiconductor module 1 and is provided below the busbar module 3. The capacitor 4 is a member for filtering voltage ripples accompanying switching of semiconductor elements, and a film capacitor or an electrolytic capacitor is used.

[0029] The pressing member 5 is provided on the surface (the upper surface shown in the figure) on the opposite side of the surface abutting against the semiconductor module 1 of the second cooler 2B to cover the second cooler 2B. The pressing member 5 is a member for pressing and fixing the semiconductor module 1, the first cooler 2A and the second cooler 2B to the housing 6, and is made of aluminum, iron, etc. The pressing member 5 is formed with a total of 8 protrusions formed integrally with the pressing member 5 on the bus bar module 3 side and the opposite side thereof. On the protrusions, the pressing member 5 is fixed to a part of the housing 6 by bolts 5A, 5B.

[0030] The housing 6 accommodates the semiconductor module 1, the first cooler 2A, the second cooler 2B, the busbar module 3, the capacitor 4, and the pressing member 5. The bottom of the housing 6 is provided with convex parts 6A and 6B as the positioning of the accommodated components and the receiving parts of the bolts 5A and 5B. The convex parts 6A and 6B can be provided integrally with the housing 6 or separately, and in either case, they constitute a part of the housing 6. The material of the housing 6 and the convex parts 6A and 6B is aluminum with high thermal conductivity.

[0031] Figure 2 It is a perspective view of the power conversion device 100 according to the present embodiment.

[0032] like Figure 2As shown, semiconductor module 1, first cooler 2A, second cooler 2B, bus bar module 3, capacitor 4, and pressing member 5 are accommodated in case 6. Case 6 is provided with a cover covering the upper portion of case 6, but is not shown.

[0033] The power conversion device 100 performs power conversion between direct current and alternating current by switching operations of a plurality of semiconductor elements in the semiconductor module 1 and operations of the capacitor 4 for filtering voltage ripples caused by switching of the semiconductor elements.

[0034] Figure 3 FIG. 1 is a top view of the power conversion device 100 according to the present embodiment. Figure 1 The same parts are denoted by the same reference numerals, and their description is omitted.

[0035] In this embodiment, there are three semiconductor modules 1, each having two DC terminals 1A and one AC terminal 1B. The two DC terminals 1A are respectively connected to the negative bus bar and the positive bus bar in the bus bar module 3, and are connected to the capacitor 4 via each bus bar. The AC terminal 1B is connected to the motor provided outside the power conversion device 100. The power supply terminal 3A derived from the positive and negative bus bars is connected to the DC power supply provided outside the power conversion device 100.

[0036] Figure 4 (A) is a cross-sectional view of the power conversion device 100, and is Figure 3 The cross section along line XX′ is shown. Figure 4 (B) is a cross-sectional view of the power conversion device 100, and is Figure 3 The cross section of line YY′ is shown.

[0037] like Figure 4 As shown in (A), the DC terminal 1A of the semiconductor module 1 is connected to the bus bar 31 in the bus bar module 3. The insulating member 32 in the bus bar module 3 insulates the bus bar 31 having different potentials.

[0038] like Figure 4As shown in (B), the pressing member 5 is fixed to the convex parts 6A and 6B of the housing 6 by bolts 5A and 5B. Thus, the pressing member 5 presses the second cooler 2B, the semiconductor module 1, and the first cooler 2A to the housing 6. In addition, the pressing member 5 sandwiches the bus bar module 3 between the convex part 6A of the housing 6. That is, a part of the bus bar module 3 is sandwiched between a part of the housing 6 and the pressing member. The annular conductor 8 is arranged in the sandwiched bus bar module 3 and around the bolt 5A. Although an example has been described in which a part of the bus bar module 3 is sandwiched between a part of the housing 6 and the pressing member 5, a part of the bus bar module 3 only needs to be in contact with a part of the housing 6 and the pressing member 5. For example, the bus bar module 3 and the pressing member 5 are arranged side by side in the same plane, so that the end face 3E of the bus bar module 3 is in contact with the end face 5E of the pressing member 5. The bus bar module 3 and the pressing member 5 are fixed to the convex part 6A of the housing 6 by bolts 5A.

[0039] like Figure 4 As shown in (A), the heat generated in the semiconductor module 1 is cooled by the first cooler 2A and the second cooler 2B. In addition, the heat generated in the semiconductor module 1 is transferred to the busbar module 3 via the DC terminal 1A of the semiconductor module 1. Figure 4 As shown in (B), the heat transferred to the bus bar module 3 is transferred to the pressing member 5 via the annular conductor 8 and the bolt 5A. The annular conductor 8 is a conductor built into the bus bar module 3 and supported by the bolt 5A. The material of the annular conductor 8 is copper or aluminum. By providing the annular conductor 8, the thermal resistance of the bolt fastening part can be reduced, thereby further improving the heat dissipation.

[0040] Since the pressing member 5 is in close contact with the second cooler 2B, the heat transferred to the pressing member 5 is cooled by the second cooler 2B. On the other hand, the heat transferred to the convex portion 6A of the housing 6 is transferred to the first cooler 2A via the housing 6 and cooled.

[0041] Thus, in a structure in which the capacitor 4 is connected to the semiconductor module 1 via the bus bar module 3 , it is possible to suppress heat transfer from the semiconductor module 1 to the capacitor 4 via the bus bar module 3 .

[0042] [Implementation Method 2] Figure 5 , Figure 6 A power conversion device 200 according to the second embodiment will be described.

[0043] Figure 5 FIG. 2 is a top view of the power conversion device 200 according to the present embodiment. Figure 3 The same parts of the power conversion device 100 according to the illustrated embodiment 1 are denoted by the same reference numerals, and description thereof will be omitted.

[0044] In this embodiment, if Figure 5 As shown, the shape of the pressing member 5 ′ is different from that of the first embodiment, and the pressing member 5 ′ is formed in a shape covering the DC terminal 1A.

[0045] Figure 6 (A) is a cross-sectional view of the power conversion device 200, and is Figure 5 The cross section along line XX′ is shown. Figure 6 (B) is a cross-sectional view of the power conversion device 200, and is Figure 5 The cross section of the YY' line is shown. Figure 4 (A) Figure 4 The same parts of the power conversion device 100 of the first embodiment shown in (B) are assigned the same reference numerals, and description thereof will be omitted.

[0046] like Figure 6 As shown in (A), the pressing member 5' is formed into a shape covering the DC terminal 1A, and the pressing member 5' contacts the DC terminal 1A via the insulating sheet 7, and further contacts the busbar module 3. The insulating sheet 7 is a thermally conductive sheet having an electrical insulating function.

[0047] like Figure 6 As shown in (B), the pressing member 5' is fixed to the convex parts 6A and 6B of the housing 6 by bolts 5A and 5B. The ring-shaped conductor 8 is arranged around the bolt 5A.

[0048] like Figure 6 As shown in (A), the heat generated in the semiconductor module 1 is cooled by the first cooler 2A and the second cooler 2B. In addition, the heat generated in the semiconductor module 1 is transferred to the bus bar module 3 and the insulating sheet 7 via the DC terminal 1A of the semiconductor module 1 .

[0049] The heat transferred to the insulating sheet 7 is transferred to the second cooler 2B via the pressing member 5' and cooled there. Figure 5 As shown in (B), the heat transferred to the bus bar module 3 is transferred to the pressing member 5' via the annular conductor 8 and the bolt 5A and cooled by the second cooler 2B. On the other hand, the heat transferred to the protrusion 6A of the case 6 is transferred to the first cooler 2A via the case 6 and cooled.

[0050] Thus, in a structure in which the capacitor 4 is connected to the semiconductor module 1 via the bus bar module 3 , heat transferred from the semiconductor module 1 to the capacitor 4 via the bus bar module 3 can be more effectively suppressed.

[0051] [Implementation Method 3] Figure 7 A power conversion device 300 according to Embodiment 3 will be described.

[0052] Figure 7is a cross-sectional view of a power conversion device 300 according to this embodiment, and Figure 3 The cross section of the YY' line shown is equivalent to Figure 4 The same parts of the power conversion device 100 according to the illustrated embodiment 1 are denoted by the same reference numerals, and description thereof will be omitted.

[0053] In this embodiment, if Figure 7 As shown, a heat conductive material 9 is disposed between the pressing member 5 and the second cooler 2B. The heat conductive material 9 is, for example, grease or a heat sink. The heat conductive material 9 reduces the contact thermal resistance between the pressing member 5 and the second cooler 2B. As a result, the heat transferred from the bus bar module 3 to the pressing member 5 is cooled more effectively by the second cooler 2B. In addition, this embodiment is applicable not only to embodiment 1 but also to embodiment 2.

[0054] [Implementation Method 4] Figure 8 A motor-integrated power conversion device 800 according to a fourth embodiment will be described.

[0055] Figure 8 FIG. 8 is a cross-sectional view of the motor-integrated power conversion device 800. Figure 8 As shown, the motor-integrated power conversion device 800 is obtained by integrating the power conversion device 100 and the motor 20 . Figure 8 The power conversion device 100 shown is equivalent to Figure 3 The cross section of the YY' line shown in Figure 4 The same parts of the power conversion device 100 according to the illustrated embodiment 1 are denoted by the same reference numerals, and description thereof will be omitted.

[0056] The motor-integrated power converter 800 includes a motor 20 which is integrally formed with the power converter 100 and is disposed on the opposite side of the pressing member 5 with the bus bar module 3 and the first and second coolers 2A and 2B interposed therebetween. The power converter 100 converts a DC power source into a three-phase AC power to drive the motor 20 .

[0057] The motor 20 includes a rotor 21 , a stator 22 , a motor housing 23 , an inlet pipe 24 for the refrigerant W, and an outlet pipe 25 for the refrigerant W.

[0058] The stator 22 generates heat by passing current through the stator 22 to drive the motor 20. Although the stator 22 is cooled by the refrigerant W flowing in the motor housing 23, the flow path in the motor housing 23 near the power conversion device 100 is interrupted in order to suppress the height of the entire device to be low. Therefore, the heat generated by the stator 22 may be transmitted to the housing 6 of the power conversion device 100. In this case, the heat dissipation path from the busbar module 3 to the first cooler 2A on the motor 20 side overlaps with the heat conduction path M from the stator 22, and heat dissipation becomes difficult. However, in the present embodiment, when viewed from the motor 20, the heat dissipation path from the busbar module 3 is also ensured in the second cooler 2B on the opposite side of the semiconductor module 1, so that the busbar module 3 can be sufficiently radiated. That is, even in the motor-integrated power conversion device 800, the busbar module 3 can be sufficiently radiated, and the heat transferred to the capacitor 4 can be more effectively suppressed.

[0059] In this embodiment, the power conversion device 100 shown in Embodiment 1 is described as an example, but not only Embodiment 1 but also the power conversion device 200 shown in Embodiment 2 and the power conversion device 300 shown in Embodiment 3 may be used.

[0060] [Implementation Method 5] Fig. 9 A motor-integrated power conversion device 900 according to the fifth embodiment will be described.

[0061] Fig. 9 is a cross-sectional view of the motor-integrated power conversion device 900. Fig. 9 As shown, the motor-integrated power conversion device 900 is obtained by integrating the power conversion device 400 and the motor 20 . Fig. 9 The power conversion device 400 shown is equivalent to Figure 3 The cross section of the YY' line shown in Figure 4 The same parts of the power conversion device 100 according to the illustrated embodiment 1 are denoted by the same reference numerals, and description thereof will be omitted.

[0062] In the power conversion device 400, as Fig. 9 As shown, the heat insulating member 12 is arranged between the capacitor 4 and the housing 6, and the convex parts 6A and 6B of the housing 6 to which the pressing member 5 is attached by bolts 5A and 5B are formed by the heat insulating member 12. The other structures are the same as those of the power conversion device 100. In addition, in the power conversion device 200 shown in Embodiment 2 and the power conversion device 300 shown in Embodiment 3, the heat insulating member 12 shown in the power conversion device 400 can also be provided.

[0063] The motor 20 has the same configuration as that shown in the fourth embodiment, and the same reference numerals are given to the same parts, and the description thereof will be omitted.

[0064] When the thermal resistance of the heat conduction path from the busbar module 3 to the first cooler 2A is small, it is easy to dissipate the heat received by the busbar module 3 to the first cooler 2A, but conversely, it is also easily affected by the heat generated by the stator 22. Therefore, in the present embodiment, the thermal resistance between the first cooler 2A and the busbar module 3 is greater than the thermal resistance between the second cooler 2B and the busbar module 3. Thus, by mainly dissipating the heat received by the busbar module 3 to the second cooler 2B, the temperature of the busbar module 3 in the motor-integrated power conversion device 900 can be further reduced.

[0065] The heat insulating member 12 is provided in the heat conduction path from the stator 22 to the bus bar module 3, thereby increasing the thermal resistance of the path. The material of the heat insulating member 12 is resin or the like.

[0066] In addition, by providing a heat insulating member 12 between the pressing member 5 and the housing 6 of the power conversion device 400, specifically, the heat insulating member 12 constitutes the protrusions 6A and 6B of the housing 6 to which the pressing member 5 is mounted by bolts 5A and 5B, thereby suppressing the heat from being transferred from the stator 22 to the bus bar module 3 via the pressing member 5.

[0067] Furthermore, by providing the heat insulating member 12 between the motor 20 and the capacitor 4 , heat conduction from the stator 22 to the capacitor 4 can be suppressed.

[0068] According to the above-described embodiment, the following effects can be obtained.

[0069] (1) The power conversion device 100, 200, 300, 400 includes a semiconductor module 1 having a built-in semiconductor element; a cooler 2A, 2B for cooling the semiconductor module 1; a pressing member 5, 5' for pressing the cooler 2A, 2B onto the semiconductor module 1; a bus bar module 3 obtained by sealing a bus bar 31 that electrically connects the semiconductor module 1 and the capacitor 4 with an insulating member 32; and a housing 6 that accommodates the semiconductor module 1, the cooler 2A, 2B, and the bus bar module 3, and a portion of the bus bar module 3 is in contact with a portion of the housing 6 and the pressing members 5, 5'. Thus, heat transferred from the semiconductor module to the capacitor via the bus bar module can be suppressed.

[0070] The present invention is not limited to the above-described embodiments, and other embodiments that can be considered within the technical concept of the present invention are also included in the scope of the present invention as long as the features of the present invention are not impaired. In addition, a configuration combining the above-described embodiments is also possible.

[0071] Description of symbols

[0072] 1...semiconductor module, 1A...DC terminal, 1B...AC terminal, 2A...first cooler, 2B...second cooler, 3...busbar module, 3A...power terminal, 4...capacitor, 5, 5′...pressing member, 5A, 5B...bolt, 6...housing, 6A, 6B...protrusion, 7...insulating sheet, 8...annular conductor, 9...heat conductive material, 20...motor, 21...rotor, 22...stator, 23...motor housing, 24...inlet pipe, 25...outlet pipe, 31...busbar, 32...insulating member, 100, 200, 300, 400...power conversion device.

Claims

1. A power conversion device, characterized in that: include: A semiconductor module having a semiconductor element built therein; A cooler, the cooler being used to cool the semiconductor module; a pressing member that presses the cooler onto the semiconductor module; a bus bar module obtained by sealing a bus bar for electrically connecting the semiconductor module and the capacitor with an insulating member; as well as a housing for housing the semiconductor module, the cooler, and the bus bar module, A portion of the bus bar module is in contact with a portion of the housing and the pressing member, The cooler is configured to include a first cooler disposed between the semiconductor module and the housing, and a second cooler disposed between the pressing member and the semiconductor module.

2. The power conversion device according to claim 1, characterized in that: A portion of the bus bar module is sandwiched between a portion of the housing and the pressing member.

3. The power conversion device according to claim 1 or 2, characterized in that: The pressing member is in contact with the main terminal of the semiconductor module via an insulating sheet.

4. The power conversion device according to claim 1 or 2, characterized in that: A heat conductive material is provided between the second cooler and the pressing member.

5. A motor-integrated power conversion device, characterized in that: include: The power conversion device as claimed in claim 1 or 2; and An electric motor is integrally formed with the power conversion device and is arranged on the opposite side of the pressing member with the bus bar module and the cooler interposed therebetween.

6. The motor-integrated power conversion device according to claim 5, characterized in that: The cooler is configured to include a first cooler disposed between the semiconductor module and the electric motor, and a second cooler disposed between the pressing member and the semiconductor module.

7. The motor-integrated power conversion device according to claim 6, characterized in that: A thermal resistance between the first cooler and the bus bar module is greater than a thermal resistance between the second cooler and the bus bar module.

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