JP2018166400A - Electric power conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric power conversion device which inhibits heat from a switching device, which serves as a heating source during high-frequency driving, from being transmitted to a capacitor element to achieve downsizing of the entire device.SOLUTION: An electric power conversion device includes: a switching device 12a which orthogonally transforms input power; a capacitor 11 which smooths the input power to the switching device 12a; a cooler 16 which cools the switching device 12a and the capacitor 11; and a block shaped heat transmission relaxation constitution part (a cooling block 16d) which is provided between the switching device 12a and the capacitor 11 and serves as a partition wall that reduces heat transmission from the switching device 12a to the capacitor 11.SELECTED DRAWING: Figure 14

Description

  The present invention relates to a power converter for driving a rotating electrical machine represented by, for example, a permanent magnet AC synchronous motor mounted on a vehicle, and more particularly to a power converter capable of suppressing a temperature rise of a mounted capacitor. It is.

In recent years, vehicles equipped with electric powertrain components such as hybrid vehicles, plug-in hybrid vehicles, and electric vehicles have become widespread. These vehicles are equipped with a motor (hereinafter referred to as a rotating electrical machine) for obtaining a driving force and an inverter (hereinafter referred to as a power converter) for driving the motor. This power conversion device converts power stored in a battery from direct current to alternating current using a power semiconductor element, and is equipped with a smoothing capacitor for the purpose of removing ripples generated during the conversion. About this power converter, there is a need for downsizing because of its ease of mounting. The volume ratio occupied by the smoothing capacitor in the power conversion device is large, and therefore proposals for reducing the size have been made.
In order to reduce the size of the capacitor, it is effective to suppress the temperature rise. In the conventional power conversion device, part of the connection conductor connecting the capacitor elements is the positive and negative terminals of the capacitor, another part is the heat transfer part, and the electrical insulation is in contact with the heat transfer part of the connection conductor. By adopting a configuration including the heat radiation plate, it has been proposed to reduce the size of the capacitor by reducing the thermal resistance of the heat transfer path from the capacitor element to the cooler. (For example, Patent Document 1)

JP 2008-148530 A

  On the other hand, in recent years, it has been considered to apply a wide band gap semiconductor such as silicon carbide (SiC) to a switching device in order to reduce the size and increase the efficiency of the power converter. Passive components can be reduced in size by switching the switching device to a high frequency drive. When considering the temperature rise in such high frequency drive, compared with the capacitor element and the switching device and the wiring conductor (hereinafter referred to as busbar) connected to the switching device from the capacitor element via the positive and negative terminals, The temperature rise of the switching device and the bus bar is larger than the temperature rise. That is, when high frequency driving is considered, it can be said that a configuration in which the bus bar is actively cooled is effective in order to make it difficult to transmit the temperature rise of the switching device or the bus bar to the capacitor element. In the structure of Patent Document 1 described above, when the switching device is driven at a high frequency and the temperature rise of the switching device or the bus bar becomes larger than the temperature rise of the capacitor element, the heat generated by the switching device or the bus bar is generated in the capacitor element. Heat transfer causes the capacitor element to become hot. As described above, in the conventional power conversion device, at the time of high frequency driving, heat from the switching device or bus bar serving as a heat source is transferred to the capacitor element via the bus bar serving also as the heat transfer unit, and thus the switching device or bus bar. Since the capacitor becomes hot under the influence of the heat generation, there is a problem that it is not possible to sufficiently obtain the effect of downsizing the entire apparatus by cooling the capacitor.

  The present invention has been made to solve the above-described problems, and suppresses heat from a switching device or a bus bar serving as a heat generation source during high-frequency driving from being transferred to the capacitor element. It aims at providing the power converter device which can be reduced in size.

  The power conversion device according to the present invention includes a switching device that orthogonally converts input power, a capacitor that smoothes input power to the switching device, a cooling device that cools the switching device and the capacitor, and the switching device. It is provided with a block-shaped heat transfer mitigation structure portion provided between the capacitor and serving as a partition wall for reducing heat transfer from the switching device to the capacitor.

  According to the present invention, a switching device that orthogonally converts input power, a capacitor that smoothes input power to the switching device, a cooling device that cools the switching device and the capacitor, the switching device and the capacitor, Is provided between the switching device and the block to reduce heat transfer from the switching device to the capacitor, so that the heat from the switching device serving as a heat generation source during high frequency driving is transferred to the capacitor. There is an effect that it is possible to obtain a power conversion device capable of suppressing heat transfer to the element.

It is a connection diagram which shows schematic structure in the case of driving the rotary electric machine mounted in the vehicle by the power converter device in Embodiment 1 of this invention. It is a perspective view which shows the external appearance structure of the power converter device in Embodiment 1 of this invention. It is sectional drawing which shows the power converter device in Embodiment 1 of this invention in the AA cross section of FIG. It is a perspective view which shows the structure of the capacitor | condenser of the power converter device in Embodiment 1 of this invention. It is a disassembled perspective view which shows the component of the capacitor | condenser of the power converter device in Embodiment 1 of this invention. It is sectional drawing which shows the power converter device in Embodiment 2 of this invention in the AA cross section of FIG. It is a perspective view which shows the structure of the capacitor | condenser of the power converter device in Embodiment 2 of this invention. It is a disassembled perspective view which shows the component of the capacitor | condenser of the power converter device in Embodiment 2 of this invention. It is sectional drawing which shows the power converter device in Embodiment 3 of this invention in the AA cross section of FIG. It is sectional drawing which shows the power converter device in Embodiment 4 of this invention in the AA cross section of FIG. It is a disassembled perspective view which shows the structure of the connection part of the power converter device in Embodiment 4 of this invention. It is sectional drawing which shows the power converter device in Embodiment 5 of this invention in the AA cross section of FIG. It is sectional drawing which shows the power converter device in Embodiment 6 of this invention in the AA cross section of FIG. It is a disassembled perspective view which shows the structure of the connection part of the power converter device in Embodiment 6 of this invention. It is sectional drawing which shows the power converter device in Embodiment 6 of this invention in the AA cross section of FIG. It is sectional drawing which shows the power converter device in Embodiment 7 of this invention in the AA cross section of FIG. It is sectional drawing which shows the power converter device in Embodiment 8 of this invention in the AA cross section of FIG. It is sectional drawing which shows the power converter device in Embodiment 9 of this invention in the AA cross section of FIG. It is sectional drawing which shows the power converter device in Embodiment 9 of this invention in the AA cross section of FIG.

Hereinafter, embodiments of the present invention will be described. In the drawings, the same or corresponding parts will be described with the same reference numerals.
Embodiment 1 FIG.
1 is a connection diagram showing a schematic configuration when a rotating electrical machine mounted on a vehicle is driven by a power conversion device according to Embodiment 1 of the present invention, and FIG. 2 is an external view of the power conversion device according to Embodiment 1 of the present invention. FIG. 3 is a cross-sectional view showing the power conversion device according to the first embodiment of the present invention in section AA in FIG. 2, and FIG. 4a is a diagram of the capacitor of the power conversion device according to the first embodiment of the present invention. FIG. 4B is an exploded perspective view showing components of the capacitor of the power conversion device according to Embodiment 1 of the present invention. As for the cross-sectional view, the cross-sectional portion is generally hatched, but the hatching is omitted because the drawing becomes difficult to see.

  In FIG. 1, a power conversion device 10 in a vehicle equipped with an electric power train component performs direct current and alternating current power conversion between a high voltage battery 20 that stores electric power and a motor 30 that drives the electric power train component. The power converter 10 includes a capacitor 11 that smoothes power input to the circuit, switching devices 12a, 12b, 12c, 12d, 12e, and 12f that are driven by control from a control device (not shown), and a switching device 12a. , 12b, 12c, 12d, 12e, and 12f are provided with diodes 13a, 13b, 13c, 13d, 13e, and 13f, respectively.

  In the first embodiment, the high voltage battery 20 uses a nickel metal hydride battery or a lithium ion battery, and the switching devices 12a, 12b, 12c, 12d, 12e, and 12f are silicon (Si) IGBTs (insulated gates). Bipolar transistors) and wide band semiconductors such as silicon (Si) or silicon carbide (SiC) field effect transistors (MOSFETs, etc.) are used, and the capacitors 11 are film capacitors. It may be other than this. In the first embodiment, the diodes 13a, 13b, 13c, 13d, 13e, and 13f are shown in FIG. 1 for the case where the switching devices 12a, 12b, 12c, 12d, 12e, and 12f are provided together. When the devices 12a, 12b, 12c, 12d, 12e, and 12f are MOSFETs, a parasitic diode may be used so that no diode is provided outside the switching device.

  In FIG. 2 showing the external configuration of the power conversion device 10, the capacitor 11 and the switching device 12 a are mounted on the same plane of the cooler 16. Although illustration and description are omitted, the relationship between each of the switching devices 12b, 12c, 12d, 12e, and 12f, the capacitor 11, and the cooler 16 is also configured in the same manner as in FIG. FIG. 3 is a sectional view taken along the line AA in FIG.

  In FIG. 3, the capacitor 11 and the switching device 12 a are arranged on the same plane of the cooler 16. A first connection portion 14 connected to the switching device 12a is provided. As shown in detail in FIGS. 4a and 4b, the capacitor 11 is potted with a plurality of capacitor elements 11a (four in the figure) having electrode surfaces arranged on both side surfaces in a case 11b made of resin or the like. The second connecting portion 15 connected to the capacitor element 11a is drawn out of the case 11b of the capacitor 11. The second connection portion 15 is composed of two-pole parallel plate wirings 15a and 15b that are in contact with both side surfaces of the capacitor element 11a. Note that the number of capacitor elements 11a and the number of terminals taken out from the capacitors 11 of the second connection portion 15 may not be the numbers shown in FIGS. 4a and 4b. The first connection portion 14 and the second connection portion 15 are connected by welding. Between the first connection portion 14 and the second connection portion 15 and the cooler 16, an electrically insulating heat composed of a resin-formed electrical insulating material 17a and a heat transfer material 17b using heat transfer grease. The conductive material 17 is provided, and the thickness of the electrically insulating heat conductive material 17 is set so that no gap is generated in accordance with the dimension between the cooler 16 and the first connection portion 14 and the second connection portion 15. The heat generated by the switching device 12 a and the bus bar is transferred to the cooler 16.

  A fluid passage 16a indicated by a broken line in FIG. 3 is formed in the cooler 16, and the cooling fluid is passed through the fluid passage 16a. In this case, the cooling effect can be further enhanced with respect to the first connection portion 14 and the second connection portion 15 via the switching device 12a, the capacitor 11, and the electrically insulating heat conductive material 17. Note that the fluid path 16a may be provided only in a portion where it is desired to cool intensively, such as being formed only in a portion of the cooler 16 that is in contact with the electrically insulating heat conductive material 17. By doing in this way, the structure of the cooler 16 can be simplified, the development / manufacturing process can be reduced, and the cost can be reduced. In FIG. 3, the electrically insulating heat conducting material 17 is shown mounted on one of the two poles of the connecting portion of the capacitor 11 and the switching device 12a, and the other pole is shown. Although not configured in the same way.

  In the present embodiment, it is assumed that the capacitor 11 is for ripple removal, but a capacitor for a noise filter, for example, may be included. In FIG. 3, the capacitor 11 is illustrated assuming a configuration in which the capacitor element 11 a is enclosed in a case 11 b such as a resin. However, the configuration is not limited to this, and for example, the capacitor element 11 a is connected to the power conversion device 10. It may be configured to be directly mounted on the housing. 2 and 3, the switching device 12a is illustrated as a switching device 12a. However, this portion may be a module in which a plurality of switching devices 12a, 12b, 12c, 12d, 12e, and 12f are incorporated, and a diode 13a. , 13b, 13c, 13d, 13e, and 13f may be incorporated as a whole.

  Moreover, although the case where the electrical insulating material 17a of the electrical insulating heat conductive material 17 uses resin and the heat transfer material 17b uses heat transfer grease has been described, the electric insulating heat conductive material 17 is not limited thereto. For example, it may be molded. Furthermore, although the case where the 1st connection part 14 and the 2nd connection part 15 were connected by welding was demonstrated, the connection means of the 1st connection part 14 and the 2nd connection part 15 is not restricted to this. Also good. The electrically insulating heat conductive material 17 may be mounted in the cooler 16 in advance, or may be fixed in advance to the first connection portion 14 or the second connection portion 15. Further, the electrically insulating heat conductive material 17 has a function of elastic deformation or dimensional adjustment that absorbs a change in dimensions between the first connecting portion 14 and the second connecting portion 15 and the cooler 16. Therefore, it becomes possible to absorb the dimensional tolerances such as the taking-out position of the first connection part 14 to the second connection part 15 with the electrically insulating heat conductive material 17, and to suppress the decrease in heat transfer due to poor contact. it can.

As described above, the heat transfer component by the electrically insulating heat conductive material that transfers the heat from the first connection connected to the switching device and the second connection connected to the capacitor to the cooler. As a result, heat from the switching device, which is a heat source during high-frequency driving, and the bus bar, which is the first and second connections, is suppressed from being transferred to the capacitor element by actively cooling the bus bar. It is possible to obtain a power conversion device that can be used.
Further, by making the two-pole bus bar into parallel plates, the wiring inductance can be minimized, noise and surge can be suppressed, and the bus bar member can be minimized.

Embodiment 2. FIG.
5 is a cross-sectional view showing the power conversion device according to Embodiment 2 of the present invention in the AA cross section of FIG. 2, and FIG. 6a is a perspective view showing the configuration of the capacitor of the power conversion device according to Embodiment 2 of the present invention. FIG. 6b is an exploded perspective view showing components of the capacitor of the power conversion device according to Embodiment 2 of the present invention. In the first embodiment, the case where the electrode surfaces of the capacitor element 11a are arranged toward both side surfaces has been described. However, in the second embodiment, as shown in FIGS. 5, 6a, and 6b, the capacitor element 11a The electrode surfaces are arranged facing the upper and lower surfaces. Further, the configurations of the capacitor element 11a and the second connecting portion 15 may be other than these.
Since other parts are the same as those in the first embodiment, description thereof is omitted.

Embodiment 3 FIG.
7 is a cross-sectional view showing the power conversion device according to Embodiment 3 of the present invention, taken along the line AA in FIG. In the first embodiment, the case where the heat transfer component is provided with the electrically insulating heat conductive material 17 between the first connecting portion 14 and the second connecting portion 15 and the cooler 16 has been described. In Embodiment 3, the case where the cooling block 16b is provided in the heat transfer component will be described.
In FIG. 7, there is provided a cooling block 16b that is interposed between the capacitor 11 mounted on the cooler 16 and the switching device 12a and whose one surface is structurally in contact with the cooler 16, and penetrates the cooling block 16b. The first connecting portion 14 and the second connecting portion 15 are arranged so as to be brought into contact with the cooling block 16b through the electrically insulating heat conductive material 17.

Thus, the bus bar can be positively cooled by configuring the first connecting portion 14 and the second connecting portion 15 to be surrounded by the cooling block 16b. For this reason, even when high frequency driving is attempted, even if the temperature rise of the bus bar is larger than that of the capacitor element in this situation, the bus bar is actively cooled, so that the temperature rise is mitigated and the heat from the bus bar is reduced. Can be suppressed with a minimum number of bus bar members. In addition, the capacitor or the capacitor element itself can also suppress a rise in temperature because heat reception from the switching device that is at a high temperature via the bus bar can be suppressed.
Since other parts are the same as those in the first embodiment, description thereof is omitted.

Embodiment 4 FIG.
8 is a cross-sectional view showing the power conversion device according to Embodiment 4 of the present invention in the AA cross section of FIG. 2, and FIG. 9 is an exploded perspective view showing the configuration of the connecting portion of the power conversion device according to Embodiment 4 of the present invention. FIG. In FIG. 9, the switching device 12a to which the first connection portion 14 is connected and the capacitor 11 to which the second connection portion 15 is connected are omitted. In the first embodiment, the heat transfer component connects the first connection 14 and the second connection 15 by welding, and the electrically insulating heat conductive material 17 is provided between the cooler 16 and the heat transfer component. Although demonstrated, Embodiment 3 demonstrates the case where the 1st connection part 14 and the 2nd connection part 15 are connected by screwing.

8 and 9, the electric insulating material 17a of the electric insulating heat conducting material 17 is a cap nut having a screw hole 17c provided in the center of the plane, and the bolt 18 is a screw hole 17c of the electric insulating material 17a. The first connecting portion 14 and the second connecting portion 15 are fastened by screwing. The electrical insulating material 17a provided with the screw holes 17c may be mounted in the cooler 16 in advance, or may be configured to be fixed in advance to the first connecting portion 14 or the second connecting portion 15.
Although not shown in the drawing, the first connection portion 14 and the second connection portion 15 are bent in the thickness direction by absorbing the first connection portion 14 or the second connection portion 15 to thereby absorb the dimensional difference. The certainty of contact at the fastening portion of the portion 15 can be improved, an increase in resistance component and heat due to poor contact can be suppressed, and a decrease in heat transfer to the cooler can be suppressed.

As described above, since the first connecting portion 14 and the second connecting portion 15 are screwed with the bolt 18 using the electrical insulating material 17a as a cap nut, there is no need to use another nut. It is possible to suppress a decrease in heat transfer to the cooler 16 due to an increase in thermal resistance due to the above, and an inhibition of downsizing due to the need for additional space for nuts, and an increase in cost can be suppressed.
In addition, by adopting a configuration in which the electrically insulating heat conductive material 17 is fixed in advance to the cooler 16 or the first connection portion 14 or the second connection portion 15, the bus bar can be positively maintained while ensuring ease of assembly. Cooling can be realized.
Since other parts are the same as those in the first embodiment, description thereof is omitted.

Embodiment 5. FIG.
10 is a cross-sectional view showing a power conversion device according to Embodiment 5 of the present invention, taken along the line AA of FIG. In the first embodiment, the case where the first connection portion 14 and the second connection portion 15 are flat has been described. However, in the fifth embodiment, the first connection portion 14 and the second connection portion 15 are connected to each other. The case where each is comprised by the laminate bus bar is demonstrated.
In FIG. 10, a first connecting portion 14c and a second connecting portion 15c using a laminated bus bar in which a conductive layer and an insulating layer are overlapped and heat and pressure are applied to form an integrated structure are connected to a cooler 16 by an adhesive 17d. It is fixed in contact with. Since the laminated bus bar is covered with an insulating layer, the laminated bus bar can be directly brought into contact with the cooler 16 without providing an additional insulating material, so that the laminated bus bar can be cooled well and an additional insulating material is provided. Since it is not necessary, the structure can be simplified and the cost can be reduced by reducing the number of members.

The contact fixing to the cooler 16 may not necessarily use the adhesive 17d. However, the first connection portion 14c and the second connection 14c can be fixed to the cooler 16 with the adhesive 17d. The connecting portion 15c can be reliably brought into contact with the cooler 16 and fixed to obtain a cooling effect, and an increase in resistance component and heat due to poor contact can be suppressed.
Since other parts are the same as those in the first embodiment, description thereof is omitted.

Embodiment 6 FIG.
11 is a cross-sectional view showing the power conversion device according to Embodiment 6 of the present invention in the AA cross section of FIG. 2, and FIG. 12 is an exploded perspective view showing the configuration of the connecting portion of the power conversion device according to Embodiment 6 of the present invention. FIGS. 13A and 13B are cross-sectional views showing the power conversion device according to Embodiment 6 of the present invention, taken along the line AA in FIG. In FIG. 12, the switching device 12a to which the first connection portion 14c using the laminated bus bar is connected and the capacitor 11 to which the second connection portion 15c is connected are omitted. In the fifth embodiment, the case where the first connection portion 14c and the second connection portion 15c using the laminate bus bar are fixed to the cooler 16 by the adhesive 17d has been described. However, in the sixth embodiment, the laminate is laminated. A case where the first connecting portion 14c and the second connecting portion 15c using the bus bar are fixed to the cooler 16 by screwing will be described.

  In FIG. 11 and FIG. 12, a cooling block 16b whose one surface is structurally in contact with the cooler 16 is provided in the cooler 16 at a position where the first connection portion 14c and the second connection portion 15c using the laminated bus bar are attached. The cooling block 16b is a cap nut provided with a screw hole 16c. The bolt 18 is screwed into the cap nut of the cooling block 16b, and the first connecting portion 14c and the second connecting portion 15c using the laminated bus bar are screwed. With this configuration, a screw hole is provided in the cooling block 16b of the cooler 16, and the first connection portion 14c and the second connection portion 15c are fastened to the cooling block 16b by bolts 18. By reducing the heat transfer to the cooler 16 by increasing the thermal resistance by bolting the first connecting portion 14c and the second connecting portion 15c using an additional nut, and by requiring a space for adding the nut Inhibition of downsizing can be suppressed, and cost increase can also be suppressed. This configuration is particularly applied to the ground side terminal portion of the two poles.

Further, since the laminated bus bar can be easily bent, as shown in FIG. 13, the first connection portion 14c taken out from the switching device 12a and the second connection portion 15c taken out from the capacitor 11 are taken out. It is good also as a structure which provides a bending structure from a position to the connection part screwed in the screw hole of the cooling block 16b by the both connection part, ie, the volt | bolt 18, for example. In this way, by providing a structure in which the bent portion is provided between the take-out position and the connection portion, the reliability of the contact at the fastening portion of the first connection portion 14c and the second connection portion 15c is improved, and the contact An increase in resistance component and heat due to defects can be suppressed, and a decrease in heat transfer to the cooler 16 can be suppressed.
Since other parts are the same as those in the first embodiment, description thereof is omitted.

Embodiment 7 FIG.
14 is a cross-sectional view showing the power conversion device according to Embodiment 7 of the present invention, taken along the line AA of FIG. In the first embodiment, the heat transferred from the first connection portion 14 and the second connection portion 15 to the cooler 16 is transferred between the capacitor 11 installed in the cooler 16 and the switching device 12a. Although the case where the thermal component is provided has been described, in the seventh embodiment, cooling as a heat transfer mitigation structure that suppresses heat transfer from the switching device 12a to the capacitor 11 between the capacitor 11 and the switching device 12a. A case where the block 16d is provided will be described.

In FIG. 14, a cooling block 16 d as a heat transfer relaxation structure is provided between the capacitor 11 installed in the cooler 16 and the switching device 12 a. The cooling block 16d has a lower surface structurally connected to the cooler 16, and is disposed in a state of being separated from the capacitor 11 and / or the switching device 12a without contact (hereinafter referred to as isolation). Yes. By disposing the cooling block 16d separately from the capacitor 11 or the switching device 12a, it is possible to suppress heat from the switching device 12a having reached a high temperature from being transferred to the capacitor 11 through the cooling block 16d. Can be prevented from receiving heat from the switching device 12a and rising in temperature.
Since other parts are the same as those in the first embodiment, description thereof is omitted.

Embodiment 8 FIG.
15 is a cross-sectional view showing the power conversion device according to Embodiment 8 of the present invention, taken along the line AA in FIG. In the said Embodiment 7, although the case where the heat-transfer mitigation structure part was the cooling block 16d was demonstrated, in Embodiment 8, the case where a heat-transfer mitigation structure part is a heat insulating material block is demonstrated.
In FIG. 15, a heat insulating material block 19 is provided as a heat transfer mitigation structure portion, which is interposed between the capacitor 11 installed in the cooler 16 and the switching device 12 a. The heat insulating material block 19 may be arranged in contact with the capacitor 11 and the switching device 12a or may be arranged so as to be isolated as shown in FIG.

As described above, by adopting a configuration in which the heat insulating material block 19 is interposed between the capacitor 11 and the switching device 12a, heat transfer from the switching device 12a to the capacitor 11 is suppressed, and as a result, the capacitor 11 becomes the switching device. It is possible to suppress an increase in temperature due to heat received from 12a. Further, since the design for adding the cooling block 16d to the cooler 16 can be realized only by providing the heat insulating material block 19, and the structure and structural design of the cooler 16 can be simplified. It is possible to reduce the number of members and reduce the cost.
Since other parts are the same as those in the first embodiment, description thereof is omitted.

Embodiment 9 FIG.
FIG. 16 is a cross-sectional view showing a power converter according to Embodiment 9 of the present invention in the AA cross section of FIG. 2, and FIG. 17 is a cross section of the power converter according to Embodiment 9 of the present invention in the AA cross section of FIG. It is sectional drawing shown. Since the difference between FIG. 16 and FIG. 17 is only the difference in the configuration between the capacitor and the switching device already described, the description of this part is omitted in the ninth embodiment. In the first embodiment, the case where the upper surface of the cooler 16 is brought into contact with the lower surface of the capacitor 11 for cooling has been described, but in the ninth embodiment, surfaces other than the lower surface of the capacitor 11 are also brought into contact with the cooler 16. The case will be described.

16 and 17, the capacitor 11 and the switching device 12 a are installed on the upper surface of the cooler 16, and the lower surface of the capacitor 11 faces the cooler 16 on the surface opposite to the surface facing the switching device 12 a. A structurally connected cooling block 16e is provided, and the cooling block 16e and the capacitor 11 are in contact with each other. 16 and 17, the cooling block 16e is formed on the surface of the capacitor 11 opposite to the surface facing the switching device 12a. However, the arrangement of the cooling block 16e with respect to the capacitor 11 is not limited to this. Further, it may be disposed on the upper surface of the capacitor 11 or may be disposed so as to surround the periphery of the side surface of the capacitor 11, and the cooling effect can be further enhanced by arranging it on a plurality of surfaces.
As described above, by providing the cooling block 16e in contact with a surface other than the lower surface of the capacitor 11, the heat of the capacitor 11 can be radiated from the cooling block 16e to the cooler 16, so that a high cooling effect can be obtained.
Since other parts are the same as those in the first embodiment, description thereof is omitted.

  In the present invention, the embodiments can be freely combined within the scope of the invention, or the embodiments can be appropriately modified and omitted, and the present invention is not limited to the above embodiments. Absent.

DESCRIPTION OF SYMBOLS 10 Power converter, 11 Capacitor, 11a Capacitor element, 11b Case, 12a Switching device, 13a Diode, 14 1st connection part, 14c 1st connection part, 15 2nd connection part, 15a Parallel plate wiring, 15b Parallel Flat wiring, 15c Second connection part, 16 Cooler, 16a Fluid path, 16b Cooling block, 16c Screw hole, 16d Cooling block, 16e Cooling block, 17 Electrical insulating heat conductive material, 17a Electrical insulating material, 17b Heat transfer Material, 17c Screw hole, 17d Adhesive, 18 Volt, 19 Thermal insulation block, 20 High voltage battery, 30 Motor

Claims (5)

  A switching device that orthogonally transforms input power; a capacitor that smoothes input power to the switching device; a cooling device that cools the switching device and the capacitor; and the switching device and the capacitor provided between the switching device and the capacitor A power converter comprising a block-shaped heat transfer mitigation structure portion serving as a partition wall that reduces heat transfer from the switching device to the capacitor.   The power conversion device according to claim 1, wherein the heat transfer mitigation structure is a cooling block structurally connected to the cooler.   The power converter according to claim 2, wherein the cooling block is installed in a state separated from the switching device or the capacitor.   The power conversion device according to claim 1, wherein the heat transfer relaxation structure is a heat insulating material block.   The power converter according to claim 1, wherein the switching device is a wide band gap semiconductor.

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