WO2024004266A1

WO2024004266A1 - Power conversion device

Info

Publication number: WO2024004266A1
Application number: PCT/JP2023/005823
Authority: WO
Inventors: 浩輝松田; 努川水
Original assignee: 三菱重工業株式会社
Priority date: 2022-06-29
Filing date: 2023-02-17
Publication date: 2024-01-04
Also published as: JP2024004714A

Abstract

A power conversion device according to the present disclosure is provided with: a casing; a capacitor housed in the casing; a power module that is housed in the casing and converts a DC voltage from the capacitor into an AC voltage; a cooling device that cools the power module; a control substrate that is housed in the casing with a gap interposed between said substrate and the power module and controls the driving of the power module; a heat insulation part that is housed in the casing and divides the interior of the casing into a space in which the power module is disposed and a space in which the control substrate is disposed; and heat dissipation parts disposed to the heat insulation part. The heat insulation part has: a flat plate portion disposed in the gap between the power module and the control substrate; and a plurality of side wall plate portions that, by connecting the outer edge portions of the flat plate portion with the cooling device, surround the power module from the extending directions of the flat plate portion. The plurality of heat dissipation parts are disposed in the in-plane direction in at least one of the flat plate portion and the side wall plate portions.

Description

power converter

The present disclosure relates to a power conversion device.
This application claims priority to Japanese Patent Application No. 2022-104478 filed in Japan on June 29, 2022, the contents of which are incorporated herein.

For example, Patent Document 1 discloses a semiconductor device (power conversion device) in which a power module is covered with a heat shielding member. In this semiconductor device, a control board on which a circuit for controlling a power module is mounted is placed above a heat shielding member.

The heat shielding member has a flat part that covers the upper surface of the power module, and a pair of support legs that hang down from both ends of the flat part and cover the sides of the power module. The lower end of the base plate is fixed in contact with the surface of the base plate. This suppresses heat from being transmitted from the power module to the control board, and when heat is transmitted to the heat shielding member, it is radiated to the outside from the lower end of the support leg via the base plate.

Japanese Patent Application Publication No. 2005-333074

In recent years, in the field of power converters with power modules, there has been an increasing trend toward higher voltage, larger current, higher frequency, and faster switching of power semiconductor elements in order to improve added value. As a result, the power module may become even hotter. Therefore, a member that blocks heat transmitted from the power module to the control board is required to have higher heat shielding performance.

The present disclosure has been made in order to solve the above problems, and an object of the present disclosure is to provide a power conversion device that can better block heat transmitted from a power module to a control board.

In order to solve the above problems, a power conversion device according to the present disclosure includes a casing, a capacitor housed in the casing, and a power module housed in the casing that converts a DC voltage from the capacitor into an AC voltage. a cooler that cools the power module; a control board that is housed in the casing with a gap between the power module and the control board that controls driving of the power module; A heat shield section that partitions a space in which a power module is arranged and a space in which the control board is arranged, and a heat radiation section arranged in the heat shield section, and the heat shield section is arranged in a space where the power module and the control board are arranged. a flat plate portion disposed in the gap between the control board and a plurality of side walls surrounding the power module from an in-plane direction of the flat plate portion by connecting an outer edge of the flat plate portion and the cooler; A plurality of the heat radiating parts are arranged in one or more of the in-plane direction of the flat plate part and the in-plane direction of the side wall plate part.

According to the present disclosure, it is possible to provide a power conversion device that can further block heat transmitted from the power module to the control board.

1 is a perspective view showing a schematic configuration of a power conversion device according to an embodiment of the present disclosure. FIG. 2 is a plan view of the power module according to the embodiment of the present disclosure in the II-II line direction shown in FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III shown in FIG. 2. FIG. FIG. 3 is a diagram showing a direction in which heat is conducted in a heat shield according to an embodiment of the present disclosure. 4 is a cross-sectional view of a power conversion device according to another embodiment of the present disclosure, and is a diagram corresponding to the portion shown in FIG. 3. FIG. 4 is a cross-sectional view of a power conversion device according to another embodiment of the present disclosure, and is a diagram corresponding to the portion shown in FIG. 3. FIG. 4 is a cross-sectional view of a power conversion device according to another embodiment of the present disclosure, and is a diagram corresponding to the portion shown in FIG. 3. FIG.

Hereinafter, embodiments for implementing a power conversion device according to the present disclosure will be described with reference to the accompanying drawings.

[Power converter]
A power converter is a device that converts DC power into three-phase AC power or the like. The power conversion device of this embodiment includes, for example, an inverter used in a system such as a power plant, an inverter used to drive a motor of an electric vehicle, etc.

As shown in FIG. 1, the power converter 100 includes a casing 1, an external input conductor 2, a capacitor 3, a power converter 4, a cooler 5, a control board 6, a heat shield 7, and a heat dissipator. 8 (see FIG. 3). In addition, in FIG. 1, the casing 1, the cooler 5, the control board 6, and the heat shield part 7 are shown by two-dot chain lines due to space limitations.

(casing)
The casing 1 forms the outer shell of the power converter 100. The casing 1 in this embodiment is made of metal such as aluminum or synthetic resin, and has a rectangular parallelepiped shape. The casing 1 has two side surfaces arranged back to back to each other.

Hereinafter, for convenience of explanation, of these two side surfaces, the side facing one side will be referred to as the "input side side 1a", and the side facing the other side will be referred to as the "output side side 1b". An external input conductor 2 for inputting DC power is drawn out from the input side surface 1a.

(External input conductor)
The external input conductors 2 are a pair of electric conductors (bus bars) that supply DC power supplied from a power system or the like external to the power converter 100 to the capacitor 3. The external input conductor 2 in this embodiment is made of metal containing copper or the like. One end of the external input conductor 2 is connected to the capacitor 3, and the other end of the external input conductor 2 extends in a direction intersecting the input side surface 1a of the casing 1.

(capacitor)
The capacitor 3 is a smoothing capacitor that stores charges input from the external input conductor 2 and suppresses voltage fluctuations associated with power conversion. Capacitor 3 is housed in casing 1. The DC voltage input from the external input conductor 2 is supplied to the power converter 4 via the capacitor 3. The capacitor 3 has a main body portion 3a and a connecting conductor 3b.

The main body portion 3a is a portion that primarily functions as the smoothing capacitor described above. The connecting conductor 3b is an electric conductor (bus bar) for transmitting power from the main body 3a to the power converter 4. The connection conductor 3b is made of metal such as copper. The connecting conductor 3b has a positive terminal 3p and a negative terminal 3n.

The positive terminal 3p constitutes the positive electrode of the capacitor 3, and is a current path connecting the main body portion 3a and the positive electrode of the power module 40. The negative terminal 3n constitutes the negative electrode of the capacitor 3, and is a current path connecting the main body 3a and the negative electrode of the power module 40.

These positive terminals 3p and negative terminals 3n are arranged side by side with an interval between them. One end of each of the positive terminal 3p and the negative terminal 3n is connected to the main body 3a. Note that detailed illustration of the connection state between the positive terminal 3p and the negative terminal 3n and the main body portion 3a is omitted. The other ends of the positive terminal 3p and the negative terminal 3n are connected to the power module 40.

(Power conversion section)
The power converter 4 converts the voltage input from the capacitor 3. Power converter 4 is housed in casing 1 . The power converter 4 in this embodiment has three power modules 40 each responsible for outputting U-phase, V-phase, and W-phase output in order to output three-phase AC power. Therefore, the power conversion device 100 in this embodiment is a three-phase inverter including three power modules 40.

(power module)
The power module 40 is a device that converts input power and outputs the converted power. As shown in FIGS. 2 and 3, the power module 40 includes a base plate 41, a circuit board 42, an external output conductor 43, a case 44, an insulating section 45, and a bonding wire Wb.

The base plate 41 is a flat member. The base plate 41 has a front surface 41a and a back surface 41b located on the back side of the front surface 41a. That is, the front surface 41a and the back surface 41b of the base plate 41 are parallel to each other and are placed back to back. The back surface 41b of the base plate 41 is fixed to the cooler 5 via a bonding material or the like (not shown). For example, copper is used for the base plate 41 in this embodiment. Note that the base plate 41 may be made of metal such as aluminum.

The circuit board 42 has an insulating plate 421, a front pattern 422, a power semiconductor element 423, and a back pattern 424.

The insulating plate 421 has a flat plate shape. The insulating plate 421 has a first surface 421a and a second surface 421b located on the back side of the first surface 421a. That is, the first surface 421a and the second surface 421b of the insulating plate 421 are parallel to each other and back to back. On the second surface 421b of the insulating plate 421, a back pattern 424, which is a pattern of copper foil or the like, is formed over one surface. The back pattern 424 is fixed to the center of the front surface 41a of the base plate 41 via a bonding material S.

The insulating plate 421 in this embodiment is made of an insulating material such as ceramic, for example. Note that as the insulating material forming the insulating plate 421, in addition to ceramics, paper phenol, paper epoxy, glass composite, glass epoxy, glass polyimide, fluororesin, etc. can be used.

The surface pattern 422 is a pattern of copper foil or the like that is formed on the first surface 421a of the insulating plate 421 and spreads in a plane. The surface pattern 422 is formed, for example, by being fixed to the first surface 421a of the insulating plate 421 by bonding or the like and then etching or the like.

A plurality of surface patterns 422 are arranged on the first surface 421a of the insulating plate 421. These plurality of surface patterns 422 are arranged adjacent to each other with a gap in the direction in which the insulating plate 421 spreads. In this embodiment, a case will be described as an example in which three surface patterns 422 are arranged on the first surface 421a of the insulating plate 421. Hereinafter, for convenience of explanation, these three surface patterns 422 will be referred to as a first surface pattern 422a, a second surface pattern 422b, and a third surface pattern 422c.

The first surface pattern 422a and the second surface pattern 422b are patterns for exchanging input and output of DC current with the capacitor 3, and correspond to an inlet portion or an outlet portion of a loop between PNs formed in the surface pattern 422. . In this embodiment, the other end of the positive terminal 3p of the capacitor 3 is connected to the first surface pattern 422a, and the other end of the negative terminal 3n of the capacitor 3 is connected to the second surface pattern 422b. An external output conductor 43 for outputting the alternating current converted by the power semiconductor element 423 to a load (not shown) provided outside the power conversion device 100 is connected to the third surface pattern 422c.

The power semiconductor element 423 is a circuit element that converts power through a switching operation that turns on and off voltage and current. The power semiconductor element 423 is, for example, a switching element such as an IGBT or a MOSFET. This embodiment shows, as an example, a case where a MOSFET is applied to a power semiconductor. These four power semiconductor elements 423 are connected to the surface pattern 422 of the circuit board 42. Note that when an IGBT is used as the power semiconductor element 423, a diode that allows current to flow in the opposite direction to the IGBT needs to be arranged in parallel.

The four power semiconductor elements 423 in this embodiment are comprised of two first power semiconductor elements 423a and two second power semiconductor elements 423b. The first power semiconductor element 423a is connected to the first surface pattern 422a. The second power semiconductor element 423b is connected to the third surface pattern 422c.

When the power semiconductor element 423 is a MOSFET, the power semiconductor element 423 has an input surface on which an input terminal (not shown) corresponding to a drain is formed, and an output surface on which an output terminal (not shown) corresponding to a source is formed. and a gate (not shown) corresponding to a control signal input terminal for controlling switching of the power semiconductor element 423.

The input surface of the power semiconductor element 423 is electrically connected to the surface pattern 422 via a bonding material. One end of a bonding wire Wb serving as a conducting wire is electrically connected to the output surface of the power semiconductor element 423. The bonding wire Wb is made of metal such as aluminum. That is, the surface patterns 422 formed on the first surface 421a are electrically connected to each other by wire bonding.

The input surface of the first power semiconductor element 423a is connected to the first surface pattern 422a. One end of the bonding wire Wb is connected to the output surface of the first power semiconductor element 423a, and the other end of the bonding wire Wb is connected to the third surface pattern 422c. The input surface of the second power semiconductor element 423b is connected to the third surface pattern 422c. One end of the bonding wire Wb is connected to the output surface of the second power semiconductor element 423b, and the other end of the bonding wire Wb is connected to the second surface pattern 422b.

DC power is input to the first power semiconductor element 423a via the first surface pattern 422a, and the second power semiconductor element 423b has a second surface pattern 422b and a second surface pattern 422b and a second power semiconductor. DC power is input through the bonding wire Wb that connects the element 423b. When the first power semiconductor element 423a and the second power semiconductor element 423b perform a switching operation, the above DC power is converted to AC power and output to the third surface pattern 422c.

A control signal generated by a gate driving circuit board (not shown) provided outside the circuit board 42 is input to the power semiconductor element 423. The power semiconductor element 423 performs switching according to this control signal. Note that when the power semiconductor element 423 is an IGBT, the power semiconductor element 423 has an input surface corresponding to a collector, an output surface corresponding to an emitter, and a gate corresponding to a control signal input terminal.

Note that the bonding between the front surface 41a of the base plate 41 and the back surface pattern 424 formed on the second surface 421b of the insulating plate 421, the bonding between the power semiconductor element 423 and the front surface pattern 422, and the bonding between the back surface 41b of the base plate 41 and the cooler 5 As the bonding material used for bonding, for example, solder, sintered material (powder of metal, etc.), etc. can be used.

The external output conductor 43 is an electric conductor (bus bar) for outputting the AC power converted by the power semiconductor element 423 to the outside of the power conversion device 100. The external output conductor 43 is made of metal containing copper or the like. One end of the external output conductor 43 is connected to the third surface pattern 422c on the circuit board 42. As shown in FIG. 1, the other end of the external output conductor 43 extends outward from the output side surface 1b of the casing 1. The other end of the external output conductor 43 is connected to, for example, a current output wiring (not shown) connected to a load such as a motor.

The case 44 is a member that mechanically reinforces the external output conductor 43 and the connecting conductor 3b of the capacitor 3 while being fixed to the surface 41a of the base plate 41. The case 44 is made of, for example, a synthetic resin material (insulating material). For example, PPS (polyphenylene sulfide) can be used as the material for forming the case 44 in this embodiment. Note that the case 44 may be made of a synthetic resin material other than PPS. The case 44 is fixed to the surface 41a of the base plate 41 using, for example, adhesive.

The case 44 surrounds the circuit board 42 from the outside while covering the positive terminal 3p and negative terminal 3n of the connection conductor 3b and the external output conductor 43 from the outside. As shown in FIGS. 2 and 3, the case 44 surrounds the circuit board 42 in a direction along the surface 41a of the base plate 41. As shown in FIGS. Therefore, the case 44 defines a space in which the circuit board 42 is housed together with the base plate 41. In this embodiment, for convenience of explanation, this space in which the circuit board 42 is accommodated is referred to as a "potting space Rp."

The insulating portion 45 is an insulating portion 45 material placed within the potting space Rp. The potting space Rp is filled with a liquid potting material from the outside (potting) to seal the members exposed within the potting space Rp. The potting material filled in the potting space Rp hardens over a predetermined period of time, and electrically insulates each member in the potting space Rp and between each member and the space outside the power module 40.

For example, silicon gel or epoxy resin can be used as the potting material in this embodiment. Note that synthetic resins other than silicone gel and epoxy resin may be used as the potting material. Therefore, the insulating portion 45 is formed of this potting material. The insulating section 45 in the potting space Rp is arranged to cover each surface 41a of the circuit board 42, the bonding wire Wb, the external output conductor 43, and the connection conductor 3b of the capacitor 3.

(Cooler)
As shown in FIG. 1, the cooler 5 is a device that mainly cools the power module 40 of the power converter 4. The cooler 5 is provided so as to be stacked on the casing 1, and is fixed and integrated with the casing 1. The cooler 5 has a base 51 and radiation fins 52. In addition, in FIG. 3, the base 51 and the radiation fins 52 are shown by dotted lines.

The base 51 has a plate shape. The base portion 51 has a bonding surface 51a that is bonded to the back surface 41b of the base plate 41 in the power module 40 via a bonding material, and a heat dissipation surface 51b that faces opposite to the bonding surface 51a.

The joint surface 51a and the heat radiation surface 51b are parallel to each other and are placed back to back. The radiation fins 52 are columnar members arranged in plural on the radiation surface 51b of the base 51. Each heat radiation fin 52 projects from the heat radiation surface 51b toward the side opposite to the power module 40 with the base 51 as the center.

For example, a liquid refrigerant W such as water is introduced into the cooler 5 from the outside. The heat radiation surface 51b of the base 51 and the radiation fins 52 are cooled by contacting with the liquid refrigerant W introduced from the outside. The liquid refrigerant W is warmed by exchanging heat with the heat conducted from the power module 40 to the base 51 and the radiation fins 52, and at the same time cools the power module 40.

(control board)
The control board 6 is a board that controls the driving of the power semiconductor element 423 and the like in the power module 40. The control board 6 is housed in the casing 1 with a gap interposed between the control board 6 and the power module 40 . As shown in FIGS. 2 and 3, the control board 6 is supported from the power module 40 side by, for example, bolts B fixed to the base plate 41 of the power module 40. In this embodiment, the bolts B are fastened to the base plate 41 and the control board 6, so that the control board 6 is positioned within the casing 1 with a gap between it and the power module 40. Note that the control board 6 and the power semiconductor element 423 are electrically connected by a signal line or the like (not shown).

(heat shield)
The heat shield 7 suppresses heat from being transferred from the power module 40 to the control board 6. The heat shield 7 is housed in the casing 1. The heat shielding part 7 has a box shape that divides the inside of the casing 1 into a first space R1 where the power module 40 is placed and a second space R2 where the control board 6 is placed. The heat shielding part 7 in this embodiment has a flat plate part 71 and a plurality of side wall plate parts 72.

The flat plate portion 71 has a plate shape. The flat plate portion 71 is arranged in a gap between the power module 40 and the control board 6. The flat plate portion 71 has an outer edge portion 71a as a surface corresponding to the thickness of the flat plate portion 71. The side wall plate portion 72 has a plate shape. The side wall plate part 72 in this embodiment is fixed to the joint surface 51a of the base 51 of the cooler 5 while being connected to each of the four outer edges 71a of the flat plate part 71 so as to be integral with the flat plate part 71. has been done. The outer edge portion 72a of the side wall plate portion 72 is in contact with the joint surface 51a. Therefore, the four side wall plate parts 72 are housed in the casing 1 integrally with the flat plate part 71, and connect the flat plate part 71 and the joint surface 51a of the cooler 5.

Among the four side wall plate portions 72, adjacent side wall plate portions 72 are integrally connected to each other. Therefore, the space inside the casing 1 is divided by the flat plate portion 71 and the four side wall plate portions 72 into a first space R1 where the power module 40 is placed and a second space R2 where the control board 6 is placed. has been done. The volume of the first space R1 in this embodiment is smaller than the volume of the second space R2.

The four side wall plate parts 72 surround the power module 40 from the direction in which the flat plate part 71 extends. That is, the four side wall plate parts 72 surround the power module 40 from the in-plane direction of the flat plate part 71. In FIG. 3, due to space limitations, only the cross sections of two of the four side wall plate parts 72 facing each other with the control board 6 sandwiched therebetween are shown.

Although detailed illustrations are omitted, the flat plate portion 71 is formed with holes, for example, through which the bolts B mentioned above that connect the base plate 41 and the control board 6 in the power module 40 are inserted. Further, although detailed illustrations are omitted, holes and recesses through which the connection conductor 3b of the capacitor 3 and the external output conductor 43 of the power module 40 can be inserted, for example, are formed in the side wall plate part 72. The portion 72 is arranged within the casing 1 so as not to interfere with the connection conductor 3b and the external output conductor 43.

The flat plate portion 71 is formed of a thermally conductive material having higher thermal conductivity in the in-plane direction of the flat plate portion 71 than in the thickness direction of the flat plate portion 71. Further, the side wall plate portion 72 is formed of a thermally conductive material having higher thermal conductivity in the in-plane direction of the side wall plate portion 72 than in the thickness direction of the side wall plate portion 72 . The flat plate part 71 and the side wall plate part 72 in this embodiment are formed of graphene.

Here, with reference to FIG. 4, the direction in which the heat moves in the heat shield part 7 when heat is transferred from the power module 40 to the heat shield part 7 in this embodiment will be explained. In FIG. 4, solid arrows indicate how heat moves. The heat in the heat shield part 7 moves in the in-plane direction of the flat plate part 71 and the side wall plate part 72 of the heat shield part 7, and is cooled through the outer edge part 72a of the side wall plate part 72 in contact with the joint surface 51a. Move to the base 51 and radiation fins 52 of the container 5. That is, the heat transmitted from the first space R1 side where the power module 40 is arranged to the heat shielding part 7 is suppressed from moving to the second space R2 side by the flat plate part 71 and the side wall plate part 72. Further, this heat does not remain in the flat plate portion 71 and the side wall plate portion 72, but is conducted from the side wall plate portion 72 to the base portion 51 and the radiation fins 52 in the cooler 5.

(heat dissipation part)
The heat dissipation section 8 suppresses heat from remaining in the heat shield section 7. The heat radiation part 8 is arranged on the flat plate part 71 and the side wall plate part 72 of the heat shield part 7. The heat radiation part 8 in this embodiment is a plurality of holes 81 arranged at equal intervals in the in-plane direction of the flat plate part 71 and the side wall plate part 72. That is, each hole 81 penetrates the flat plate part 71 and the side wall plate part 72 in the thickness direction, and opens into both the first space R1 and the second space R2.

Here, the opening diameter of the hole 81 in this embodiment is such that the area of the entire surface 41a of the flat plate part 71 and the side wall plate part 72 does not decrease because the hole 81 is formed in the flat plate part 71 and the side wall plate part 72. It is set as follows. That is, the area of the inner peripheral surface of the hole 81 is larger than twice the opening area of the hole 81.

(action/effect)
According to the above configuration, the movement of heat from the first space R1 to the second space R2 in the casing 1 is suppressed, and the heat transmitted to the flat plate part 71 and the side wall plate part 72 of the heat shield part 7 is transferred to the cooler. Move to 5. Further, since a plurality of heat dissipating parts 8, which are holes 81, are arranged in the flat plate part 71 and the side wall plate part 72, it is possible to suppress heat from remaining in the heat shield part 7. Therefore, compared to the heat shield part 7 in which the heat radiation part 8 is not arranged, the heat transmitted to the heat shield part 7 can be released to the cooler 5 without being retained in the heat shield part 7. As a result, heat transmitted from the power module 40 to the control board 6 can be further blocked.

Further, according to the above configuration, the flat plate part 71 and the side wall plate part 72 of the heat shielding part 7 are formed of a thermally conductive material having higher thermal conductivity in the in-plane direction than in the thickness direction. Therefore, it is possible to further suppress the heat from moving from the first space R1 to the second space R2, and to further suppress the heat from remaining in the heat shielding part 7.

(Other embodiments)
Although the embodiments of the present disclosure have been described above in detail with reference to the drawings, the specific configurations are not limited to those of the embodiments, and additions and omissions of configurations may be made within the scope of the gist of the present disclosure. , substitutions, and other changes are possible.

Note that the heat dissipation part 8 described in the first embodiment is not limited to the hole 81 that penetrates the flat plate part 71 and the side wall plate part 72 of the heat shield part 7 in the thickness direction. As shown in FIG. 5, the heat radiation part 8 may be a dimple 82 that opens only toward the first space R1 side where the power module 40 is arranged. The dimple 82 is a groove recessed from the first space R1 side to the second space R2 side in the plate thickness direction, and the inner surface 10 has a spherical shape. This also allows the heat radiating section 8 to achieve the functions and effects described in the above embodiment. Note that the dimple 82 may be opened only on the second space R2 side where the control board 6 is arranged. Further, the heat radiation section 8 may be realized by, for example, a combination of a dimple 82 that opens only to the first space R1 side and a dimple 82 that opens only to the second space R2 side.

Furthermore, as shown in FIG. 6, the heat dissipation section 8 may be a fin 83 that protrudes only toward the first space R1 side where the power module 40 is arranged. The fins 83 are formed integrally with the heat shield 7 and may be made of the same material as the heat shield 7. The fins 83 have, for example, a rectangular parallelepiped shape. This also allows the heat radiating section 8 to achieve the functions and effects described in the above embodiment.

Furthermore, the heat dissipation section 8 may be arranged only on one of the flat plate section 71 of the heat shield section 7 or the side wall plate section 72 of the heat shield section 7. That is, a plurality of heat radiating parts 8 may be arranged in the in-plane direction of one or more of the flat plate part 71 and the side wall plate part 72.

Moreover, the flat plate part 71 and the side wall plate part 72 of the heat shielding part 7 described in the above embodiment are not limited to the structure formed of graphene, and may be formed of a material such as borophene, for example. . Therefore, the flat plate part 71 and the side wall plate part 72 described in the above embodiments may be formed of a thermally conductive material having higher thermal conductivity in the in-plane direction than in the thickness direction.

Furthermore, the side wall plate portion 72 described in the above embodiment may be configured to abut (surface contact) with the side surface 12 of the inner surface 10 of the casing 1. Note that the inner surface 10 has four side surfaces 12 and a top surface 11 that connects these four side surfaces while facing the joint surface 51a of the base 51 of the cooler 5.

Further, the power conversion device 100 described above further includes a gate driving substrate (not shown) that is disposed between the flat plate portion 71 of the heat shielding portion 7 and the power module 40 and is capable of controlling switching of the power semiconductor element 423. It's okay. The gate driving substrate is electrically connected to, for example, the gate of the power semiconductor element 423 and the control substrate 6 by a signal line or the like. Further, the gate drive board is formed with a hole 81 through which the bolt B described above is inserted, and by inserting the bolt B into the hole 81, the gate drive board is inserted into the power module 40 within the casing 1. It may also be supported from the side.
Therefore, the heat shielding section 7 may have any configuration as long as it thermally protects the above-described control circuit from the power module 40 within the casing 1.

Furthermore, as shown in FIG. 7, the power conversion device 100 may further include a current sensor 9 that is housed in the casing 1 and can detect the value of the current flowing through the external output conductor 43. The current sensor 9 is a through-type current sensor (current transformer) that can measure a current value without contacting the external output conductor 43. The current sensor 9 is arranged so as to surround a part of the outer surface of the external output conductor 43 while being in contact with the joint surface 51 a of the base 51 of the cooler 5 . When the power conversion device 100 includes the current sensor 9, the side wall plate portion 72 of the heat shielding portion 7 described in the above embodiment may, for example, come into contact with the current sensor 9 (surface contact).

Note that in the embodiment described above, an inverter is used as an example of the power conversion device 100, but the power conversion device 100 is not limited to an inverter. The power conversion device 100 may be a device that performs power conversion using the power semiconductor element 423, such as a converter or a combination of an inverter and a converter. When the power conversion device 100 is a converter, an AC voltage is input from an external input power source (not shown) to the external output conductor 43, and the power semiconductor element 423 on the circuit board 42 converts this AC voltage into a DC voltage, and generates power. The structure may be such that the DC voltage from the semiconductor element 423 is output to the outside of the power conversion device 100 through the connection conductor 3b.

[Additional notes]
The power conversion device described in the embodiment can be understood, for example, as follows.

(1) The power conversion device 100 according to the first aspect includes a casing 1, a capacitor 3 housed in the casing 1, and a capacitor 3 housed in the casing 1, which converts a DC voltage from the capacitor 3 into an AC voltage. a power module 40, a cooler 5 that cools the power module 40, a control board 6 that is housed in the casing 1 with a gap between the power module 40 and the control board 6 that controls the drive of the power module 40; A heat shielding section 7 accommodated in the casing 1 and dividing the inside of the casing 1 into a space where the power module 40 is arranged and a space where the control board 6 is arranged; and a heat radiation disposed in the heat shielding section 7. The heat shielding part 7 includes a flat plate part 71 disposed in the gap between the power module 40 and the control board 6, and an outer edge part 71a of the flat plate part 71 and the cooler. 5, and a plurality of side wall plate parts 72 that surround the power module 40 from the in-plane direction of the flat plate part 71; A plurality of them are arranged in one or more in-plane directions of the side wall plate portion 72.

As a result, heat transfer from the space in the casing 1 where the power module 40 is arranged to the space where the control board 6 is arranged is suppressed, and the heat is not transferred to the flat plate part 71 and the side wall plate part 72 of the heat shield part 7. The heat is transferred to the cooler 5. Further, since a plurality of heat dissipating parts 8 are arranged on the flat plate part 71 and the side wall plate part 72, it is possible to suppress heat from remaining in the heat shielding part 7.

(2) The power conversion device 100 according to the second aspect is the power conversion device 100 according to the first aspect, in which the heat radiation section 8 includes one of the flat plate section 71 and the side wall plate section 72. A hole 81 passing through the above in the thickness direction may be used.

Thereby, it is possible to suppress heat from remaining in the heat shielding part 7 with higher precision.

(3) The power conversion device 100 according to the third aspect is the power conversion device 100 according to the first aspect, in which the heat radiation section 8 opens toward the space side where the power module 40 is arranged. Dimples 82 may also be used.

(4) The power conversion device 100 according to the fourth aspect is the power conversion device 100 according to the first aspect, in which the heat radiation section 8 protrudes toward the space side in which the power module 40 is arranged. It may also be the fin 83.

(5) The power conversion device 100 according to a fifth aspect is the power conversion device 100 according to any one of the first to fourth aspects, and includes the flat plate portion 71 and the side wall plate. The portion 72 is formed of a thermally conductive material having a higher thermal conductivity in the in-plane direction of the flat plate portion 71 and the side wall plate portion 72 than that of the flat plate portion 71 and the side wall plate portion 72 in the thickness direction. may have been done.

This further suppresses heat transfer between the spaces in the casing 1 divided by the heat shielding part 7, and further suppresses heat staying in the flat plate part 71 and side wall plate part 72 of the heat shield part 7. can do.

1...Casing 1a...Input side side 1b...Output side side 2...External input conductor 3...Capacitor 3a...Body part 3b...Connecting conductor 3p...Positive side terminal 3n...Negative side terminal 4...Power converter section 5...Cooler 6... Control board 7...Heat shield part 8...Heat radiation part 9...Current sensor 10...Inner surface 11...Top surface 12...Side surface 40...Power module 41...Base plate 41a...Front surface 41b...Back surface 42...Circuit board 43...External output conductor 44...Case 45... Insulating part 51... Base 51a... Joint surface 51b... Heat radiation surface 52... Heat radiation fin 70...

Heat shield plate

71a, 72a... Outer edge part 71... Flat plate part 72... Side wall plate part 81... Hole 82... Dimple 83... Fin 100... Power conversion device 421...Insulating plate 421a...First surface 421b...Second surface 422...Surface pattern 422a...First surface pattern 422b...Second surface pattern 422c...Third surface pattern 423...Power semiconductor element 423a...First power semiconductor Element 423b... Second power semiconductor element 424... Back pattern B... Bolt R1... First space R2... Second space Rp... Potting space S... Bonding material W... Liquid refrigerant Wb... Bonding wire

Claims

casing and
a capacitor housed in the casing;
a power module housed in the casing and converting DC voltage from the capacitor into AC voltage;
a cooler that cools the power module;
a control board that is housed in the casing with a gap in between the power module and controls the drive of the power module;
a heat shield part that is housed in the casing and partitions the inside of the casing into a space where the power module is placed and a space where the control board is placed;
a heat radiating section disposed in the heat shielding section;
Equipped with
The heat shield part is
a flat plate portion disposed in the gap between the power module and the control board;
a plurality of side wall plate parts surrounding the power module from an in-plane direction of the flat plate part by connecting an outer edge part of the flat plate part and the cooler;
has
A plurality of the heat radiating parts are arranged in one or more of the in-plane direction of the flat plate part and the in-plane direction of the side wall plate part. The power conversion device.
The power conversion device according to claim 1, wherein the heat dissipation section is a hole that penetrates one or more of the flat plate section and the side wall plate section in the thickness direction.
The power conversion device according to claim 1, wherein the heat radiation section is a dimple that opens toward the space in which the power module is arranged.
The power conversion device according to claim 1, wherein the heat radiation section is a fin that protrudes toward the space in which the power module is arranged.
The flat plate portion and the side wall plate portion are made of a thermally conductive material having a higher thermal conductivity in the in-plane direction of the flat plate portion and the side wall plate portion than in the thickness direction of the flat plate portion and the side wall plate portion. The power converter device according to any one of claims 1 to 4, formed by.