JP7383979B2 - power converter - Google Patents

Description

The disclosure described in this specification relates to a power converter device including a discharge resistor.

The power conversion device described in Patent Document 1 includes a semiconductor module containing a semiconductor element, a control circuit board that controls the switching operation of the semiconductor module, a DC bus bar connected to the semiconductor module, and an electrical connection to the DC bus bar. and a discharge resistance.

JP2018-207718A

The discharge resistor and control circuit board are housed in a case. Inside the case, the discharge resistor and control circuit board are lined up.

A discharge resistor generates heat when energized. Radiant heat is emitted from the discharge resistor. This radiant heat is applied to the control circuit board. This may cause the temperature of the control circuit board to rise.

Therefore, an object of the disclosure described in this specification is to provide a power conversion device in which temperature rise of a control circuit board is suppressed.

One of the disclosures is
a control circuit board (330) connected to the plurality of switches (511, 512);
a discharge resistor (320) connected to the plurality of switches;
a bracket (820) provided between the control circuit board and the discharge resistor and holding the discharge resistor;
It has a case (600) that houses a control circuit board, a discharge resistor, and a bracket, respectively,
The case includes a frame part (610), a base part (620) which is connected to the frame part between the control circuit board and the bracket and fixes the control circuit board, and a base part (620) which is connected to the base part and extends toward the discharge resistor side away from the control circuit board. It has a protrusion (621),
A discharge resistor and a bracket are provided in a space surrounded by the frame, the base, and the protrusion.

According to this, the bracket prevents the control circuit board from being irradiated with radiant heat generated by the discharge resistor. Therefore, temperature rise of the control circuit board is suppressed.

Note that the reference numbers in parentheses above merely indicate correspondence with the configurations described in the embodiments described later, and do not limit the technical scope in any way.

1 is a circuit diagram showing an in-vehicle system. FIG. 3 is a top view of the power conversion device. FIG. 3 is a bottom view of the power conversion device. FIG. 3 is a top view of the power converter device shown in FIG. 2 with the control circuit board removed. FIG. 3 is a cross-sectional view of the power converter taken along line VV shown in FIG. 2. FIG. 3 is a cross-sectional view of the power conversion device along line VI-VI shown in FIG. 2. FIG. 6 is an enlarged view of a part of the power conversion device shown in FIG. 5. FIG. 7 is an enlarged view of a part of the power conversion device shown in FIG. 6. FIG. It is an enlarged view which expanded a part of power conversion device for explaining a 1st modification. FIG. 7 is an enlarged view of a part of the power conversion device for explaining a second modification. It is a top view of a power conversion device for explaining a 3rd modification.

Hereinafter, embodiments will be described based on the drawings.

(First embodiment)
First, an in-vehicle system 100 provided with a power conversion device 300 will be described based on FIG. 1. This in-vehicle system 100 constitutes a system for electric vehicles. In-vehicle system 100 includes a battery 200, a power converter 300, and a motor 400.

In-vehicle system 100 also includes a plurality of ECUs (not shown). These plurality of ECUs mutually transmit and receive signals via bus wiring. Multiple ECUs work together to control the electric vehicle. Regeneration and power running of the motor 400 are controlled according to the SOC of the battery 200 under the control of the plurality of ECUs. SOC is an abbreviation for state of charge. ECU is an abbreviation for electronic control unit.

Battery 200 includes a plurality of secondary batteries. These plurality of secondary batteries constitute a battery stack connected in series. The SOC of this battery stack corresponds to the SOC of the battery 200. As the secondary battery, a lithium ion secondary battery, a nickel hydride secondary battery, an organic radical battery, etc. can be employed.

<Power converter>
Power conversion device 300 includes an inverter 500. Power conversion device 300 performs power conversion between battery 200 and motor 400 as inverter 500 . Power converter 300 converts DC power of battery 200 into AC power. The power conversion device 300 converts AC power generated by power generation (regeneration) of the motor 400 into DC power.

Motor 400 is connected to an output shaft of an electric vehicle (not shown). The rotational energy of motor 400 is transmitted to the running wheels of the electric vehicle via the output shaft. Conversely, the rotational energy of the running wheels is transmitted to the motor 400 via the output shaft.

The motor 400 is powered by AC power supplied from the power conversion device 300. As a result, propulsion force is applied to the running wheels. Further, the motor 400 is regenerated by rotational energy transmitted from the running wheels. The AC power generated by this regeneration is converted into DC power by the power conversion device 300. This DC power is supplied to battery 200. DC power is also supplied to various electrical loads mounted on electric vehicles.

Inverter 500 includes semiconductor elements such as switches described below. In this embodiment, an n-channel IGBT is used as the switch. However, MOSFETs can be used instead of IGBTs as these switches. If a MOSFET is used as the switch, the diode may be omitted.

These switches can be manufactured from semiconductors such as Si and wide gap semiconductors such as SiC. The constituent material of the semiconductor element is not particularly limited.

<Inverter>
Inverter 500 includes a discharge resistor 320, a capacitor 310, and a leg group 510. A first power supply bus bar 301 and a second power supply bus bar 302 are connected to the battery 200 . A capacitor 310, a discharge resistor 320, and a leg group 510 are connected in parallel between the first power supply bus bar 301 and the second power supply bus bar 302. Leg group 510 and motor 400 are connected via output bus bar 440. The first power supply bus bar 301 and the second power supply bus bar 302 correspond to conductors.

Leg group 510 includes a U-phase leg 513, a V-phase leg 514, and a W-phase leg 515. Each of these three phase legs has two switches connected in series.

Each of the U-phase legs 513 to W-phase legs 515 has a high-side switch 511 and a low-side switch 512 as switches. Further, each of the U-phase legs 513 to W-phase legs 515 has a high-side diode 511a and a low-side diode 512a as diodes.

As shown in FIG. 1, the collector electrode of the high-side switch 511 is connected to the first power supply bus bar 301. The emitter electrode of the high-side switch 511 and the collector electrode of the low-side switch 512 are connected. An emitter electrode of the low-side switch 512 is connected to the second power supply bus bar 302. Thereby, the high-side switch 511 and the low-side switch 512 are connected in series in order from the first power supply bus bar 301 to the second power supply bus bar 302.

These switches are resin-sealed with a resin member 521 to constitute a switch module 520. A part of the collector terminal 516 connected to the collector electrode of the high side switch 511 is exposed from the resin member 521. A part of the emitter terminal 517 connected to the emitter electrode of the low-side switch 512 is exposed from the resin member 521. A portion of the gate terminal 518 connected to the gate electrode of each of the high side switch 511 and the low side switch 512 is exposed from the resin member 521.

In addition to these multiple terminals, a portion of the output terminal 519 connected to the emitter electrode of the high-side switch 511 and the collector electrode of the low-side switch 512 is exposed from the resin member 521.

A cathode electrode of a high side diode 511a is connected to a collector electrode of the high side switch 511. The emitter electrode of the high side switch 511 is connected to the anode electrode of the high side diode 511a. As a result, the high side diode 511a is connected in antiparallel to the high side switch 511.

A cathode electrode of a low-side diode 512a is connected to a collector electrode of the low-side switch 512. The emitter electrode of the low-side switch 512 is connected to the anode electrode of the low-side diode 512a. As a result, the low-side diode 512a is connected in antiparallel to the low-side switch 512.

A U-phase bus bar 410 is connected to a midpoint between a high-side switch 511 and a low-side switch 512 of the U-phase leg 513. U-phase bus bar 410 is connected to the U-phase stator coil of motor 400.

A V-phase bus bar 420 is connected to the midpoint between the high-side switch 511 and the low-side switch 512 of the V-phase leg 514. V-phase bus bar 420 is connected to a V-phase stator coil of motor 400.

A W-phase bus bar 430 is connected to the midpoint between the high-side switch 511 and the low-side switch 512 of the W-phase leg 515. W-phase bus bar 430 is connected to the W-phase stator coil of motor 400.

When the motor 400 is powered, the high side switch 511 and the low side switch 512 included in the leg group 510 are each subjected to PWM control using a control signal from the ECU. As a result, inverter 500 generates three-phase alternating current. When the motor 400 generates electricity (regenerates), the ECU stops outputting the control signal, for example. As a result, the AC power generated by the motor 400 passes through the diodes included in the three-phase leg group 510. As a result, AC power is converted to DC power.

<Configuration of power converter>
Next, the configuration of power conversion device 300 will be explained. In the following, three orthogonal directions are referred to as an x direction, a y direction, and a z direction.

In addition to the circuit components described above, the power conversion device 300 includes a control circuit board 330, a capacitor case 340, a case 600, a cover, a cooler 700, a biasing body 720, a fixing base 800, a bracket 820, and It has a wire 830.

A control circuit board 330, a condenser case 340, a cooler 700, a biasing body 720, a fixing base 800, a bracket 820, and a wire 830 are housed in a space closed by the case 600 and the cover.

An ECU and a gate driver that control the inverter 500 are mounted on the control circuit board 330.

Capacitor case 340 functions to house capacitor 310. At the same time, the capacitor case 340 functions to support the first power feeding bus bar 301 and the second power feeding bus bar 302. Capacitor case 340 is fixed to case 600 with bolts or the like (not shown).

The cover includes a first cover 670 and a second cover 680. The first cover 670 and the second cover 680 are each connected to the case 600 in such a manner as to close an opening of the case 600.

The cooler 700 functions to house and cool the plurality of switch modules 520 described above. A plurality of switch modules 520 are housed in a cooler 700 to constitute a power module 710. The contact state between the switch module 520 and the cooler 700 is ensured by the biasing force applied from the biasing body 720.

The fixing base 800 is fixed to the case 600 and serves to fix the bracket 820. The fixing base 800 is provided with a first terminal 811 and a second terminal 812 that are conductive terminals 810 .

The bracket 820 is fixed to the fixed base 800 and functions to hold the discharge resistor 320. A first electrode 321 and a second electrode 322 are formed on the discharge resistor 320. The discharge resistor 320 generates heat when energized. Radiant heat is isotropically radiated from the discharge resistor 320.

The wire 830 has a first wire 831 and a second wire 832. Each of the first wire 831 and the second wire 832 has a third terminal 833 at one end. Each of the first wire 831 and the second wire 832 has a fourth terminal 834 at the other end.

A third terminal 833 of the first wire 831 is connected to the first electrode 321 of the discharge resistor 320. A fourth terminal 834 of the first wire 831 is connected to the first terminal 811. The first electrode 321 and the first terminal 811 are electrically connected via the first wire 831.

A third terminal 833 of the second wire 832 is connected to the second electrode 322 of the discharge resistor 320. A fourth terminal 834 of the second wire 832 is connected to the second terminal 812. The second electrode 322 and the second terminal 812 are electrically connected via the second wire 832.

<Case>
As shown in FIGS. 3 and 5, the case 600 includes a frame 610, a base 620, a first inner wall 621, a second inner wall 622, and a third inner wall 623. The frame portion 610 extends in the circumferential direction around the z direction and has an annular shape. A base 620 is connected to one of the two tips of the frame 610, and partially closes the opening of the frame 610. The first to third inner wall portions 621 to 623 will be explained in detail later. The first inner wall portion 621 corresponds to a protrusion.

As shown in FIG. 2, the frame portion 610 has a first side wall 611 and a second side wall 612 arranged in the x direction, and a third side wall 613 and a fourth side wall 614 arranged in the y direction. The first side wall 611, the third side wall 613, the second side wall 612, and the fourth side wall 614 are connected in order in an annular manner in the circumferential direction.

The base 620 has a flat shape with a thin thickness in the z direction and includes a first main surface 620a and a second main surface 620b that are arranged in the z direction. The second main surface 620b side of the base portion 620 is connected to one of the two tips of the frame portion 610.

The first inner wall portion 621 to the third inner wall portion 623 have a flat shape with a thin thickness in the x direction. The second inner wall portion 622 extends in the x direction and is connected to the first side wall 611 and the second side wall 612. The first inner wall portion 621 extends in the y direction and is connected to the third side wall 613 and the second inner wall portion 622. The third inner wall portion 623 extends in the y direction and is connected to the third side wall 613 and the second inner wall portion 622.

Each of these first to third inner wall portions 621 to 623 functions as a reinforcing member to maintain the mechanical strength of the case 600. Note that the third inner wall portion 623 does not need to be connected to the second side wall 612.

Further, an opening window 640 is formed in the base 620, passing through the first main surface 620a and the second main surface 620b in the z direction. As shown in FIGS. 2 and 5, the opening window 640 has a rectangular shape.

The first inner wall portion 621 is connected to the first edge portion 624 located on the second side wall 612 side among the plurality of edges that partition the opening window 640 in the base portion 620 . The first inner wall portion 621 extends in the z direction from the first edge 624 side toward the inner space side of the frame portion 610.

Further, the second inner wall portion 622 is connected to a second edge portion 625 located on the fourth side wall 614 side among the plurality of edges that partition the opening window 640 in the base portion 620 . The second inner wall portion 622 extends in the z direction from the second edge portion 625 side toward the inner space side of the frame portion 610.

<Cover>
As shown in FIG. 5, a first cover 670 is connected to one of the two ends of the frame 610. An opening window 640 provided in the base portion 620 connected to the tip of the frame portion 610 is closed by the first cover 670.

Further, a second cover 680 is connected to the other of the two ends of the frame portion 610. An opening formed at the other of the two tips of the frame portion 610 is closed by the second cover 680.

For this purpose, a storage space is defined inside the case 600, first cover 670, and second cover 680 shown above.

<Power module>
As shown above, the power module 710 includes a plurality of switch modules 520 and a cooler 700. As shown in FIG. 5, the resin member 521 of the switch module 520 has a flat shape with a thin thickness in the x direction. A portion of the plurality of gate terminals 518 and sensor terminals are exposed from the upper surface 521a of the resin member 521. Parts of the collector terminal 516, emitter terminal 517, and output terminal 519 are exposed from the lower surface 521b of the resin member 521.

The cooler 700 has a supply pipe 701, a discharge pipe 702, and a plurality of relay pipes 703, as shown in FIG. The supply pipe 701 and the discharge pipe 702 are connected via a plurality of relay pipes 703. Refrigerant is supplied to the supply pipe 701 . This refrigerant flows from the supply pipe 701 to the discharge pipe 702 via the plurality of relay pipes 703 . A supply port 701a in the supply pipe 701 through which refrigerant is supplied from the outside and a discharge port 702a in the discharge pipe 702 through which the refrigerant supplied from the relay pipe 703 is discharged to the outside are spaced apart from each other in the y direction.

The supply pipe 701 and the discharge pipe 702 extend in the x direction. The supply pipe 701 and the discharge pipe 702 are spaced apart in the y direction. Each of the plurality of relay pipes 703 extends along the y direction from the supply pipe 701 toward the discharge pipe 702. The plurality of relay pipes 703 are spaced apart in the x direction. A gap is formed between two adjacent relay pipes 703. The cooler 700 includes a total of three voids. A switch module 520 is individually provided in each of these three gaps.

<Power module storage format>
As shown in FIG. 3, a power module 710 and a biasing body 720 are housed between the first side wall 611 and the third inner wall portion 623. The power module 710 is located closer to the first side wall 611 than the biasing body 720 in the x direction. A convex portion 601 is formed on the first side wall 611 and protrudes from the first side wall 611 toward the third inner wall portion 623 in the x direction.

The relay pipe 703 on the third inner wall portion 623 side of the cooler 700 included in the power module 710 is in contact with the biasing body 720 in the x direction. The biasing body 720 is compressed in the x direction between the relay pipe 703 and the third inner wall portion 623. The biasing body 720 applies a biasing force toward the convex portion 601 from the third inner wall portion 623 to the power module 710 .

This urging force causes the relay pipe 703 on the first side wall 611 side of the power module 710 to be pressed against the convex portion 601 in the x direction. For this purpose, the power module 710 is compressed in the x direction. As a result, the switch module 520 provided in the gap of the relay pipe 703 is actively cooled.

<Capacitor case>
As shown in FIG. 3, a capacitor case 340 is housed between the fourth side wall 614 and the second inner wall portion 622. Capacitor case 340 has a housing shape. A capacitor 310 is placed inside a capacitor case 340.

As shown in FIG. 6, the first power supply bus bar 301 is connected to one of the two electrodes of the capacitor 310. A second power supply bus bar 302 is connected to the other of the two electrodes of the capacitor 310. The capacitor 310 is resin-sealed with a coating resin inside the capacitor case 340.

As shown in FIG. 3, the first power supply bus bar 301 exposed from the coating resin has a first conductive part 331 and a first power supply part 332. The first conductive portion 331 has a flat shape with a thin thickness in the z direction. The first conductive portion 331 extends in the y direction from the fourth side wall 614 side toward the third side wall 613 side.

A part of the first conductive portion 331 extending toward the third side wall 613 is located on the first side wall 611 side. The remaining part of the first conductive portion 331 extending toward the third side wall 613 is located on the second side wall 612 side. A part of the first conductive part 331 located on the first side wall 611 side is aligned with the power module 710 in the z direction. A part of the first conductive portion 331 located on the first side wall 611 side is located closer to the first cover 670 than the power module 710 in the z direction.

A plurality of through holes penetrating in the z direction are formed in the first conductive portion 331 that is aligned with the power module 710 . As shown in FIG. 3, a first power feeding section 332 that stands up in the z direction and is thin in the x direction is connected to the edge of the through hole on the second side wall 612 side.

The collector terminal 516 exposed from the resin member 521 of the switch module 520 is passed through a plurality of through holes formed in the first conductive portion 331 that is aligned with the power module 710 . As shown in FIGS. 3 and 5, the first power feeding section 332 and the collector terminal 516 face each other in the x direction. The first power feeding section 332 and the collector terminal 516 are welded using a laser or the like.

The remaining portion of the first conductive portion 331 extending toward the third side wall 613 is aligned with the first terminal 811 in the z direction and connected to the first terminal 811 by a bolt or the like. A portion of the first conductive portion 331 connected to the first terminal 811 is referred to as a first connection portion 333. A through hole penetrating in the z direction is formed in the first connection portion 333 . In FIG. 3, the first connection portion 333 is shown surrounded by a broken line. The connection form between the first connection portion 333 and the first terminal 811 will be explained in detail later.

Similarly, the second power supply bus bar 302 exposed from the coating resin has a second conductive part 341 and a second power supply part 342. The second conductive portion 341 has a flat shape with a thin thickness in the z direction. The second conductive portion 341 extends in the y direction from the fourth side wall 614 side toward the third side wall 613 side.

A part of the second conductive portion 341 extending toward the third side wall 613 is located on the first side wall 611 side. The remaining part of the second conductive portion 341 extending toward the third side wall 613 is located on the second side wall 612 side. A part of the second conductive part 341 located on the first side wall 611 side is aligned with the power module 710 in the z direction. A part of the second conductive portion 341 located on the first side wall 611 side is located closer to the first cover 670 than the power module 710 in the z direction.

A plurality of through holes penetrating in the z direction are formed in the second conductive portion 341 that is aligned with the power module 710 . As shown in FIG. 3, a second power supply section 342 that stands up in the z direction and is thinner in the x direction is connected to the edge of the through hole on the second side wall 612 side.

The emitter terminal 517 exposed from the resin member 521 of the switch module 520 is passed through a plurality of through holes formed in the second conductive portion 341 . As shown in FIGS. 3 and 5, the second power feeding section 342 and the emitter terminal 517 face each other in the x direction. The second power feeding section 342 and the emitter terminal 517 are welded using a laser or the like.

The remaining portion of the second conductive portion 341 extending toward the third side wall 613 is aligned with the second terminal 812 in the z direction and is connected to the second terminal 812 by a bolt or the like. A portion of the second conductive portion 341 connected to the second terminal 812 is referred to as a second connection portion 343. A through hole penetrating in the z direction is formed in the second connection portion 343 . In FIG. 3, the second connection portion 343 is shown surrounded by a dashed line. The connection form between the second connection portion 343 and the second terminal 812 will be explained in detail later.

<Storage form of control circuit board>
As shown in FIG. 5, a control circuit board 330 is disposed between the base 620 of the case 600 and the first cover 670. The control circuit board 330 is connected to the first main surface 620a side of the base 620 by bolts or the like.

As shown in FIGS. 2 and 5, the control circuit board 330 faces the power module 710 in the z direction. The control circuit board 330 has a first board surface and a second board surface that are lined up in the z direction, and a through hole that penetrates these board surfaces in the z direction.

A gate terminal 518 exposed from the resin member 521 of the switch module 520 is passed through a through hole formed in the control circuit board 330 . Gate terminal 518 is connected to the substrate by solder or the like.

<Fixed stand>
As shown in FIG. 5, a fixing base 800 is located between the second side wall 612 and the first inner wall portion 621. The fixing base 800 has a first fixing part 801 and a second fixing part 802. The first fixing portion 801 has a rectangular parallelepiped shape. The first fixing part 801 is fixed to the base part 620 with a bolt or the like (not shown). The fixed base 800 corresponds to a support section.

As shown in FIG. 6, the second fixing portion 802 has a flat shape with a thin thickness in the z direction. The second fixing portion 802 is connected to a portion of the first fixing portion 801 on the third side wall 613 side, and extends in the y direction toward the third side wall 613 side. The second fixing part 802 is spaced apart from the base part 620 in the z direction. The second fixing part 802 corresponds to a support wall part.

A first holding part 804 and a second holding part 805 extending from the second fixing part 802 toward the base 620 are formed on the first fixing surface 802a of the second fixing part 802 on the base 620 side. The first holding part 804 and the second holding part 805 are spaced apart from each other in the y direction. The first fixing surface 802a corresponds to the second support surface.

As shown in FIG. 6, the first holding part 804 is located closer to the third side wall 613 in the y direction than the second holding part 805 is. Each of the first holding part 804 and the second holding part 805 has a bolt hole (not shown) in which a bolt groove is formed in a wall surface defining an opening recessed in the z direction. A bracket 820 is mounted on the holding surface 806 of each of the first holding part 804 and the second holding part 805 on the base 620 side. The connection form between the bracket 820 and these holding parts will be explained in detail later.

As shown in FIG. 5, a plurality of terminal blocks 850 extending in the z direction from the second fixing part 802 toward the second cover 680 are formed on the second fixing surface 802b on the back side of the first fixing surface 802a. These plurality of terminal blocks 850 have bolt holes (not shown) in which bolt grooves are formed in the wall surfaces defining openings recessed in the z direction. The second fixed surface 802b corresponds to the first support surface.

Further, as shown in FIGS. 5 and 7, the second fixing surface 802b side of the second fixing portion 802 is provided with a conductive first terminal 811 and a second conductive terminal 812 that are spaced apart from each other in the x direction. The first terminal 811 is located closer to the second side wall 612 than the second terminal 812 in the x direction.

As shown in FIG. 7, the first terminal 811 and the second terminal 812 each have a first extension part 813 extending in the z direction from the second fixing surface 802b, and a first extension part 813 extending from the tip of the first extension part 813 in the x direction toward the first side wall 611. It has a second extension portion 814 extending to . As shown in FIG. 5, the second extension part 814 is located closer to the second cover 680 in the z direction than the plurality of terminal blocks 850 formed on the second fixing part 802.

The second extension portion 814 has a flat shape with a small thickness in the z direction. Two through holes are formed in the second extension portion 814, which extend through the z direction and are lined up in the y direction. The connection form between the terminal block 850 and the second extension part 814 will be explained in detail later.

<Bracket>
As shown in FIGS. 6 to 8, a bracket 820 is mounted on the holding surface 806 of each of the first holding part 804 and the second holding part 805. The bracket 820 has a mounting part 821 , a first claw part 822 connected to the mounting part 821 , and a second claw part 823 .

As shown in FIG. 8, the mounting portion 821 has a flat shape with a thin thickness in the z direction. The mounting portion 821 has a first mounting surface 821a on the base 620 side and a second mounting surface 821b on the holding surface 806 side that face each other in the z direction. The mounting portion 821 has two through holes that penetrate the first mounting surface 821a and the second mounting surface 821b in the z direction.

One of the two through holes formed in the mounting portion 821 communicates with a bolt hole formed in the first holding portion 804 in the z direction. The other of the two through holes formed in the mounting portion 821 communicates with the bolt hole formed in the second holding portion 805 in the z direction. The shaft portion of the bolt is passed through a first communication hole formed by communicating a through hole formed in the mounting portion 821 with a bolt hole formed in the holding portion. The tip of the shaft portion of the bolt is fastened to the bolt groove of the bolt hole of the holding portion. As a result, the mounting portion 821 is bolted to the holding portion.

Further, the mounting portion 821 is connected with a first claw portion 822 and a second claw portion 823 that extend in the z direction from the second mounting surface 821b toward the first fixing surface 802a side of the second fixing portion 802. As shown in FIG. 7, the first claw part 822 and the second claw part 823 are spaced apart from each other in the x direction. A first claw portion 822 is connected to an edge of the mounting portion 821 on the second side wall 612 side. A second claw portion 823 is connected to an edge of the mounting portion 821 on the first side wall 611 side.

The first claw part 822 and the second claw part 823 each have a third extension part 824 extending in the z direction from the second mounting surface 821b, and a third extension part 824 extending from the tip of the third extension part 824 toward the other third extension part 824 in the x direction. It has a fourth extension portion 825 extending toward the end.

<Fixing the bracket and discharge resistor>
As shown in FIG. 7, the discharge resistor 320 is mounted on the second mounting surface 821b of the mounting section 821. The discharge resistor 320 has a rectangular parallelepiped shape. The discharge resistor 320 has a first resistance surface 320a on the second mounting surface 821b side and a second resistance surface 320b on the first fixing surface 802a side of the second fixing part 802. A portion of the second resistance surface 320b faces the fourth extension portions 825 of the first claw portion 822 and the second claw portion 823, respectively, in the z direction. The discharge resistor 320 is held and fixed in the z direction by the second mounting surface 821b and the fourth extension part 825.

Further, as shown in FIG. 7, the discharge resistor 320 includes, in addition to the first resistance surface 320a and the second resistance surface 320b, a first connection surface 320c that connects them and is spaced apart in the x direction, and a first connection surface 320c that connects these surfaces and is spaced apart in the y direction. It has two connecting surfaces 320d. The first connecting surface 320c faces the fourth extension portions 825 of the first claw portion 822 and the second claw portion 823 in the x direction. Therefore, movement of the discharge resistor 320 held in the z direction by the second mounting surface 821b and the fourth extension part 825 in the x direction is restricted by the fourth extension part 825.

Further, as shown in FIG. 7, the first resistance surface 320a, a portion of the second resistance surface 320b, and the first connection surface 320c each face the bracket 820. The remaining portions of the second connecting surface 320d and the second resistance surface 320b do not face the bracket 820. Hereinafter, these will be referred to as non-opposed portions 325 as appropriate.

<Discharge resistance>
As described above, the discharge resistor 320 has a rectangular parallelepiped shape with the first resistance surface 320a and the second resistance surface 320b arranged in the z direction. As shown in FIGS. 7 and 8, the discharge resistor 320 is provided with a first electrode 321 and a second electrode 322 extending in the z direction from the second resistance surface 320b. The first electrode 321 is located closer to the first claw portion 822 than the second electrode 322 in the x direction.

As shown in FIGS. 7 and 8, each of the first electrode 321 and the second electrode 322 has a fifth extension part 323 and a sixth extension part 324. The fifth extension portion 323 extends from the second resistance surface 320b toward the first fixed surface 802a in the z direction. The sixth extension part 324 extends from the tip of the fifth extension part 323 toward the first holding part 804 in the y direction.

<Electrical connection between discharge resistor and capacitor>
As described above, each of the first wire 831 and the second wire 832 includes a third terminal 833 and a fourth terminal 834 at one end and the other end, respectively. Each of the third terminal 833 and the fourth terminal 834 has a flat shape with a thin thickness in the z direction. A through hole penetrating in the z direction is formed in the fourth terminal 834.

The sixth extension portion 324 of the first electrode 321 of the discharge resistor 320 and the third terminal 833 of the first wire 831 are aligned in the z direction. The sixth extension portion 324 of the first electrode 321 and the third terminal 833 of the first wire 831 are joined by laser welding or the like. Discharge resistor 320 and first wire 831 are electrically connected.

As shown in FIG. 3, the second extension portion 814 of the first terminal 811 and the fourth terminal 834 of the first wire 831 are lined up in the z direction. As shown in FIG. 5, the terminal block 850 formed on the second fixing surface 802b, the second extension part 814 of the first terminal 811, and the fourth terminal 834 of the first wire 831 are lined up in the z direction.

The bolt hole formed in the terminal block 850, the through hole formed in the second extension part 814 of the first terminal 811, and the through hole formed in the fourth terminal 834 of the first wire 831 communicate with each other in the z direction. The shaft portion of the bolt is passed through this second communication hole. The first terminal 811 and the fourth terminal 834 are electrically connected. The first terminal 811 and the fourth terminal 834 are mechanically connected to the terminal block 850. Note that the first terminal 811 and the fourth terminal 834 may be welded using a laser or the like.

As shown in FIG. 3, the second extension portion 814 of the first terminal 811 and the first connection portion 333 are lined up in the z direction. The terminal block 850 formed on the second fixing surface 802b, the second extension portion 814 of the first terminal 811, and the first connection portion 333 are lined up in the z direction.

The bolt hole formed in the terminal block 850, the through hole formed in the first terminal 811, and the through hole formed in the first connection portion 333 communicate with each other in the z direction. The shaft portion of the bolt is passed through this third communication hole. As a result, the first terminal 811 and the first connection portion 333 are electrically connected. The first terminal 811 and the first connection portion 333 are mechanically connected to the terminal block 850.

Similarly, the sixth extension portion 324 of the second electrode 322 of the discharge resistor 320 and the third terminal 833 of the second wire 832 are aligned in the z direction. The sixth extension portion 324 of the second electrode 322 and the third terminal 833 of the second wire 832 are joined by laser welding or the like. Discharge resistor 320 and second wire 832 are electrically connected.

As shown in FIG. 7, the second elongated portion 814 of the second terminal 812 and the fourth terminal 834 of the second wire 832 are aligned in the z direction. The terminal block 850 formed on the second fixing surface 802b, the second extension portion 814 of the second terminal 812, and the fourth terminal 834 of the second wire 832 are lined up in the z direction.

A bolt hole formed in the terminal block 850, a through hole formed in the second extension part 814 of the second terminal 812, and a through hole formed in the fourth terminal 834 of the second wire 832 communicate with each other in the z direction. The shaft portion of the bolt is passed through this fourth communication hole. The second terminal 812 and the fourth terminal 834 are electrically connected. A second terminal 812 and a fourth terminal 834 are mechanically coupled to the terminal block 850. Note that the second terminal 812 and the fourth terminal 834 may be welded using a laser or the like.

As shown in FIG. 3, the second extension portion 814 of the second terminal 812 and the second connection portion 343 are lined up in the z direction. The terminal block 850 formed on the second fixing surface 802b, the second extension portion 814 of the second terminal 812, and the second connection portion 343 are lined up in the z direction.

The bolt hole formed in the terminal block 850, the through hole formed in the second terminal 812, and the through hole formed in the second connection portion 343 communicate with each other in the z direction. The shaft portion of the bolt is passed through this fifth communication hole. Thereby, the second terminal 812 and the second connection portion 343 are electrically connected. The second terminal 812 and the second connection portion 343 are mechanically connected to the terminal block 850.

<Effect>
As described above, the discharge resistor 320 is held between the second mounting surface 821b of the mounting portion 821 and the fourth extension portions 825 of the first claw portion 822 and the second claw portion 823 in the z direction. As shown in FIGS. 5 and 6, the projected area of the mounting portion 821 in the z direction is larger than the projected area of the discharge resistor 320 in the z direction. The discharge resistor 320 is included in the projection area of the mounting portion 821 in the z direction.

The discharge resistor 320 is located closer to the second fixing part 802 than the mounting part 821 in the z direction. The mounting portion 821 is located closer to the base portion 620 than the discharge resistor 320 in the z direction. The mounting portion 821 is located on the second main surface 620b side of the base portion 620. The control circuit board 330 is connected to the first main surface 620a on the back side of the second main surface 620b of the base 620. The control circuit board 330, the mounting section 821, and the discharge resistor 320 are arranged in this order in the z direction.

Radiant heat is isotropically radiated from the discharge resistor 320. Therefore, the radiant heat radiated from the discharge resistor 320 toward the control circuit board 330 is easily blocked by the mounting portion 821. As a result, the radiant heat emitted from the discharge resistor 320 is less likely to be received by the control circuit board 330. The temperature rise of the control circuit board 330 is easily suppressed.

As described above, the first inner wall portion 621 is connected to the first edge portion 624 . As shown in FIG. 5, the first inner wall portion 621 and the discharge resistor 320 are lined up in the x direction. The first inner wall portion 621 is located between the non-opposed portion 325 of the discharge resistor 320 and the control circuit board 330. Radiant heat radiated toward the control circuit board 330 from the non-opposing portion 325 of the discharge resistor 320 is easily blocked by the first inner wall portion 621.

As shown above, the mounting portion 821 is mounted on the holding surface 806 of each of the first holding portion 804 and the second holding portion 805. A discharge resistor 320 is fixed to the mounting portion 821. The first holding part 804 and the second holding part 805 are connected to the second fixing part 802.

As shown in FIG. 6, one end of the second fixing part 802 is connected to the first fixing part 801. The second fixing portions 802 are spaced apart from the base portion 620 in the z direction. The discharge resistor 320 fixed to the mounting part 821 and the first fixed part 801 are lined up in the y direction.

As shown in FIG. 6, the first fixing portion 801 is located between the non-opposed portion 325 of the discharge resistor 320 and the control circuit board 330. Radiant heat radiated toward the control circuit board 330 from the non-opposing portion 325 of the discharge resistor 320 is easily blocked by the first fixing portion 801.

Further, as shown in FIG. 6, the discharge resistor 320 is located between the first holding part 804 and the second holding part 805 in the y direction. The first holding part 804 and the second holding part 805 are located between the non-opposed portion 325 of the discharge resistor 320 and the control circuit board 330. Radiant heat radiated toward the control circuit board 330 from the non-opposing portion 325 of the discharge resistor 320 is easily blocked by the first holding portion 804 and the second holding portion 805.

Further, as shown in FIG. 6, the second resistance surface 320b of the discharge resistor 320 and the first fixing surface 802a of the second fixing part 802 are spaced apart from each other in the z direction. The second fixing surface 802b is provided with a first terminal 811 and a second terminal 812. A first connection portion 333 of the first power supply bus bar 301 and a second connection portion 343 of the second power supply bus bar 302 are connected to the first terminal 811 and the second terminal 812, respectively.

The first power supply bus bar 301 and the second power supply bus bar 302 generate heat when energized. However, since the second resistance surface 320b is separated from the first fixed surface 802a in the z direction, the thermal resistance between the first power supply bus bar 301, the second power supply bus bar 302, and the discharge resistor 320 tends to increase. Therefore, heat transfer from the first power feeding bus bar 301 and the second power feeding bus bar 302 to the discharge resistor 320 is easily suppressed. As a result, heat transfer from discharge resistor 320 to control circuit board 330 is easily suppressed.

Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above, and can be implemented with various modifications within the scope of the gist of the present disclosure.

(First modification)
As shown in FIG. 9, the second resistance surface 320b of the discharge resistor 320 may be in contact with the first fixing surface 802a of the second fixing part 802. Even in the configuration in which the second resistance surface 320b and the first fixing surface 802a are in contact, the mounting portion 821, the first inner wall portion 621, and the first fixing portion are provided between the non-opposed portion 325 of the discharge resistor 320 and the control circuit board 330. portion 801, a first holding portion 804, and a second holding portion 805 are located. The radiant heat radiated from the non-opposing portion 325 of the discharge resistor 320 to the control circuit board 330 is easily blocked by these portions.

(Second modification)
As shown in FIG. 10, the capacitor case 340 may be lined up with the discharge resistor 320 in the z direction. As shown above, the second resistance surface 320b and the first fixed surface 802a are spaced apart from each other in the z direction. In that case, the thermal resistance between the discharge resistor 320 and the capacitor 310 provided in the capacitor case 340 tends to increase by the distance in the z direction between the second resistance surface 320b and the first fixed surface 802a. Therefore, in the configuration of FIG. 10, heat transfer from discharge resistor 320 to capacitor 310 is easily suppressed.

(Third modification)
As shown in FIG. 11, a fourth inner wall portion 626 may be formed to connect the first inner wall portion 621 and the second side wall 612. The fourth inner wall portion 626 may be located closer to the third side wall 613 than the fixing base 800. In that case, the fourth inner wall portion 626 extends in the z direction toward the inner space of the frame portion 610, so that the fourth inner wall portion 626 and the discharge resistor 320 are aligned in the y direction. The fourth inner wall portion 626 is located between the non-opposed portion 325 of the discharge resistor 320 and the control circuit board 330. Radiant heat radiated toward the control circuit board 330 from the non-opposing portion 325 of the discharge resistor 320 is easily blocked by the fourth inner wall portion 626.

(Other variations)
In this embodiment, an example in which the inverter 500 is included in the power conversion device 300 is shown. However, power conversion device 300 may include a converter in addition to inverter 500.

In this embodiment, an example is shown in which the power conversion device 300 is included in the in-vehicle system 100 for an electric vehicle. However, the application of the power conversion device 300 is not particularly limited to the above example. For example, a configuration in which the power converter 300 is included in a hybrid system including a motor and an internal combustion engine can also be adopted.

In this embodiment, an example is shown in which one motor 400 is connected to the power conversion device 300. However, a configuration in which a plurality of motors 400 are connected to the power conversion device 300 may also be adopted. In this case, the power conversion device 300 has a plurality of three-phase switch modules for configuring an inverter.

301... 1st power feeding bus bar, 302... 2nd feeding bus bar, 320... discharge resistor, 330... control circuit board, 325... non-opposing part, 511... high side switch, 512... low side switch, 600... case, 621... base, 800...Fixing base, 802...Second fixing part, 802a...First fixing surface, 802b...Second fixing surface, 820...Bracket

Claims (4)

a control circuit board (330) connected to the plurality of switches (511, 512);
a discharge resistor (320) connected to the plurality of switches;
a bracket (820) provided between the control circuit board and the discharge resistor and holding the discharge resistor;
a case (600) that houses each of the control circuit board, the discharge resistor, and the bracket;
The case includes a frame (610), a base (620) that extends to the frame between the control circuit board and the bracket and fixes the control circuit board, and a base (620) that extends to the base and moves away from the control circuit board. a protrusion (621) extending toward the discharge resistance side,
A power converter device , wherein the discharge resistor and the bracket are provided in a space surrounded by the frame portion, the base portion, and the protrusion portion . further comprising a power module (710) including a plurality of switch modules (520) in which a plurality of the switches are sealed with resin,
The frame portion has a first side wall (611) and a second side wall (612) arranged in one direction,
A portion of the base portion is continuous with the second side wall,
A portion of the base that is continuous with the second side wall extends toward the first side wall,
The protrusion is provided at a tip of the base on the first side wall side of a portion continuous with the second side wall,
the first side wall, the protrusion, and the second side wall are arranged in the one direction;
the power module is provided between the first side wall and the protrusion,
The discharge resistor is provided between the protrusion and the second side wall,
The control circuit board extends in the one direction and is provided so as to overlap the power module, the protrusion, and the base in the direction of extension of the protrusion,
With respect to an oblique direction connecting the discharge resistor and a portion of the control circuit board that overlaps with the power module in the extension direction, the The power conversion device according to claim 1, wherein the protrusion is located. a fixing base (800) that supports the bracket;
The frame further includes a third side wall (613) that is aligned with the discharge resistor and the bracket in an orthogonal direction (y) that is orthogonal to both the one direction and the extension direction,
The fixing base includes a first fixing part (801) fixed to the base and extending toward the discharge resistor side so as to move away from the control circuit board, and a first fixing part (801) connected to the first fixing part and extending toward the third side wall in the orthogonal direction. a second fixing part (802) extending towards the bracket and supporting the bracket;
The power conversion device according to claim 2, wherein the first fixing part and the discharge resistor face each other in a direction in which the second fixing part extends. a conductor (301, 302) connected to the switch ;
Wires (831, 832) connected to the discharge resistor;
further comprising conductive terminals (811, 812) that electrically connect the conductor and the wire,
The second fixing part provided with the terminal includes a first fixing surface (802a) on the base side where the bracket is provided, and a second fixing surface (802a) on the side where the terminal is provided on the back side of the first fixing surface. further comprising a surface (802b) ;
A holding part (804, 805) on the first fixing surface, extending from the second fixing part toward the base, and having the bracket mounted on a holding surface (806) at a tip remote from the first fixing surface. is formed,
The bracket has a first mounting surface (821a) on the base side and a second mounting surface (821b) on the holding surface side on which the discharge resistor is mounted,
electrodes (321, 322) are formed on the resistance surface (320b) on the first fixed surface side of the discharge resistor;
The wire straddles the second fixing part and connects the electrode and the terminal, so that the discharge resistor and the terminal are electrically connected,
The power conversion device according to claim 3, wherein the discharge resistor is spaced apart from the first fixed surface.

Images