JP7294058B2 - power converter - Google Patents

Description

The disclosure described herein relates to a power conversion device with stays.

The power conversion device described in Patent Document 1 includes two electronic circuit boards and a metal stay arranged between the two electronic circuit boards.

JP 2009-159767 A

Each of the two electronic circuit boards is fixed to the stay. The stays provide a conductive path between these two electronic circuit boards. Noise is likely to be input from one of the two electronic circuit boards to the other via the stay.

Therefore, an object of the disclosure described in this specification is to provide a power conversion device in which noise input between a plurality of circuit boards is suppressed.

One of the disclosures is
a first circuit board (710) connected to a plurality of switches (511, 512);
a second circuit board (720) connected to the first circuit board;
a stay (600) to which the second circuit board is electrically and mechanically connected ;
a housing (100) in which the first circuit board and the stay are respectively supported;
a first connection (810) that mechanically and electrically connects the first circuit board to the housing;
a second connection part (820) that mechanically and electrically connects the second circuit board to the housing by electrically and mechanically connecting the stay and the housing;
The first circuit board and the stay are non-contact,
Grooves (901, 902) are formed between a first connecting portion (811) to which the first connecting portion is connected and a second connecting portion (821) to which the second connecting portion is connected in the housing.

According to this, the first circuit board (710) and the second circuit board (720) are electrically connected via the stay (600) and the housing (100). Therefore, the conductive path between the first circuit board (710) and the second circuit board (720) is lengthened by the amount of the housing (100) interposed therebetween. The electrical resistance of the conductive path between the first circuit board (710) and the second circuit board (720) is high.

Therefore, input of noise from one of the first circuit board (710) and the second circuit board (720) to the other of the first circuit board (710) and the second circuit board (720) is suppressed. It is easier to be

It should be noted that the reference numbers in parentheses above merely indicate the 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. It is a top view of a power converter. 3 is a cross-sectional view taken along line III-III shown in FIG. 2; FIG. FIG. 3 is a top view of the power conversion device with the second circuit board shown in FIG. 2 removed; FIG. 5 is a top view of the power conversion device excluding the stay shown in FIG. 4; FIG. 6 is a top view of the power conversion device with the first circuit board shown in FIG. 5 removed; It is a top view for demonstrating the modification of a power converter device. It is a top view for demonstrating the modification of a power converter device. It is a sectional view for explaining a modification of a power converter. It is a sectional view for explaining a modification of a power converter.

Embodiments will be described below with reference to the drawings.

(First embodiment)
First, based on FIG. 1, the vehicle-mounted system 1000 provided with the power converter 300 is demonstrated. This in-vehicle system 1000 constitutes a system for an electric vehicle. In-vehicle system 1000 has battery 200 , power converter 300 , and motor 400 .

In-vehicle system 1000 also includes a plurality of ECUs (not shown). These multiple ECUs transmit and receive signals to and from each other via bus wiring. A plurality of ECUs cooperate to control the electric vehicle. A plurality of ECUs control regeneration and power running of motor 400 according to the SOC of battery 200 . SOC is an abbreviation for state of charge. ECU is an abbreviation for electronic control unit.

Battery 200 has a plurality of secondary batteries. These secondary batteries constitute a battery stack connected in series. The SOC of this battery stack corresponds to the SOC of battery 200 . A lithium-ion secondary battery, a nickel-hydrogen secondary battery, an organic radical battery, or the like can be used as the secondary battery.

<Power converter>
The power conversion device 300 has an inverter 500 . Power conversion device 300 performs power conversion between battery 200 and motor 400 as inverter 500 . The power conversion device 300 converts the DC power of the 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 motor 400 via the output shaft.

The motor 400 is driven by AC power supplied from the power converter 300 . As a result, a driving force is applied to the running wheels. Also, 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 . The DC power is also supplied to various electrical loads mounted on the electric vehicle.

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

These switches can be made 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 has legs 510 . A first power supply bus bar 301 and a second power supply bus bar 302 are connected to the battery 200 . A leg group 510 is connected 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 .

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

Each of the U-phase leg 513 to W-phase leg 515 has a high-side switch 511 and a low-side switch 512 as switches. Each of the U-phase leg 513 to W-phase leg 515 has a high-side diode 511a and a low-side diode 512a as diodes. The high side switch 511 and the low side switch 512 correspond to switches.

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

A switch module 520 is configured by resin-sealing these switches with a resin member 521 . A part of the collector terminal connected to the collector electrode of the high-side switch 511 is exposed from the resin member 521 . A part of the emitter terminal connected to the emitter electrode of the low-side switch 512 is exposed from the resin member 521 . Part of the gate terminal 518 connected to the gate electrodes of the high-side switch 511 and the low-side switch 512 is exposed from the resin member 521 .

A cathode electrode of a high side diode 511 a 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 511 a is connected in anti-parallel to the high side switch 511 .

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

U-phase bus bar 410 is connected to a midpoint between high-side switch 511 and low-side switch 512 provided in U-phase leg 513 . U-phase bus bar 410 is connected to a 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 provided in 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 provided on the W-phase leg 515 . W-phase bus bar 430 is connected to a W-phase stator coil of motor 400 .

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

<Configuration of power converter>
Next, the configuration of the power converter 300 will be described. The three orthogonal directions are hereinafter referred to as the x direction, the y direction, and the z direction.

In addition to the circuit components described above, the power conversion device 300 includes a housing 100, a stay 600, a first circuit board 710, a second circuit board 720, a first bolt 810, a second bolt 820, and a third bolt. 830 , cooler 900 and spring body 920 .

The housing 100 is made of metal material. The housing 100 has a storage space that opens in the z direction. A power module 910 and a spring body 920, which will be described later, are housed in this housing space.

The stay 600 is made of metal material. The stay 600 is positioned on the opening side of the housing 100 . As shown in FIGS. 3 and 4, the stay 600 includes a frame portion 610 opening in the z direction and having a frame shape; It has a reinforcing portion 630 connected to the inner frame inner surface 611a.

The first circuit board 710 has a flat shape with a thin thickness in the z direction. The first circuit board 710 is positioned on the opening side of the housing 100 . However, the first circuit board 710 and the stay 600 are not in contact with each other. A gate driver having a low-voltage drive circuit for switching driving the switch module 520 is mounted on the first circuit board 710 .

The second circuit board 720 has a flat shape with a thin thickness in the z direction. The second circuit board 720 is positioned on the opening side of the housing 100 . More specifically, the second circuit board 720 is positioned on the second end face 610b side behind the first end face 610a of the frame portion 610 . An ECU having a high-voltage control circuit for controlling the drive state based on vehicle information is mounted on the second circuit board 720 .

<Cooler>
The cooler 900 has a supply pipe 901, a discharge pipe 902 and a plurality of relay pipes 903 as shown in FIG. The supply pipe 901 and the discharge pipe 902 are connected via a plurality of relay pipes 903 . Refrigerant is supplied to the supply pipe 901 . Refrigerant flows from the supply pipe 901 to the discharge pipe 902 via a plurality of relay pipes 903 .

Supply pipe 901 and discharge pipe 902 extend in the x-direction. The supply pipe 901 and the discharge pipe 902 are spaced apart in the y direction. Each of the multiple relay pipes 903 extends from the supply pipe 901 toward the discharge pipe 902 along the y direction. A plurality of relay pipes 903 are spaced apart in the x direction and arranged side by side.

<Power module>
A gap is formed between the two adjacent relay pipes 903 described above. A total of three air gaps are configured in the cooler 900 . U-phase to W-phase switch modules 520 are individually provided in each of these three gaps. A power module 910 is thus configured.

As shown in FIG. 6, the three-phase switch module 520 has a flat shape with a thin thickness in the x direction. A major surface of each switch module 520 is in contact with the relay pipe 903 .

The plurality of relay pipes 903 are compressed in the x direction by the biasing force applied from the spring body 920 . The width in the x direction of the gap between the relay pipes 903 is narrowed. This increases the contact area between the switch module 520 and the relay pipe 903 . Heat generated in each of the three-phase switch modules 520 can be radiated to the coolant through the relay pipe 903 .

Part of the gate terminal 518 and the sensor terminal are exposed from the resin member 521 of the switch module 520 . As shown in FIG. 5, the gate terminal 518 extends in the z-direction toward the opening side of the housing 100 and is electrically and mechanically connected to the first circuit board 710 .

<Storage of housing>
As shown in FIGS. 2 to 6, the housing 100 has a bottom portion 110 thin in the z-direction and a side portion 120 annularly rising from the inner bottom surface 110a of the bottom portion 110 in the z-direction. The side portion 120 has a first sidewall 121 and a third sidewall 123 spaced apart from each other in the x direction, and a second sidewall 122 and a fourth sidewall 124 spaced apart from each other in the y direction. The first side wall 121, the second side wall 122, the third side wall 123, and the fourth side wall 124 are annularly connected in the circumferential direction around the z-direction. The boundaries of these four sidewalls are indicated by dashed lines in FIGS.

2 to 6, the stay 600, the first circuit board 710, the housing 100, the power module 910, the first bolt 810, and the spring body 920 are indicated by dashed lines as necessary. In FIGS. 4 to 6, the same guideline as the III-III line is indicated by a dashed line.

A power module 910 and a spring body 920 are housed in a storage space defined by the bottom portion 110 and the side portion 120 . The first circuit board 710 and the stay 600 are supported on the edge surface 140 on the opening side of the side portion 120 . The form of connection between these elements and the housing 100 will be described in detail later.

As shown in FIG. 6, the housing 100 is formed with a projecting portion 125 and a supporting portion 126 . The protrusion 125 is connected to the first sidewall 121 and protrudes from the first sidewall 121 toward the third sidewall 123 in the x-direction. The support portion 126 is connected to the bottom portion 110 and extends from the bottom portion 110 toward the opening side.

The power module 910 and the spring body 920 are arranged between the projecting portion 125 and the supporting portion 126 in the housing 100 . These are arranged in the x-direction from the first side wall 121 to the third side wall 123 in the order of the protruding portion 125, the power module 910, the spring body 920, and the supporting portion 126. As shown in FIG. The power module 910 is fixed to the housing 100 by being pressed against the projecting portion 125 by a spring body 920 bent in the x direction between the power module 910 and the supporting portion 126 .

Further, as shown in FIG. 3, a first cutout portion 131 and a second cutout portion 132 are formed in the first side wall 121 of the housing 100 by cutting in the z direction from the edge surface 140 toward the bottom portion 110. . The first notch 131 and the second notch 132 are spaced apart in the y direction. The first notch 131 and the second notch 132 correspond to grooves.

As shown in FIG. 6, a projecting portion 125 formed on the first side wall 121 is positioned between the first notch portion 131 and the second notch portion 132 in the y direction. A first notch 131 is positioned between the second side wall 122 and the protrusion 125 . A second notch 132 is located between the fourth side wall 124 and the protrusion 125 .

A supply pipe 901 of the cooler 900 is passed through the first notch 131 . A discharge pipe 902 of the cooler 900 is passed through the second notch 132 .

<Conductive part>
As shown in FIG. 3, a conductive portion 150 is formed on the second side wall 122 of the housing 100 so as to protrude away from the second side wall 122 in the y direction. The conductive portion 150 is formed with a bolt hole that opens at the tip of the conductive portion 150 and extends in the y direction.

The opening and terminals of a wire harness (not shown) connected to the vehicle body are arranged side by side. A terminal of a wire harness is formed with, for example, a through hole penetrating the main surface of the terminal. A shaft portion of a bolt (not shown) is passed through a communication hole formed by aligning the opening of the conductive portion 150 and the through hole of the terminal of the wire harness. The tip side of the shaft portion of this bolt is fastened to the bolt hole of the conductive portion 150 . This electrically and mechanically connects the conductive portion 150 and the vehicle body.

Therefore, noise that flows from electronic components such as a circuit board provided in the power conversion device 300 to the housing 100 flows from the conductive portion 150 to the vehicle body via the wire harness. In this manner, the conductive portion 150 plays a role of allowing the noise that has flowed through the housing 100 to flow toward the vehicle body.

<Connection form with housing>
As shown in FIGS. 3 and 5, the first circuit board 710 and the edge surface 140 of the first side wall 121 are aligned in the z-direction.

A through-hole is formed in the first circuit board 710 so as to penetrate the main surface in the z-direction. The first side wall 121 is formed with a bolt hole that opens in the edge surface 140 of the first side wall 121 and extends in the z direction.

A shaft portion of the first bolt 810 is passed through a communication hole formed by aligning the through hole of the first circuit board 710 and the opening of the edge surface 140 of the first side wall 121 . The tip side of the shaft portion of the first bolt 810 is fastened to a bolt hole that opens in the edge surface 140 of the first side wall 121 and extends in the z direction. Thereby, the first circuit board 710 and the edge surface 140 of the first side wall 121 are mechanically and electrically connected. Although the details are omitted, the first circuit board 710 is similarly mechanically and electrically connected to the support portion 126 . The first bolt 810 corresponds to the first connecting portion.

Note that the first circuit board 710 does not have to be bolted to the edge surface 140 of the first side wall 121 . The first circuit board 710 may be mechanically and electrically connected to the protrusion 125 . In FIG. 3, the boundary line between the first side wall 121 and the projecting portion 125 is indicated by a dashed line.

As shown in FIGS. 3 and 4, the leg portion 620 of the stay 600 and the edge surfaces 140 of the second side wall 122 and the fourth side wall 124 are aligned in the z direction.

Through holes are formed in the stay 600 so as to penetrate the frame portion 610 and the leg portions 620 in the z-direction. The edge surfaces 140 of the second side wall 122 and the fourth side wall 124 are formed with bolt holes that open in the edge surfaces 140 of the second side wall 122 and the fourth side wall 124 and extend in the z-direction.

A shaft portion of the second bolt 820 is passed through a communication hole formed by aligning the through hole of the stay 600 and the openings of the edge surfaces 140 of the second side wall 122 and the fourth side wall 124 . The tip side of the shaft portion of the second bolt 820 is fastened to a bolt hole that opens in the edge surface 140 of the second side wall 122 and the fourth side wall 124 and extends in the z direction. This mechanically and electrically connects the stay 600 and the edge surfaces 140 of the second side wall 122 and the fourth side wall 124 . The second bolt 820 corresponds to the second connecting portion.

The stay 600 does not have to be bolted to the edge surfaces 140 of the second side wall 122 and the fourth side wall 124 . The stay 600 may be mechanically and electrically connected to at least the edge surface 140 of the second side wall 122 on which the conductive portion 150 is formed.

As shown in FIGS. 2 and 3, the second circuit board 720 and the frame portion 610 of the stay 600 are aligned in the z direction.

A through-hole is formed in the second circuit board 720 so as to penetrate the main surface in the z-direction. The frame portion 610 has a bolt hole extending in the z-direction from the second end face 610b toward the first end face 610a.

A shaft portion of the third bolt 830 is passed through a communication hole formed by aligning the through hole of the second circuit board 720 and the opening of the frame portion 610 . The tip side of the shaft portion of the third bolt 830 is fastened to a bolt hole extending in the z-direction from the second end surface 610b of the frame portion 610 toward the first end surface 610a. Thereby, the second circuit board 720 and the stay 600 are mechanically and electrically connected.

A reinforcement portion 630 is connected to the frame inner surface 611a of the stay 600 to connect the frame portion 610 diagonally. As shown in FIGS. 2 to 4, at least a portion of the first circuit board 710 faces the reinforcing portion 630 in the z direction. At least a portion of the second circuit board 720 faces the reinforcing portion 630 in the z direction.

Note that the reinforcing portion 630 does not have to connect the frame portion 610 diagonally. The reinforcing portion 630 may be connected to the frame inner surface 611a so as to be located between the first circuit board 710 and the second circuit board 720 at least in the z-direction.

Note that the second circuit board 720 does not have to be bolted to the frame portion 610 . Second circuit board 720 may be mechanically and electrically connected to reinforcing portion 630 .

<Effect>
The first circuit board 710 is mechanically and electrically connected to the housing 100 as described above. Stay 600 is mechanically and electrically connected to housing 100 . Second circuit board 720 is mechanically and electrically connected to stay 600 . The first circuit board 710 and the second circuit board 720 are mechanically and electrically connected to the housing 100 via the stay 600 .

For example, if the first circuit board 710 is not bolted to the edge surface 140 of the side portion 120 of the housing 100 but is directly bolted to the stay 600 , the stay 600 is not connected to the first circuit board 710 and the second circuit board 720 . It is a conductive path between

However, in this embodiment, the conductive path between the first circuit board 710 and the second circuit board 720 is long because the housing 100 is interposed therebetween. Therefore, the electrical resistance of the conductive path between the first circuit board 710 and the second circuit board 720 is high.

Noise is less likely to be input from one of first circuit board 710 and second circuit board 720 to the other. The other of first circuit board 710 and second circuit board 720 is less likely to malfunction due to noise from one of first circuit board 710 and second circuit board 720 .

In the following, in order to simplify the description of the effects, the part where the first circuit board 710 in the housing 100 and the edge surface 140 of the first side wall 121 on the side of the second side wall 122 are bolted by the first bolts 810 is shown. It is shown as a first connection portion 811 .

A portion where the stay 600 in the housing 100 and the edge surface 140 of the second side wall 122 on the side of the first side wall 121 are bolted by a second bolt 820 is indicated as a second connection portion 821 .

A portion of the stay 600 where the second circuit board 720 and the frame portions 610 on the first side wall 121 side and the second side wall 122 side are bolted by a third bolt 830 is indicated as a third connection portion 831 .

A first notch 131 is positioned between the first connection portion 811 and the second connection portion 821 . The conductive path between the first connection portion 811 and the second connection portion 821 bypasses the first cutout portion 131 as compared to the case where the first cutout portion 131 is not formed in the first side wall 121. Minutes are getting longer.

Since the conductive path between the first connection portion 811 and the second connection portion 821 is thus lengthened, the electrical resistance between the first connection portion 811 and the second connection portion 821 is increased. This makes it difficult for noise to be input from one of the first circuit board 710 and the second circuit board 720 to the other.

Similarly, a portion where the first circuit board 710 in the housing 100 and the edge surface 140 of the first side wall 121 on the side of the fourth side wall 124 are bolted by the first bolt 810 is indicated as a fourth connection portion 812 .

A portion where the stay 600 in the housing 100 and the edge surface 140 of the fourth side wall 124 on the side of the first side wall 121 are bolted by a second bolt 820 is indicated as a fifth connection portion 822 .

A portion of the stay 600 where the second circuit board 720 and the frame portions 610 on the first side wall 121 side and the fourth side wall 124 side are bolted by the third bolts 830 is indicated as a sixth connection portion 832 .

A second notch 132 is positioned between the fourth connection portion 812 and the fifth connection portion 822 . The conductive path between the fourth connection portion 812 and the fifth connection portion 822 bypasses the second cutout portion 132 as compared to the case where the second cutout portion 132 is not formed in the first side wall 121. Minutes are getting longer.

Since the conductive path between the fourth connection portion 812 and the fifth connection portion 822 is longer, the electrical resistance between the fourth connection portion 812 and the fifth connection portion 822 is likely to increase. Noise is less likely to be input from one of first circuit board 710 and second circuit board 720 to the other.

As described above, the second side wall 122 is formed with the conductive portion 150 electrically connected to the vehicle body. Noise is propagated from the first circuit board 710 to the housing 100 via the first bolts 810 fastened to the first connection portions 811 . Before the noise propagated to the housing 100 is input to the second circuit board 720 via the second bolt 820 fastened to the second connection portion 821, it is likely to flow into the vehicle body via the conductive portion 150. there is Therefore, noise is less likely to be input from the first circuit board 710 to the second circuit board 720 .

Further, noise is propagated from the second circuit board 720 to the housing 100 via the second bolts 820 fastened to the second connection parts 821 and the third bolts 830 fastened to the third connection parts 831 . The noise propagated to the housing 100 is likely to flow into the vehicle body via the conductive portion 150 before being input to the first circuit board 710 via the first bolt 810 fastened to the first connection portion 811. there is Noise is less likely to be input from the second circuit board 720 to the first circuit board 710 .

As described above, the reinforcing portion 630 of the stay 600 faces at least a portion of each of the first circuit board 710 and the second circuit board 720 in the z-direction. Therefore, the radiation noise radiated from one of the first circuit board 710 and the second circuit board 720 to the other easily enters the reinforcing portion 630 .

The amount of noise radiated from one of first circuit board 710 and second circuit board 720 to the other is likely to be reduced by the amount of noise that has entered reinforcing portion 630 . Radiation noise is less likely to be input from one of first circuit board 710 and second circuit board 720 to the other.

Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present disclosure.

(First modification)
As shown in FIG. 7, the reinforcing portion 630 provided in the stay 600 may not be connected to the frame portion 610 diagonally. For example, as shown in FIG. 7, the reinforcing portion 630 may be connected to cross the frame inner surface 611a in a mesh pattern. Hereinafter, the reinforcing portion 630 that connects the frame inner surface 611a in a mesh shape will be referred to as a mesh portion 631. As shown in FIG.

In this case, a facing region facing the mesh portion 631 and a non-facing region not facing the reinforcing portion 630 are continuously and uniformly repeated on the entire surfaces of the first circuit board 710 and the second circuit board 720 . The concentration of the non-opposing regions is suppressed at any position on the entire surface of each of the first circuit board 710 and the second circuit board 720 .

Radiation noise radiated from one of the first circuit board 710 and the second circuit board 720 to the other is not input to the mesh portion 631, and the noise from the first circuit board 710 and the second circuit board 720 is transmitted from the non-facing region to the input from one to the other is easily suppressed.

(Second modification)
As shown in FIG. 8, the stay 600 may have a frame portion 610 and a plate-like portion 612 closing the frame portion 610 without the reinforcement portion 630 . In that case, as shown in FIG. 9, the entire surfaces of the first circuit board 710 and the second circuit board 720 face the plate-like portion 612 in the z-direction. 8 and 9, the boundary between the frame portion 610 and the plate-like portion 612 is indicated by a chain double-dashed line.

Radiation noise radiated from one of first circuit board 710 and second circuit board 720 to the other easily enters plate-like portion 612 . Input of noise from one of first circuit board 710 and second circuit board 720 to the other is easily suppressed.

(Third modification)
In this embodiment, the form in which the stay 600 is made of a metal material is shown. However, a non-conductive stay 600 may be employed. As the non-conductive stay 600, for example, there is a stay 600 made of resin. Note that the non-conductive stay 600 does not have to be frame-shaped.

In this case, noise propagated from first circuit board 710 to housing 100 via first bolt 810 is less likely to be input to stay 600 via second bolt 820 . Similarly, noise is less likely to be input from second circuit board 720 to stay 600 via third bolt 830 .

Note that noise propagated from the first circuit board 710 to the housing 100 flows from the conductive portion 150 to the vehicle body. Further, as described above, the noise generated from the second circuit board 720 is less likely to flow into the housing 100 because the non-conductive stay 600 is interposed between the second circuit board 720 and the housing 100 .

In that case, as shown in FIG. 10, a connector 840 electrically connected to the vehicle body may be separately connected to the second circuit board 720 . Noise generated from the second circuit board 720 is easily transmitted to the vehicle body via the connector 840 .

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

In this embodiment, an example in which the power conversion device 300 is included in the vehicle-mounted system 1000 for an electric vehicle is shown. However, application of the power converter 300 is not particularly limited to the above example. For example, a configuration in which power conversion device 300 is included in a hybrid system that includes a motor and an internal combustion engine can also be adopted.

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

DESCRIPTION OF SYMBOLS 100... Case, 150... Conductive part, 511... High side switch, 512... Low side switch, 600... Stay, 630... Reinforcement part, 631... Mesh part, 710... First circuit board, 720... Second circuit board, 810 1st bolt 811 1st connection part 820 2nd bolt 821 2nd connection part 901 1st notch 902 2nd notch

Claims (4)

a first circuit board (710) connected to a plurality of switches (511, 512);
a second circuit board (720) connected to the first circuit board;
a stay (600) to which the second circuit board is electrically and mechanically connected ;
a housing (100) in which the first circuit board and the stay are respectively supported;
a first connection portion (810) that mechanically and electrically connects the first circuit board to the housing;
a second connection part (820) that mechanically and electrically connects the second circuit board to the housing by electrically and mechanically connecting the stay and the housing;
The first circuit board and the stay are in non-contact,
Grooves (901, 902) are formed between a first connection portion (811) to which the first connection portion is connected and a second connection portion (821) to which the second connection portion is connected in the housing. power converters. A conductive portion (150) connected to the vehicle body is formed in the housing,
2. The power conversion device according to claim 1 , wherein said conductive portion is positioned on one side of said first connection portion and said second connection portion arranged via said groove portion. The stay has a reinforcing portion that crosses and is connected in a mesh-like manner ,
3. The power converter according to claim 1, wherein said reinforcing portion is positioned between said first circuit board and said second circuit board. The stay is positioned between the first circuit board and the second circuit board,
3. The power converter according to claim 1, wherein at least one of the stay-side surfaces of each of the first circuit board and the second circuit board faces the stay.

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