Power conversion device

Abstract

To provide a power conversion device that shortens main circuit wiring and realizes low loss, low cost, and miniaturization.SOLUTION: A power conversion device 1 includes: a substrate 8 on which a filter circuit component 9 having one or more capacitors for removing noise is provided; a power module 7 having a power semiconductor element 7a; and main circuit wiring connected to the power module, wherein at least a part of the main circuit wiring consists of a bus bar, the bus bar has a main bus bar 11 constituting the main circuit wiring and a branch bus bar 12 branching from the main circuit wiring, and the branch bus bar is electrically connected to the substrate.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a power conversion device. [Background technology]

[0002] Electrically powered vehicles using a motor as a drive source, such as hybrid vehicles, plug-in hybrid vehicles, electric vehicles, and fuel cell vehicles, are equipped with power conversion devices such as inverters for driving the drive motor and converters for stepping up and down the power supply voltage of a battery. These power conversion devices generally contain switching circuits, such as chopper circuits and bridge circuits, that generate a lot of high-frequency noise. To combat noise from the switching circuits, various filter circuits and shielding structures are used in power conversion devices. In recent years, there has been a trend toward reducing the cost, weight to improve fuel efficiency, and size to reduce installation space.

[0003] The configuration of a power supply device has been disclosed that can supply power to an external device while reducing the effects of leakage magnetic flux from a transformer while reducing costs (see, for example, Patent Document 1). Also, the configuration of a power conversion device has been disclosed that can efficiently cool a noise removal capacitor and a noise removal core while satisfying the demand for miniaturization of the power conversion device (see, for example, Patent Document 2).

[0004] In the configuration disclosed in Patent Document 1, the power supply device has a first shielding section disposed between the transformer and the filter mechanism, and a second shielding section disposed between the filter section, which comprises components mounted on a circuit board to reduce AC components contained in DC power and the output stabilization section, which comprises components mounted on a circuit board to stabilize and output DC power with reduced AC components. Power is supplied to the transformer, filter section, and output stabilization section in that order through connecting wires to each shielding section. The shielding sections prevent noise, including leakage flux, from being superimposed on each other between the transformer, filter section, and output stabilization section.

[0005] In the configuration disclosed in Patent Document 2, a power conversion device includes a first thermally conductive partition wall provided between the noise reduction capacitor and the noise reduction core and between the first smoothing capacitor section and the second smoothing capacitor section, a second thermally conductive partition wall provided between the filter circuit section and the smoothing capacitor, a first DC bus bar connecting the DC power supply terminal, the noise reduction capacitor, and the noise reduction core to transmit power, and a second DC bus bar connecting the first DC bus bar through which the noise reduction core passes, the smoothing capacitor, and the power semiconductor circuit to transmit power. The power conversion device is configured so that the noise reduction capacitor, the noise reduction core, and the smoothing capacitor are wired in this order via the first DC bus bar and the second DC bus bar, and power is supplied to the power conversion device. Each bus bar is thermally connected to and cooled by a thermally conductive member, and the respective partition walls are cooled. A shield formed in the second partition wall prevents noise current from the smoothing capacitor and the power semiconductor module from leaking into the DC power supply terminal. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5516999 [Patent Document 2] Patent No. 7319945 Summary of the Invention [Problem to be solved by the invention]

[0007] In the above-mentioned Patent Document 1, the effects of leakage magnetic flux can be reduced by providing a shielding portion. However, because the transformer constituting the main circuit and the filter mechanism constituting the noise-removing filter circuit and mounted on the circuit board are arranged side by side on the same plane and electrically connected in series, the main circuit wiring is long due to the electrical connection wiring with the filter. The longer the main circuit wiring, the greater the wiring loss and heat generation, which can cause components constituting the filter circuit, such as capacitors and circuit boards, to exceed their maximum operating temperature. Furthermore, the provision of multiple shielding portions, which act as partitions, restricts the layout and creates wasted space, resulting in an increase in the size of the device.

[0008] In Patent Document 2, the noise reduction capacitor and the noise reduction core can be efficiently cooled. However, since the filter circuit section, which is made up of the noise reduction capacitor and the noise reduction core, is wired with a bus bar, and the bus bar is in contact with a partition wall between the filter section and the smoothing capacitor section via a thermally conductive member to dissipate heat, there is a problem similar to the problem in Patent Document 1, in that the provision of the partition wall restricts the layout and creates wasted space, resulting in an increase in the size of the device. In addition, there is a problem in that the addition of a cooling member for the bus bar increases the number of assembly steps, which increases costs.

[0009] Therefore, an object of the present disclosure is to obtain a power conversion device that has a reduced main circuit wiring, low loss, low cost, and small size. [Means for solving the problem]

[0010] The power conversion device of the present disclosure includes a substrate provided with a filter circuit component having one or more capacitors that remove noise, a power module having power semiconductor elements, and main circuit wiring connected to the power module, at least a portion of the main circuit wiring consisting of bus bars, the bus bars including a main bus bar that constitutes the main circuit wiring and branch bus bars branching from the main bus bar, and the branch bus bars are electrically connected to the substrate. [Effects of the Invention]

[0011] According to the power conversion device of the present disclosure, the power conversion device includes a substrate provided with filter circuit components, a power module, and main circuit wiring connected to the power module, wherein at least a portion of the main circuit wiring is formed by a busbar, the busbar including a main busbar constituting the main circuit wiring and a branch busbar branching from the main busbar. The branch busbar is electrically connected to the substrate, and the busbar electrically connected to the power module is branched and connected to the substrate provided with the filter circuit components through the branch busbar. This allows the length of the main busbar to be shortened without routing the main busbar through which a large current flows, thereby reducing loss in the busbar and suppressing heat generation in the busbar. The reduced loss in the busbar allows the power conversion device to be reduced. Furthermore, since no components for cooling the busbar are required, layout constraints for cooling are eliminated, thereby allowing the power conversion device to be miniaturized. Furthermore, the absence of components for cooling the busbar allows the power conversion device to be manufactured at a lower cost. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating a configuration of a power conversion device according to a first embodiment. [Figure 2] 1 is a plan view showing an outline of a power conversion device according to a first embodiment. [Figure 3] 3 is a cross-sectional view of the power converter taken along the line AA in FIG. 2. [Figure 4] 3 is a cross-sectional view of the power converter taken along the line BB in FIG. 2. [Figure 5] 3 is a cross-sectional view of the power converter taken along the CC cross section in FIG. 2. [Figure 6] 3 is a cross-sectional view of another power converter taken along the line BB in FIG. 2. [Figure 7] FIG. 10 is a plan view showing a main part of a power conversion device according to a second embodiment. [Figure 8]8 is a cross-sectional view of a main part of the power converter taken along the line DD in FIG. 7. [Figure 9] 8 is a cross-sectional view of a main part of the power converter taken along the EE cross section of FIG. 7. [Figure 10] FIG. 10 is a plan view showing a main part of another power conversion device according to the second embodiment. [Figure 11] FIG. 10 is a plan view showing a main part of another power conversion device according to the second embodiment. [Figure 12] 12 is a cross-sectional view of a main part of another power converter taken along the FF cross section position in FIG. 11. FIG. [Figure 13] FIG. 10 is a plan view showing a main part of another power conversion device according to the second embodiment. [Figure 14] 14 is a cross-sectional view of a main part of another power converter taken along the line GG in FIG. 13. [Figure 15] FIG. 11 is a plan view showing an outline of a power conversion device according to a third embodiment. [Figure 16] 16 is a cross-sectional view of the power converter taken along the line HH in FIG. 15. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, a power conversion device according to an embodiment of the present disclosure will be described with reference to the drawings. Note that the same or equivalent members and parts in each drawing will be denoted by the same reference numerals.

[0014] Embodiment 1 FIG. 1 is a block diagram showing the configuration of a power converter 1 according to a first embodiment. FIG. 2 is a plan view showing an outline of the power converter 1, with the cover 18 removed from the power converter 1 and only the outline of the board 8 being shown, showing the component layout. FIG. 3 is a cross-sectional view of the power converter 1 taken along the line AA in FIG. 2, with the interior of the smoothing capacitor 6 indicated by a dashed line. FIG. 4 is a cross-sectional view of the power converter 1 taken along the line BB in FIG. 2, showing the area surrounding the branch busbar 12 at the line BB. FIG. 5 is a cross-sectional view of the power converter 1 taken along the line CC in FIG. 2, with a portion of the main busbar 11 omitted and showing the area surrounding the branch busbar 12 adjacent to the line CC. FIG. 6 is a cross-sectional view of another power converter 1 taken along the line equivalent to the line BB in FIG. 2, showing the area surrounding the branch busbar 12 at the line BB. The power converter 1 is a device that converts, for example, an input current from DC to AC, or from AC to DC, or an input voltage to a different voltage.

[0015] <Power conversion device 1> The power conversion device 1 is mounted on an electrically powered vehicle such as an electric vehicle or a hybrid vehicle that uses a motor as one of its drive sources. In this embodiment, as shown in FIG. 1, the power conversion device 1 converts a predetermined power (e.g., DC power) supplied from an external power source 2 into another predetermined power (e.g., AC power) and supplies the power to a load 3 (e.g., a motor). This embodiment shows a power conversion device 1 that outputs three-phase AC, and as shown in FIG. 2, the power module is made up of three power modules 7 corresponding to each phase. The configuration of the power conversion device 1 is not limited to this, and it may also be a device that converts an input current from AC to DC.

[0016] As shown in FIG. 1 , the power conversion device 1 includes a substrate 8 on which a filter circuit component 9 having one or more capacitors for removing noise is provided, a power module 7 having a power semiconductor element 7a, and main circuit wiring connected to the power module 7. At least a portion of the main circuit wiring is made up of a bus bar 30. In this embodiment, the power conversion device 1 further includes a housing 4 having a bottom wall 4c (not shown in FIG. 1 ) and accommodating the substrate 8 and the power module 7, and a smoothing capacitor 6 arranged alongside the power module 7 along the bottom wall 4c. In this embodiment, all of the main circuit wiring is made up of the bus bar 30, but this is not a limitation, and some of the main circuit wiring may be wiring provided on the substrate 8. The bus bar 30 is made of, for example, copper or an aluminum alloy, which has low electrical resistivity and excellent conductivity.

[0017] The main circuit section 5 that converts power is formed by a smoothing capacitor 6 that smooths DC power and a power module 7. A filter circuit component 9 suppresses electromagnetic noise generated by the main circuit section 5 during power conversion. In addition to the filter circuit component 9, the substrate 8 is provided with one or more other circuit components, such as control and power circuit components 10, that form the control circuit and drive circuit of the power module 7. The substrate 8 and the power module 7 are electrically connected by a power module terminal 14 that extends from the power module 7 toward the substrate 8. The substrate 8 and an external device 31 are electrically connected by a control wiring 15.

[0018] <Branch bus bar 12> The branch busbar 12, which is a key part of this disclosure, will now be described. The busbar 30 includes a main busbar 11 constituting the main circuit wiring and a branch busbar 12 branching from the main busbar 11, and the branch busbar 12 is electrically connected to the substrate 8. The external power supply 2, the main circuit unit 5, and the load 3, through which a large current flows, are electrically connected by the busbar 30 and the main busbar 11. FIG. 3 shows the positive-side branch busbar 12a, which is the branch busbar 12 branching from the positive-side main busbar 11a, which is the main busbar 11. FIG. 4 shows the positive-side branch busbar 12a and the negative-side branch busbar 12b, which is the branch busbar 12 branching from the negative-side main busbar 11b, which is the main busbar 11.

[0019] With this configuration, bus bar 30 electrically connected to main circuit unit 5 is branched, and is connected to substrate 8 on which filter circuit components 9 are provided by branched branch bus bar 12. This shortens the length of main bus bar 11 without routing main bus bar 11, through which a large current flows, thereby reducing loss in bus bar 30 and suppressing heat generation in bus bar 30. Since the loss in bus bar 30 is reduced, the loss of power conversion device 1 can also be reduced. Furthermore, since components for cooling bus bar 30 are not required, layout restrictions for cooling are eliminated, and power conversion device 1 can be made smaller. Furthermore, since components for cooling bus bar 30 are not required, the cost of power conversion device 1 can be reduced.

[0020] 3 , in the present embodiment, the branch busbar 12 is connected to wiring (not shown in FIG. 3 ) on the substrate 8 adjacent to the filter circuit component 9, and is electrically connected to the filter circuit component 9 via the wiring on the substrate 8. With this configuration, the busbar 30 can be electrically connected to the filter circuit component 9 adjacent to the branch busbar 12 via the branch busbar 12, and the wiring of the branch busbar 12 electrically connected to the filter circuit component 9 can be separated from the busbar 30. This shortens the wiring distance between the filter circuit component 9 and the main busbar 11 and the length of the main busbar 11, thereby reducing loss in the busbar 30 and suppressing heat generation in the busbar 30. Since the busbar 30 has low loss, the power conversion device 1 also has low loss.

[0021] In this embodiment, the substrate 8 is disposed opposite the power module 7 and the main bus bar 11, which is the main circuit wiring, with a gap therebetween, and the branch bus bar 12 extends from the main bus bar 11 of the main circuit wiring toward the substrate 8 and is electrically connected to the filter circuit components 9 via the wiring of the substrate 8. With this configuration, the wiring distance between the filter circuit components 9 and the main bus bar 11 is shortened, thereby suppressing the influence of noise superimposed on the branch bus bar 12. Furthermore, because the distance between the substrate 8 and the power module 7 and the main bus bar 11 is shortened, the power conversion device 1 can be made smaller.

[0022] <4 housings, 18 covers> Next, the configuration of each part of the power conversion device 1 will be described in detail. First, the housing 4 and the cover 18 will be described. The housing 4 is formed, for example, in a cylindrical shape with a bottom. The inside of the housing 4 is a component housing section that houses each component. An outer wall 4a, which is a peripheral wall erected from a bottom wall 4c, is formed around the component housing section. The cover 18, which is formed in a plate shape, covers the open portion of the housing 4, thereby forming a box-like shape with a sealed interior. The potential of the housing 4 and the cover 18 is ground. The shapes of the housing 4 and the cover 18 are not limited thereto, and the cover 18 may also be formed in a cylindrical shape with a bottom. The housing 4 and the cover 18 are made of, for example, a metal material such as an aluminum alloy. The housing 4 and the cover 18 are manufactured by, for example, aluminum die-casting. The housing 4 and the cover 18 may also be made of sheet metal made of a metal material with high magnetic permeability (for example, iron). By constructing the housing 4 and cover 18 from a metal with high magnetic permeability, an electromagnetic shielding effect can be obtained, making it easier to suppress the intrusion and radiation of noise, and by constructing them from sheet metal, the cost of the power conversion device 1 can be reduced compared to forming them using aluminum die-cast molding.

[0023] The housing 4 has an inner wall 4b, which is a portion of the housing 4 that protrudes from a bottom wall 4c on the inside of the housing 4. As shown in FIG. 2, both ends of the inner wall 4b are connected to the outer wall 4a, forming small compartments 16a and 16b surrounded by the inner wall 4b and the outer wall 4a. In this embodiment, two small compartments 16a and 16b are formed in the housing 4, but this is not limited to this. Additional small compartments may be formed and other components may be placed in the small compartments. In this embodiment, the inner wall 4b has a boss 4b2. The board 8 is fixed to the housing 4 using the boss 4b2, for example, with a screw. The boss 4b2 may be formed not only on the inner wall 4b but also on the outer wall 4a.

[0024] In this embodiment, as shown in FIG. 3 , a refrigerant flow path 17 for cooling the power module 7 is provided in the bottom wall 4c of the housing 4. The power module 7 is thermally connected to the portion of the bottom wall 4c where the refrigerant flow path 17 is provided. The thermal connection is not limited to a configuration in which the bottom wall 4c and the power module 7 are connected by direct contact. The bottom wall 4c and the power module 7 may also be thermally connected via a heat-conducting member such as grease or a heat-dissipating sheet. A refrigerant flows through the refrigerant flow path 17. For example, a liquid such as water or ethylene glycol liquid, or a gas such as air is used as the refrigerant. The housing 4 has a refrigerant inlet / outlet (not shown) through which the refrigerant flows in and out. Multiple cooling fins may be provided on the portion of the refrigerant flow path 17 on the power module 7 side. A refrigerant flow path 17 may also be provided on the side of the bottom wall 4c where the smoothing capacitor 6 is provided.

[0025] <Busbar 30> Next, the bus bar 30 will be described. As shown in FIG. 1 , the bus bar 30 has an external power supply bus bar 21 connected to the external power supply 2. As shown in FIG. 2 , the external power supply bus bar 21 is connected to the main bus bar 11 inside the housing 4. Power is supplied to the external power supply bus bar 21 from an external source. The external power supply bus bar 21 is composed of a positive-side external power supply bus bar 21a, which is a positive-side bus bar portion, and a negative-side external power supply bus bar 21b, which is a negative-side bus bar portion. As shown in FIG. 3 , the positive-side external power supply bus bar 21a and the negative-side external power supply bus bar 21b pass through outer-wall through-holes 4a1 formed in the outer wall 4a and are provided inside the external power supply connection portion 20. The external power supply connection portion 20 is fixed to the outer wall 4a of the housing 4 on the side where the filter circuit component 9 is arranged. The external power supply connection portion 20 is a connector connected to the external power supply 2. The external power supply connection portion 20 is made of a highly heat-resistant resin material, such as PPS. The outer wall through-hole 4a1 is sealed by the external power supply connection part 20, and the inside of the housing 4 is hermetically sealed. The external power supply connection part 20 and the housing of the external power supply 2 may be sealed together, or the external power supply connection part 20 may be configured as a panel-mounted connector.

[0026] The main busbar 11 and the branch busbars 12 each include a positive busbar portion and a negative busbar portion, with at least a portion of the positive busbar portion and the negative busbar portion facing each other. As shown in FIG. 2, the main busbar 11 includes a positive main busbar 11a, which is the positive busbar portion, and a negative main busbar 11b, which is the negative busbar portion. The branch busbar 12 includes a positive branch busbar 12a, which is the positive busbar portion, and a negative branch busbar 12b, which is the negative busbar portion. The positive busbar portion and the negative busbar portion, which are facing each other, are parallel plate portions so that the current flows in opposite directions when a high-frequency current is applied. The parallel plate portions of the main busbar 11 are shown in FIG. 3, and the parallel plate portions of the branch busbars 12 are shown in FIG. 4.

[0027] By forming these parallel plate portions, the magnetic flux generated in the busbars is concentrated inside the busbars, reducing high-frequency resistance and heat loss in the busbars. Furthermore, the magnetic flux generated in the busbars is canceled outside the busbars, suppressing the occurrence of parasitic inductance. Furthermore, because the opposing surfaces of the opposing busbars are covered by the opposing busbars, there are no open busbars, making noise coupling less likely.

[0028] The external power supply bus bar 21 and the main bus bar 11 are connected to an external power supply terminal block 19 provided adjacent to the outer wall 4a inside the small chamber 16a of the housing 4. The external power supply terminal block 19 is formed, for example, in a rectangular parallelepiped shape from a resin material. The external power supply terminal block 19 is provided in contact with the bottom wall 4c. The positive external power supply bus bar 21a and the positive main bus bar 11a are provided overlapping and electrically connected on the surface of the external power supply terminal block 19 opposite the bottom wall 4c. The negative external power supply bus bar 21b and the negative main bus bar 11b are provided overlapping and electrically connected on the surface of the external power supply terminal block 19 opposite the bottom wall 4c. The connection between the positive external power supply bus bar 21a and the positive main bus bar 11a, and the connection between the negative external power supply bus bar 21b and the negative main bus bar 11b are connected by, for example, welding or screws. The electrical connection between the metal parts is not limited to this, and other methods of connection such as connection via solder may also be used.

[0029] In this embodiment, as shown in Fig. 2, branch bus bar 12 branches off from main bus bar 11 at a position inside small room 16a and adjacent to external power supply side terminal block 19. After branching, branch bus bar 12 is bent toward board 8 and inserted into board 8 as shown in Fig. 4. Branch bus bar 12 inserted into board 8 is electrically connected to wiring provided on board 8 by, for example, solder (not shown).

[0030] The inner wall 4b has an inner-wall through-hole 4b1, which is a through-hole, and the main bus bar 11 passes through the inner-wall through-hole 4b1. The main bus bar 11 that passes through the inner-wall through-hole 4b1 is electrically connected to the main circuit unit 5. With this configuration, the length of the main bus bar 11 is shortened, which reduces loss in the bus bar 30 and suppresses heat generation in the bus bar 30. Since the bus bar 30 has low loss, the power conversion device 1 also has low loss.

[0031] In the present embodiment, the main busbar 11 and the branch busbars 12 are formed from the same integrated member, but this is not limiting. The main busbar 11 and the branch busbars 12 may be formed from separate busbars and connected to each other, for example, by welding or screws. The main busbar 11 and the branch busbars 12 may be formed from different metals and connected to each other. Forming the main busbar 11 and the branch busbars 12 from the same integrated member reduces the number of components, thereby reducing the cost of the power converter 1. Forming the main busbar 11 and the branch busbars 12 from separate busbars allows the same main busbar 11 to be used for wiring on different boards. This enables the main busbar 11 to be used for a variety of products, thereby reducing the development time and man-hours for the power converter 1. Forming the main busbar 11 and the branch busbars 12 from different metals facilitates adding value to the power converter 1. An example of a value-added configuration is a configuration in which the vibration resistance of the substrate 8 is improved by changing the branch busbar 12 to a stronger metal, or a configuration in which the shape of a portion of the branch busbar 12 is changed to reduce the cross-sectional area thereof, thereby suppressing heat transfer and thereby suppressing thermal damage to the substrate 8 caused by the branch busbar 12.

[0032] As shown in FIG. 1 , the busbar 30 includes a load-connecting busbar 23 connected to the load 3. As shown in FIG. 2 , the load-connecting busbar 23 is connected to the main busbar 11 inside the housing 4. The load-connecting busbar 23 supplies power to the outside. In this embodiment, three power modules 7 are provided, and therefore the load-connecting busbar 23 is connected to the main busbar 11 of each of the three power modules 7. As shown in FIG. 3 , the load-connecting busbar 23 penetrates an outer-wall through-hole 4a1 formed in the outer wall 4a and is provided inside the load connection portion 22. The load connection portion 22 is fixed to the outer wall 4a of the housing 4 on the side of the power module main terminal 13b opposite the side of the smoothing capacitor 6 of the power module 7. The load connection portion 22 is a connector connected to the load 3. The load connection portion 22 is made of a highly heat-resistant resin material, such as PPS. The outer-wall through-hole 4a1 is sealed by the load connection portion 22, and the inside of the housing 4 is hermetically sealed.

[0033] The load connection busbar 23 and the main busbar 11 are connected at a load side terminal block 24 provided adjacent to the outer wall 4a. The load side terminal block 24 is formed, for example, in a rectangular parallelepiped shape from a resin material. The load side terminal block 24 is provided in contact with the bottom wall 4c. The load connection busbar 23 and the main busbar 11 are provided overlapping on the surface of the load side terminal block 24 opposite the bottom wall 4c side, and are electrically connected. The load connection busbar 23 and the main busbar 11 are connected, for example, by welding or screws. The electrical connection between the metal parts is not limited to this, and other methods such as connection via solder may also be used.

[0034] <Smoothing capacitor 6> Next, the smoothing capacitor 6 will be described. As shown in FIG. 3, the smoothing capacitor 6 includes a capacitor element 6a, a capacitor main busbar 11c that is a portion of the main busbar 11 connected to the capacitor element 6a, and a capacitor case 6b that houses these. A sealing material is filled inside the capacitor case 6b. The sealing material is an insulating material made of epoxy resin or the like. The capacitor element 6a smoothes DC power. The capacitor element 6a is, for example, a film capacitor having a laminated structure in which a metal foil and a resin film that serve as internal electrodes are wound into a roll. The capacitor element 6a has electrodes (not shown) on both ends. Each of the electrodes is a positive electrode or a negative electrode. The portion of the capacitor main busbar 11c of the positive-side main busbar 11a that is connected to the capacitor main busbar 11c is connected to the positive electrode, and the portion of the capacitor main busbar 11c of the negative-side main busbar 11b that is connected to the negative electrode.

[0035] Although the present embodiment shows an example in which one capacitor element 6a is provided, the number of capacitor elements 6a is not limited to this. Three capacitor elements may be provided, and each of the three capacitor elements may be connected to each of the three power modules 7. The capacitor case 6b is made of, for example, aluminum die-cast molding or a resin material having high heat resistance, such as PPS.

[0036] <Power Module 7> Next, the power module 7 will be described. As shown in FIG. 2, the power module 7 is disposed adjacent to the smoothing capacitor 6. As shown in FIG. 3, the power module 7 includes a power semiconductor element 7a (not shown in FIG. 3) for power conversion, a power module main terminal 13a connected to the smoothing capacitor 6 via the main bus bar 11, a power module main terminal 13b connected to the load-connecting bus bar 23 via the main bus bar 11, and a plurality of power module terminals 14 connected to the substrate 8. The power module main terminal 13a is disposed on the side of the smoothing capacitor 6, and the power module main terminal 13b is disposed on the side of the outer wall 4a opposite to the side of the smoothing capacitor 6. The power semiconductor element 7a is sealed, for example, with a sealing resin that surrounds the power semiconductor element 7a. The power module main terminals 13a, 13b and the power module terminal 14 are made, for example, of copper or aluminum alloy, which have low electrical resistivity and excellent conductivity. The number of power semiconductor elements 7a may be one or more.

[0037] The power semiconductor element 7a may be a power control semiconductor element such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) or an IGBT (Insulated Gate Bipolar Transistor), or a freewheeling diode. The power semiconductor element 7a is not limited to these, and may be other semiconductor elements such as a bipolar transistor. It may also be an RC-IGBT (Reverse Conducting IGBT) in which a switching element and a freewheeling diode are integrated.

[0038] The power semiconductor element 7a is formed on a semiconductor substrate made of a material such as silicon, silicon carbide, or gallium nitride, and a wide bandgap semiconductor element having a wider bandgap than silicon can be used for the power semiconductor element 7a. When a MOSFET made of silicon carbide, which is a wide bandgap semiconductor element, is used, the time change di / dt of the current generated during switching can be made larger than that of a MOSFET made of silicon. Furthermore, wide bandgap semiconductor elements have low on-resistance, low loss, and low heat generation, allowing for a reduction in chip area. Because the chip area is reduced, the power module 7 can be made smaller.

[0039] <Board 8> The substrate 8 is, for example, a printed circuit board formed of a multilayer board. As shown in FIG. 3 , the substrate 8 is arranged on the opening side of the housing 4 above the main circuit unit 5 so as to overlap at least a portion of the smoothing capacitor 6 and the power module 7, which are the main circuit unit 5 including the main bus bar 11. The substrate 8 and the power module 7 are connected by a plurality of power module terminals 14 provided on the power module 7. The substrate 8 is fixed to bosses 4b2 provided on the inner wall 4b and bosses 4b2 provided adjacent to the outer wall 4a of the housing 4, for example, with screws. It is preferable that the substrate 8 be fixed at multiple points. Fixing the substrate 8 at multiple points can improve the vibration resistance and heat dissipation of the substrate 8.

[0040] As shown in FIG. 1, the substrate 8 has a control wiring 15 connected to an external device 31. As shown in FIG. 2, the control wiring 15 is electrically connected to the substrate 8 inside a small chamber 16b provided in the housing 4. A control signal is sent from the external device 31 to a circuit provided on the substrate 8 via the control wiring 15. The control wiring 15 passes through an outer wall through-hole (not shown) formed in the outer wall 4a and is provided inside the external device connection unit 25. The external device connection unit 25 is fixed to the outer wall 4a of the housing 4 on the side where the smoothing capacitor 6 is disposed. The external device connection unit 25 is a connector connected to the external device 31. The external device connection unit 25 is made of a highly heat-resistant resin material such as PPS. The outer wall through-hole is sealed by the external device connection unit 25, and the inside of the housing 4 is hermetically sealed. The control wiring 15 and the main circuit unit 5 are separated by the inner wall 4b forming the small chamber 16b, thereby suppressing the influence of noise from the main circuit unit 5 on the control wiring 15.

[0041] The capacitors included in the filter circuit component 9 are either or both of an X capacitor and a Y capacitor. In this embodiment, the filter circuit component 9 includes both an X capacitor and a Y capacitor. The X capacitor is electrically connected between the positive branch bus bar 12a and the negative branch bus bar 12b of the branch bus bar 12 to reduce normal mode noise. The Y capacitors are connected between the positive branch bus bar 12a and a ground connected to the housing 4, and between the negative branch bus bar 12b and a ground connected to the housing, to remove common mode noise. By providing the filter circuit component 9 with either or both of an X capacitor and a Y capacitor in this way, noise generated in the power conversion device 1 can be efficiently removed.

[0042] In this embodiment, since the filter circuit components 9 are arranged on the substrate 8, when a change occurs in the required noise performance of the power conversion device 1, the changed requirement can be easily accommodated simply by changing the components mounted on the substrate 8. Furthermore, in this embodiment, the filter circuit components 9 are arranged on the main circuit unit 5 side of the board surface of the substrate 8, but this is not limitative and the filter circuit components 9 may be arranged on the opening side of the housing 4. When the filter circuit components 9 are arranged on the main circuit unit 5 side, the inner wall 4b suppresses noise from the main circuit unit 5 to the filter circuit components 9, and when the filter circuit components 9 are arranged on the opening side, the substrate 8 suppresses noise from the main circuit unit 5 to the filter circuit components 9.

[0043] <Shield> The power conversion device 1 includes a shield that is grounded in contact with the substrate 8 and disposed adjacent to the filter circuit components 9. In this embodiment, as shown in FIG. 3 , the shield is formed by an inner wall 4b that defines a small chamber 16a. At least a portion of the inner wall 4b is connected to a ground pattern disposed on the substrate 8. The ground pattern is, for example, a solid pattern disposed on the surface of the substrate. In this embodiment, the ground pattern is a housing ground pattern 32. The shield is disposed between the filter circuit components 9 and one or more other circuit components, namely, control and power circuit components 10, disposed on the substrate 8, and separates the filter circuit components 9 from the control and power circuit components 10. By providing the shield that separates the filter circuit components 9 from the control and power circuit components 10, the influence of noise from the control and power circuit components 10 on the filter circuit components 9 can be reduced, thereby suppressing the influence of noise.

[0044] In this embodiment, the shield is disposed between the control and power circuit components 10 and the filter circuit components 9 and branch bus bar 12, and separates the control and power circuit components 10 from the filter circuit components 9 and branch bus bar 12. This configuration reduces the influence of noise from the control and power circuit components 10 on the branch bus bar 12, including the external power supply side terminal block 19, and the filter circuit components 9, thereby suppressing the influence of noise. It also reduces layout constraints for noise suppression. Furthermore, by providing the inner wall 4b in a curved shape, the main circuit unit 5 and the filter circuit components 9 can be arranged overlapping each other, thereby reducing noise and eliminating wasted space, thereby enabling the power conversion device 1 to be made smaller.

[0045] In this embodiment, the inner wall 4b forms a shield, and the main bus bar 11 penetrates the inner-wall through-hole 4b1. With this configuration, the inner wall 4b, which is part of the housing 4, abuts against the substrate 8, and the substrate 8 is fixed to the inner wall 4b. This strengthens the connection between the ground pattern of the substrate 8 and the housing ground, thereby reducing the impact of noise on the substrate 8. Furthermore, the main bus bar 11 penetrates the inner-wall through-hole 4b1 and is electrically connected to the main circuit unit 5. This ensures contact with the substrate surface of the substrate 8 on the surface of the inner wall 4b facing the substrate 8, while allowing the electrical connection with the main circuit unit 5 to be made using the smallest inner-wall through-hole 4b1. This suppresses the impact of noise from the main circuit unit 5 on the filter circuit component 9.

[0046] <Arrangement of Components of Power Conversion Device 1 and Other Configurations> The arrangement of each part of the power conversion device 1 and other configurations will be described. In this embodiment, as shown in FIG. 2, the filter circuit component 9 is provided adjacent to a portion of the peripheral wall surrounding the bottom surface of the smoothing capacitor 6 on the side opposite to the power module 7. In this embodiment, the peripheral wall of the smoothing capacitor 6 is a capacitor case 6b formed in a rectangular shape when viewed from the opening side of the housing 4. The filter circuit component 9 is provided inside the small chamber 16a and is electrically connected to the branch bus bar 12 and the substrate 8 inside the small chamber 16a via the branch bus bar 12. At least a portion of the surface of the substrate 8 is a solid pattern to separate the filter circuit component 9 provided on the substrate 8 from the control and power circuit components 10 other than the filter circuit component 9. A portion of the solid pattern is connected to the housing ground. The portion of the housing ground to which the solid pattern is connected is, for example, the inner wall 4b to which the substrate 8 is fixed.

[0047] By providing the filter circuit component 9 adjacent to a portion of the peripheral wall surrounding the bottom surface of the smoothing capacitor 6 on the side opposite to the power module 7, it is possible to increase the distance between the filter circuit component 9 and the power module 7, which is one of the noise sources, and thereby reduce the influence of noise on the filter circuit component 9 from the power module 7. Furthermore, because the influence of noise is reduced, for example, the capacitance of the filter circuit component 9 can be reduced, thereby making it possible to reduce the size and cost of the filter circuit component 9. Furthermore, to reduce the influence of noise, a cutout of, for example, several millimeters can be provided in part of the configuration of the small chamber 16a, and components can be placed in the cutout, thereby alleviating layout restrictions and miniaturizing the power conversion device 1.

[0048] In this embodiment, the branch bus bar 12, the filter circuit components 9, and the inner wall 4b serving as a shield are provided adjacent to the connection between the external power supply bus bar 21 and the main bus bar 11. This configuration reduces the effect of noise on the filter circuit components 9, including the external power supply bus bar 21 connected to the outside. It also makes it possible to reduce the size of the filter circuit components 9 portion where the shield is provided. Because the filter circuit components 9 portion is reduced in size, the power conversion device 1 can be made smaller.

[0049] In this embodiment, as shown in FIG. 3 , the substrate 8 has a wiring pattern on the surface of the substrate 8 where the inner wall 4b, which serves as a shield, abuts. The inner wall 4b and the wiring pattern are electrically connected, and at least a portion of the wiring pattern is a housing ground pattern 32 connected to the housing 4. This configuration reduces the effects of noise passing through the substrate surface of the substrate 8. Furthermore, since the housing ground pattern 32 is connected to the housing 4 not only electrically but also thermally, the number of heat dissipation paths for the substrate 8 is increased, facilitating heat dissipation from the substrate 8 and suppressing heat transfer to components provided on the substrate 8. Furthermore, since the substrate 8 abuts against the housing 4, the vibration resistance of the substrate 8 is ensured. Therefore, components with low vibration resistance can be mounted adjacent to the abutting portion, facilitating the layout of the substrate 8.

[0050] 4, in this embodiment, the substrate 8 is a multi-layer substrate, and the inner layer of the substrate 8 has an inner layer housing ground pattern 33 connected to the housing ground pattern 32. With this configuration, the influence of noise passing through the inner layer of the substrate 8 can be reduced, and the influence of noise can be suppressed.

[0051] In this embodiment, as shown in Fig. 3, the power module 7, bus bar 30, and inner wall 4b, which is a shield, are provided on one surface 8a of the substrate 8, and the power module 7 is covered by the substrate 8. The bus bar 30 shown in Fig. 3 is the main bus bar 11. With this configuration, the power module 7 and inner wall 4b, which are noise sources, are concentrated on one surface 8a of the substrate 8, making it easy to block noise by the inner wall 4b.

[0052] In this embodiment, the housing 4 is formed in a cylindrical shape with a bottom, and one surface 8a of the substrate 8 faces the bottom wall 4c. The power module 7, the inner wall 4b serving as a shield, and the filter circuit components 9 are arranged in this order along the bottom wall 4c, with the inner wall 4b separating the power module 7 and the filter circuit components 9. With this configuration, the power module 7 and the filter circuit components 9 are separated by the inner wall 4b, so that the influence of noise from the power module 7 on the filter circuit components 9 can be reliably suppressed.

[0053] In this embodiment, as shown in Fig. 2, small rooms 16a and 16b are provided separately, but this is not limiting. Small rooms 16a and 16b may be provided integrally. By providing small rooms 16a and 16b integrally, the inner wall 4b can be eliminated, and layout restrictions due to the inner wall 4b can be alleviated, allowing the power conversion device 1 to be made more compact. Furthermore, the cost of materials for the housing 4 is reduced, allowing the cost of the power conversion device 1 to be reduced.

[0054] In the present embodiment, the external power supply side terminal block 19 and the smoothing capacitor 6 are configured as separate bodies, but this is not limiting and the external power supply side terminal block 19 and the smoothing capacitor 6 may be configured as an integrated unit. An integrated configuration is, for example, a configuration in which the external power supply side terminal block 19 does not abut against the bottom wall 4c, but extends from the capacitor case 6b through the inner wall through-hole 4b1 into the small chamber 16a. This configuration reduces wasted space between the inner wall 4b and the external power supply side terminal block 19, allowing the power conversion device 1 to be further miniaturized.

[0055] <Modification> A modified example in which an additional shield 26 is provided in addition to the above-described configuration will be described with reference to FIG. 6 . The inner wall 4b, which serves as the shield, is provided on one surface 8a of the substrate 8. The power conversion device 1 further includes an additional shield 26 that abuts against the other surface 8b of the substrate 8 and is grounded to the substrate 8 and the housing 4. At least a portion of the additional shield 26 overlaps the inner wall 4b via the substrate 8. In this embodiment, the additional shield 26 is a portion of the cover 18 that protrudes from the cover 18 toward the other surface 8b of the substrate 8. The additional shield 26 is grounded to the housing 4 via the cover 18. The additional shield 26 separates the filter circuit components 9 from the control and power circuit components 10 on the other surface 8b of the substrate 8.

[0056] With this configuration, it is possible to block and suppress noise generated by, for example, the control and power circuit components 10 from propagating to the filter circuit components 9, even on the other surface 8b of the substrate 8. Because noise propagating to the filter circuit components 9 can be blocked and suppressed on both the one surface 8a and the other surface 8b of the substrate 8, it is possible to alleviate restrictions on the placement of the filter circuit components 9 due to the influence of noise. Because restrictions on the placement of the filter circuit components 9 are alleviated, it is possible to reduce the placement area of ​​the filter circuit components 9 and make the substrate 8 more compact.

[0057] Because the additional shield 26, which is grounded to the housing 4, abuts against the board 8, the number of heat dissipation paths for the board 8 increases, facilitating heat dissipation from the board 8 and suppressing heat transfer to components provided on the board 8. Furthermore, because the board 8 abuts against the housing 4 and the additional shield 26, the vibration resistance of the board 8 is ensured, and components with low vibration resistance can be mounted in positions adjacent to the abutting parts, facilitating the layout of the board 8.

[0058] The additional shield 26 is not limited to being provided integrally with the cover 18. The additional shield 26 may be formed of a separate metal member that is grounded to the housing 4, and at least a portion of the additional shield 26 may be in contact with the substrate 8. Alternatively, the additional shield 26 may be a portion of the cover 18 that is recessed toward the other surface 8b of the substrate 8 by, for example, press working.

[0059] As described above, the power conversion device 1 according to the first embodiment includes the substrate 8 on which the filter circuit components 9 are provided, the power module 7, and the main circuit wiring connected to the power module 7. At least a portion of the main circuit wiring is formed by the busbar 30. The busbar 30 includes the main busbar 11 constituting the main circuit wiring and the branch busbar 12 branching from the main busbar 11. The branch busbar 12 is electrically connected to the substrate 8, so that the busbar 30 electrically connected to the power module 7 is branched and connected to the substrate 8 on which the filter circuit components 9 are provided by the branched branch busbar 12. Therefore, the length of the main busbar 11 is shortened without routing the main busbar 11 through which a large current flows, thereby reducing loss in the busbar 30 and suppressing heat generation in the busbar 30. The reduced loss in the busbar 30 allows the power conversion device 1 to have reduced loss. Furthermore, because a member for cooling the busbar 30 is not required, layout constraints for cooling are eliminated, allowing the power conversion device 1 to be made smaller. Furthermore, since no member for cooling the bus bar 30 is required, the cost of the power converter 1 can be reduced.

[0060] When branch busbar 12 is connected to wiring on substrate 8 adjacent to filter circuit component 9 and electrically connected to filter circuit component 9 via the wiring on substrate 8, busbar 30 can be electrically connected to filter circuit component 9 adjacent to branch busbar 12 via branch busbar 12, and the wiring of branch busbar 12 electrically connected to filter circuit component 9 can be separated from busbar 30. This reduces the wiring distance between filter circuit component 9 and main busbar 11 and the length of main busbar 11, thereby reducing loss in busbar 30 and suppressing heat generation in busbar 30. Because loss in busbar 30 is reduced, loss in power conversion device 1 can also be reduced.

[0061] When the substrate 8 is provided opposite the power module 7 and the main bus bar 11, which is the main circuit wiring, with a gap therebetween, and the branch bus bar 12 extends from the main bus bar 11 of the main circuit wiring toward the substrate 8 and is electrically connected to the filter circuit components 9 via the wiring of the substrate 8, the wiring distance between the filter circuit components 9 and the main bus bar 11 is shortened, thereby suppressing the influence of noise superimposed on the branch bus bar 12. Furthermore, because the distance between the substrate 8 and the power module 7 and the main bus bar 11 is shortened, the power conversion device 1 can be made smaller.

[0062] When the power conversion device 1 further includes a housing 4 having a bottom wall 4c and accommodating a substrate 8 and a power module 7, and a smoothing capacitor 6 arranged alongside the power module 7 along the bottom wall 4c, and the filter circuit component 9 is provided adjacent to a portion of the peripheral wall surrounding the bottom surface of the smoothing capacitor 6 on the side opposite to the power module 7, the distance between the filter circuit component 9 and the power module 7, which is one of the noise sources, can be increased, thereby reducing the influence of noise from the power module 7 on the filter circuit component 9. Furthermore, because the influence of noise is reduced, for example, the capacitance of the filter circuit component 9 can be reduced, thereby enabling the filter circuit component 9 to be made smaller and less expensive.

[0063] When the power conversion device 1 is grounded in contact with the substrate 8 and further includes a shield provided adjacent to the filter circuit components 9, and the shield is disposed between the filter circuit components 9 and one or more other circuit components, namely, the control and power circuit components 10, provided on the substrate 8, and separates the filter circuit components 9 from the control and power circuit components 10, the influence of noise from the control and power circuit components 10 on the filter circuit components 9 can be reduced, and the influence of noise can be suppressed.

[0064] When the shield is disposed between the control and power circuit components 10, which are other circuit components, and the filter circuit components 9 and branch bus bar 12, and separates the control and power circuit components 10 from the filter circuit components 9 and branch bus bar 12, the influence of noise from the control and power circuit components 10 on the branch bus bar 12 including the portion of the external power supply side terminal block 19 and the filter circuit components 9 can be reduced, and the influence of noise can be suppressed. In addition, layout restrictions for noise suppression can be reduced.

[0065] When the housing 4 has an inner wall 4b that is a part of the housing 4 protruding from a portion of the bottom wall 4c inside the housing 4, the inner wall 4b forms a shield, the inner wall 4b has an inner-wall through-hole 4b1 that is a through-hole, and the main busbar 11 passes through the inner-wall through-hole 4b1, the inner wall 4b that is a part of the housing 4 abuts against the circuit board 8 and the circuit board 8 is fixed to the inner wall 4b, thereby strengthening the connection between the ground pattern of the circuit board 8 and the housing ground and reducing the impact of noise on the circuit board 8. Furthermore, the main busbar 11 passes through the inner-wall through-hole 4b1 and is electrically connected to the main circuit unit 5. This ensures contact between the surface of the inner wall 4b facing the circuit board 8 and the circuit board surface of the circuit board 8, while allowing the electrical connection with the main circuit unit 5 to be configured with the smallest inner-wall through-hole 4b1. This reduces the impact of noise from the main circuit unit 5 on the filter circuit component 9.

[0066] When the bus bar 30 has an external power supply bus bar 21 connected to the external power supply 2, the external power supply bus bar 21 is connected to the main bus bar 11 inside the housing 4, and the branch bus bar 12, the filter circuit components 9, and the inner wall 4b serving as a shield are provided adjacent to the connection between the external power supply bus bar 21 and the main bus bar 11, it is possible to reduce the effect of noise on the filter circuit components 9, including the external power supply bus bar 21 connected to the outside. In addition, it is possible to reduce the size of the portion of the filter circuit components 9 where the shield is provided. Because the portion of the filter circuit components 9 is reduced in size, it is possible to reduce the size of the power conversion device 1.

[0067] When the substrate 8 has a wiring pattern on the surface of the substrate 8 that abuts against the inner wall 4b, the inner wall 4b is electrically connected to the wiring pattern, and at least a portion of the wiring pattern is a housing ground pattern 32 connected to the housing 4, it is possible to reduce the effects of noise passing through the substrate surface of the substrate 8. Furthermore, because the housing ground pattern 32 is connected to the housing 4 not only electrically but also thermally, the number of heat dissipation paths for the substrate 8 is increased, facilitating heat dissipation from the substrate 8 and suppressing heat transfer to components provided on the substrate 8. Furthermore, because the substrate 8 abuts against the housing 4, the vibration resistance of the substrate 8 is ensured, and components with low vibration resistance can be mounted in positions adjacent to the abutting portion, facilitating the layout of the substrate 8.

[0068] If the substrate 8 is a multilayer substrate and the inner layer of the substrate 8 has an inner layer housing ground pattern 33 connected to the housing ground pattern 32, the influence of noise passing through the inner layer of the substrate 8 can be reduced and the influence of noise can be suppressed.

[0069] When the power module 7, bus bar 30, and inner wall 4b, which is a shield, are provided on one surface 8a of the substrate 8 and the power module 7 is covered by the substrate 8, the power module 7 and inner wall 4b, which are noise sources, are concentrated on the one surface 8a side of the substrate 8, making it easy to block noise by the inner wall 4b.

[0070] When the housing 4 is formed in a cylindrical shape with a bottom, one surface 8a of the substrate 8 faces the bottom wall 4c, the power module 7, the inner wall 4b serving as a shield, and the filter circuit components 9 are arranged in this order along the bottom wall 4c, and the inner wall 4b separates the power module 7 from the filter circuit components 9, the effect of noise from the power module 7 on the filter circuit components 9 can be reliably suppressed because the power module 7 and the filter circuit components 9 are separated by the inner wall 4b.

[0071] When the inner wall 4b, which is a shield, is provided on one side 8a of the substrate 8, the power conversion device 1 further includes an additional shield 26 that abuts the other side 8b of the substrate 8 and is grounded to the substrate 8 and the housing 4, and at least a portion of the additional shield 26 is stacked on the inner wall 4b via the substrate 8, noise generated by, for example, the control and power circuit components 10 can be blocked and suppressed from propagating to the filter circuit components 9, even on the other side 8b of the substrate 8. Because noise propagating to the filter circuit components 9 can be blocked and suppressed on both the one side 8a and the other side 8b of the substrate 8, restrictions on the placement of the filter circuit components 9 due to the influence of noise can be alleviated. Because restrictions on the placement of the filter circuit components 9 are alleviated, the placement area for the filter circuit components 9 can be reduced, and the substrate 8 can be made smaller.

[0072] When the main busbar 11 and the branch busbars 12 are each composed of a positive busbar portion and a negative busbar portion, and at least a portion of the positive busbar portion and the negative busbar portion are arranged facing each other, the magnetic flux generated in the busbars is concentrated inside the busbars, reducing high-frequency resistance and heat loss in the busbars. In addition, the magnetic flux generated in the busbars is canceled outside the busbars, suppressing the occurrence of parasitic inductance.

[0073] When the capacitor included in the filter circuit component 9 is one or both of an X capacitor and a Y capacitor, noise generated in the power conversion device 1 can be efficiently removed.

[0074] Embodiment 2 The power conversion device 1 according to the second embodiment will be described. FIG. 7 is a plan view showing a main part of a power conversion device 1 according to embodiment 2, with cover 18 removed from power conversion device 1 and only the outline of substrate 8 shown, and showing the component arrangement around branch busbar 12; FIG. 8 is a cross-sectional view of a main part of power conversion device 1 taken at DD cross section in FIG. 7; FIG. 9 is a cross-sectional view of a main part of power conversion device 1 taken at EE cross section in FIG. 7, showing the part around separate shield 27 at EE cross section; FIG. 10 is a plan view showing a main part of another power conversion device 1 according to embodiment 2, showing the same part as in FIG. 7; FIG. 11 is a plan view showing a main part of yet another power conversion device 1 according to embodiment 2, showing the same part as in FIG. 7; FIG. 12 is a cross-sectional view of a main part of yet another power conversion device 1 taken at FF cross section in FIG. 11; FIG. 13 is a plan view showing a main part of yet another power conversion device 1 according to embodiment 2, showing the same part as in FIG. 7; and FIG. 14 is a cross-sectional view of a main part of yet another power conversion device 1 taken at GG cross section in FIG. 13. The shield of the power conversion device 1 shown in embodiment 1 was the inner wall 4b of the housing 4, but the power conversion device 1 of embodiment 2 is configured to have a separate shield 27 that is not part of the housing 4.

[0075] As shown in FIG. 9 , the portion of separate shield 27, which serves as a shield, opposite the portion that abuts and is grounded against substrate 8 abuts against housing 4, excluding at least the wiring arrangement portion. Main bus bar 11 penetrates the space of the wiring arrangement portion. The portion of main bus bar 11 that penetrates the space, separate shield 27, and substrate 8 are arranged in order in a direction away from bottom wall 4c of housing 4. In this embodiment, the portion of housing 4 that abuts separate shield 27 is inner wall 4b. A cutout portion 4b3 is provided in inner wall 4b, and the portion of cutout portion 4b3 covered by separate shield 27 forms wiring space 28, which is the space for the wiring arrangement portion. Main bus bar 11 penetrates wiring space 28. The portion of main bus bar 11 that penetrates wiring space 28 is arranged so that it at least partially overlaps with inner wall 4b, cutout portion 4b3, separate shield 27, and substrate 8 when viewed perpendicular to bottom wall 4c.

[0076] 7, the small chamber 16a is formed by an outer wall 4a, an inner wall 4b, and a separate shield 27. The external power supply side terminal block 19 and the branch bus bar 12 provided inside the small chamber 16a are separated from the main circuit section 5 by the outer wall 4a, the inner wall 4b, and the separate shield 27. In addition, the filter circuit components 9 provided in the portion of the board 8 inside the small chamber 16a are separated from the control and power circuit components 10 by the outer wall 4a, the inner wall 4b, and the separate shield 27.

[0077] By providing the separate shield 27 and forming the small chamber 16a, as shown in FIG. 8 , the power converter 1 can be simply assembled by sequentially arranging the main bus bar 11, the separate shield 27, and the substrate 8 on the bottom wall 4c from the open side of the housing 4, thereby improving the ease of assembly of the power converter 1. Furthermore, the assembly time of the power converter 1 can be shortened, thereby reducing the assembly cost of the power converter 1. Furthermore, while a shield formed solely by the inner wall 4b imposes manufacturing constraints on the shape of the inner wall 4b, providing the separate shield 27 can eliminate these manufacturing constraints. Since the manufacturing constraints of the separate shield 27 are eliminated and the shape of the separate shield 27 can be freely changed, other functions can be imparted to the separate shield 27. The other functions imparted to the separate shield 27 will be described in a modified example below.

[0078] The configuration of wiring space 28 is not limited to the configuration shown in Fig. 9. In the configuration shown in Fig. 9, cutout portion 4b3 is provided in inner wall 4b, but cutout portion 4b3 may be provided in separate shield 27. Also, a configuration may be adopted in which separate shield 27 provided with cutout portion 4b3 is abutted against bottom wall 4c without providing inner wall 4b.

[0079] The separate shield 27 is made of a metal material such as an aluminum alloy. The separate shield 27 is made, for example, by aluminum die-casting. The separate shield 27 abuts against the substrate surface of the substrate 8 at a portion opposite the bottom wall 4c. At least a portion of the separate shield 27 abuts against the inner wall 4b at the portion on the bottom wall 4c side, and is fixed to the inner wall 4b at multiple locations, for example, with screws. This fixation connects the separate shield 27 to the housing ground. Similarly, the separate shield 27 is also connected to the substrate 8 at multiple locations, for example, with screws. Connecting the substrate 8 to the separate shield 27 can improve the vibration resistance and heat dissipation of the substrate 8.

[0080] The substrate 8 has a solid pattern on the substrate surface where the separate shield 27 abuts, and the separate shield 27 and the solid pattern are electrically connected. At least a portion of the solid pattern is connected to the housing ground. The filter circuit components 9 and the control and power circuit components 10, which are arranged inside the small chamber 16a, are separated by the separate shield 27. Furthermore, a portion of the inner layer of the substrate 8 has a solid pattern connected to the solid pattern provided on the substrate surface, and the solid pattern on the inner layer is also connected to the housing ground.

[0081] <Variation 1> A modified example of the separate shield 27 will be described with reference to FIG. 10 . The separate shield 27 has an extension 27a extending from the main body of the shield along the surface of the substrate 8. The extension 27a is disposed between and separates multiple other circuit components. The multiple other circuit components are control and power circuit components 10. In this embodiment, the extension 27a separates the control and power circuit components 10a and 10b. By providing the extension 27a and increasing the contact area of ​​the separate shield 27 with the substrate 8, cooling of the substrate 8 can be enhanced. Heat transfer to components disposed on the substrate 8 can be suppressed. Vibration resistance of the substrate 8 and the components disposed on the substrate 8 can also be improved. Furthermore, because the extension 27a is disposed between and separates multiple control and power circuit components 10, the influence of noise between the components disposed on the substrate 8 can be reduced. In this embodiment, the main body and extension 27a of the separate shield 27 are integrated, but this is not limited to this. The main body and extension 27a may be formed separately and connected to each other.

[0082] The power conversion device 1 may have the following configuration. At least some of the filter circuit components 9 and the control and power circuit components 10 are thermally connected to the shield via a heat conductive member. In this embodiment, the control and power circuit component 10a is thermally connected to an extension 27a of the separate shield 27 via a heat conductive member 29a. The heat conductive member 29a is, for example, thermal grease. With this configuration, a path for heat dissipation from the components arranged on the board 8 is formed, thereby improving the heat dissipation performance of the components arranged on the board 8.

[0083] The power conversion device 1 may further include the following configuration. At least some of the filter circuit components 9 and the control and power circuit components 10 are fixed to the shield with adhesive 29b. In this embodiment, the control and power circuit components 10b are fixed to the extension portion 27a of the separate shield 27, which serves as a shield, with adhesive 29b. With this configuration, the components arranged on the substrate 8 are fixed to the extension portion 27a with adhesive, thereby improving the vibration resistance of the components arranged on the substrate 8.

[0084] <Variation 2> Another modified example of the separate shield 27 will be described with reference to FIGS. 11 and 12 . As shown in FIG. 12 , the separate shield 27 has an opposing extension 27b that extends from a portion of the shield's main body opposite the substrate 8 toward the substrate surface of the substrate 8. The filter circuit component 9 is provided on the substrate surface on which the separate shield 27 is provided, and the opposing extension 27b covers a portion of the filter circuit component 9 opposite the substrate surface. With this configuration, at least a portion of the substrate 8, the filter circuit component 9, the opposing extension 27b, and the main bus bar 11 are stacked. This lengthens the noise propagation path to the filter circuit component 9, thereby reducing the effect of noise on the filter circuit component 9. Note that in this embodiment, the main body and the opposing extension 27b of the separate shield 27 are integrated, but the present invention is not limited to this. The main body and the opposing extension 27b of the separate shield 27 may be formed separately and connected to each other.

[0085] 10, at least some of the filter circuit components 9 and the control and power circuit components 10 may be thermally connected to the facing extension 27b of the separate shield 27 via a heat conductive member 29a. Also, at least some of the filter circuit components 9 and the control and power circuit components 10 may be fixed to the facing extension 27b of the separate shield 27 with an adhesive 29b.

[0086] <Variation 3> Another modified example of the separate shield 27 will be described with reference to FIGS. 13 and 14. In the configuration described in Modification 2, the influence of noise on the filter circuit components 9 can be reduced, so as shown in FIG. 14, the inner wall 4b may be removed from the portion between the external power supply side terminal block 19 and the smoothing capacitor 6. By removing the inner wall 4b, the smoothing capacitor 6, which is the main circuit section 5, can be placed in the location where the inner wall 4b was previously located, thereby reducing wasted space and making it possible to miniaturize the power conversion device 1. Furthermore, because the main bus bar 11 can be further shortened, loss in the bus bar 30 is suppressed and heat generation in the bus bar 30 can be reduced.

[0087] As shown in the above-described modified example, by changing the shape of the separate shield 27 without being restricted by the housing 4, it is possible to easily accommodate changes in the external shape of the power conversion device 1 and changes in the connection position of the external interface while reducing the impact of noise on the filter circuit components 9, thereby shortening the design time and development man-hours for the power conversion device 1.

[0088] Embodiment 3 A power converter 1 according to a third embodiment will now be described. Fig. 15 is a plan view showing an outline of the power converter 1, in which the cover 18 has been removed from the power converter 1 and only the outline of the board 8 is shown to illustrate the component layout, and Fig. 16 is a cross-sectional view of the power converter 1 taken at the HH cross section position in Fig. 15, illustrating the area around the branch busbar 12 at the HH cross section position. The power converter 1 according to the third embodiment has a configuration in which the filter circuit components 9 are provided at a position different from that of the first and second embodiments.

[0089] The power module 7 and the smoothing capacitor 6 are electrically connected by a main bus bar 11, and the filter circuit component 9 is provided adjacent to a portion of the peripheral wall surrounding the bottom surface of the smoothing capacitor 6 other than the side opposite to the power module 7 side, or adjacent to the power module 7. As shown in FIG. 15 , in this embodiment, the filter circuit component 9 is provided on the power module 7 side of the smoothing capacitor 6, adjacent to the power module 7. The external power supply connection portion 20 is also provided on the power module 7 side of the smoothing capacitor 6, adjacent to the power module 7. As shown in FIG. 16 , a portion of the main bus bar 11 is arranged to overlap the power module 7.

[0090] By arranging the filter circuit components 9 in this manner, the main busbars 11 can be concentrated around the power module main terminals 13a (not shown in FIG. 15 ) provided on the smoothing capacitor 6 side, which are the electrical connection points with the smoothing capacitor 6, thereby making it possible to reduce the size of the main busbars 11. Because the main busbars 11 are made smaller, the loss, heat generation, and costs of the main busbars 11 can be reduced. Because the main busbars 11 are made smaller, the loss and heat generation of the main busbars 11 can be reduced, thereby reducing heat damage from the main busbars 11 to components around the main busbars 11, such as the control and power circuit components 10 provided on the board 8. Furthermore, the wiring of the portion of the main busbars 11 that passes through the inside of the smoothing capacitor 6 can be simplified and made smaller, making it possible to reduce the size and costs of the smoothing capacitor 6.

[0091] The positive and negative busbar portions are arranged to face at least a portion of the internal wiring 34 of the power module 7. As shown in FIG. 16 , in this embodiment, the positive main busbar 11a, which is the positive busbar portion, and the negative main busbar 11b, which is the negative busbar portion, are arranged to face the internal wiring 34. The internal wiring 34 is made of, for example, a busbar, and the main surfaces of the busbar face the positive main busbar 11a and the negative main busbar 11b. The facing positive and negative busbar portions are parallel plate portions so that the current flows in opposite directions when a high-frequency current is applied. Similarly, the positive and negative busbar portions are parallel plate portions so that the current flows in opposite directions when a high-frequency current is applied.

[0092] By forming the parallel plate portions in this manner, the magnetic flux generated in the main busbar 11 and the internal wiring 34 is concentrated inside the main busbar 11 and the internal wiring 34, thereby reducing the high-frequency resistance of the main busbar 11 and the internal wiring 34 and thereby reducing heat loss generated in the main busbar 11 and the internal wiring 34. Furthermore, the magnetic flux generated in the main busbar 11 and the internal wiring 34 can be canceled outside the main busbar 11 and the internal wiring 34, thereby suppressing the generation of parasitic inductance. Furthermore, because the opposing surfaces of the opposing main busbar 11 and the internal wiring 34 are covered by the opposing portions, there are no open portions and noise coupling is less likely to occur.

[0093] Although the example has been shown in which the filter circuit component 9 is provided on the power module 7 side of the smoothing capacitor 6, adjacent to the power module 7, the arrangement of the filter circuit component 9 is not limited to this. In FIG. 15 , the filter circuit component 9 may be provided above or below the smoothing capacitor 6, or between the smoothing capacitor 6 and the power module 7. Even when the filter circuit component 9 is provided in such a position, the main bus bars 11 can be concentrated around the power module main terminals 13a, which are the electrical connection parts with the smoothing capacitor 6, and therefore the same effect as that described above can be obtained.

[0094] Like the filter circuit component 9, the external power supply connection unit 20 and the external power supply side terminal block 19 are provided on the power module 7 side of the smoothing capacitor 6, adjacent to the power module 7, but the arrangement of the external power supply connection unit 20 and the external power supply side terminal block 19 is not limited to this. Like the filter circuit component 9, in FIG. 15 , the external power supply connection unit 20 and the external power supply side terminal block 19 may be provided with space above or below the smoothing capacitor 6 and the power module 7. With this configuration, it is possible to easily accommodate changes in the external shape of the power conversion device 1 and changes in the connection position of the external interface, thereby reducing the time required for designing and the number of development steps for the power conversion device 1.

[0095] In this embodiment, the separate shield 27 having the opposing extension portion 27b shown in the second embodiment is provided, but the configuration around the filter circuit component 9 is not limited to this. As shown in the first embodiment, the shield may be formed by the inner wall 4b.

[0096] Furthermore, the configurations shown in Embodiments 2 and 3 may also be provided with the additional shield 26 shown in Embodiment 1. By providing the additional shield 26, noise propagating to the filter circuit component 9 on both the side of one surface 8a and the side of the other surface 8b of the substrate 8 can be blocked and suppressed, thereby reducing the effect of noise on the filter circuit component 9.

[0097] Although the present disclosure describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not exemplified are conceivable within the scope of the technology disclosed in this specification, including, for example, cases where at least one component is modified, added, or omitted, and cases where at least one component is extracted and combined with components of another embodiment.

[0098] Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) a substrate provided with a filter circuit component having one or more capacitors for removing noise; a power module having a power semiconductor element; a main circuit wiring connected to the power module, At least a portion of the main circuit wiring is made of a bus bar, The busbars include a main busbar that constitutes the main circuit wiring and a branch busbar that branches off from the main busbar, and the branch busbar is electrically connected to the circuit board. (Appendix 2) 2. The power conversion device according to claim 1, wherein the branch bus bar is connected to wiring on the board adjacent to the filter circuit component and is electrically connected to the filter circuit component via the wiring on the board. (Appendix 3) the substrate is provided opposite the power module and the main circuit wiring with a gap therebetween, The power conversion device according to claim 1 or 2, wherein the branch bus bar extends from the main bus bar of the main circuit wiring toward the circuit board and is electrically connected to the filter circuit components via wiring on the circuit board. (Appendix 4) a housing having a bottom wall and accommodating the substrate and the power module; a smoothing capacitor arranged alongside the power module along the bottom wall, The power conversion device according to any one of appendixes 1 to 3, wherein the filter circuit component is provided adjacent to a portion of a peripheral wall surrounding a bottom surface of the smoothing capacitor on the opposite side from the power module. (Appendix 5) a housing having a bottom wall and accommodating the substrate and the power module; a smoothing capacitor arranged alongside the power module along the bottom wall, the power module and the smoothing capacitor are electrically connected by the main bus bar, The power conversion device according to any one of appendixes 1 to 3, wherein the filter circuit component is provided adjacent to a portion of a peripheral wall surrounding a bottom surface of the smoothing capacitor other than the side opposite to the power module, or adjacent to the power module. (Appendix 6) a shield that is grounded in contact with the substrate and is provided adjacent to the filter circuit component; The power conversion device according to any one of appendixes 1 to 5, wherein the shield is disposed between the filter circuit component and one or more other circuit components provided on the substrate, and separates the filter circuit component from the other circuit components. (Appendix 7) The power conversion device according to Supplementary Note 6, wherein the shield is disposed between the other circuit components and the filter circuit components and the branch bus bar, and separates the other circuit components from the filter circuit components and the branch bus bar. (Appendix 8) a housing having a bottom wall and accommodating the substrate and the power module; the housing has an inner wall that is a part of the housing and that protrudes from a part of the bottom wall inside the housing; the inner wall forms the shield; The inner wall has a through hole, 8. The power conversion device according to claim 6, wherein the main bus bar passes through the through hole. (Appendix 9) a housing having a bottom wall and accommodating the substrate and the power module; a portion of the shield opposite to a portion that is in contact with the circuit board and grounded, the portion being in contact with the housing, except for at least a wiring arrangement portion; The main bus bar passes through the space in the wiring arrangement portion, The power conversion device according to claim 6 or 7, wherein the portion of the main bus bar that passes through the space, the shield, and the substrate are arranged in order in a direction away from the bottom wall. (Appendix 10) a housing having a bottom wall and accommodating the substrate and the power module; the bus bar includes an external power supply bus bar connected to an external power supply, the external power bus bar is connected to the main bus bar inside the enclosure; The power conversion device according to any one of appendixes 6 to 9, wherein the branch bus bar, the filter circuit components, and the shield are provided adjacent to a connection portion between the external power supply bus bar and the main bus bar. (Appendix 11) a housing having a bottom wall and accommodating the substrate and the power module; the substrate has a wiring pattern on the substrate surface on which the shield abuts, the shield and the wiring pattern are electrically connected, 11. The power conversion device according to claim 6, wherein at least a portion of the wiring pattern is a housing ground pattern connected to the housing. (Appendix 12) the substrate is a multilayer substrate, 12. The power conversion device according to claim 11, wherein an inner layer of the substrate has an inner layer housing ground pattern connected to the housing ground pattern. (Appendix 13) the power module, the bus bar, and the shield are provided on one surface of the substrate; 13. The power conversion device according to any one of claims 6 to 12, wherein the power module is covered by the substrate. (Appendix 14) a cylindrical housing having a bottom wall and accommodating the substrate and the power module; one surface of the substrate faces the bottom wall, and the power module, the shield, and the filter circuit component are arranged in this order along the bottom wall; 14. The power conversion device according to claim 13, wherein the shield separates the power module and the filter circuit component. (Appendix 15) the shield is provided on one surface of the substrate; a housing having a bottom wall and accommodating the board and the power module; and an additional shield abutting against the other surface of the board and grounded to the board and the housing, 15. The power conversion device according to any one of claims 6 to 14, wherein at least a portion of the additional shield is stacked with the shield via the substrate. (Appendix 16) the shield has an extension extending from a main body of the shield along a substrate surface of the substrate, The power conversion device according to any one of appendices 9 to 15, wherein the extension portion is disposed between the plurality of other circuit components and separates the plurality of other circuit components. (Appendix 17) the shield has an opposing extension portion that extends from a portion of the main body of the shield on the opposite side to the substrate side toward a substrate surface of the substrate, 17. The power conversion device according to any one of appendixes 9 to 16, wherein the filter circuit component is provided on the substrate surface on which the shield is provided, and the opposing extension portion covers a portion of the filter circuit component on an opposite side to the substrate surface. (Appendix 18) 18. The power conversion device according to claim 9, wherein at least some of the filter circuit components and the other circuit components are thermally connected to the shield via a heat conductive member. (Appendix 19) The power conversion device according to any one of appendixes 9 to 18, wherein at least some of the filter circuit components and the other circuit components are fixed to the shield with an adhesive. (Appendix 20) the main busbar and the branch busbar each include a positive busbar portion and a negative busbar portion, 20. The power conversion device according to any one of claims 1 to 19, wherein at least a portion of the positive bus bar portion and a portion of the negative bus bar portion are arranged opposite to each other. (Appendix 21) The power conversion device according to claim 20, wherein the positive bus bar portion and the negative bus bar portion are arranged opposite at least a part of internal wiring of the power module. (Appendix 22) The power conversion device according to any one of appendices 1 to 21, wherein the capacitor included in the filter circuit component is one or both of an X capacitor and a Y capacitor. [Explanation of symbols]

[0099] 1 power conversion device, 2 external power supply, 3 load, 4 housing, 4a outer wall, 4a1 outer wall through-hole, 4b inner wall, 4b1 inner wall through-hole, 4b2 boss, 4b3 cutout, 4c bottom wall, 5 main circuit section, 6 smoothing capacitor, 6a capacitor element, 6b capacitor case, 7 power module, 7a power semiconductor element, 8 board, 8a one side, 8b other side, 9 filter circuit components, 10, 10a, 10b control and power circuit components, 11 main bus bar, 11a positive side main bus bar, 11b negative side main bus bar, 11c capacitor main bus bar, 12 branch bus bar, 12a positive side branch bus bar, 12b negative side branch bus bar, 13a, 13b power module main terminal, 14 power module terminal, 15 control wiring, 16a, 16b Small compartment, 17 refrigerant flow path, 18 cover, 19 external power supply side terminal block, 20 external power supply connection portion, 21 external power supply bus bar, 21a positive side external power supply bus bar, 21b negative side external power supply bus bar, 22 load connection portion, 23 load connection bus bar, 24 load side terminal block, 25 external device connection portion, 26 additional shield, 27 separate shield, 27a extension portion, 27b opposing extension portion, 28 wiring space, 29a heat conductive material, 29b adhesive, 30 bus bar, 31 external device, 32 housing ground pattern, 33 inner layer housing ground pattern, 34 internal wiring

Claims

1. a substrate provided with a filter circuit component having one or more capacitors for removing noise; a power module having a power semiconductor element; a main circuit wiring connected to the power module, At least a portion of the main circuit wiring is made of a bus bar, The busbars include a main busbar that constitutes the main circuit wiring and a branch busbar that branches off from the main busbar, and the branch busbar is electrically connected to the circuit board.

2. The power conversion device according to claim 1 , wherein the branch bus bar is connected to wiring on the board adjacent to the filter circuit component, and is electrically connected to the filter circuit component via the wiring on the board.

3. the substrate is provided opposite the power module and the main circuit wiring with a gap therebetween, The power conversion device according to claim 1 , wherein the branch bus bar extends from the main bus bar of the main circuit wiring toward the circuit board and is electrically connected to the filter circuit component via wiring on the circuit board.

4. a housing having a bottom wall and accommodating the substrate and the power module; a smoothing capacitor arranged alongside the power module along the bottom wall, 4. The power conversion device according to claim 1, wherein the filter circuit component is provided adjacent to a portion of a peripheral wall surrounding a bottom surface of the smoothing capacitor on a side opposite to the power module.

5. a housing having a bottom wall and accommodating the substrate and the power module; a smoothing capacitor arranged alongside the power module along the bottom wall, the power module and the smoothing capacitor are electrically connected by the main bus bar, 4. The power conversion device according to claim 1, wherein the filter circuit component is provided adjacent to a portion of a peripheral wall surrounding a bottom surface of the smoothing capacitor other than a side opposite to the power module, or adjacent to the power module.

6. a shield that is grounded in contact with the substrate and is provided adjacent to the filter circuit component; 2. The power conversion device according to claim 1, wherein the shield is disposed between the filter circuit component and one or more other circuit components provided on the substrate, and separates the filter circuit component from the other circuit components.

7. The power conversion device according to claim 6, wherein the shield is disposed between the other circuit components and the filter circuit components and the branch bus bar, and separates the other circuit components from the filter circuit components and the branch bus bar.

8. a housing having a bottom wall and accommodating the substrate and the power module; the housing has an inner wall that is a part of the housing and that protrudes from a part of the bottom wall inside the housing; the inner wall forms the shield; The inner wall has a through hole, The power conversion device according to claim 6 or 7, wherein the main bus bar passes through the through hole.

9. a housing having a bottom wall and accommodating the substrate and the power module; a portion of the shield opposite to a portion that is in contact with the circuit board and grounded, the portion being in contact with the housing, except for at least a wiring arrangement portion; The main bus bar passes through the space in the wiring arrangement portion, The power conversion device according to claim 6 or 7, wherein the portion of the main bus bar that passes through the space, the shield, and the substrate are arranged in order in a direction away from the bottom wall.

10. a housing having a bottom wall and accommodating the substrate and the power module; the bus bar includes an external power supply bus bar connected to an external power supply, the external power bus bar is connected to the main bus bar inside the enclosure; The power conversion device according to claim 6 or 7, wherein the branch bus bar, the filter circuit component, and the shield are provided adjacent to a connection portion between the external power supply bus bar and the main bus bar.

11. a housing having a bottom wall and accommodating the substrate and the power module; the substrate has a wiring pattern on the substrate surface on which the shield abuts, the shield and the wiring pattern are electrically connected, 8. The power converter according to claim 6, wherein at least a part of the wiring pattern is a chassis ground pattern connected to the chassis.

12. the substrate is a multilayer substrate, The power conversion device according to claim 11 , wherein an inner layer of the substrate has an inner-layer chassis ground pattern connected to the chassis ground pattern.

13. the power module, the bus bar, and the shield are provided on one surface of the substrate; The power conversion device according to claim 6 or 7, wherein the power module is covered by the substrate.

14. a cylindrical housing having a bottom wall and accommodating the substrate and the power module; one surface of the substrate faces the bottom wall, and the power module, the shield, and the filter circuit component are arranged in this order along the bottom wall; The power conversion device according to claim 13 , wherein the shield separates the power module and the filter circuit component.

15. the shield is provided on one surface of the substrate; a housing having a bottom wall and accommodating the board and the power module; and an additional shield abutting against the other surface of the board and grounded to the board and the housing, The power conversion device according to claim 6 or 7, wherein at least a portion of the additional shield is stacked with the shield via the substrate.

16. the shield has an extension extending from a main body of the shield along a substrate surface of the substrate, The power conversion device according to claim 9 , wherein the extension portion is disposed between a plurality of the other circuit components and separates the plurality of the other circuit components.

17. the shield has an opposing extension portion that extends from a portion of the main body of the shield on the opposite side to the substrate side toward a substrate surface of the substrate, 10. The power conversion device according to claim 9, wherein the filter circuit component is provided on the substrate surface on which the shield is provided, and the opposing extension portion covers a portion of the filter circuit component on the opposite side to the substrate surface.

18. The power conversion device according to claim 9 , wherein at least some of the filter circuit components and the other circuit components are thermally connected to the shield via a thermally conductive member.

19. The power conversion device according to claim 9, wherein at least some of the filter circuit components and the other circuit components are fixed to the shield with an adhesive.

20. the main busbar and the branch busbar each include a positive busbar portion and a negative busbar portion, The power conversion device according to claim 1 , wherein at least a portion of the positive bus bar portion and at least a portion of the negative bus bar portion are arranged to face each other.

21. The power conversion device according to claim 20 , wherein the positive bus bar portion and the negative bus bar portion are arranged to face at least a part of internal wiring of the power module.

22. 4. The power conversion device according to claim 1, wherein the capacitor included in the filter circuit component is one or both of an X capacitor and a Y capacitor.

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