Electric power conversion apparatus

Abstract

An electric power conversion apparatus (4) comprises a partition wall (12c) that partitions the interior of a housing (12) into a first accommodation chamber (121) and a second accommodation chamber (122), and a communication busbar (15). The communication busbar (15) is provided across the first accommodation chamber (121) and the second accommodation chamber (122) and is included in an electric power path that connects a terminal portion of a noise filter (7) and a terminal portion (90a) of a semiconductor device. The communication busbar (15) has a through-busbar portion (152). The through-busbar portion (152) extends across the first accommodation chamber (121) and the second accommodation chamber (122) at one location inside the housing (12) and penetrates the partition wall (12c). Due to the configuration of having the through-busbar portion at one location, the electric power conversion apparatus (4) makes it possible for the location where electric components are arranged to be formed in a compact manner.

Description

Power Conversion Device CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2023-124336 filed in Japan on July 31, 2023, and the contents of the original application are incorporated by reference in their entirety.

[0002] The disclosure herein relates to power conversion devices.

[0003] Patent Document 1 discloses a power converter that houses a capacitor and a semiconductor module in an upper chamber of a housing and a noise filter in a lower chamber. The upper and lower chambers are separated by a bottom wall provided inside the housing. At least a first internal bus bar, a second internal bus bar, and an output bus bar penetrate the bottom wall.

[0004] Japanese Patent Application Laid-Open No. 2022-107381

[0005] In the power conversion device of Patent Document 1, the bus bars penetrate the bottom wall at least three times. This requires space for the bus bars to penetrate the bottom wall. Therefore, when the interior of the housing is viewed from the bottom in a plan view, the area required for installing electrical components becomes large.

[0006] An object of the disclosure in this specification is to provide a power conversion device that can reduce the area for accommodating electrical components when the inside of the housing is viewed from above.

[0007] The multiple aspects disclosed in this specification employ different technical means to achieve their respective objectives. Furthermore, the reference numerals in parentheses in the claims are merely examples showing the correspondence between specific means described in the embodiments below as one aspect, and do not limit the technical scope.

[0008] One of the disclosed power conversion devices includes a housing having a first storage chamber and a second storage chamber therein, a partition wall separating the first storage chamber and the second storage chamber, a plurality of semiconductor devices housed in the first storage chamber and forming a power conversion circuit, a smoothing capacitor housed in the first storage chamber and connected to the semiconductor devices, a noise filter housed in the second storage chamber and connected to the smoothing capacitor, a cooling passage formed in the partition wall through which cooling water flows, and a communication bus bar provided between the first storage chamber and the second storage chamber and included in a power path connecting a terminal portion of the noise filter and a terminal portion of the semiconductor device, wherein the communication bus bar has a through bus bar portion that extends between the first storage chamber and the second storage chamber at one location inside the housing and passes through the partition wall.

[0009] According to the power conversion device, the bus bar penetrates the partition wall at one location within the housing, allowing for a compact arrangement of electrical components such as noise filters and smoothing capacitors. This reduces the size of the interior of the housing when the partition wall is viewed in plan. Therefore, when the interior of the housing is viewed in plan relative to the partition wall, the power conversion device reduces the area required to accommodate the electrical components. Furthermore, because only the through-hole bus bar portion penetrates the partition wall, a configuration can be realized in which the bus bar can be positioned close to or along the cooling passage over a wide area. This reduces the portion of the bus bar that is difficult to cool with coolant, improving the bus bar cooling capacity.

[0010] 1 is a circuit diagram of a power conversion device of a first embodiment; FIG. 2 is a cross-sectional view showing the configuration of a power conversion device; FIG. 3 is a plan view showing the position of a through bus bar portion in a partition wall; FIG. 4 is a plan view showing the position of a through bus bar portion of another first example; FIG. 5 is a plan view showing the position of a through bus bar portion of another second example; FIG. 6 is a plan view showing the position of a through bus bar portion of another third example; FIG. 7 is a perspective view showing the configuration of a terminal coupling portion in a terminal block unit; FIG. 8 is a perspective view showing a terminal block unit; FIG. 9 is a perspective view showing a bus bar built into the terminal block unit; FIG. 10 is a perspective view showing a bus bar of the terminal block unit; FIG. 11 is a partial cross-sectional view showing the coupled state of multiple terminals at the terminal coupling portion; FIG. 12 is a partial cross-sectional view showing the coupled state of multiple terminals at the terminal coupling portion; FIG. 13 is a partial cross-sectional view showing the coupled state of multiple terminals in a second embodiment; FIG. 14 is a cross-sectional view showing the configuration of a power conversion device of a third embodiment;

[0011] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in the preceding embodiment will be assigned the same reference numerals, and duplicate descriptions may be omitted. In each embodiment, when only a part of the configuration is described, other previously described embodiments may be applied to the other parts of the configuration. In addition to combinations of parts that are specifically specified as being combinable in each embodiment, it is also possible to partially combine embodiments even if not specified, as long as there is no particular problem with the combination.

[0012] First Embodiment A first embodiment disclosing an example of a power conversion device will be described with reference to FIGS. 1 to 12. Application examples of the power conversion device are as follows. The power conversion device can be applied to an on-board power conversion device mounted on vehicles such as electric vehicles, hybrid vehicles, and plug-in hybrid vehicles. The power conversion device can also be mounted on flying objects such as electric vertical take-off and landing aircraft and drones, ships, construction machinery, agricultural machinery, etc. Below, an example in which the power conversion device is applied to a vehicle will be described.

[0013] As shown in FIG. 1 , a vehicle drive system 1 includes a DC power supply 2, a motor generator 3, and a power conversion device 4. The DC power supply 2 is a DC voltage source configured with a chargeable and dischargeable secondary battery. The secondary battery is, for example, a lithium-ion battery, a nickel-metal hydride battery, or the like. The motor generator 3 is, for example, a three-phase AC rotating electric machine. The motor generator 3 functions as a drive source for the vehicle, i.e., an electric motor. The motor generator 3 functions as a generator during regeneration. The power conversion device 4 converts power between the DC power supply 2 and the motor generator 3.

[0014] The power conversion device 4 includes a power conversion circuit. As shown in Fig. 1, the power conversion device 4 includes a smoothing capacitor 5, an inverter 6 which is a power conversion circuit, and a noise filter 7. The smoothing capacitor 5 mainly functions to smooth the DC voltage supplied from the DC power supply 2. The smoothing capacitor 5 is connected to a P line 10 which is a power supply line on the high potential side and an N line 11 which is a power supply line on the low potential side.

[0015] The smoothing capacitor 5 is connected in parallel to the DC power supply 2. The P line 10 is connected to the positive terminal of the DC power supply 2. The N line 11 is connected to the negative terminal of the DC power supply 2. The positive terminal of the smoothing capacitor 5 is connected to the P line 10 between the DC power supply 2 and the inverter 6. The negative terminal of the smoothing capacitor 5 is connected to the N line 11 between the DC power supply 2 and the inverter 6. The P line 10 includes a plurality of P bus bars that connect electrical components to each other. The N line 11 includes a plurality of N bus bars that connect electrical components to each other.

[0016] The inverter 6 is a DC-AC conversion circuit. In accordance with switching control by a control circuit provided on the control circuit board 93, the inverter 6 converts DC voltage into three-phase AC voltage and outputs it to the motor generator 3. This operation drives the motor generator 3 to generate a predetermined torque. During regenerative braking of the vehicle, the inverter 6 converts the three-phase AC voltage generated by the motor generator 3 in response to rotational force from the wheels into DC voltage in accordance with switching control of the control circuit. The converted DC power is output to the P line 10. In this way, the inverter 6 performs bidirectional power conversion between the DC power source 2 and the motor generator 3.

[0017] The noise filter 7 is connected to each of the P line 10 and the N line 11. The noise filter 7 is connected in parallel to the DC power supply 2. The positive terminal of the noise filter 7 is connected to the P line 10 between the DC power supply 2 and the smoothing capacitor 5. The negative terminal of the noise filter 7 is connected to the N line 11 between the DC power supply 2 and the smoothing capacitor 5. The noise filter 7 removes noise input to and output from the P line 10 and the N line 11. The noise filter 7 may be configured to include a capacitor. The capacitor included in the noise filter 7 has a smaller capacitance than the smoothing capacitor 5.

[0018] The inverter 6 includes upper and lower arm circuits 9 corresponding to each of the three phases. The upper and lower arm circuits 9 are sometimes referred to as legs. The upper and lower arm circuits 9 have an upper arm 9H and a lower arm 9L. The upper arm 9H and the lower arm 9L are connected in series between the P line 10 and the N line 11, with the upper arm 9H on the P line 10 side and the lower arm 9L on the N line 11 side.

[0019] The connection point between the upper arm 9H and the lower arm 9L is connected to the winding 3a of the corresponding phase in the motor generator 3 via an output line 8. Of the upper and lower arm circuits 9, the U-phase upper and lower arm circuit 9U is connected to the U-phase winding 3a via a corresponding output line 8. The V-phase upper and lower arm circuit 9V is connected to the V-phase winding 3a via a corresponding output line 8. The W-phase upper and lower arm circuit 9W is connected to the W-phase winding 3a via a corresponding output line 8. At least a portion of the output lines 8 is formed of a conductive member such as a bus bar.

[0020] The inverter 6 has six arms. Each arm is equipped with a switching element. The number of switching elements constituting each arm is not particularly limited. There may be one or more. When there are more than one switching elements, the multiple switching elements connected in parallel are turned on and off at the same timing by a common gate drive signal.

[0021] In this specification, an n-channel MOSFET 91 is used as the switching element constituting each arm. MOSFET is an abbreviation for Metal Oxide Semiconductor Field Effect Transistor. In the upper arm 9H, the drain of the MOSFET 91 is connected to a P line 10. In the lower arm 9L, the source of the MOSFET 91 is connected to an N line 11. The source of the MOSFET 91 in the upper arm 9H and the drain of the MOSFET 91 in the lower arm 9L are connected to each other.

[0022] A freewheeling diode 92 is connected in antiparallel to each MOSFET 91. The diode 92 may be a parasitic diode of the MOSFET 91 or may be provided separately from the parasitic diode. The anode of the diode 92 is connected to the source of the corresponding MOSFET 91. The cathode of the diode 92 is connected to the drain.

[0023] The switching element is not limited to the MOSFET 91. An IGBT (Insulated Gate Bipolar Transistor) may be used as the switching element. In the case of an IGBT, a freewheeling diode is also connected in anti-parallel.

[0024] As shown in FIG. 2 , the power conversion device 4 includes a plurality of semiconductor devices 90, a control circuit board 93, a smoothing capacitor 5, a noise filter 7, and the like, all of which are provided inside a housing 12. The semiconductor device 90 provides at least one arm of the power conversion circuit. The semiconductor device 90 provides one phase of upper and lower arm circuits 9. The plurality of semiconductor devices 90 are connected in parallel to provide the power conversion circuit. The plurality of semiconductor devices 90 may also be referred to as a semiconductor module. Hereinafter, three mutually orthogonal directions are referred to as the X direction, the Y direction, and the Z direction. The X direction and the Y direction indicate directions along a horizontal plane. The Z direction corresponds to the vertical direction.

[0025] The housing 12 is a container that houses electrical components such as the smoothing capacitor 5, the semiconductor device 90, the control circuit board 93, and the noise filter 7. The housing 12 is formed by combining multiple case members. The housing 12 is made of aluminum or an alloy. Each member is formed, for example, by aluminum die-casting. The interior of the housing 12 is roughly divided into a first storage chamber 121 and a second storage chamber 122 by a partition wall 12c. The first storage chamber 121 is a space defined above the partition wall 12c. The second storage chamber 122 is a space defined below the partition wall 12c. The partition wall 12c is made of a material that allows for good heat transfer to members that come into contact with the partition wall 12c.

[0026] The first housing chamber 121 is provided with a smoothing capacitor 5, a control circuit board 93, a semiconductor device 90, etc. The second housing chamber 122 is provided with a noise filter 7, etc. An input line connecting the DC power supply 2 and the noise filter 7 is inserted through a side wall 12a of the housing 12. The side wall 12a is a wall portion adjacent to the top wall and bottom wall of the housing 12 and connecting the top wall and the bottom wall. The side wall 12a forms a side surface that extends in the vertical direction and is parallel to the Y direction and the Z direction. A side wall 12b of the housing is provided at a position opposite the side wall 12a.

[0027] The input line is configured to include a portion of the P line 10 and a portion of the N line 11. The input line includes two input bus bars 14. The input line is provided in the second housing chamber 122. The input line is insulated from the side wall 12a by an insulating component. The insulating component is, for example, an input connector. A terminal connected to the tip of the input bus bar 14 is provided inside the input connector. A terminal of a wire harness extending from the DC power supply 2 is connected to the terminal inside the input connector. As a result, each of the P line 10 and the N line 11 is electrically connected to the DC power supply 2.

[0028] An output line 8 that connects the motor generator 3 and the semiconductor device 90 is inserted through the side wall 12a of the housing 12. The output line 8 includes three output bus bars 16. The output bus bars 16 are provided in the first housing chamber 121. The output line 8 is insulated from the side wall 12a by an insulating component. The insulating component is, for example, an output connector. Inside the output connector, a terminal is provided that is connected to the tip of the output bus bar 16. A terminal of a wire harness extending from the motor generator 3 is connected to the terminal inside the output connector. As a result, each phase of the upper and lower arm circuits 9 is electrically connected to the windings 3a of the motor generator 3.

[0029] The smoothing capacitor 5 includes a capacitor element, a sealing member, an electrode 5a connected to the capacitor element, a terminal portion 5b, and the like. The smoothing capacitor 5 includes a capacitor element and a sealing member filled in the capacitor element's housing to seal the capacitor element. The sealing member seals the capacitor element in the housing space. The sealing member forms the outer shell of the smoothing capacitor 5. The outer shell of the smoothing capacitor 5 has a rectangular parallelepiped shape, excluding the terminal portion 5b and the like. The sealing member is made of a thermosetting resin such as epoxy resin. The sealing member is an insulating material that fills the gap between the capacitor element and the electrode 5a and the capacitor element's housing. With this configuration, the sealing member seals the capacitor element and the electrode 5a, and the like. One end of the terminal portion 5b is connected to the electrode 5a inside the smoothing capacitor 5, and the other end protrudes from the sealing member into the first housing chamber 121. In the first housing chamber 121, the terminal portion 5b is connected to the P line 10 and the N line 11 via a terminal coupling portion of the terminal base unit 13.

[0030] The smoothing capacitor 5 is installed in the first housing chamber 121 in a position where the height direction, which is the smallest outer length, is in the vertical direction. This configuration makes it possible to reduce the vertical length of the first housing chamber 121 that the smoothing capacitor 5 occupies. Furthermore, the smoothing capacitor 5 is installed in the first housing chamber 121 in a position where the largest outer surface is aligned with the partition wall 12c.

[0031] The semiconductor device 90 has a flattened outer shape due to the sealing member, except for terminal portions 90a that protrude from the sealing member. The semiconductor device 90 is installed in the first housing chamber 121 with the thickness direction, which is the smallest side dimension, aligned along the vertical direction. The control circuit board 93 is installed above the semiconductor device 90 with the thickness direction of the board aligned along the vertical direction. This configuration makes it possible to reduce the vertical length of the first housing chamber 121 occupied by the semiconductor device 90 and the control circuit board 93. Furthermore, the semiconductor device 90 is installed in the first housing chamber 121 with the largest surface of its flattened outer shape aligned along the partition wall 12c.

[0032] A terminal portion 90a forming a collector terminal and an emitter terminal protrudes from one side of the flat body. The terminal portion 90a protrudes toward the smoothing capacitor 5 and is connected to the P line 10 and the N line 11 via the terminal coupling portion of the terminal base unit 13. A relay terminal protrudes from the other side of the flat body. The relay terminal is connected to the output line 8. The gate terminal of the semiconductor device 90 is connected to a control circuit board 93. The control circuit board 93 forms a control circuit on which electronic components such as an arithmetic element that controls the operation of the MOSFET 91 are mounted.

[0033] As shown in FIG. 2 , the power conversion device 4 includes a power path connecting the terminal of the noise filter 7 and the terminal 90 a of the semiconductor device. This power path is formed by including a communication bus bar 15. The communication bus bar 15 extends between the first accommodating chamber 121 and the second accommodating chamber 122 and is provided along the partition wall 12 c. The communication bus bar 15 includes a first bus bar portion 151 located mainly in the second accommodating chamber 122, a second bus bar portion located mainly in the first accommodating chamber 121, and a through bus bar portion 152. The relay bus bar 153 shown in FIG. 2 corresponds to the second bus bar portion. The relay bus bar 153 is formed by including a P-side bus bar included in the P line 10 on the high potential side and an N-side bus bar included in the N line 11 on the low potential side.

[0034] The first bus bar portion 151 extends along the cooling passage 124 in the second accommodation chamber 122 toward the through bus bar portion 152. The first bus bar portion 151 includes a bus bar that is part of the P line 10 and a bus bar that is part of the N line 11. The first bus bar portion 151 is in heat-transferable contact with the partition wall 12c via an insulating member 125. The insulating member 125 is formed of an insulating material, such as a sheet-like member, grease, a gel-like substance, a gap filler, or a resin molded portion that covers the bus bar. The first bus bar portion 151 is provided along the cooling passage 124. The first bus bar portion 151 is provided so as to overlap the cooling passage 124 in a plan view.

[0035] The relay bus bar 153 extends from the side of the through bus bar portion 152 toward the semiconductor device 90 along the cooling passage 124 in the first housing chamber 121. The relay bus bar 153 is provided so as to be along the cooling passage 124. The relay bus bar 153 is provided so as to overlap the cooling passage 124 in a plan view. The relay bus bar 153 includes a portion that is arranged below the smoothing capacitor 5 and a portion that is not arranged above the smoothing capacitor 5. The portion that is arranged below the smoothing capacitor 5 utilizes the space below the smoothing capacitor 5 to perform bus bar cooling, while providing a bus bar arrangement that does not spread outward significantly.

[0036] The relay bus bar 153 includes a bus bar that is part of the P line 10 and a bus bar that is part of the N line 11. The relay bus bar 153 is covered with an insulating sealing member. The portion of the relay bus bar 153 that is covered with the sealing member is in contact with the partition wall 12c via a thermally conductive member 126. The thermally conductive member 126 is a sheet-like member, grease, a gel-like substance, a gap filler, or the like, made of a material with high thermal conductivity.

[0037] A through hole 123 that connects the first storage chamber 121 and the second storage chamber 122 is formed in the partition wall 12c. The through bus bar portion 152 is a portion of the communication bus bar 15 that is located between the first bus bar portion 151 and the relay bus bar 153 and that passes through the through hole 123 in the partition wall 12c in the vertical direction. Therefore, the communication bus bar 15 may be configured with three bus bars, namely, the first bus bar portion 151, the through bus bar portion 152, and the relay bus bar 153, connected together, or may be configured with two bus bars connected together. In the case of a configuration with two bus bars connected together, the portion corresponding to the through bus bar portion 152 is, for example, a part of the first bus bar portion 151 or a part of the relay bus bar 153. The through bus bar portion 152 includes a bus bar that is a part of the P line 10 and a bus bar that is a part of the N line 11. The through bus bar portion 152 penetrates the partition wall 12 c at a location adjacent to the cooling passage 124 .

[0038] 3 shows the position of the through bus bar portion 152 inside the housing 12 in a plan view. As shown in FIGS. 3 to 6, the through bus bar portion 152 may be located in an area on the opposite side of the smoothing capacitor 5, farther from the semiconductor device 90 than the side surface portion 51 on the outer periphery of the smoothing capacitor 5. The side surface portion 51 is the portion of the side surface of the smoothing capacitor 5 that is closest to the semiconductor device 90.

[0039] In plan view, the through bus bar portion 152 is provided in a range located closer to the side wall 12b than the extension of the side surface portion 51 indicated by the two-dot chain line in FIG. 3 . This range occupies an area between the extension of the side surface portion 51 and the inner surface of the side wall 12b in plan view in FIG. 3 . The through bus bar portion 152 shown in FIG. 3 is provided outside the outer surface portion of the smoothing capacitor 5 located on the opposite side of the semiconductor device 90. In plan view, this outer surface portion is located so as to face the side wall 12b of the housing located on the opposite side of the semiconductor device 90. In plan view, the through bus bar portion 152 is located between this outer surface portion and the side wall 12b. In plan view, the noise filter 7 and the smoothing capacitor 5 are installed so as to overlap in a direction perpendicular to the partition wall 12c. In plan view, the smoothing capacitor 5 and the semiconductor device 90 are installed so as not to overlap in a direction perpendicular to the partition wall 12c.

[0040] Further, other examples regarding the position of the through bus bar portion 152 will be described with reference to FIGS. 4 to 6. FIG. 4 shows another first example. The through bus bar portion 152 shown in FIG. 4 is located in an area on the opposite side of the smoothing capacitor 5, farther from the semiconductor device 90 than the side surface portion 51 in the outer periphery of the smoothing capacitor 5. The through bus bar portion 152 shown in FIG. 4 is provided outside the smoothing capacitor in a direction perpendicular to the direction in which the semiconductor device and the smoothing capacitor are arranged in a plan view. This makes it possible to reduce the physical size of the power conversion device 4 in the direction in which the semiconductor device and the smoothing capacitor are arranged in a plan view, as shown in FIG.

[0041] FIG. 5 shows another second example. The through bus bar portion 152 shown in FIG. 5 is located in an area on the opposite side of the smoothing capacitor 5, farther from the semiconductor device 90 than the side surface portion 51 on the outer periphery of the smoothing capacitor 5. The through bus bar portion 152 shown in FIG. 5 is provided outside the smoothing capacitor in a direction perpendicular to the direction in which the semiconductor device and the smoothing capacitor are aligned in a plan view. The through bus bar portion 152 shown in FIG. 5 is provided outside the smoothing capacitor on the opposite side of the through bus bar portion 152 shown in FIG. 4. This makes it possible to reduce the size of the power conversion device 4 in the direction in which the semiconductor device and the smoothing capacitor are aligned in a plan view, as shown in FIG.

[0042] Fig. 6 shows another third example. The through bus bar portion 152 shown in Fig. 6 is located in an area on the opposite side of the side surface portion 51 of the outer casing of the smoothing capacitor 5, farther from the semiconductor device 90. The through bus bar portion 152 shown in Fig. 6 is provided in an area that overlaps with the smoothing capacitor in a plan view. This makes it possible to reduce the size of the power conversion device 4 in both the direction in which the semiconductor device and the smoothing capacitor are aligned in a plan view and in a direction perpendicular to this direction, as shown in Fig. 6.

[0043] A cooling passage 124 through which cooling water flows is provided within the partition wall 12c. The cooling passage 124 is formed along the partition wall 12c. The cooling passage 124 is a passage disposed throughout the entire partition wall 12c. The cooling passage 124 is a passage disposed in a serpentine manner along the partition wall 12c over a wide area. The cooling water flowing through the cooling passage 124 functions to cool electrical components and bus bars disposed above or below the partition wall 12c. The cooling water may be a phase-change refrigerant such as water or ammonia, or a phase-non-change refrigerant such as an ethylene glycol-based refrigerant. The cooling passage 124 is arranged so as to overlap at least a portion of the smoothing capacitor 5, the semiconductor device 90, and the noise filter 7 in a plan view. Preferably, the cooling passage 124 is arranged so as to overlap the entire smoothing capacitor 5, the semiconductor device 90, and the noise filter 7 in a plan view. The line of sight in a plan view described in this specification is perpendicular to the partition wall 12c.

[0044] The input bus bar 14 is in heat-transferable contact with the partition wall 12c via an insulating member 128. The insulating member 128 is formed from an insulating material, such as a sheet-like member, grease, a gel-like substance, a gap filler, or a resin molded portion that covers the bus bar. The insulating member 128 is preferably made of a material that is insulating and has high thermal conductivity. The input bus bar 14 is provided along the cooling passage 124. The input bus bar 14 is provided so as to overlap the cooling passage 124 in a plan view. The input bus bar 14 extends from the side wall 12a to the outside of the housing 12 at a position lower than the output bus bar 16.

[0045] The output bus bar 16 is in heat-transferable contact with the partition wall 12c via an insulating member 127. The insulating member 127 is made of an insulating material, such as a sheet-like member, grease, a gel-like substance, a gap filler, or a resin molded portion that covers the bus bar. The output bus bar 16 is provided along the cooling passage 124. At least a portion of the output bus bar 16 is provided so as to overlap the cooling passage 124 in a plan view. The insulating member may be, for example, a ceramic plate or a resin sheet. Furthermore, the insulating member may be made of silicone gel or the like to improve thermal conductivity.

[0046] The configuration of the terminal block unit 13 will be described with reference to Figures 7 to 12. The power conversion device 4 includes a terminal block unit 13 having a relay bus bar 153 and resin molded portions 131 and 132 that house the relay bus bar 153. As shown in Figure 8, the resin molded portions 131 and 132 are resin portions that cover the relay bus bar 153 except for the first terminal portion 153a and the second terminal portion 153b. The resin molded portions 131 and 132 are formed of an insulating material that insulates the relay bus bar 153 from surrounding conductive members. A set of relay bus bars 153 can be installed integrally with the resin portion of the terminal block unit 13 by insert molding when the terminal block unit 13 is molded.

[0047] The first terminal portion 153a is a bus bar terminal portion provided at one end of the relay bus bar 153. The second terminal portion 153b is provided at the other end of the relay bus bar 153. The second terminal portion 153b is connected to one end of the bus bar corresponding to the through bus bar portion 152. The other end of the bus bar corresponding to the through bus bar portion 152 is connected to the end of the first bus bar portion 151. Note that in addition to the terminal base unit 13, FIG. 8 also illustrates the terminal portion 90a of the semiconductor device connected to the first terminal portion 153a.

[0048] As shown in FIG. 9 , the terminal block unit 13 has two relay bus bars 153. The two relay bus bars 153 are insulated from each other by resin molded portions 131 and 132. This pair of relay bus bars 153 includes a P-side bus bar included in the P line 10 on the high potential side and an N-side bus bar included in the N line 11 on the low potential side. Each relay bus bar 153 includes a main body portion 1531 extending in the X direction and multiple branch portions 1532 branching from the main body portion 1531. The multiple branch portions 1532 are arranged side by side in the Y direction. The end of the main body portion 1531 corresponds to the second terminal portion 153b. The relay bus bar 153 of this embodiment has three branch portions 1532 connected to each of the three-phase upper and lower arm circuits 9. The end of the branch portion 1532 corresponds to the first terminal portion 153a. As shown in FIG. 7 , the six branch portions 1532 are arranged side by side in the Y direction.

[0049] The resin molded portion 131 covers the two main body portions 1531, insulating the pair of main body portions 1531 from each other and from surrounding conductive members. The resin molded portion 132 covers the three branch portions 1532, insulating the three branch portions 1532 from each other and from surrounding conductive members. The resin molded portions 131, 132 are formed to contact the partition wall 12c via the heat conductive member 126 when the terminal base unit 13 is installed.

[0050] As shown in Fig. 7, the terminal portion 90a of the semiconductor device and the terminal portion 5b of the smoothing capacitor are each fixed to the relay bus bar 153 while in surface contact with the first terminal portion 153a. As shown in Figs. 11 and 12, the terminal portion 90a of the semiconductor device is fastened and fixed by a bolt member 171 while in surface contact with the first terminal portion 153a. As shown in Fig. 7, the terminal portion 5b of the smoothing capacitor is similarly fastened and fixed by a bolt member 171 and a nut member 172 while in surface contact with the first terminal portion 153a. In other words, the terminal portion 90a shown in Figs. 11 and 12 can be shown as being replaced with the terminal portion 5b of the smoothing capacitor.

[0051] The female thread formed on the inner peripheral surface of the nut member 172 screws into the male thread of the bolt member 171, so that the terminal portion 90a is sandwiched between the head of the bolt member 171 and the first terminal portion 153a. The nut member 172 is fixed to the resin molded portion 132 while being covered with a resin material. The nut member 172 is provided on the terminal base unit 13 in a state of contact with the heat conduction member 126.

[0052] This configuration forms a heat transfer path through which heat moves in the following order: terminal 90a, bolt member 171, nut member 172, thermally conductive member 126, partition wall 12c, and cooling water. The nut member 172 preferably contacts the first terminal 153a at the end opposite the portion that contacts thermally conductive member 126. This configuration forms another heat transfer path through which heat moves in the following order: terminal 90a, nut member 172, thermally conductive member 126, partition wall 12c, and cooling water, in addition to the above-described heat transfer path. The formation of these heat transfer paths improves the heat dissipation capabilities of the terminal 5b of the smoothing capacitor, the terminal 90a of the semiconductor device, the bus bar, and the like. The nut member 172 can be integrally installed with the resin molded portion 132 by insert molding during molding of the terminal base unit 13.

[0053] Each of the P-side bus bar and the N-side bus bar of the relay bus bar 153 has an extension 1533 that bends from the first terminal 153a and is embedded in the resin molded portion 132. As shown in FIGS. 10 to 12 , the extension 1533 of the P-side bus bar and the extension 1533 of the N-side bus bar extend toward the partition wall while facing each other. The pair of extensions 1533 may be configured so that their tips contact the thermal conductive member 126 or may be configured to be slightly spaced apart from the thermal conductive member 126. The extensions 1533 form a heat transfer path that dissipates heat from the first terminal 153a of the relay bus bar to the thermal conductive member 126 via the extensions. In this way, multiple heat transfer paths, including the heat transfer path via the nut member 172, can improve heat dissipation performance from the first terminal 153a. Furthermore, with the configuration of the extension 1533, the extension can be formed so that currents flow in opposite directions between the extension of the P-side bus bar and the extension of the N-side bus bar, thereby reducing the inductance between the P-side bus bar and the N-side bus bar.

[0054] The effects of the power converter 4 disclosed in the specification will be described. The power converter 4 includes a partition wall 12c that divides the interior of the housing 12 into a first housing chamber 121 and a second housing chamber 122. A plurality of semiconductor devices 90 and a smoothing capacitor 5 are housed in the first housing chamber 121. The noise filter 7 is housed in the second housing chamber 122. The partition wall 12c has a cooling passage 124 through which cooling water flows. The power converter 4 includes a communication bus bar 15 included in a power path that connects a terminal of the noise filter with a terminal of the semiconductor device 90a. The communication bus bar 15 has a through bus bar portion 152 that extends between the first housing chamber 121 and the second housing chamber 122 and penetrates the partition wall 12c at one location inside the housing 12. The through bus bar portion 152 is in heat-transferable contact with the partition wall 12c via an insulating member. The insulating member is formed from an insulating material and is a sheet-like member, grease, a gel-like substance, a gap filler, a resin molded portion that covers the bus bar, or the like.

[0055] In the power conversion device 4, the bus bar penetrates the partition wall 12c at only one location inside the housing 12. This allows for a compact area required to accommodate electrical components such as the noise filter 7 and the smoothing capacitor 5. In other words, the projected area of ​​the electrical components projected onto the partition wall can be made compact. This allows for a smaller interior size of the housing 12 when the partition wall 12c is viewed in plan. Therefore, the power conversion device 4 allows for a smaller area required to accommodate electrical components when viewed in plan. Furthermore, because only the through bus bar portion penetrates the partition wall 12c, a configuration can be realized in which the bus bar can be positioned close to or along the cooling passage over a wide area. This allows for a smaller portion of the bus bar that is difficult to cool with cooling water, improving the bus bar cooling capacity.

[0056] When the partition wall is viewed from above, the through bus bar portion 152 penetrates the partition wall in an area farther from the semiconductor device than the side surface portion 51 of the smoothing capacitor that is closest to the semiconductor device. This configuration allows the smoothing capacitor and the semiconductor device to be installed closer together in a plan view. This allows the bus bar connecting the smoothing capacitor and the semiconductor device to be set shorter, thereby reducing inductance.

[0057] In a plan view of the partition wall, the through busbar portion 152 penetrates the partition wall outside the outer surface of the smoothing capacitor located on the opposite side of the semiconductor device. This makes it possible to reduce the size of the power conversion device 4 in a direction perpendicular to the direction in which the semiconductor device and the smoothing capacitor are arranged in a plan view, as shown in FIG.

[0058] 2, the smoothing capacitor 5 is located closer to the semiconductor device 90 than the through bus bar portion 152. With this configuration, the cooling passage 124 can be made compact in configuration and size.

[0059] 2, the noise filter 7 is located closer to the semiconductor device 90 than the smoothing capacitor 5 is to the through bus bar portion 152. According to this configuration, the relay bus bar 153 can be arranged along the cooling passage 124, thereby improving the ability to cool the relay bus bar 153.

[0060] The communication bus bar 15 further includes a first bus bar portion 151 extending along the cooling passage in the second housing chamber toward the through-hole bus bar portion, and a second bus bar portion extending along the cooling passage from the through-hole bus bar side toward the semiconductor device in the first housing chamber. The through-hole bus bar portion 152 penetrates the partition wall 12c at a position adjacent to the cooling passage 124. This configuration allows the first and second bus bar portions to extend along the flow of cooling water. This increases the heat dissipation capacity of the first and second bus bar portions over a wide range in the longitudinal direction. Furthermore, since the through-hole bus bar portion 152 can be placed close to the cooling water, the heat dissipation effect of the bus bar can be improved at the portion penetrating the partition wall 12c. This allows the bus bar extending from the noise filter 7 through the partition wall 12c toward the semiconductor device 90 to have a wide area that can be cooled.

[0061] The first bus bar portion 151 is provided between the smoothing capacitor 5 and the cooling passage 124, in contact with the partition wall 12c via an insulator. This configuration provides an effective heat transfer path whereby heat generated in the first bus bar portion 151 moves to the partition wall 12c and is absorbed by the cooling water. Therefore, it is possible to provide a power conversion device 4 that can effectively cool the first bus bar portion 151.

[0062] The first accommodation chamber 121 is located above the second accommodation chamber 122. The through busbar portion 152 extends in the vertical direction between the first accommodation chamber and the second accommodation chamber at one location inside the housing 12 and penetrates the partition wall 12c. This allows the accommodation chambers in the housing to have a two-layer structure, and thereby makes it possible to provide a power conversion device that can reduce the horizontal length of the housing.

[0063] The power conversion device 4 includes an input bus bar 14 for an input line connecting the DC power supply 2 and the noise filter 7, and an output bus bar 16 for an output line connected to the semiconductor device. The input bus bar and the output bus bar extend from the same side wall 12a of the housing 12 to the outside of the housing. This configuration allows the power input section and the power output section of the power conversion device to be taken out from the same side of the housing. This allows the installation space occupied by the power conversion device 4, the DC power supply 2, and the output device to be compact.

[0064] Second Embodiment A second embodiment will be described with reference to Fig. 13. The power conversion device of the second embodiment differs from the first embodiment in that it has a heat transfer path from the first terminal portion 153a to the contact heat dissipation portion 153a1. The configuration, operation, and effects of the second embodiment that are not specifically described are the same as those of the first embodiment, and only the differences from the first embodiment will be described below.

[0065] Each of the P-side bus bar and the N-side bus bar of the relay bus bar 153 is provided with a contact heat dissipation portion 153a1 extending from the first terminal portion 153a toward the bent partition wall 12c. The contact heat dissipation portion 153a1 is disposed so as to contact the heat conduction member 126. The heat conduction member 126 of the second embodiment is formed of a material having high thermal conductivity and insulating properties, such as a sheet-like member, grease, a gel-like substance, or a gap filler. The portion extending from the first terminal portion 153a toward the bent partition wall 12c is covered with a resin molded portion 132. The portion in contact with the heat conduction member 126 protrudes from the resin molded portion 132.

[0066] The P-side bus bar and the N-side bus bar in the second embodiment have contact heat dissipation portions 153a1 that contact the partition wall via an insulator. With this configuration, a heat transfer path can be formed that dissipates heat from the first terminal portion 153a to the thermal conductive member 126 via the contact heat dissipation portions 153a1. In the second embodiment, by forming multiple heat transfer paths, including the heat transfer path via the extension portion 1533, it is possible to improve the heat dissipation performance from the first terminal portion 153a.

[0067] Third Embodiment A third embodiment will be described with reference to Fig. 14. The power conversion device of the third embodiment differs from the first embodiment in that the first housing chamber 121 is provided below the second housing chamber 122. Configurations, actions, and effects of the third embodiment that are not specifically described are the same as those of the previously described embodiments, and only the differences from the previously described embodiments will be described below.

[0068] The input bus bar 14 extends from the side wall 12a to the outside of the housing 12 at a position higher than the output bus bar 16. The semiconductor devices 90 and the smoothing capacitor 5 are housed in a housing chamber located below the noise filter 7 inside the housing 12. The first bus bar portion 151 is housed in a housing chamber located above the relay bus bar 153 inside the housing 12.

[0069] In the power conversion device 4 of the third embodiment, the first accommodation chamber 121 is located below the second accommodation chamber 122. The through bus bar portion 152 penetrates the partition wall 12c in the vertical direction between the first accommodation chamber and the second accommodation chamber at one location inside the housing 12. According to the third embodiment, a power conversion device can be provided that realizes reducing the horizontal length of the housing by configuring the accommodation chamber inside the housing to have a two-layer structure.

[0070] Other Embodiments The disclosure of this specification is not limited to the exemplified embodiments. The disclosure encompasses the exemplified embodiments and modifications thereto by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and elements shown in the embodiments, and various modifications can be made. The disclosure can be implemented in various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure encompasses the omission of parts and elements from the embodiments. The disclosure encompasses the substitution or combination of parts and elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. The disclosed technical scope is defined by the claims, and should be interpreted as including all modifications within the meaning and scope of the claims.

[0071] A power conversion device that can achieve the object disclosed in the specification may have a configuration that includes at least the first housing chamber 121 and the second housing chamber 122 inside the housing 12. Therefore, the power conversion device may have a configuration that includes one or more chambers inside the housing 12 in addition to the first housing chamber 121 and the second housing chamber 122.

[0072] The power conversion device in the above-described embodiment may be configured without the terminal block unit 13. In this case, for example, the following configuration is adopted: The relay bus bar 153 is directly connected to one end of the capacitor bus bar that is connected to the capacitor element. The other end of the capacitor bus bar is connected to the terminal portion 90a of the semiconductor device. As another example, a nut member 172 may be built into the capacitor case that forms the smoothing capacitor 5, and the terminal portion 90a and the terminal portion 5b may be coupled to the first terminal portion 153a.

[0073] The relay bus bar 153 may be configured to be in heat-transferable contact with the partition wall 12c via an insulating member. The insulating member may be a sheet-like member, grease, a gel-like substance, a gap filler, or the like, made of an insulating material.

[0074] (Disclosure of Technical Ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be described in a multiple dependent form, with the subsequent clause alternatively referring to the preceding clause. Furthermore, some clauses may be described in a multiple dependent form, with the subsequent clause referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0075] a smoothing capacitor (5) housed in the first housing chamber and connected to the semiconductor device; a noise filter (7) housed in the second housing chamber and connected to the smoothing capacitor; a cooling passage (124) formed in the partition wall and through which cooling water flows; and a communication bus bar (15) provided across the first housing chamber and the second housing chamber and included in a power path connecting a terminal portion of the noise filter and a terminal portion (90a) of the semiconductor device, wherein the communication bus bar has a through bus bar portion (152) extending across the first housing chamber and the second housing chamber at one location inside the housing and penetrating the partition wall.

[0076] (Technical Idea 2) The power conversion device according to Technical Idea 1, wherein, when the partition wall is viewed in a plane, the through busbar portion penetrates the partition wall in an area farther from the semiconductor device than a side portion (51) of the smoothing capacitor that is closest to the semiconductor device.

[0077] (Technical Idea 3) The power conversion device according to Technical Idea 2, wherein the through busbar portion penetrates the partition wall outside an outer surface portion of the smoothing capacitor located on the opposite side from the semiconductor device when the partition wall is viewed in a plane.

[0078] (Technical Idea 4) A power conversion device described in any one of Technical Ideas 1 to 3, wherein the connecting bus bar further has a first bus bar portion (151) extending along the cooling passage in the second accommodating chamber toward the through bus bar portion, and a second bus bar portion (153) extending along the cooling passage from the through bus bar portion side toward the semiconductor device in the first accommodating chamber, and the through bus bar portion penetrates the partition wall at a position adjacent to the cooling passage.

[0079] (Technical Concept 5) The power conversion device according to Technical Concept 4, wherein the first bus bar portion is provided between the smoothing capacitor and the cooling passage in contact with the partition wall via an insulator.

[0080] (Technical Idea 6) A power conversion device according to any one of Technical Ideas 1 to 3, comprising a terminal block unit (13) having a resin molded portion (131, 132) incorporating a relay bus bar (153) connected to a terminal portion of the semiconductor device, wherein the relay bus bar has a P-side bus bar included in a P line (10) on the high potential side and an N-side bus bar included in an N line (11) on the low potential side, and the P-side bus bar and the N-side bus bar include bus bar terminal portions (153a) coupled to the terminal portions of the semiconductor device, and a pair of extension portions (1533) bent from the bus bar terminal portions and incorporated in the resin molded portion, extending toward the partition wall in opposing orientations.

[0081] (Technical Idea 7) The power conversion device according to Technical Idea 6, wherein the P-side bus bar and the N-side bus bar have a contact heat dissipation portion (153a1) that extends from the bus bar terminal portion toward the partition wall and contacts the partition wall via an insulator.

[0082] (Technical Idea 8) A power conversion device described in any one of Technical Ideas 1 to 7, wherein the first storage chamber is located above the second storage chamber, and the through busbar portion extends in the vertical direction between the first storage chamber and the second storage chamber at one location inside the housing and penetrates the partition wall.

[0083] (Technical Idea 9) A power conversion device described in any one of Technical Ideas 1 to 7, wherein the second storage chamber is located above the first storage chamber, and the through busbar portion extends in the vertical direction between the first storage chamber and the second storage chamber at one location inside the housing and penetrates the partition wall.

[0084] (Technical Idea 10) A power conversion device according to any one of Technical Ideas 1, 2, 3, 8, and 9, comprising: an input bus bar (14) included in an input line connecting a DC power supply (2) and the noise filter; and an output bus bar (16) included in an output line connected to the semiconductor device, wherein the input bus bar and the output bus bar extend from the same side wall (12a) of the housing to the outside of the housing.

Claims

1. A power conversion device comprising: a housing (12) having a first accommodating chamber (121) and a second accommodating chamber (122) therein; a partition wall (12c) dividing the housing into the first accommodating chamber and the second accommodating chamber; a plurality of semiconductor devices (90) accommodated in the first accommodating chamber and forming a power conversion circuit; a smoothing capacitor (5) accommodated in the first accommodating chamber and connected to the semiconductor devices; a noise filter (7) accommodated in the second accommodating chamber and connected to the smoothing capacitor; a cooling passage (124) formed in the partition wall through which cooling water flows; and a communication bus bar (15) provided between the first accommodating chamber and the second accommodating chamber and included in a power path connecting a terminal portion of the noise filter and a terminal portion (90a) of the semiconductor device, wherein the communication bus bar has a through bus bar portion (152) that extends between the first accommodating chamber and the second accommodating chamber at one location inside the housing and passes through the partition wall.

2. A power conversion device as described in claim 1, wherein, when the partition wall is viewed in a plane, the through busbar portion penetrates the partition wall in an area farther from the semiconductor device than a side portion (51) of the smoothing capacitor that is closest to the semiconductor device.

3. A power conversion device as described in claim 2, wherein the through busbar portion penetrates the partition wall outside an outer surface portion of the smoothing capacitor located on the opposite side to the semiconductor device when the partition wall is viewed in a plan view.

4. A power conversion device as claimed in any one of claims 1 to 3, wherein the connecting bus bar further has a first bus bar portion (151) extending along the cooling passage in the second accommodating chamber toward the through bus bar portion, and a second bus bar portion (153) extending along the cooling passage from the side of the through bus bar portion in the first accommodating chamber toward the semiconductor device, and the through bus bar portion penetrates the partition wall at a position adjacent to the cooling passage.

5. A power conversion device according to claim 4, wherein the first bus bar portion is disposed between the smoothing capacitor and the cooling passage and in contact with the partition wall via an insulator.

6. A power conversion device as described in any one of claims 1 to 3, comprising a terminal block unit (13) having a resin molded portion (131, 132) incorporating an intermediate bus bar (153) connected to a terminal portion of the semiconductor device, the intermediate bus bar having a P-side bus bar included in a P line (10) on the high potential side and an N-side bus bar included in an N line (11) on the low potential side, the P-side bus bar and the N-side bus bar including a bus bar terminal portion (153a) connected to the terminal portion of the semiconductor device, and a pair of extension portions (1533) bent from the bus bar terminal portion and incorporated in the resin molded portion, the extension portions extending toward the partition wall in an opposing orientation.

7. A power conversion device as described in claim 6, wherein the P-side bus bar and the N-side bus bar have a contact heat dissipation portion (153a1) that extends from the bus bar terminal portion toward the partition wall and contacts the partition wall via an insulator.

8. A power conversion device as described in any one of claims 1 to 3, wherein the first accommodating chamber is located above the second accommodating chamber, and the through busbar portion extends in the vertical direction between the first accommodating chamber and the second accommodating chamber at one location inside the housing and penetrates the partition wall.

9. A power conversion device as described in any one of claims 1 to 3, wherein the second accommodating chamber is located above the first accommodating chamber, and the through busbar portion extends in the vertical direction between the first accommodating chamber and the second accommodating chamber at one location inside the housing and penetrates the partition wall.

10. A power conversion device as described in any one of claims 1 to 3, comprising: an input bus bar (14) included in an input line connecting a DC power supply (2) and the noise filter; and an output bus bar (16) included in an output line connected to the semiconductor device, wherein the input bus bar and the output bus bar extend from the same side wall (12a) of the housing to the outside of the housing.

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