Capacitors for power modules, and power conversion devices equipped therewith.

Abstract

To suppress a conductor connecting a capacitor element with a power module from being increased in temperature while suppressing the generation of inductance in the conductor.SOLUTION: A capacitor includes: a plurality of capacitor elements arranged side by side in a housing; positive electrode conductors that each connect the positive electrode of each capacitor element with the positive electrode of a power module; negative electrode conductors that each connect the negative electrode of each capacitor element with the negative electrode of the power module while holding the plurality of capacitor elements between the positive and negative electrode conductors; insulation portions that are disposed in the housing to fill spaces between the inner surfaces of the housing, the plurality of capacitor elements, the positive electrode conductors, and the negative electrode conductors and thereby insulate the same from each other; and a conductive plate that is formed from a material with higher heat conductivity than the insulation portions and that is disposed, with the intermediation of the insulation portions, between a positive electrode conductor current path extending from each capacitor element to the power module and a negative electrode conductor current path extending from each capacitor element to the power module in the housing such that the insulation portions are interposed between the positive and negative electrode conductors.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a capacitor for a power module and a power conversion device including the same.

Background Art

[0002] For example, Patent Document 1 discloses a capacitor module in which an adjusting member is disposed close to at least one of a plurality of capacitor cells (capacitor elements). By the adjusting member being close to the capacitor cell, the adjusting member affects the magnetic flux generated by the loop current flowing through the capacitor cell, and as a result, the inductance of the capacitor cell is adjusted.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, the capacitor cell of Patent Document 1 is connected to the switching unit through a bus bar (conductor). The inductance in the current path through which the loop current flows may be generated more in the bus bar connected to the switching unit than in the capacitor cell.

[0005] In recent years, in the field of power conversion devices including power modules, there has been an increasing trend toward higher voltage, higher current, higher frequency, and faster switching of power modules in order to improve added value. Along with this, the bus bar connecting the capacitor cell and the power module as the switching unit may become hotter. Therefore, in the capacitor module, it is required to suppress the increase in temperature of the bus bar.

[0006] This disclosure was made to solve the above problems and aims to provide a capacitor for a power module and a power conversion device that can suppress the generation of inductance in the conductor connecting the capacitor element and the power module, while also suppressing the temperature rise of the conductor. [Means for solving the problem]

[0007] To solve the above problems, the capacitor for a power module according to this disclosure comprises a housing, a plurality of capacitor elements housed in the housing and arranged adjacently, a positive electrode side conductor connecting the positive electrodes of the plurality of capacitor elements and the positive electrode of a power module located outside the housing, a negative electrode side conductor connecting the negative electrodes of the plurality of capacitor elements and the negative electrode of the power module with the plurality of capacitor elements sandwiched between them together with the positive electrode side conductor, and a housing housed in the housing, the inner surface of the housing, the plurality of capacitor elements, the positive electrode side conductor, and the negative electrode side The device comprises an insulating portion that is arranged to fill the space formed between each of the conductors, thereby insulating the housing, the capacitor element, the positive electrode conductor, and the negative electrode conductor from each other; a conductive plate housed in the housing and arranged between the current path of the positive electrode conductor extending from the capacitor element to the power module and the current path of the negative electrode conductor extending from the capacitor element to the power module, with the positive electrode conductor and the negative electrode conductor being separated by the insulating portion, wherein the conductive plate is made of a material with higher thermal conductivity than the insulating portion.

[0008] To solve the above problems, the power conversion device according to the present disclosure comprises the above-mentioned capacitor for the power module, the power module, and a cooler for cooling the capacitor for the power module and the power module, wherein the housing is connected to the cooler, and the conductive plate is arranged integrally with the housing. [Effects of the Invention]

[0009] According to this disclosure, it is possible to provide a capacitor for a power module and a power conversion device that can suppress the generation of inductance in the conductor connecting the capacitor element and the power module, while also suppressing the temperature rise of the conductor. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view showing the schematic configuration of a power conversion device according to the first embodiment of this disclosure. [Figure 2] This figure shows a capacitor for a power module and a power module according to the first embodiment of this disclosure, viewed from the direction of line II-II shown in Figure 1. [Figure 3] Figure 2 is a cross-sectional view of a capacitor for a power module in the III-III direction. [Figure 4] This figure shows the inside of a capacitor for a power module according to the second embodiment of this disclosure, and corresponds to a partially enlarged view of the portion shown in Figure 2. [Figure 5] This figure shows the inside of a capacitor for a power module according to the second embodiment of this disclosure, and corresponds to the portion shown in Figure 3. [Figure 6] This figure shows the inside of a capacitor for a power module according to the third embodiment of this disclosure, and corresponds to a partially enlarged view of the portion shown in Figure 2. [Figure 7] This figure shows the inside of a capacitor for a power module according to the third embodiment of this disclosure, and corresponds to the part shown in Figure 3. [Figure 8] This figure shows the internal structure of a power module capacitor according to another embodiment of the present disclosure, and corresponds to the portion shown in Figure 3. [Figure 9] This figure shows the inside of a capacitor for a power module according to another embodiment of the present disclosure, and corresponds to a partially enlarged view of the portion shown in Figure 2. [Figure 10] This figure shows the internal structure of a power module capacitor according to another embodiment of the present disclosure, and corresponds to the portion shown in Figure 3. [Embodiments for Carrying Out the Invention]

[0011] Hereinafter, with reference to the accompanying drawings, embodiments for carrying out a capacitor for a power module according to the present disclosure and a power conversion device including the same will be described.

[0012] [First Embodiment] [Power Conversion Device] A power conversion device is a device that converts DC power into three-phase AC power or the like. Examples of the power conversion device of the present embodiment include an inverter used in a power system such as a power plant and an inverter used to drive an electric motor (motor) of an electric vehicle or the like.

[0013] As shown in FIG. 1, the power conversion device 100 includes a casing 1, an external input conductor 20, a capacitor for a power module 2, a power conversion unit 3, and a cooler 4. In FIG. 1, the casing 1 and the cooler 4 are shown by two-dot chain lines.

[0014] [Casing] The casing 1 forms the outer shell of the power conversion device 100. The casing 1 is formed of a metal such as aluminum or a synthetic resin or the like. The casing 1 in the present embodiment is formed of aluminum and has a rectangular parallelepiped shape. The outer surface of the casing 1 has two side surfaces arranged so as to face each other.

[0015] Hereinafter, for convenience of explanation, of these two side surfaces, the side surface facing one side is referred to as "input side surface 1a", and the side surface facing the other side is referred to as "output side surface 1b". An external input conductor 20 for inputting DC power is drawn out from the input side surface 1a. The input side surface 1a and the output side surface 1b in the present embodiment are in a parallel relationship.

[0016] [External Input Conductor] The external input conductor 20 is a pair of electrical conductors that supply DC power supplied from an external power system of the power conversion device 100 or a DC power source such as a battery to the capacitor 2 for the power module. The external input conductor 20 in the present embodiment is formed of a metal containing copper or the like.

[0017] The external input conductor 20 has a first conductor 20a as a positive electrode and a second conductor 20b as a negative electrode. One ends of the first conductor 20a and the second conductor 20b are connected to the capacitor 2 for the power module, and the other ends of these first conductor 20a and second conductor 20b extend outside the casing 1 in a direction intersecting the input side surface 1a of the casing 1. The first conductor 20a and the second conductor 20b in the present embodiment have the same shape.

[0018] (Capacitor for power module) The capacitor 2 for the power module is a smoothing capacitor module that stores the charges input from the external input conductor 20 and suppresses voltage fluctuations accompanying power conversion. The capacitor 2 for the power module is housed in the casing 1.

[0019] The DC voltage input from the external input conductor 20 is suppressed in ripple and smoothed by passing through this capacitor 2 for the power module, and is applied to the power conversion unit 3. Hereinafter, for convenience of explanation, the capacitor 2 for the power module is simply referred to as "capacitor 2".

[0020] As shown in FIGS. 1 to 3, the capacitor 2 includes a housing 21, a capacitor element 22, a positive electrode side conductor 23, a negative electrode side conductor 24, an insulating portion 25, and a conductive plate 26.

[0021] (Housing) The housing 21 forms the outer shell of the capacitor 2 and houses the various components that make up the capacitor 2. The housing 21 is made of a metal such as aluminum. In this embodiment, the housing 21 has a rectangular cross-section and forms a cylindrical shape that extends from the input side surface 1a to the output side surface 1b when housed in the casing 1. Therefore, the housing 21 has an inner surface 210 and two openings.

[0022] The inner surface 210 defines a rectangular parallelepiped space for housing the components of the capacitor 2 other than the housing 21. The inner surface 210 is composed of four surfaces. For the sake of explanation, one of the four surfaces constituting this inner surface 210 will be referred to as the "top surface 211," and the inner surface 210 opposite to this top surface 211 will be referred to as the bottom surface 212. The top surface 211 and the bottom surface 212 are, for example, parallel to each other.

[0023] Furthermore, the two inner surfaces 210 that connect the top surface 211 and the bottom surface 212 and face each other are referred to as "side surfaces 213". The two side surfaces 213 are, for example, parallel and, for example, perpendicular to the top surface 211 and the bottom surface 212. The two openings described above open in a direction perpendicular to the direction in which the input side surface 1a and the output side surface 1b of the casing 1 expand.

[0024] (Capacitor element) The capacitor element 22 is a film capacitor housed in the housing 21. The capacitor element 22 is positioned between the top surface 211 and the bottom surface 212 on the inner surface 210, and forms a columnar shape extending between these top surface 211 and bottom surface 212. Multiple capacitor elements 22 are arranged adjacent to each other within the housing 21. As shown in Figure 2, each capacitor element 22 is positioned within the housing 21 with a gap S between it and adjacent capacitor elements 22.

[0025] The capacitor element 22 has an upper surface 22a facing the top surface 211 on the inner surface 210, and a lower surface 22b facing the opposite side of the upper surface 22a. That is, the lower surface 22b faces the bottom surface 212 on the inner surface 210. As shown in Figures 2 and 3, the capacitor element 22 has a positive electrode 22p located on the upper surface 22a and a negative electrode 22n located on the lower surface 22b.

[0026] (Positive conductor) The positive electrode conductor 23 is a conductor that electrically connects the positive electrode 22p of the capacitor element 22 to the positive electrode of the power module 30 in the power conversion unit 3 located outside the capacitor 2. The positive electrode conductor 23 is made of a metal, such as copper. The positive electrode conductor 23 has a first plate portion 232 and a P busbar 233.

[0027] In this embodiment, the first plate portion 232 is flat. The first plate portion 232 is arranged to span the upper surfaces 22a of each of the multiple capacitor elements 22 and is connected to the positive electrodes 22p of each of the multiple capacitor elements 22. The first plate portion 232 is arranged within the housing 21 with a gap between it and the top surface 211. The first plate portion 232 has an outer edge portion 232a which corresponds to the thickness of the first plate portion 232.

[0028] The P busbar 233 extends integrally with the first plate portion 232 toward the power module 30 located outside the housing 21. The P busbar 233 has a first hanging portion 233a and a first connecting portion 233b. The first hanging portion 233a extends from the outer edge portion 232a of the first plate portion 232a that faces the output side surface 1b toward the bottom surface 212 on the inner surface 210 of the housing 21.

[0029] The first connection portion 233b extends from the end of the first hanging portion 233a toward the output side surface 1b, integrally with the first hanging portion 233a. The first connection portion 233b extends from inside the housing 21, through an opening in the housing 21 facing the output side surface 1b, toward the power module 30. The end of the first connection portion 233b is connected to the positive terminal of the power module 30. In this embodiment, the first connection portion 233b extends in a direction perpendicular to the direction in which the first hanging portion 233a extends.

[0030] Furthermore, one end of the first conductor 20a of the external input conductor 20 is connected to the outer edge portion 232a of the first plate portion 232a that faces the input side surface 1a.

[0031] (Negative conductor) The negative electrode conductor 24 is a conductor that electrically connects the negative electrode 22n of the capacitor element 22 to the negative electrode of the power module 30 in the power conversion unit 3 located outside the capacitor 2. The negative electrode conductor 24 is made of a metal including, for example, copper. The negative electrode conductor 24 has a second plate portion 242 and an N busbar 243.

[0032] In this embodiment, the second plate portion 242 is flat and has the same shape as the first plate portion 232. The second plate portion 242 is arranged to span the lower surfaces 22b of each of the multiple capacitors 2 and is connected to the negative electrodes 22n of each of the multiple capacitors 2. The second plate portion 242, together with the first plate portion 232 of the positive electrode side conductor 23, sandwiches the multiple capacitor elements 22 between them. The second plate portion 242 is arranged within the housing 21 with a gap between it and the bottom surface 212. The second plate portion 242 has an outer edge portion 242a which corresponds to the thickness of the second plate portion 242.

[0033] The N busbar 243 extends integrally with the second plate portion 242 toward the power module 30 located outside the housing 21. The N busbar 243 and the P busbar 233 have the same shape. The N busbar 243 has a second hanging portion 243a and a second connecting portion 243b. The second hanging portion 243a extends from the outer edge portion 242a of the second plate portion 242a that faces the output side surface 1b toward the top surface 211 on the inner surface 210 of the housing 21.

[0034] The second connection portion 243b extends from the end of the second hanging portion 243a toward the output side surface 1b, integrally with the second hanging portion 243a. The second connection portion 243b extends from inside the housing 21, through an opening in the housing 21 facing the output side surface 1b, toward the power module 30. The end of the second connection portion 243b is connected to the negative terminal of the power module 30.

[0035] In this embodiment, the second connecting portion 243b extends in a direction perpendicular to the direction in which the second hanging portion 243a extends. The second connecting portion 243b is arranged side by side with the first connecting portion 233b via a gap G. The second connecting portion 243b is aligned with the first connecting portion 233b in a direction in which the side surfaces 213 on the inner surface 210 of the housing 21 face each other.

[0036] The gap G created by the side-by-side arrangement of the second connection portion 243b and the first connection portion 233b ensures a spatial distance (insulation distance). In this embodiment, the dimensions of the gap G are, for example, 1 mm or more and 10 mm or less. Furthermore, if an insulating member (not shown) made of insulating paper, synthetic resin, or the like is placed between the first connecting portion 233b and the second connecting portion 243b to fill the gap G, the dimension of the gap G may be, for example, greater than 0 mm and less than 1 mm.

[0037] Of the outer edge portion 242a of the second plate portion 242, the outer edge portion 242a facing the input side surface 1a is connected to one end of the second conductor 20b of the external input conductor 20.

[0038] (Insulation part) The insulating part 25 is an insulating member housed in the housing 21. The insulating part 25 is formed from a synthetic resin material or the like. In the drawing, the insulating part 25 is shown with hatching due to space limitations.

[0039] The insulating portion 25 is positioned to fill the spaces formed between the inner surface 210 of the housing 21, the multiple capacitor elements 22, the positive electrode conductor 23, and the negative electrode conductor 24, thereby insulating the housing 21, the capacitor elements 22, the positive electrode conductor 23, and the negative electrode conductor 24 from each other. In other words, the insulating portion 25 is interposed between each component that makes up the capacitor 2. At the same time, the insulating portion 25 supports and positions each component that makes up the capacitor 2 within the housing 21.

[0040] The insulating portion 25 is formed when the potting material is filled into the housing 21 and then subjected to a predetermined temperature and time for the potting material to harden. For example, silicone gel or epoxy resin can be used as the potting material.

[0041] For example, the potting material is filled into the housing 21 from above through the other opening, with one opening in the housing 21 closed using a predetermined member and the other opening facing upward in the vertical direction.

[0042] (Conductive plate) As shown in Figures 1 to 3, the conductive plate 26 is housed in the housing 21 and is a flat conductive member. In this embodiment, the conductive plate 26 is positioned between the P busbar 233 of the positive electrode conductor 23 and the N busbar 243 of the negative electrode conductor 24 via an insulating portion 25.

[0043] Specifically, the conductive plate 26 is positioned to span the gap G between the first connection portion 233b of the P busbar 233 and the second connection portion 243b of the N busbar 243, between the first hanging portion 233a of the P busbar 233 and the side surface 213 inside the housing 21, and between the second hanging portion 243a of the N busbar 243 and the side surface 213 inside the housing 21.

[0044] Furthermore, the conductive plate 26 is integrally arranged with the housing 21, with its top surface 211 and bottom surface 212 on the inner surface 210 of the housing 21 connected to each other. The conductive plate 26 is made of a material with higher thermal conductivity than the insulating part 25. In this embodiment, the conductive plate 26 is made of the same material as the housing 21. Therefore, the conductive plate 26 is made of aluminum.

[0045] Therefore, the conductive plate 26 is positioned between the current path of the positive electrode conductor 23 extending from the capacitor element 22 to the power module 30 and the current path of the negative electrode conductor 24 extending from the capacitor element 22 to the power module 30, with the positive electrode conductor 23 and the negative electrode conductor 24 separated by an insulating portion 25.

[0046] (Power conversion unit) The power conversion unit 3 converts the power input from the capacitor 2 and outputs the converted power to the outside. The power conversion unit 3 is housed in the casing 1. In this embodiment, the power conversion unit 3 has three power modules 30, each responsible for the output of the U-phase, V-phase, and W-phase, in order to output three-phase AC power. Therefore, the power conversion device 100 in this embodiment is a three-phase inverter equipped with three power modules 30.

[0047] (Power module) The power module 30 converts the input power and outputs it. As shown in Figure 2, the power module 30 comprises a base plate 31, a circuit board 32, an external output conductor 34, a resin case 35, a sealing part 36, and a bonding wire Wb.

[0048] The base plate 31 is a flat plate-shaped member. The base plate 31 has a surface 31a and a back surface 31b located on the back side of the surface 31a. That is, the surface 31a and the back surface 31b of the base plate 31 are parallel to each other and are back to back. The back surface 31b of the base plate 31 is fixed to the cooler 4 via a bonding material or the like (not shown). In this embodiment, the base plate 31 is made of a metal including, for example, copper. However, the base plate 31 may also be made of a metal including aluminum.

[0049] The circuit board 32 includes an insulating plate 321, a surface pattern 322, a power semiconductor element 323, and a back surface pattern (not shown).

[0050] The insulating plate 321 is flat. The insulating plate 321 has a first surface 321a and a second surface 321b located on the back side of the first surface 321a. That is, the first surface 321a and the second surface 321b of the insulating plate 321 are parallel to each other and are back to back. A back surface pattern, which is a pattern of copper foil or the like, is formed on one surface of the second surface 321b of the insulating plate 321. This back surface pattern is fixed to the center of the surface 31a of the base plate 31 via a bonding material.

[0051] In this embodiment, the insulating plate 321 is formed of an insulating material such as ceramic. In addition to ceramic, other materials such as paper phenol, paper epoxy, glass composite, glass epoxy, glass polyimide, and fluororesin can be used as the insulating material for forming the insulating plate 321.

[0052] The surface pattern 322 is a planar pattern of copper foil or the like that is formed on the first surface 321a of the insulating plate 321. The surface pattern 322 is formed, for example, by fixing it to the first surface 321a of the insulating plate 321 by bonding or the like, and then etching or the like.

[0053] Multiple surface patterns 322 are arranged on the first surface 321a of the insulating plate 321. These multiple surface patterns 322 are arranged adjacent to each other with gaps in between in the direction in which the insulating plate 321 expands. In this embodiment, the case in which three surface patterns 322 are arranged on the first surface 321a will be described as an example. Hereinafter, for the sake of explanation, these three surface patterns 322 will be referred to as the first surface pattern 322a, the second surface pattern 322b, and the third surface pattern 322c.

[0054] The first surface pattern 322a and the second surface pattern 322b are patterns for exchanging DC current input and output with the capacitor 2, and correspond to the inlet or outlet portion of the loop between PN formed on the surface pattern 322. An external output conductor 34 is connected to the third surface pattern 322c for outputting the AC current converted by the power semiconductor element 323 to a load (not shown) such as an AC rotating electric machine located outside the power converter 100.

[0055] The power semiconductor element 323 is a circuit element that converts power through switching operations that turn voltage and current on and off. The power semiconductor element 323 is, for example, a switching element such as an IGBT or a MOSFET. In this embodiment, as an example, a case in which a MOSFET is used as the power semiconductor is shown, and four power semiconductor elements 323 are connected to the surface pattern 322 of the circuit board 32. When using an IGBT, it is necessary to arrange a diode in parallel that allows current to flow in the opposite direction to the IGBT.

[0056] In this embodiment, the four power semiconductor elements 323 are composed of two first power semiconductor elements 323a and two second power semiconductor elements 323b. The first power semiconductor elements 323a are connected to the first surface pattern 322a. The second power semiconductor elements 323b are connected to the third surface pattern 322c.

[0057] When the power semiconductor element 323 is a MOSFET, the power semiconductor element 323 has an input surface on which an input terminal corresponding to the drain (not shown) is formed, an output surface on which an output terminal corresponding to the source (not shown) is formed, and a gate corresponding to a control signal input terminal for controlling the switching of the power semiconductor element 323.

[0058] The input surface of the power semiconductor element 323 is electrically connected to the surface pattern 322 via a bonding material or the like. One end of a bonding wire Wb, which acts as a conductor, is electrically connected to the output surface of the power semiconductor element 323. The bonding wire Wb is made of a metal including aluminum or the like. That is, the surface patterns 322 formed on the first surface 321a are electrically connected to each other by wire bonding.

[0059] The input surface of the first power semiconductor element 323a is connected to the first surface pattern 322a. The other end of a bonding wire Wb, one end of which is connected to the output surface of the first power semiconductor element 323a, is connected to the third surface pattern 322c. The input surface of the second power semiconductor element 323b is connected to the third surface pattern 322c. The other end of a bonding wire Wb, one end of which is connected to the output surface of the second power semiconductor element 323b, is connected to the second surface pattern 322b.

[0060] DC power is input to the first power semiconductor element 323a via the first surface pattern 322a, and DC power is input to the second power semiconductor element 323b via the second surface pattern 322b and the bonding wire Wb connecting the second surface pattern 322b and the second power semiconductor element 323b. By switching between the first power semiconductor element 323a and the second power semiconductor element 323b, the above DC power is converted to AC power and output to the third surface pattern 322c.

[0061] The power semiconductor element 323 receives a control signal generated by a control unit (not shown) which includes a gate drive circuit board and the like, located outside the circuit board 32. The power semiconductor element 323 switches according to this control signal. If the power semiconductor element 323 is an IGBT, it has an input surface corresponding to the collector, an output surface corresponding to the emitter, and a gate corresponding to a control signal input terminal.

[0062] Furthermore, for joining the surface 31a of the base plate 31 to the back surface pattern formed on the second surface 321b of the insulating plate 321, joining the power semiconductor element 323 to the surface pattern 322, and joining the back surface 31b of the base plate 31 to the cooler 4, for example, solder or sintered material (metal powder, etc.) can be used.

[0063] The main terminal section 33 is an electrical conductor that exchanges DC power between the capacitor 2 and the circuit board 32. The main terminal section 33 is made of a metal including copper. The main terminal section 33 has a P terminal 331 as the positive electrode in the power module 30 and an N terminal 332 as the negative electrode in the power module 30. These P terminal 331 and N terminal 332 are arranged side by side with a gap of the same spacing as the gap G.

[0064] The P terminal 331 is connected to the first connection portion 233b of the P busbar 233 of the capacitor 2 by a fastening part such as a bolt. The N terminal 332 is connected to the second connection portion 243b of the N busbar 243 of the capacitor 2 by a fastening part such as a bolt. Note that in Figure 2, the connection portion between the P terminal 331 and the first connection portion 233b, and the connection portion between the N terminal 332 and the second connection portion 243b are not shown.

[0065] The external output conductor 34 is an electrical conductor for outputting AC power, which has been converted by the power semiconductor element 323, to the outside of the power converter 100. The external output conductor 34 is made of a metal including copper. One end of the external output conductor 34 is connected to the third surface pattern 322c on the circuit board 32. As shown in Figure 1, the other end of the external output conductor 34 extends to the outside of the casing 1 in a direction intersecting the output side surface 1b. Wiring for power output (not shown) connected to a load such as a motor is connected to the other end of the external output conductor 34.

[0066] As shown in Figure 2, the resin case 35 is a component that mechanically reinforces the external output conductor 34 and the main terminal portion 33 while being fixed to the surface 31a of the base plate 31. The resin case 35 is formed from, for example, a synthetic resin material (insulating material). In this embodiment, for example, PPS (polyphenylene sulfide) can be used as the material forming the resin case 35. However, synthetic resin materials other than PPS may also be used for the resin case 35. The resin case 35 is fixed to the surface 31a of the base plate 31 by, for example, an adhesive.

[0067] The resin case 35 surrounds the circuit board 32 from the outside, covering the P terminal 331 and N terminal 332 of the main terminal section 33, as well as the external output conductor 34, from the outside. The resin case 35 is formed in a direction along the surface 31a of the base plate 31, surrounding the circuit board 32 from all sides. Therefore, the resin case 35, together with the base plate 31, defines the space in which the circuit board 32 is housed. In this embodiment, for the sake of explanation, this space in which the circuit board 32 is housed is referred to as the "potting space Rp".

[0068] The sealing portion 36 is an insulating member placed within the potting space Rp. Liquid potting material is filled into the potting space Rp from the outside (potting) to seal the components exposed within the potting space Rp. The potting material filled into the potting space Rp hardens when subjected to a predetermined temperature and time, electrically insulating each component within the potting space Rp, and each component from the space outside the power module 30. In this embodiment, the same potting material as the potting material filled into the housing 21 of the capacitor 2 can be used.

[0069] Therefore, the sealing portion 36 is formed by this potting material. Within the potting space Rp, the sealing portion 36 is positioned to cover the surfaces of the circuit board 32, bonding wire Wb, external output conductor 34, and main terminal portion 33, respectively.

[0070] (cooler) The cooler 4 is a device for cooling the capacitor 2 and the power module 30 of the power conversion unit 3. As shown in Figure 1, the cooler 4 is installed stacked on the casing 1 and is fixed and integrated with the casing 1. As shown in Figure 3, the cooler 4 has a base 41 and heat dissipation fins 42. In Figure 3, the base 41 and heat dissipation fins 42 are shown by dotted lines.

[0071] The base portion 41 is plate-shaped. The base portion 41 has a bonding surface 41a and a heat dissipation surface 41b. The bonding surface 41a is the surface that is bonded to the outer surface of the housing 21 of the capacitor 2 and the back surface 31b of the base plate 31 of the power module 30 via a bonding material or the like (see also Figure 2). The heat dissipation surface is the surface facing the opposite side from the bonding surface 41a. In other words, the base portion 41 of the cooler 4 is connected to the housing 21 of the capacitor 2 and the base plate 31 of the power module 30.

[0072] The bonding surface 41a and the heat dissipation surface 41b are back-to-back and parallel to each other. The heat dissipation fins 42 are columnar members arranged in multiple locations on the heat dissipation surface 41b of the base 41. Each heat dissipation fin 42 protrudes from the heat dissipation surface 41b on the side opposite to the capacitor 2 and power module 30, with the base 41 as the center.

[0073] A liquid coolant W, such as water, is introduced into the cooler 4 from an external source. The heat dissipation surface 41b of the base 41 and the heat dissipation fins 42 are cooled by contact with the liquid coolant W introduced from the external source. The liquid coolant W is heated by heat exchange with the heat conducted from the condenser 2 and power module 30 to the base 41 and heat dissipation fins 42, while simultaneously cooling the condenser 2 and power module 30.

[0074] (Effects and Benefits) DC power input to the first plate portion 232 of the positive electrode side conductor 23 through the first conductor 20a of the external input conductor 20, which acts as the positive electrode, is input to the P terminal 331, which is the positive electrode of the power module 30, through the first hanging portion 233a and the first connection portion 233b of the P busbar 233. DC power input to the positive electrode side conductor 23 is also input into the capacitor element 22 from the positive electrode 22p of the capacitor element 22. DC power input from the P terminal 331 to the surface pattern 322 is converted to AC power by the power semiconductor element 323. This AC power is used by an AC rotating electric machine or other load outside the power conversion device 100 through the external output conductor 34 connected to the surface pattern 322. The AC power returning from the external load is input to the surface pattern 322 again through the external output conductor 34, converted to DC power by the power semiconductor element 323, and then input to the N terminal 332. The DC power input to terminal N 332 flows through the negative terminal conductor 24 and the second conductor 20b of the external input conductor 20. The DC power input from the positive terminal 22p of the capacitor element 22 is stored as charge within the capacitor element 22 (charging) and repeatedly discharged through the negative terminal 22n. As the above charging and discharging in the capacitor element 22 is repeated, the DC current flowing through the positive terminal conductor 23 and the negative terminal conductor 24 is smoothed. When DC current flows through the P busbar 233 of the positive terminal conductor 23 and the N busbar 243 of the negative terminal conductor 24, magnetic flux is generated from these P busbars 233 and N busbars 243, respectively.

[0075] According to the above configuration, since the conductive plate 26 is positioned between the P busbar 233 and the N busbar 243, the magnetic flux generated by the current flowing through these P busbars 233 and N busbars 243 links with the conductive plate 26. As a result, an induced current (back electromotive force) corresponding to the amount of magnetic flux linked with the conductive plate 26 flows through the conductive plate 26, and the magnetic flux generated by this induced current cancels out the magnetic flux from the P busbars 233 and N busbars 243. In other words, the density of magnetic flux generated by the current flowing through the P busbars 233 and N busbars 243 inside the housing 21 decreases. Consequently, the inductance in the positive electrode conductor 23 and the negative electrode conductor 24 is reduced.

[0076] Furthermore, the heat generated in the P busbar 233 and N busbar 243 is conducted to the conductive plate 26 through the insulating part 25. The heat conducted to the conductive plate 26 is diffused within the conductive plate 26. With the above configuration, since the thermal conductivity of the conductive plate 26 is higher than that of the insulating part 25, the heat generated from the P busbar 233 and N busbar 243 can be diffused more effectively within the housing 21 compared to a configuration in which the conductive plate 26 is not provided. In other words, the P busbar 233 and N busbar 243 can be cooled more effectively.

[0077] Therefore, it is possible to suppress the generation of inductance in the conductor connecting the capacitor element 22 and the power module 30 while also suppressing the conductor from becoming excessively hot.

[0078] Furthermore, with the above configuration, since the housing 21 connected to the cooler 4 and the conductive plate 26 are integrated, the heat conducted from the P busbar 233 and N busbar 243 to the conductive plate 26 is dissipated to the housing 21, while the housing 21 is cooled by the cooler 4. Therefore, the overheating of the conductor can be further suppressed.

[0079] <Second Embodiment> Next, a second embodiment of the power converter 100 according to this disclosure will be described with reference to Figures 4 and 5. In the second embodiment described below, components common to the first embodiment described above are denoted by the same reference numerals in the figures and their descriptions are omitted. In the second embodiment, the configuration of the conductive plate 26a in the capacitor 2 differs from the configuration of the conductive plate 26 described in the first embodiment.

[0080] (Conductive plate) The conductive plate 26a is housed in the housing 21. The conductive plate 26a is made of a material with higher thermal conductivity than the insulating portion 25 and is made of the same material as the housing 21. In this embodiment, the conductive plate 26a has a first portion 261 and a second portion 262.

[0081] The first part 261 is a flat conductive member. The first part 261 is positioned between the P busbar 233 of the positive electrode conductor 23 and the N busbar 243 of the negative electrode conductor 24 via an insulating portion 25.

[0082] Specifically, the first part 261 is positioned between the gap G between the first connection part 233b of the P bus bar 233 and the second connection part 243b of the N bus bar 243, between the first hanging part 233a of the P bus bar 233 and the side surface 213 inside the housing 21, and between the second hanging part 243a of the N bus bar 243 and the side surface 213 inside the housing 21.

[0083] Therefore, the first part 261 is positioned between the current paths of the positive conductor 23 and the negative conductor 24, on the side of the capacitor element 22 that is closer to the power module 30. Furthermore, the first part 261 is integrally positioned with the housing 21, with the top surface 211 and the bottom surface 212 of the inner surface 210 of the housing 21 connected to each other.

[0084] The second portion 262 is a conductive member formed integrally with the first portion 261. The second portion 262 is positioned in the gap S between adjacent capacitor elements 22. In this embodiment, the second portion 262 is positioned between adjacent capacitor elements 22 via an insulating portion 25, so as to separate the adjacent capacitor elements 22. Furthermore, the second portion 262 is sandwiched between the first plate portion 232 of the positive electrode conductor 23 and the second plate portion 242 of the negative electrode conductor 24 via the insulating portion 25.

[0085] As shown in Figure 5, the conductive plate 26a, composed of the first part 261 and the second part 262, forms a T-shape when viewed from the direction in which the side surfaces 213 of the inner surface 210 of the housing 21 face each other.

[0086] (Effects and Benefits) According to the above configuration, since the second portion 262 of the conductive plate 26a is positioned between adjacent capacitor elements 22, the magnetic flux generated by the current flowing through the capacitor elements 22 links with this second portion 262. As a result, an induced current (back electromotive force) corresponding to the amount of magnetic flux linked with the second portion 262 flows through the second portion 262, and the magnetic flux generated by this induced current cancels out the magnetic flux from the capacitor elements 22. In other words, the density of magnetic flux generated by the current flowing through the capacitor elements 22 decreases. Consequently, the inductance in the capacitor elements 22 as a current path is reduced.

[0087] Furthermore, the heat generated in the capacitor element 22 is conducted through the insulating portion 25 to the second portion 262 of the conductive plate 26a. The heat conducted to the second portion 262 is then diffused within this second portion 262. With the above configuration, since the thermal conductivity of the second portion 262 is higher than that of the insulating portion 25, the heat generated from the capacitor element 22 can be diffused more effectively within the housing 21 compared to a configuration in which the second portion 262 is not placed between the capacitor elements 22. In other words, the capacitor element 22 can be cooled more effectively.

[0088] Furthermore, with the above configuration, the housing 21 connected to the cooler 4 and the first portion 261 of the conductive plate 26a are integrated, and the first portion 261 and the second portion 262 are integrated. Therefore, heat conducted from the P busbar 233 and N busbar 243 to the first portion 261, and heat conducted from the capacitor element 22 to the second portion 262 can be dissipated to the housing 21. Consequently, the overheating of the conductor and the capacitor element 22 can be further suppressed.

[0089] <Third Embodiment> Next, a third embodiment of the power converter 100 according to the present disclosure will be described with reference to Figures 6 and 7. In the third embodiment described below, components common to the second embodiment described above are denoted by the same reference numerals in the figures and their descriptions are omitted. In the third embodiment, the configuration of the P busbar 233 of the positive electrode conductor 23 and the N busbar 243 of the negative electrode conductor 24 differs from the configuration of the P busbar 233 and N busbar 243 described in the second embodiment.

[0090] The P busbar 233 in this embodiment has a first extension portion 233c, a first hanging portion 233a, and a first connecting portion 233b. The first extension portion 233c extends from the outer edge portion 232a of the first plate portion 232a that faces the output side surface 1b toward the output side surface 1b. The first hanging portion 233a extends from the end of the extension portion 233c toward the bottom surface 212 on the inner surface 210 of the housing 21, integrally with the first extension portion 233c.

[0091] The first connection portion 233b extends from the end of the first hanging portion 233a toward the output side surface 1b, integrally with the first hanging portion 233a. The first connection portion 233b extends from inside the housing 21, through an opening in the housing 21 facing the output side surface 1b, toward the power module 30. The end of the first connection portion 233b is connected to the positive terminal of the power module 30. In this embodiment, the first connection portion 233b extends in a direction perpendicular to the direction in which the first hanging portion 233a extends. Furthermore, the first connection portion 233b extends in the same direction as the first extending portion 233c extends.

[0092] In this embodiment, the N busbar 243 and the P busbar 233 have the same shape. The N busbar 243 has a second extension portion 243c, a second hanging portion 243a, and a second connecting portion 243b. The second extension portion 243c extends from the outer edge portion 242a of the second plate portion 242a that faces the output side surface 1b towards the output side surface 1b. The second hanging portion 243a extends from the end of the extension of the second extension portion 243c, integrally with the second extension portion 243c, toward the top surface 211 on the inner surface 210 of the housing 21.

[0093] The second connection portion 243b extends from the end of the second hanging portion 243a, integrally with the second hanging portion 243a, toward the output side surface 1b. The second connection portion 243b extends from inside the housing 21, through an opening in the housing 21 facing the output side surface 1b, toward the power module 30.

[0094] In this embodiment, the second connecting portion 243b extends in a direction perpendicular to the direction in which the second hanging portion 243a extends. The second connecting portion 243b is arranged side by side with the first connecting portion 233b via a gap G. The second connecting portion 243b is aligned with the first connecting portion 233b in a direction in which the side surfaces 213 on the inner surface 210 of the housing 21 face each other.

[0095] (Effects and Benefits) According to the configuration of the third embodiment, the area of ​​the first portion 261 of the conductive plate 26a arranged between the capacitor elements 22 can be increased compared to the configuration described in the second embodiment. For example, the surface area of ​​the first portion 261 of the conductive plate 26a can be increased by the length of the first extended portion 233c and the second extended portion 243c. Therefore, the amount of magnetic flux acting (linking) on ​​the conductive plate 26a from the capacitor elements 22, the P busbar 233, and the N busbar 243 can be increased. As a result, the inductance can be further reduced.

[0096] Furthermore, compared to the configuration described in the second embodiment, the adjacent sections of the side surfaces 213 of the housing 21 in opposing directions are shortened by the length of the first extension portion 233c and the length of the second extension portion 243c. Therefore, for example, when current flows through the P busbar 233 and N busbar 243 and heat is generated, it is possible to suppress the concentration of heat conducted from these P busbars 233 and N busbars 243 to the first portion 261 of the conductive plate 26a via the insulating portion 25.

[0097] (Other embodiments) Although embodiments of this disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to that of the embodiments, and additions, omissions, substitutions, and other modifications to the configuration are possible without departing from the gist of this disclosure.

[0098] As shown in Figure 8, the capacitor 2 described in the above embodiment may further include a housing insulating layer 27 disposed integrally with the housing 21 on the inner surface 210 of the housing 21. In this case, the housing insulating layer 27 is an oxide of the metal material forming the housing 21. If the housing 21 is made of aluminum, it is an oxide (anodic oxide film) formed by anodizing the aluminum forming the housing 21. This makes it possible to improve the insulation between the positive electrode conductor 23 and the negative electrode conductor 24 and the housing 21. Therefore, the distance between the top surface 211 and the bottom surface 212 on the inner surface 210 of the housing 21 and the first plate portion 232 of the positive electrode conductor 23 and the second plate portion of the negative electrode conductor 24 can be reduced. As a result, the amount of magnetic flux linked to the top surface 211 and the bottom surface 212 on the inner surface 210 of the housing 21 from the magnetic flux generated by the current flowing through the first plate portion 232 and the second plate portion 242 can be increased, and the inductance can be reduced. The housing insulation layer 27 may be an insulating coating material formed from a synthetic resin material or the like.

[0099] Furthermore, as shown in Figure 9, the capacitor 2 described in the first embodiment may further include a conductive plate insulating layer 28 integrally disposed with the conductive plate 26 on the surface of the conductive plate 26. In this case, the conductive plate insulating layer 28 is an oxide of the metal material forming the conductive plate 26. If the conductive plate 26 is made of aluminum, it is an oxide (anodic oxide film) formed by anodizing the aluminum forming the conductive plate 26. This makes it possible to improve the insulation between the P busbar 233 of the positive electrode conductor 23 and the N busbar 243 of the negative electrode conductor 24 and the conductive plate 26. Therefore, the distance between the conductive plate 26 and the P busbar 233 and N busbar 243 can be reduced. As a result, the amount of magnetic flux linked to the conductive plate 26 from the magnetic flux generated by the current flowing through the P busbar 233 and N busbar 243 can be increased, and the inductance can be reduced. Note that the conductive plate insulating layer 28 may be an insulating coating material formed of a synthetic resin material or the like. Furthermore, the conductive plate insulating layer 28 may be disposed integrally with the conductive plate 26a on the surface of the conductive plate 26a described in the second embodiment.

[0100] Furthermore, as shown in Figure 10, the capacitor 2 described in the above embodiment may further include a conductor insulating layer 29 disposed integrally with the positive electrode conductor 23 and the negative electrode conductor 24 on the outer surfaces of the positive electrode conductor 23 and the negative electrode conductor 24. In this case, the conductor insulating layer 29 is an insulating coating material formed from a synthetic resin material or the like. This improves the insulation between the positive electrode conductor 23 and the negative electrode conductor 24. Therefore, the distance between the top surface 211 and the bottom surface 212 on the inner surface 210 of the housing 21 and the first plate portion 232 of the positive electrode conductor 23 and the second plate portion 242 of the negative electrode conductor 24 can be reduced. In addition, the distance between the first connection portion 233b of the P busbar 233 on the positive electrode conductor 23 and the second connection portion 243b of the N busbar 243 on the negative electrode conductor 24 can be reduced. As a result, the amount of magnetic flux linked to the top surface 211 and bottom surface 212 on the inner surface 210 of the housing 21, and the amount of magnetic flux linked to the conductive plates 26, 26a, out of the magnetic flux generated by the current flowing through the first plate portion 232 and the second plate portion 242, can be increased, thereby reducing the inductance. Although detailed illustrations are omitted, the conductor insulating layer 29 may be arranged on the outer surfaces of the first conductor 20a and the second conductor 20b of the external input conductor 20.

[0101] Furthermore, the conductive plates 26 and 26a described in the above embodiment may not be formed integrally with the housing 21, but may be positioned within the housing 21 by the insulating portion 25.

[0102] Furthermore, the capacitor element 22 of the capacitor 2 described in the above embodiment is not limited to a film capacitor. The capacitor element 22 may be, for example, an electrolytic capacitor or the like.

[0103] Furthermore, although the capacitor element 22 described in the above embodiment has a positive electrode 22p positioned on the upper surface 22a and a negative electrode 22n positioned on the lower surface 22b, it is not limited to this configuration. The capacitor element 22 may also have a negative electrode 22n positioned on the upper surface 22a and a positive electrode 22p positioned on the lower surface 22b. In this case, the first plate portion 232 of the positive electrode conductor 23 is connected to the positive electrode 22p located on the lower surface 22b, and the first conductor 20a and the P busbar 233 of the positive electrode conductor 23 are connected to this first plate portion 232. Also, the second plate portion 242 of the negative electrode conductor 24 is connected to the negative electrode 22n located on the upper surface 22a, and the second conductor 20b and the N busbar 243 of the negative electrode conductor 24 are connected to this second plate portion 242. Therefore, the arrangements of the first conductor 20a and the positive electrode conductor 23 described in the above embodiment, and the arrangements of the second conductor 20b and the negative electrode conductor 24, may be swapped. Even in this case, the first connection portion 233b of the P busbar 233 should be connected to the P terminal 331 of the power module 30, and the second connection portion 243b of the N busbar 243 should be connected to the N terminal 332 of the power module 30.

[0104] Furthermore, although the above embodiment describes a configuration in which the conductive plates 26 and 26a are formed from the same material as the housing 21, the configuration is not limited to this. The conductive plates 26 and 26a may be formed from a metal material with higher thermal conductivity than the metal material forming the housing 21.

[0105] Furthermore, the terms "parallel," "perpendicular," and "identical shape" described in the above embodiments refer to a state in which the elements are substantially parallel, perpendicular, and identical in shape, and slight manufacturing errors and design tolerances are permissible. It should also be noted that the elements may be slightly inclined from their parallel and perpendicular positions.

[0106] Furthermore, although an inverter was used as an example of the power conversion device 100 in the above embodiment, the power conversion device 100 is not limited to an inverter. The power conversion device 100 may be a device that performs power conversion using a power semiconductor element 323, such as a converter or a combination of an inverter and a converter. If the power conversion device 100 is a converter, an AC voltage may be input to the external output conductor 34 from an external input power source (not shown), the power semiconductor element 323 on the circuit board 32 converts this AC voltage to a DC voltage, and the DC voltage from the power semiconductor element 323 is output to the outside of the power conversion device 100 through the positive electrode conductor 23 and the negative electrode conductor 24.

[0107] <Note> The capacitors for power modules and power conversion devices described in each embodiment can be understood, for example, as follows.

[0108] (1) The capacitor 2 for a power module according to the first embodiment comprises a housing 21, a plurality of capacitor elements 22 housed in the housing 21 and arranged adjacently, a positive electrode side conductor 23 connecting the positive electrodes 22p of the plurality of capacitor elements 22 and the positive electrode of a power module 30 located outside the housing 21, a negative electrode side conductor 24 connecting the negative electrodes 22n of the plurality of capacitor elements 22 and the negative electrode of the power module 30, with the plurality of capacitor elements 22 sandwiched between the positive electrode side conductor 23, and the inner surface 210 of the housing 21, the plurality of capacitor elements 22, the positive electrode side conductor 23, and the negative electrode side conductor 24. The device comprises an insulating portion 25 that insulates the housing 21, the capacitor element 22, the positive electrode conductor 23, and the negative electrode conductor 24 from each other by being arranged to fill the space formed between them, and conductive plates 26, 26a that are housed in the housing 21 and arranged between the current path of the positive electrode conductor 23 extending from the capacitor element 22 to the power module 30 and the current path of the negative electrode conductor 24 extending from the capacitor element 22 to the power module 30, with the conductive plates 26, 26a being formed of a material with higher thermal conductivity than the insulating portion 25.

[0109] As a result, the conductive plates 26 and 26a are positioned between the current paths of the positive conductor 23 and the negative conductor 24, and the magnetic flux generated by the current flowing through each current path links with the conductive plates 26 and 26a. When the magnetic flux links with the conductive plates 26 and 26a, an induced current (back electromotive force) corresponding to the amount of linked magnetic flux flows through the conductive plates 26 and 26a, and the magnetic flux generated by this induced current cancels out the magnetic flux from each current path. In addition, because the thermal conductivity is higher than that of the insulating part 25, the heat generated from each current path can be more effectively diffused within the housing 21 compared to a configuration in which the conductive plates 26 and 26a are not positioned between the current paths.

[0110] (2) The capacitor 2 for the power module according to the second embodiment is the capacitor 2 for the power module according to (1), wherein the conductive plate 26a may have a first portion 261 disposed between the current path of the positive electrode conductor 23 and the current path of the negative electrode conductor 24, on the side of the capacitor element 22 that is closer to the power module 30, and a second portion 262 formed integrally with the first portion 261 and disposed between adjacent capacitor elements 22.

[0111] As a result, the second portion 262 of the conductive plate 26a is positioned between adjacent capacitor elements 22, and the magnetic flux generated by the current flowing through the capacitor elements 22 links with this second portion 262. When the magnetic flux links with the second portion 262, an induced current (back electromotive force) corresponding to the amount of linked magnetic flux flows through the second portion 262, and the magnetic flux generated by this induced current cancels out the magnetic flux from the capacitor elements 22.

[0112] (3) The power converter 100 according to the third embodiment comprises a power module capacitor 2 according to (1) or (2), the power module 30, and a cooler 4 for cooling the power module capacitor 2 and the power module 30, wherein the housing 21 is connected to the cooler 4, and the conductive plates 26, 26a are arranged integrally with the housing 21.

[0113] As a result, the heat conducted from the current path of the positive electrode conductor 23 and the current path of the negative electrode conductor 24 to the conductive plates 26 and 26a is dissipated to the housing 21, while the housing 21 is cooled by the cooler 4. [Explanation of Symbols]

[0114] 1…Casing 1a…Input side 1b…Output side 2…Power module capacitor (capacitor) 3…Power conversion unit 4…Cooler 20…External input conductor 20a…First conductor 20b…Second conductor 21…Housing 22…Capacitor element 22a…Top surface 22b…Bottom surface 22p…Positive electrode 22n…Negative electrode 23…Positive electrode side conductor 24…Negative electrode side conductor 25…Insulation part 26,26a…Conductive plate 27…Housing insulation layer 28…Conductive plate insulation layer 29…Conductor insulation layer 30…Power module 31…Base plate 31a…Front surface 31b…Back surface 32…Circuit board 33…Main terminal section 34…External output conductor 35…Resin case 36…Sealing part 41…Base part 41a…Bonding surface 41b…Heat dissipation surface 42…Heat dissipation fin 100…Power conversion device 210…Inner surface 211…Top surface 212…Bottom surface 213…Side surface 232…First plate section 232a,242a…Outer edge section 233…P busbar 233a…First hanging section 233b…First connection section 242…Second plate section 243…N busbar 243a…Second hanging section 243b…Second connection section 261…First part 262…Second part 321…Insulating plate 321a…First surface 321b…Second surface 322…Surface pattern 322a…First surface pattern 322b…Second surface pattern 322c…Third surface pattern 323…Power semiconductor element 323a…First power semiconductor element 323b…Second power semiconductor element 331…P terminal 332…N terminal G…Gap Rp…Potting space S…Gap W…Liquid coolant Wb…Bonding wire

Claims

1. The casing and Multiple capacitor elements housed in the aforementioned enclosure and arranged adjacently, A positive electrode side conductor that connects the positive electrodes of multiple capacitor elements to the positive electrode of a power module located outside the housing, With the positive electrode side conductor and the plurality of capacitor elements sandwiched in between, a negative electrode side conductor connects the negative electrodes of the plurality of capacitor elements and the negative electrode of the power module, An insulating portion is housed in the aforementioned housing and is positioned to fill the space formed between the inner surface of the housing, the plurality of capacitor elements, the positive electrode side conductor, and the negative electrode side conductor, thereby insulating the housing, the capacitor elements, the positive electrode side conductor, and the negative electrode side conductor from each other. Housed in the aforementioned enclosure, Between the current path of the positive electrode conductor extending from the capacitor element to the power module and the current path of the negative electrode conductor extending from the capacitor element to the power module, a conductive plate is arranged between these positive electrode conductors and negative electrode conductors via the insulating portion. Equipped with, The conductive plate is formed of a material with higher thermal conductivity than the insulating portion, in a capacitor for a power module.

2. The conductive plate is A first portion of the current path of the positive electrode conductor and the current path of the negative electrode conductor, which is located between the current path on the power module side of the capacitor element, A second portion is formed integrally with the first portion and is positioned between adjacent capacitor elements, A capacitor for a power module according to claim 1, having the following features.

3. A capacitor for a power module according to claim 1 or 2, The aforementioned power module, The capacitor for the power module and the cooler for cooling the power module, Equipped with, The housing is connected to the cooler, The conductive plate is a power conversion device that is integrally arranged with the housing.

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