Capacitor module and power conversion device

Abstract

To provide an effective technique for suppressing the influence of conduction noise transmitted from an inverter through a conductor.SOLUTION: A capacitor module 101 includes an energizing unit 20 on a power supply side and an energizing unit 30 on an inverter side. The energizing unit 20 on the power supply side has a first positive conductor 21 electrically connected to a positive electrode surface 11 of a capacitor 10 and a first negative electrode conductor 22 electrically connected to a negative electrode surface 12 of the capacitor 10. The energizing unit 30 on the inverter side has a second positive electrode conductor 31 electrically connected to a positive electrode surface 11 of the capacitor 10 and a second negative electrode conductor 32 electrically connected to the negative electrode surface 12 of the capacitor 10. Both of one pair of positive electrode side parallel running portions 21b and 31b that run in parallel so that the conducting directions are the same in the first positive electrode conductor 21 and the second positive electrode conductor 31 and one pair of negative electrode side parallel running portions 22b and 32b that run in parallel so that the conducting directions are the same in the first negative electrode conductor 22 and the second negative electrode conductor 32 are provided.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a capacitor module and a power conversion device. [Background technology]

[0002] Conventionally, electric vehicles, hybrid vehicles, etc. are equipped with a power conversion device that converts DC power from a battery into AC power in order to drive a motor for running the vehicle. Patent Document 1 listed below discloses this type of power conversion device.

[0003] This power conversion device includes a capacitor module and an inverter, both of which are provided between a power source and a motor. The capacitor module has a smoothing capacitor provided on the inverter side, and two noise-removing capacitors provided on the power source side. The positive side of the power source and the positive side of the inverter are electrically connected by a positive side conductor, and the negative side of the power source and the negative side of the inverter are electrically connected by a negative side conductor. The positive side conductor and the negative side conductor are provided with a laminated region where they are laminated with each other, and a non-laminated region where they are not laminated with each other. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-207780 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the above power converter, the positive and negative conductors between the two capacitors are lengthened to increase the parasitic inductance formed in the non-laminated region, thereby suppressing the voltage fluctuation between the power lines. However, the effect of suppressing the voltage fluctuation between the power lines may be reduced due to the influence of the parasitic inductance of the noise removal capacitor. In particular, with the recent trend toward miniaturization and high density of power converters, this problem becomes more pronounced when it is difficult to adopt a structure in which the conductors are lengthened.

[0006] In addition, in the above power converter, a non-laminated region is provided in the positive and negative conductors to increase the parasitic inductance, and a noise elimination capacitor is used to release common mode noise from the housing to the ground, thereby suppressing the conductive noise transmitted from the inverter side. However, the suppression effect of the conductive noise is easily affected by the layout of the ground side conductor that electrically connects the noise elimination capacitor to the housing, and depending on the layout of the ground side conductor, it may be difficult to obtain the desired suppression effect of the conductive noise. In addition, when the smoothing capacitor and the noise elimination capacitor are arranged close to each other, a problem may occur in that the noise worsens due to the influence of inductive coupling caused by mutual inductance. In particular, due to the influence of the widening of the noise band caused by the high-speed switching of recent power converters, if the layout accuracy of the ground side conductor is insufficient, these problems become more pronounced.

[0007] The present invention has been made in view of the above problems, and aims to provide a technique that is effective in suppressing the effects of conductive noise transmitted from an inverter through a conductor. [Means for solving the problem]

[0008] One aspect of the present invention is A capacitor (10); a power supply side conductive portion (20) provided between the capacitor and the power supply (1); an inverter-side current-carrying unit (30) provided between the capacitor and an inverter (102), the power supply side conductive portion includes a first positive conductor (21) electrically connected to a positive electrode surface (11) of the capacitor, and a first negative conductor (22) electrically connected to a negative electrode surface (12) of the capacitor, the inverter-side current-carrying portion includes a second positive conductor (31) electrically connected to the positive electrode surface of the capacitor, and a second negative conductor (32) electrically connected to the negative electrode surface of the capacitor, The first positive conductor and the second positive conductor have at least one of a pair of positive side parallel running portions (21b, 31b) that run in parallel so that the current flows in the same direction, and a pair of negative side parallel running portions (22b, 32b) that run in parallel so that the current flows in the same direction, in the first negative conductor and the second negative conductor. 、 The capacitor has a plurality of outer surfaces (13, 14, 15, 16) extending between the positive and negative electrode surfaces; At least one of the pair of positive electrode side parallel running portions and the pair of negative electrode side parallel running portions is provided opposite at least one of the outer surfaces of the capacitor. , capacitor module (101, 201, 301, 401), is located.

[0009] Another aspect of the present invention is A power supply system comprising: a capacitor module (501, 601, 701, 801, 901, 1001); an inverter (502) connected to the capacitor module so as to be capable of power conversion; and a conductive housing (3) that houses the capacitor module and the inverter, a power conversion device (500, 600, 700, 800, 900, 1000), wherein the capacitor module includes a first smoothing capacitor (10A), a second noise removing capacitor (10P, 10N), a first conductor (51P, 51N) extending from an intermediate connection portion (50P, 50N) between the first capacitor and a power source (1) toward the power source, a second conductor (61P, 61N) electrically connecting the second capacitor and the intermediate connection portion, and a ground conductor (62) electrically connecting the second capacitor and the housing, wherein a power source side parallel running portion (51a, 51b) is provided in the first conductor, and at least one of the second conductor and the ground conductor is provided with a ground side parallel running portion (61a, 61b, 62a) running parallel to the power source side parallel running portion so that an induced current in a direction opposite to that of a noise current is generated in the power source side parallel running portion; is located.

[0010] A further aspect of the present invention is A power supply system comprising: a capacitor module (501, 601, 701, 801, 901, 1001); an inverter (502) connected to the capacitor module so as to be capable of power conversion; and a conductive housing (3) that houses the capacitor module and the inverter, The capacitor module includes a first smoothing capacitor (10A), a second noise removing capacitor (10P, 10N), a first conductor (51P, 51N) extending from an intermediate connection (50P, 50N) between the first capacitor and a power source (1) toward the power source, an intermediate conductor (52P, 52N) electrically connecting the first capacitor and the intermediate connection, a second conductor (61P, 61N) electrically connecting the second capacitor and the intermediate connection, and a second conductor (62P, 62N) electrically connecting the second capacitor and the intermediate connection. a power conversion device (500, 600, 700, 800, 900, 1000) including: a ground conductor (62) electrically connecting a capacitor and the housing; and a magnetic shield section (51c, 53, 56) for suppressing a magnetic flux generated by a high frequency current flowing through a capacitor current path (B1) of the first capacitor from flowing in linkage with a common mode current path (B2) formed by the second capacitor, the first conductor, the second conductor, the ground conductor, and the housing; is located. Effect of the Invention

[0011] In the capacitor module of the above aspect, the power supply side conductive part provided between the capacitor and the power supply includes a first positive conductor electrically connected to the positive electrode surface of the capacitor and a first negative conductor electrically connected to the negative electrode surface of the capacitor, and the inverter side conductive part provided between the capacitor and the inverter includes a second positive conductor electrically connected to the positive electrode surface of the capacitor and a second negative conductor electrically connected to the negative electrode surface of the capacitor.

[0012] Here, the capacitor module is provided with at least one of a pair of positive side parallel running parts formed by a first positive conductor and a second positive conductor, and a pair of negative side parallel running parts formed by a first negative conductor and a second negative conductor. By running the pair of positive side parallel running parts in parallel so that the current flows in the same direction, or by running the pair of negative side parallel running parts in parallel so that the current flows in the same direction, the magnetic fluxes in these parallel running parts are strengthened. The mutual inductance of the parallel running parts acts to cancel the parasitic inductance of the capacitor, and as a result, the combined inductance can be reduced. At this time, the voltage fluctuations generated in the capacitor due to the influence of the conductive noise transmitted from the inverter side through the conductor are proportional to the combined inductance. Therefore, this capacitor module can suppress the voltage fluctuations generated in the capacitor.

[0013] In the power conversion device according to the above-mentioned alternative embodiment, a capacitor module and an inverter connected to the capacitor module so as to be capable of power conversion are housed in a conductive housing. In the capacitor module, a first conductor is provided so as to extend from an intermediate connection part of a power supply side current conducting part that electrically connects a first smoothing capacitor and a power supply to the power supply side. A second conductor is provided so as to electrically connect a second noise removing capacitor and the intermediate connection part of the power supply side current conducting part. A ground conductor is provided so as to electrically connect the second capacitor and the housing.

[0014] Here, the power supply side parallel running portion provided on the first conductor runs parallel to the ground side parallel running portion provided on at least one of the second conductor and the ground conductor. In this case, when a noise current flows from the housing side to the second capacitor side in the ground side parallel running portion, an induced voltage is generated in the power supply side parallel running portion, and an induced current flows. This induced current flows in the opposite direction to the noise current flowing from the power supply side to the power supply side parallel running portion, thereby reducing the conductive noise on the power supply side.

[0015] In the power converter according to the above-mentioned further embodiment, the capacitor module is provided with a magnetic shielding section. The magnetic shielding section has a function of suppressing a magnetic flux generated by a high-frequency current flowing through the capacitor current path of the first capacitor from flowing in a common-mode current path formed by the second capacitor, the first conductor, the second conductor, the ground conductor, and the housing. This magnetic shielding section makes it possible to prevent noise deterioration due to the influence of inductive coupling caused by mutual inductance when the first capacitor and the second capacitor are arranged close to each other.

[0016] As described above, according to the above-mentioned aspects, it is possible to provide a technique that is effective in suppressing the influence of the conductive noise transmitted from the inverter through the conductor.

[0017] In addition, the symbols in parentheses described in the claims and the means for solving the problems indicate a correspondence with the specific means described in the embodiments described below, and do not limit the technical scope of the present invention. [Brief description of the drawings]

[0018] [Figure 1] FIG. 2 is an electrical circuit diagram of the power conversion device of the first embodiment. [Diagram 2] FIG. 2 is a perspective view of the periphery of a capacitor of the capacitor module of the first embodiment. [Diagram 3] FIG. 11 is a perspective view of the periphery of a capacitor of a capacitor module according to a second embodiment. [Figure 4] FIG. 11 is a perspective view of the periphery of a capacitor of a capacitor module according to a third embodiment. [Diagram 5] FIG. 11 is a perspective view of the periphery of a capacitor of a capacitor module according to a fourth embodiment. [Figure 6] FIG. 11 is an electrical circuit diagram of a power conversion device according to a fifth embodiment. [Figure 7] FIG. 13 is a perspective view of a capacitor module according to a fifth embodiment. [Figure 8] 7 is a diagram for explaining the combined inductance of the conductors of the capacitor module in FIG. 6. [Figure 9]8 is a perspective view showing the capacitor module of FIG. 7 housed in a housing. [Figure 10] FIG. 13 is a perspective view of a capacitor module according to a sixth embodiment. [Figure 11] FIG. 13 is a perspective view of a capacitor module according to a seventh embodiment. [Figure 12] FIG. 13 is a perspective view of a power conversion device according to an eighth embodiment. [Figure 13] FIG. 13 is a side view of the power conversion device of FIG. [Figure 14] 14 is an enlarged side view of a portion of the power converter shown in FIG. 13. [Figure 15] FIG. 15 is a side view showing a modification of the power converter of FIG. [Figure 16] FIG. 13 is a perspective view of a power conversion device according to a ninth embodiment. [Figure 17] FIG. 17 is a side view of the power conversion device of FIG. 16. [Figure 18] FIG. 13 is a perspective view of a power conversion device according to a tenth embodiment. [Figure 19] FIG. 19 is a side view of the power conversion device of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of a power conversion device will be described with reference to the drawings. The present embodiment is typically suitable for use as an in-vehicle power conversion device that is mounted on a vehicle such as an electric vehicle or a hybrid vehicle and performs power conversion between DC power and AC power.

[0020] In this specification, unless otherwise specified, two mutually perpendicular directions along the positive and negative surfaces of the smoothing capacitors constituting the capacitor module are referred to as a first direction X and a second direction Y, and a direction perpendicular to both the first direction X and the second direction Y is referred to as a third direction Z.

[0021] In addition, since the posture of the capacitor module changes depending on the mounting position of the power conversion device, etc., the top and bottom of the capacitor module are not particularly limited. However, for convenience, in Figures 2 to 5, 7, and 9 to 11, the top of the drawings will be referred to as the top of the capacitor module, and the bottom of the drawings will be referred to as the bottom of the capacitor module.

[0022] (Embodiment 1) 1, the power conversion device 100 of the first embodiment is a device for performing power conversion between DC voltage and AC voltage. This power conversion device 100 includes a plurality of elements including a capacitor module 101 provided on the power source 1 side and an inverter 102 as a power conversion unit provided on the motor 2 side, and these elements are housed in a housing (not shown) as a case.

[0023] The capacitor module 101 includes a smoothing capacitor 10 on the power source 1 side, a smoothing capacitor 10 on the inverter 102 side, a power source side conducting section 20 provided between the capacitor 10 and the power source 1, and an inverter side conducting section 30 provided between the capacitor 10 and the inverter 102. The two capacitors 10, 10 are connected in parallel to the power source 1.

[0024] The inverter 102 is a semiconductor module having a plurality of semiconductor elements 102a connected to any of the three-phase electrodes (U-phase, V-phase, W-phase) of the motor 2 as an electric power device. The plurality of semiconductor elements 102a are classified into either upper arm semiconductor elements on the positive electrode side electrically connected to a high potential terminal of the power supply 1, or lower arm semiconductor elements on the negative electrode side electrically connected to a low potential terminal of the power supply 1, and the corresponding upper arm semiconductor elements and lower arm semiconductor elements are connected in series with each other.

[0025] The inverter 102 is controlled so that a plurality of semiconductor elements 102a perform switching operations. For this reason, the semiconductor elements 102a are also called "switching elements" or "semiconductor chips." As the semiconductor elements 102a, any semiconductor element such as an IGBT (i.e., insulated gate bipolar transistor) or a MOSFET (i.e., MOS field effect transistor) is typically used. The number and connection form of the semiconductor elements 102a are not particularly limited, and can be set appropriately as necessary.

[0026] 2, the capacitor 10 on the power source 1 side has a generally cylindrical outer shape, with the upper surface in the figure being the positive electrode surface 11 and the lower surface in the figure being the negative electrode surface 12 extending generally parallel to the positive electrode surface 11. Hereinafter, the capacitor 10 on the power source 1 side will be described simply as "capacitor 10."

[0027] The capacitor 10 has a plurality of outer surfaces extending in the third direction X between the positive electrode surface 11 and the negative electrode surface 12. Each outer surface is an outer surface of the capacitor 10, and may be a flat surface, or may be a curved surface or a stepped surface. The plurality of outer surfaces of the capacitor 10 includes four outer surfaces 13, 14, 15, and 16. The outer surface 13 is a surface of the outer surface of the capacitor 10 on one side in the second direction Y. The outer surface 14 is a surface of the outer surface of the capacitor 10 on one side in the second direction Y parallel to the outer surface 13. The outer surface 15 is a surface of the outer surface of the capacitor 10 on one side in the first direction X. The outer surface 16 is a surface of the outer surface of the capacitor 10 on the other side in the first direction X parallel to the outer surface 15.

[0028] As shown in Figures 1 and 2, the power supply side conductive portion 20 has a first positive electrode conductor 21 electrically connected to the positive electrode surface 11 of the capacitor 10 at one end 21a, and a first negative electrode conductor 22 electrically connected to the negative electrode surface 12 of the capacitor 10 at one end 22a.

[0029] The inverter side conductive section 30 has a second positive electrode conductor 31 electrically connected to the positive electrode surface 11 of the capacitor 10 at one end 31a, and a second negative electrode conductor 32 electrically connected to the negative electrode surface 12 of the capacitor 10 at one end 32a.

[0030] Each of the four conductors 21, 22, 31, and 32 is made of a flat metal member having a rectangular cross section, and is also called a “bus bar.” If necessary, metal wiring having a circular or elliptical cross section may be used instead of the bus bar.

[0031] The capacitor module 101 is characterized by having both a positive electrode side parallel running structure 41 and a negative electrode side parallel running structure 42.

[0032] 2, the positive electrode side parallel structure 41 is a structure in which a pair of positive electrode side parallel running portions 21b, 31b formed by the first positive electrode conductor 21 and the second positive electrode conductor 31 run parallel to each other across a gap 23 in the same current flow direction. In this structure, the lower surface of the positive electrode side parallel running portion 21b and the upper surface of the positive electrode side parallel running portion 31b extend in the same direction and face each other across the gap 23. The pair of positive electrode side parallel running portions 21b, 31b are arranged parallel to each other at positions along the positive electrode surface 11 of the capacitor 10, with the third direction Z being the plate thickness direction and the second direction Y being the plate width direction.

[0033] Similarly, the negative electrode side parallel structure 42 is a structure in which a pair of negative electrode side parallel running portions 22b, 32b of the first negative electrode conductor 22 and the second negative electrode conductor 32 run parallel to each other across a gap 24 in the same current flow direction. In this structure, the upper surface of the first negative electrode conductor 22 and the lower surface of the second negative electrode conductor 32 extend in the same direction and face each other across the gap 24. The pair of negative electrode side parallel running portions 22b, 32b are arranged parallel to each other at a position along the negative electrode surface 12 of the capacitor 10, with the three directions Z being the plate thickness direction and the second direction Y being the plate width direction.

[0034] It is preferable that the gap 23 of the positive electrode side parallel structure 41 and the gap 24 of the negative electrode side parallel structure 42 are both minute gaps of about 1 mm or less. The gap 23 and the gap 24 may have the same dimensions or different dimensions.

[0035] 1, the inverter 102 becomes a noise source and conducts noise during switching operations of the multiple semiconductor elements 102a. At this time, a high-frequency noise current C flows due to a noise voltage generated between the power supply lines. This noise current C flows from the inverter 102 to the power supply 1 side via the capacitor module 101 and circulates to the inverter 102 side. This noise current C is bypassed from the positive side to the negative side in the capacitor 10. Because the outgoing and returning directions of the noise current C between the capacitor module 101 and the power supply 1 are opposite, the conducted noise due to the noise current C at this time is called "normal mode noise (differential mode noise)."

[0036] In FIG. 2, the flow of noise current C around the capacitor 10 is indicated by a solid or dashed line with an arrow.

[0037] In the first positive conductor 21, the noise current C flows from one end 21a to the power source 1 side via the positive side parallel running portion 21b. In the second positive conductor 31, the noise current C flows from the inverter 102 side to the one end 31a via the positive side parallel running portion 31b. In the positive surface 11 of the capacitor 10, the noise current C flows from the one end 31a side of the second positive conductor 31 to the one end 21a side of the first positive conductor 21. That is, in the positive surface 11, the noise current C flows in the opposite direction to the positive side parallel running portions 21b, 31b.

[0038] In the first negative conductor 22, the noise current C flows from the power source 1 side to the one end 22a via the negative side parallel running portion 22b. In the second negative conductor 32, the noise current C flows from the one end 32a to the inverter 102 side via the negative side parallel running portion 32b. In the negative surface 12 of the capacitor 10, the noise current C flows from the one end 22a side of the first negative conductor 22 to the one end 32a side of the second negative conductor 32. That is, in the negative surface 12, the noise current C flows in the opposite direction to the negative side parallel running portions 22b, 32b.

[0039] 1, when the positive pole side parallel structure 41 having the above configuration is represented by an electric circuit, where the mutual inductance of the two conductors 21, 31 is Mp and the parasitic inductance of the capacitor 10 is ESL, the circuit is equivalent to a circuit (T-shaped circuit) in which the mutual inductance Mp is connected to the parasitic inductance ESL with a negative coefficient. According to this positive pole side parallel structure 41, by running the positive pole side parallel portion 21b of the first positive pole conductor 21 and the positive pole side parallel portion 31b of the second positive pole conductor 31 in parallel as described above, it acts to strengthen the magnetic flux generated by the noise current C flowing through the positive pole side parallel portions 21b, 31b.

[0040] Similarly, if the negative electrode side parallel structure 42 configured as above is shown as an electric circuit, then when the mutual inductance of the two conductors 22, 32 is Mn, it becomes a path (T-shaped circuit) equivalent to connecting this mutual inductance Mn with a negative coefficient to the parasitic inductance ESL of the capacitor 10. According to this negative electrode side parallel structure 42, by running the negative electrode side parallel portion 22b of the first negative electrode conductor 22 and the negative electrode side parallel portion 32b of the second negative electrode conductor 32 in parallel as described above, it acts to strengthen the magnetic flux generated by the noise current C flowing in the negative electrode side parallel portions 22b, 32b.

[0041] At this time, the total inductance of this capacitor 10 is the value (ESL-Mp-Mn) obtained by subtracting the mutual inductances Mp, Mn from the value of the parasitic inductance ESL. Therefore, the total inductance can be reduced by an amount equivalent to the mutual inductances Mp, Mn, compared to a case in which the positive electrode side parallel structure 41 and the negative electrode side parallel structure 42 are not provided. In addition, since the voltage fluctuation of the noise voltage Vbat (see FIG. 1) generated between the power supply lines is proportional to the total inductance, this voltage fluctuation can be kept low by reducing the total inductance.

[0042] 2, the pair of positive electrode side parallel running portions 21b, 31b extend in the first direction X and run parallel to each other so as to be substantially perpendicular to the current flowing direction of the third direction Z in the capacitor 10 from the positive electrode surface 11 side to the negative electrode surface 12 side. Similarly, the pair of negative electrode side parallel running portions 22b, 32b extend in the first direction X and run parallel to each other so as to be substantially perpendicular to the current flowing direction of the third direction Z. This makes it possible to prevent the magnetic flux generated in the positive electrode side parallel running portions 21b, 31b and the negative electrode side parallel running portions 22b, 32b from being weakened by the magnetic flux generated when the noise current C flows in the capacitor 10.

[0043] In addition, the term "substantially perpendicular" as used here refers not only to a configuration in which the parallel running directions of the pair of positive electrode side parallel running portions 21b, 31b and the pair of negative electrode side parallel running portions 22b, 32b are completely perpendicular to the current flow direction in the capacitor 10, but also to a configuration in which this orthogonal relationship is slightly shifted and the parallel running directions are approximately perpendicular.

[0044] In the above-mentioned capacitor module 101, in order to ensure reliability such as vibration resistance, a configuration can be adopted in which the first positive conductor 21 and the first negative conductor 22 are electrically connected in the vicinity of the capacitor 10, and the second positive conductor 31 and the second negative conductor 32 are electrically connected in the vicinity of the capacitor 10.

[0045] According to the above-described first embodiment, it is possible to suppress the voltage fluctuation occurring in the capacitor 10 of the capacitor module 101. Therefore, it is possible to suppress the influence of the conductive noise transmitted from the inverter 102 through the conductor, that is, the normal mode noise.

[0046] In a modification related to the first embodiment, only one of the pair of positive electrode side parallel running portions 21b, 31b and the pair of negative electrode side parallel running portions 22b, 32b may be provided so as to be substantially perpendicular to the current flow direction in the capacitor 10.

[0047] Next, other embodiments 2 to 4 related to the above-mentioned embodiment 1 will be described with reference to the drawings. In these embodiments 2 to 4, the same elements as those in embodiment 1 are given the same reference numerals, and the description of the same elements will be omitted.

[0048] (Embodiment 2) As shown in FIG. 3, the power converter 200 of the second embodiment differs from the capacitor module 101 of the first embodiment in the arrangement of the four conductors 21, 22, 31, and 32 in the capacitor module 201.

[0049] The capacitor module 201 has a capacitor 10 having the same structure as in the first embodiment. In this capacitor module 201, a pair of positive electrode side parallel running portions 21b, 31b constituting a positive electrode side parallel running structure 41 face one outer surface 13 of the capacitor 10, and run parallel to each other across a gap 23 so that the current flows in the same direction. At this time, the side surface of the positive electrode side parallel running portion 21b and the side surface of the positive electrode side parallel running portion 31b face each other across the gap 23. The pair of positive electrode side parallel running portions 21b, 31b are arranged parallel to each other at a position below the positive electrode surface 11 in the third direction Z, with the third direction Z being the plate width direction and the second direction Y being the plate thickness direction.

[0050] Similarly, a pair of negative electrode side parallel running portions 22b, 32b constituting the negative electrode side parallel running structure 42 face one outer surface 13 of the capacitor 10, and run parallel to each other across a gap 23 so that the current flows in the same direction. At this time, the side surface of the negative electrode side parallel running portion 22b and the side surface of the negative electrode side parallel running portion 32b face each other across a gap 24. The pair of negative electrode side parallel running portions 22b, 32b are disposed parallel to each other at a position above the negative electrode surface 12 in the third direction Z, with the third direction Z being the plate width direction and the second direction Y being the plate thickness direction.

[0051] The other configurations are the same as those in the first embodiment.

[0052] Since the noise current C flows in the positive electrode surface 11 of the capacitor 10 in the opposite direction to the positive electrode side parallel running portions 21b, 31b, when the positive electrode side parallel running portions 21b, 31b approach the positive electrode surface 11, this hinders the effect of strengthening the magnetic flux generated by the noise current C flowing in the positive electrode side parallel running portions 21b, 31b. Similarly, since the noise current C flows in the negative electrode surface 12 of the capacitor 10 in the opposite direction to the negative electrode side parallel running portions 22b, 32b, when the negative electrode side parallel running portions 22b, 32b approach the negative electrode surface 12, this hinders the effect of strengthening the magnetic flux generated by the noise current C flowing in the negative electrode side parallel running portions 22b, 32b.

[0053] Therefore, in the second embodiment, the pair of positive electrode side parallel running portions 21b, 31b of the two conductors 21, 31 are opposed to the outer surface 13 of the capacitor 10, so that they can be separated from the positive electrode surface 11. Also, the pair of negative electrode side parallel running portions 22b, 32b of the two conductors 22, 32 are opposed to the outer surface 13 of the capacitor 10, so that they can be separated from the negative electrode surface 12.

[0054] By having the four parallel running portions 21b, 31b, 22b, and 32b of the four conductors 21, 22, 31, and 32 face the same outer side surface 13 of the capacitor 10, when capacitors 10 of the same shape are used, the effect of strengthening the magnetic flux can be prevented from being hindered compared to embodiment 1. Also, the capacitor module 201 can be prevented from becoming large in size in the third direction Z.

[0055] In addition, the same effects as those of the first embodiment are achieved.

[0056] (Embodiment 3) As shown in FIG. 4, a power converter 300 according to the third embodiment differs from the capacitor module 201 according to the second embodiment in the arrangement of the conductors 22, 32 in the capacitor module 301.

[0057] In this capacitor module 301, a pair of negative electrode side parallel running portions 22b, 32b constituting the negative electrode side parallel running structure 42 are arranged parallel to each other along one outer surface 14 of the capacitor 10. That is, the pair of negative electrode side parallel running portions 22b, 32b are provided facing another outer surface 14 on the opposite side to the outer surface 13 to which the pair of positive electrode side parallel running portions 21b, 31b constituting the positive electrode side parallel running structure 41 face. In addition, the pair of negative electrode side parallel running portions 22b, 32b are provided in diagonal positions relative to the pair of positive electrode side parallel running portions 21b, 31b.

[0058] The other configurations are the same as those in the second embodiment.

[0059] According to the third embodiment, the pair of positive side parallel running portions 21b, 31b and the pair of negative side parallel running portions 22b, 32b, in which the noise currents C flow in opposite directions, can be spaced apart from each other. This makes it possible to prevent the effect of strengthening the magnetic flux in each of the pair of positive side parallel running portions 21b, 31b and the pair of negative side parallel running portions 22b, 32b from being hindered.

[0060] In addition, the same effects as those of the second embodiment are achieved.

[0061] (Embodiment 4) As shown in FIG. 5, a power converter 400 of the fourth embodiment differs from the capacitor module 101 of the first embodiment in the arrangement of the four conductors 21, 22, 31, and 32 in a capacitor module 401.

[0062] In this capacitor module 401, a pair of positive electrode side parallel running portions 21b, 31b constituting the positive electrode side parallel running structure 41 are provided facing the three outer surfaces 13, 15, 16 of the capacitor 10. The pair of positive electrode side parallel running portions 21b, 31b are arranged parallel to each other with the third direction Z as the plate width direction and the first direction X or the second direction Y as the plate thickness direction. In addition, a pair of negative electrode side parallel running portions 22b, 32b constituting the negative electrode side parallel running structure 42 are provided facing one outer surface 14 of the capacitor 10. The pair of negative electrode side parallel running portions 22b, 32b are arranged parallel to each other with the third direction Z as the plate width direction and the second direction Y as the plate thickness direction. Each of the pair of positive electrode side parallel running portions 21b, 31b is substantially U-shaped when viewed from the third direction Z, and is configured so that the parallel running length thereof exceeds the parallel running length of the pair of negative electrode side parallel running portions 22b, 32b.

[0063] The other configurations are the same as those in the first embodiment.

[0064] According to the fourth embodiment, the mutual inductance of the pair of positive electrode side parallel running parts 21b, 31b is larger than that in the case where the pair of positive electrode side parallel running parts 21b, 31b faces one or two outer surfaces, thereby enhancing the effect of reducing the combined inductance of the capacitor 10.

[0065] It is preferable to set the distance between the pair of positive electrode side parallel running portions 21b, 31b and the three outer sides 13, 15, 16 of capacitor 10 as small as possible. This makes it possible to prevent capacitor module 401 from becoming large.

[0066] In addition, the same effects as those of the first embodiment are achieved.

[0067] In a modified example particularly related to the above-mentioned embodiment 4, a configuration in which a pair of negative electrode side parallel running portions 22b, 32b are opposed to each other along two or four outer surfaces, or a configuration in which a pair of positive electrode side parallel running portions 21b, 31b have a structure similar to that of the pair of negative electrode side parallel running portions 22b, 32b, can be adopted.

[0068] In the above-described first to fourth embodiments, the capacitor modules 101, 201, 301, and 401 are illustrated as having both the positive electrode side parallel running structure 41 and the negative electrode side parallel running structure 42, but as necessary, they may be provided with only one of the positive electrode side parallel running structure 41 and the negative electrode side parallel running structure 42. In other words, the structure in which two conductors run parallel to each other can be applied to only one of the positive electrode side and the negative electrode side.

[0069] (Embodiment 5) 6, the power conversion device 500 of the fifth embodiment includes a plurality of elements including a capacitor module 501 provided on the power source 1 side and an inverter 502 provided on the motor 2 side, and these plurality of elements are housed in a housing 3 serving as a case. The inverter 502 is a semiconductor module having a plurality of semiconductor elements 502a connected to electrodes of any of the three phases (U-phase, V-phase, and W-phase) of the motor 2 serving as a power device, and is connected to the capacitor module 501 so as to be capable of power conversion. The housing 3 is typically made of a metal material having electrical conductivity, and is grounded to the ground GND.

[0070] 6 and 7, the capacitor module 501 has a plurality of first smoothing capacitors 10A connected in parallel to each other on the inverter 502 side, two second capacitors 10P, 10N for noise removal, first conductors 51P, 51N, intermediate conductors 52P, 52N, second conductors 61P, 61N, and a ground conductor 62. The first capacitors 10A are also referred to as "X capacitors," and the second capacitors 10P, 10N are also referred to as "Y capacitors."

[0071] The first conductors 51P, 51N are conductors that extend from intermediate terminals 50P, 50N serving as intermediate connection parts between the first capacitor 10A and the power source 1 to the power source 1 side of the current-carrying part 50 that electrically connects the first capacitor 10A and the power source 1. The first conductor 51P is a conductor on the positive electrode side of the current-carrying part 50, and the first conductor 51N is a conductor on the negative electrode side of the current-carrying part 50.

[0072] The intermediate conductors 52P, 52N are conductors that electrically connect the first capacitor 10A to the intermediate terminals 50P, 50N of the current-carrying unit 50. The intermediate conductor 52P is a conductor on the positive electrode side of the current-carrying unit 50, and the intermediate conductor 52N is a conductor on the negative electrode side of the current-carrying unit 50.

[0073] The second conductors 61P, 61N are conductors that electrically connect the second capacitors 10P, 10N to the intermediate terminals 50P, 50N of the current-carrying unit 60 that electrically connects the intermediate terminals 50P, 50N to the housing 3. The second conductor 61P is a conductor on the positive electrode side of the current-carrying unit 60, and the second conductor 61N is a conductor on the negative electrode side of the current-carrying unit 60. When the intermediate terminals 50P, 50N are used as starting points, the second conductors 61P, 61N extend from the intermediate terminals 50P, 50N in a direction approaching the power source 1.

[0074] The ground conductor 62 is a conductor that electrically connects the second capacitors 10P, 10N of the current-carrying unit 60 to the housing 3. The ground conductor 62 is disposed at a position closer to the power source 1 than the second conductors 61P, 61N and is spaced apart from the second conductors 61P, 61N.

[0075] 7, each of these conductors 51P, 51N, 52P, 52N, 61P, and 61N is made of a flat metal member having a rectangular cross section, and is also called a “bus bar.” If necessary, metal wiring having a circular or elliptical cross section may be used instead of the bus bar.

[0076] In this embodiment, a part of the first conductor 51P, 51N is configured to run parallel to the second conductor 61P, 61N and also parallel to the ground conductor 62. At this time, the first conductor 51P, 51N is provided with the power supply side parallel running parts 51a, 51b. The second conductor 61P, 61N is provided with the ground side parallel running parts 61a, 61b running parallel to the power supply side parallel running parts 51a, 51b. The ground conductor 62 is further provided with the ground side parallel running part 62a running parallel to the power supply side parallel running parts 51a, 51b, and the connection part 62b extending between the ground side parallel running part 62a and the housing 3. That is, the power supply side parallel running parts 51a, 51b extend in the same direction as the ground side parallel running parts 61a, 61b, 62a. The power supply side parallel running portions 51a, 51b and the ground side parallel running portions 61a, 61b, 62a all extend along a plane defined by the first direction X and the second direction Y. In the ground conductor 62 of this embodiment, the ground side parallel running portion 62a is made of a flat metal member having a rectangular cross section, and the connection portion 62b is made of a rod-shaped metal member having a circular cross section.

[0077] In the electric circuit shown in Fig. 6, the inverter 502 acts as a noise source and conducts noise. At this time, a noise current C leaking through the floating electrostatic capacitance of the motor 2 returns to the power supply line via the ground GND. The flow of the noise current C is indicated by a solid line with an arrow. Because the direction of the noise current C flowing on the positive and negative sides of the power supply 1 is the same, the conducted noise at this time is called "common mode noise."

[0078] In each of the first conductors 51P, 51N, the noise current C flows from the power supply 1 side to the inverter 502 side. In each of the second conductors 61P, 61N, the noise current C flows from the power supply 1 side to the inverter 502 side. In each of the second conductors 61P, 61N, the noise current C flows from the second capacitors 10P, 10N side to the intermediate terminals 50P, 50N side. In the ground conductor 62, the noise current C flows from the housing 3 side to the second capacitors 10P, 10N side.

[0079] Here, if a part of the conducted noise conducted from the housing 3 to the ground conductor 62 is conducted to the power source 1, it may cause a deterioration of the noise environment. Therefore, in this embodiment, a structure is adopted in which the ground side parallel parts 61a, 61b, 62a of the second conductors 61P, 61N and the ground conductor 62 run parallel to the power source side parallel parts 51a, 51b so that an induced current D in the opposite direction to the noise current C is generated in the power source side parallel parts 51a, 51b of the first conductors 51P, 51N. According to this structure, the noise current C flows in the ground side parallel parts 61a, 61b, 62a, so that an induced current in the opposite direction to the noise current C can flow in the power source side parallel parts 51a, 51b. In FIG. 6, the flow of the induced current D is indicated by a dashed line with an arrow.

[0080] 7, the lower surface of the power supply side parallel running portion 51a and the upper surface of the ground side parallel running portion 61a face each other, and the lower surface of the power supply side parallel running portion 51b and the upper surface of the ground side parallel running portion 61b face each other. The lower surfaces of the power supply side parallel running portions 51a, 51b face each other, and the upper surface of the ground side parallel running portion 62a face each other. Furthermore, the second capacitor 10P runs parallel to the power supply side parallel running portion 51a in the current flow direction (first direction X), and the second capacitor 10N runs parallel to the power supply side parallel running portion 51b in the current flow direction (first direction X).

[0081] It is preferable that the power supply side parallel running portions 51a, 51b and the ground side parallel running portions 61a, 61b, 62a run parallel to be substantially perpendicular to the current flow direction (see the arrow in FIG. 7) from the positive electrode surface 11 to the negative electrode surface 12 of the first capacitor 10A. This makes it possible to prevent the magnetic flux generated by the relatively large high-frequency current flowing through the first capacitor 10A from disturbing the magnetic flux generated in the power supply side parallel running portions 51a, 51b and the ground side parallel running portions 61a, 61b, 62a. This makes it possible to ensure mutual inductance between the power supply side parallel running portions 51a, 51b and the ground side parallel running portions 61a, 61b, 62a.

[0082] In addition, the term "substantially perpendicular" as used here refers not only to a configuration in which the parallel running directions of the power supply side parallel running portions 51a, 51b and the ground side parallel running portions 61a, 61b, 62a are completely perpendicular to the current flow direction in the first capacitor 10A, but also to a configuration in which this orthogonal relationship is slightly shifted, that is, approximately perpendicular.

[0083] 7, the intermediate conductor 52N has an opposing wiring portion 52b arranged to face the opposing surface 17 of the first capacitor 10A located on the second capacitor 10P, 10N side. The opposing wiring portion 52b is configured as a magnetic shield portion that suppresses magnetic flux generated by a high-frequency current flowing through the capacitor current path of the first capacitor 10A from flowing in linkage with the common-mode current path formed by the second capacitor 10P, 10N, the first conductors 51P, 51N, the second conductors 61P, 61N, the ground conductor 62, and the housing 3. This configuration makes it possible to prevent noise from worsening due to the influence of inductive coupling caused by mutual inductance when the first capacitor 10A and the second capacitors 10P, 10N are arranged closely to each other.

[0084] 8, in a capacitor module 501, a combined inductance of power supply side parallel running parts 51a, 51b of first conductors 51P, 51N is defined as L1. A combined inductance of second capacitors 10P, 10N, second conductors 61P, 61N and ground side parallel running parts 61a, 61b, 62a of a ground conductor 62, and a connection part 62b of the ground conductor 62 is defined as L2. At this time, a mutual inductance M is formed by the combined inductances L1 and L2 running in parallel.

[0085] Here, when the current flowing through the composite inductance L2 is i, an induced voltage (=M×(di / dt)) is generated in the composite inductance L1, which is expressed by the product of the mutual inductance M and the change in current i over time, and an induced current D flows. Since the direction of the induced current D is opposite to the direction of conduction of the conductive noise due to the noise current C, common mode noise, which is the conductive noise of the power supply 1, is reduced. This makes it possible to suppress the effects of the conductive noise (common mode noise) transmitted from the inverter 502 through the conductor.

[0086] In particular, the capacitor module 501 has a structure in which the ground side parallel running portions 61a, 61b, 62a run parallel to the power supply side parallel running portions 51a, 51b, and in addition, the second capacitors 10P, 10N run parallel to the power supply side parallel running portions 51a, 51b in the current flow direction, thereby enhancing the effect of reducing common mode noise.

[0087] On the other hand, if necessary, at least one of the following parallel structures can be adopted: a parallel structure in which the ground side parallel running portions 61a, 61b run parallel to the power supply side parallel running portions 51a, 51b; a parallel structure in which the ground side parallel running portion 62a runs parallel to the power supply side parallel running portions 51a, 51b; and a parallel structure in which the second capacitors 10P, 10N run parallel to the power supply side parallel running portions 51a, 51b in the current flow direction.

[0088] As shown in FIG. 6, the effect of reducing the conducted noise according to the fifth embodiment can be evaluated by, for example, measuring the conducted noise at a noise evaluation point E set in the vicinity of the power source 1.

[0089] In the above-mentioned embodiment 5, as shown in Fig. 9, the second capacitors 10P, 10N are preferably interposed between the power supply side parallel running parts 51a, 51b and the ground side parallel running parts 61a, 61b, 62a and the housing 3. In the third direction Z, the ground side parallel running parts 61a, 61b, 62a are arranged below the power supply side parallel running parts 51a, 51b, and the second capacitors 10P, 10N are arranged below the ground side parallel running parts 61a, 61b, 62a. The second capacitors 10P, 10N are arranged opposite to each other with a space between them and the bottom surface 3a of the housing 3. This makes it possible to prevent the housing 3, which is a conductor, from being arranged near the power supply side parallel running parts 51a, 51b and the ground side parallel running parts 61a, 61b, 62a, and to suppress a decrease in the mutual inductance M between the combined inductance L1 and the combined inductance L2.

[0090] In addition, as long as the space between the power supply side parallel running portions 51a, 51b and the ground side parallel running portions 61a, 61b, 62a and the housing 3 is sufficient to suppress a decrease in mutual inductance M, the arrangement of the second capacitors 10P, 10N is not limited to that shown in Figure 7 and can be changed as appropriate.

[0091] Next, other embodiments 6 to 10 related to the above-mentioned embodiment 5 will be described with reference to the drawings. In these embodiments 6 to 10, the same elements as those in embodiment 1 are given the same reference numerals, and the description of the same elements will be omitted.

[0092] (Embodiment 6) 10, a power conversion device 600 of the sixth embodiment differs from that of the fifth embodiment in that a capacitor module 601 has a magnetic shielding component 53. The magnetic shielding component 53 is interposed between the first capacitor 10A and the second capacitors 10P, 10N in the first direction X. A metal-containing component such as a discharge resistor can typically be used as the magnetic shielding component 53.

[0093] The other configurations are the same as those in the fifth embodiment.

[0094] According to the sixth embodiment, the magnetic flux generated by the high-frequency current (see the arrow in FIG. 10) flowing through the first capacitor 10A in the third direction Z can be shielded from the second capacitors 10P, 10N by the magnetic shield component 53. This makes it possible to prevent the magnetic flux generated on the first capacitor 10A side from interfering with the magnetic flux generated by the current flowing through the power supply side parallel running portions 51a, 51b and the ground side parallel running portions 61a, 61b, 62a. As a result, it becomes possible to ensure the mutual inductance M.

[0095] In addition, the same effects as those of the fifth embodiment are achieved.

[0096] If the magnetic shielding function provided by magnetic shielding part 53 can be achieved by another element, or if the effect of the magnetic flux generated on the first capacitor 10A side is small, magnetic shielding part 53 may be omitted as necessary.

[0097] (Embodiment 7) 11, the power conversion device 700 of the seventh embodiment differs from that of the fifth embodiment in the arrangement of the second capacitors 10P, 10N. In the capacitor module 701 of the power conversion device 700, the second capacitors 10P, 10N are arranged rotated by 90° compared to the first embodiment.

[0098] The other configurations are the same as those in the fifth embodiment.

[0099] According to the seventh embodiment, the arrangement of the second capacitors 10P and 10N can be changed as necessary.

[0100] In addition, the same effects as those of the fifth embodiment are achieved.

[0101] (Embodiment 8) 12, the power converter 800 of the eighth embodiment is a more specific embodiment of a structure related to the opposing wiring part 52b as a magnetic shield part provided in the power converter 500 of the fifth embodiment. The power converter 800 includes a capacitor module 801, an inverter 502 connected to the capacitor module 801 so as to be capable of power conversion, and a conductive housing 3 that houses the capacitor module 801 and the inverter 502.

[0102] Similar to the capacitor module 501 of embodiment 5, the capacitor module 801 includes a plurality of first capacitors 10A, second capacitors 10P, 10N, first conductors 51P, 51N, intermediate conductors 52P, 52N, second conductors 61P, 61N, a ground conductor 62, and an opposing wiring portion 52b.

[0103] The ground conductor 62 has a flat ground-side parallel portion 62a with the third direction Z as its plate thickness direction, and a connection portion 62b extending in the third direction Z. The capacitor module 801 has an opening A surrounded by the second capacitors 10P, 10N, the first conductors 51P, 51N, the intermediate conductors 52P, 52N, the second conductors 61P, 61N, the ground conductor 62, and the housing 3.

[0104] The opposing wiring part 52b is a plate-shaped part formed of a part of the intermediate conductor 52N, and has a plate thickness direction in the first direction X. The opposing wiring part 52b is arranged to face the opposing surface 17 of each of the first capacitors 10A located on the second capacitors 10P, 10N side in the first direction X. That is, when each of the first capacitors 10A is viewed from the second capacitors 10P, 10N side, the opposing surface 17 of each of the first capacitors 10A is shielded by the opposing wiring part 52b. The opposing wiring part 52b is configured such that its plate width in the second direction Y exceeds the distance between the outer edge of the first conductor 51P and the outer edge of the first conductor 51N. In contrast, the outer surfaces 18, which are the side surfaces of each of the two first capacitors 10A arranged on the outside in the second direction Y, and are different from the opposing surfaces 17, are exposed.

[0105] The inverter 502 includes a collector terminal 54P electrically connected to the intermediate conductor 52P, an emitter terminal 54N electrically connected to the intermediate conductor 52N, and an output terminal 54O. A DC voltage is applied to the inverter 502 via the collector terminal 54P and the emitter terminal 54N, and AC power is output from the inverter 502 via the output terminal 54O. The inverter 502 has an opposing surface 502b that faces the opening A in the second direction Y.

[0106] 13, a height H of the opening A in the third direction Z is defined as the height in the third direction Z between the first conductors 51P, 51N and the housing 3. The opposing surfaces 17 of each first capacitor 10A are disposed within the range of this height H, and the entire surface thereof is shielded from the second capacitors 10P, 10N by the opposing wiring portion 52b. The capacitor module 801 has a first opening surface S1 defined by a common-mode current path B2 described later.

[0107] The other configurations are the same as those in the fifth embodiment.

[0108] 14, the capacitor current path B1 is a current path through which a high-frequency current flows inside each first capacitor 10A downward in the third direction Z. The common-mode current path B2 is a current path formed by the second capacitors 10P, 10N, the first conductors 51P, 51N, the second conductors 61P, 61N, the ground conductor 62, and the housing 3.

[0109] Here, the high-frequency current flowing through the capacitor current-carrying path B1 generates magnetic flux (see the two-dot chain line arrow in FIG. 14) therearound. At this time, the opposing wiring portion 52b of the intermediate conductor 52N faces the opposing surface 17 of each first capacitor 10A. The opposing wiring portion 52b is made of a metal member having magnetic shielding performance. This makes it possible to prevent the magnetic flux generated by the high-frequency current flowing through the capacitor current-carrying path B1 from linking with and flowing through the common-mode current-carrying path B2.

[0110] Note that "flowing in an interlinked manner" here refers to a manner in which the magnetic flux flows while crossing the first opening surface S1, and typically refers to a manner in which at least a portion of the magnetic flux flows in a direction normal to the first opening surface S1.

[0111] In particular, as in this embodiment, it is preferable that the opposing wiring portion 52b of the intermediate conductor 52N is configured so that a high-frequency current flows in the opposite direction to the high-frequency current flowing through the capacitor current-carrying path B1. This allows the magnetic flux generated by the high-frequency current flowing downward in the capacitor current-carrying path B1 in Fig. 14 and the magnetic flux generated by the high-frequency current flowing upward in the opposing wiring portion 52b in Fig. 14 to cancel each other out. This is effective in reducing the magnetic flux that flows in linkage with the common-mode current-carrying path B2 due to the influence of the high-frequency current flowing through the capacitor current-carrying path B1.

[0112] On the other hand, in the case of a structure in which the opposing wiring portion 52b of the intermediate conductor 52N does not face the opposing surface 17 of each first capacitor 10A, magnetic flux leaking from the opposing surface 17 of each first capacitor 10A flows across the first opening surface S1 defined by the common mode current path B2. This can cause a noise current C to be generated in the common mode current path B2 by electromagnetic induction. Therefore, by adopting a structure in which the opposing wiring portion 52b is disposed facing the opposing surface 17 as in this embodiment, the amount of magnetic flux that flows in a linkage manner across the first opening surface S1 due to the influence of the high-frequency current flowing through the capacitor current path B1 can be reduced, and the generation of common mode noise (see "common mode noise" described in the fifth embodiment) in the common mode current path B2 can be suppressed.

[0113] In addition, the same effects as those of the fifth embodiment are achieved.

[0114] As shown in Fig. 15, in a modification particularly related to the power converter 800 of the eighth embodiment, in addition to providing the opposing wiring portion 52b in the intermediate conductor 52N, the opposing wiring portion 52a is provided in the intermediate conductor 52P. The opposing wiring portion 52a of the intermediate conductor 52P faces the upper region in the third direction Z of the opposing surface 17 of each first capacitor 10A, and the opposing wiring portion 52b of the intermediate conductor 52N faces the remaining lower region in the third direction Z of the opposing surface 17 of each first capacitor 10A. That is, the two intermediate conductors 52P and 52N form the opposing wiring portions 52a and 52b facing the opposing surface 17 of each first capacitor 10A. In both the opposing wiring portion 52a and the opposing wiring portion 52b, the high-frequency current flows upward in Fig. 15, which is opposite to the direction of the high-frequency current flowing through the capacitor current path B1.

[0115] In this configuration as well, the same effects as those in the case of the structure in which only the opposing wiring portion 52b of the intermediate conductor 52N is disposed so as to face the entire surface of the opposing surface 17 of each first capacitor 10A can be obtained. In another modified example, only the opposing wiring portion 52a of the intermediate conductor 52P may be disposed so as to face the entire surface of the opposing surface 17 of each first capacitor 10A.

[0116] (Embodiment 9) 16 and 17, a power conversion device 900 of the ninth embodiment includes a capacitor module 901, an inverter 502 connected to the capacitor module 901 so as to be capable of power conversion, and a conductive housing 3 that houses the capacitor module 901 and the inverter 502. The power conversion device 900 differs in structure from the power conversion device 800 of the eighth embodiment only in that the power conversion device 900 includes a covering member 55 and an inverter magnetic shield unit 56.

[0117] In the power conversion device 900, the covering member 55 is provided to cover the outer surfaces 18 of the first capacitors 10A on both sides in the second direction Y. The covering member 55 has a function of suppressing leakage magnetic flux leaking from the outer surfaces 18 of the first capacitors 10A. To achieve this function, the covering member 55 is made of a material having magnetic shielding performance. Typically, the covering member 55 is preferably made of a ferromagnetic material that absorbs magnetic flux. The covering member 55 can suppress leakage magnetic flux leaking from the outer surfaces 18 of the first capacitors 10A from linking with and flowing through the common mode current path B2 (see FIG. 17) of the capacitor module 901. The covering member 55 may be electrically connected to the intermediate conductor 52P or the intermediate conductor 52N.

[0118] In the power conversion device 900, the inverter magnetic shield section 56 is provided on an opposing surface 502b of the inverter 502 that faces the common mode current path B2. This inverter magnetic shield section 56 performs two functions. The first function is a magnetic shield function that suppresses a magnetic flux generated by a high frequency current flowing through the inverter 502 from flowing in linkage with the common mode current path B2 of the capacitor module 901. The second function is a cooling function that cools the inverter 502. That is, the inverter magnetic shield section 56 also serves as a cooler that cools the inverter 502. In order to achieve these two functions, the inverter magnetic shield section 56 is made of a material that has magnetic shielding performance and high thermal conductivity.

[0119] The other configurations are the same as those in the eighth embodiment.

[0120] Inside the inverter 502, an inverter current path B3 is formed through which a high-frequency current flows from the emitter terminal 54N to the collector terminal 54P via the output terminal 54O. A magnetic flux (see the two-dot chain line arrow in FIG. 17) is generated by the high-frequency current flowing through the inverter current path B3. At this time, since the inverter magnetic shield part 56 is provided on the facing surface 502b of the inverter 502, the amount of magnetic flux that flows in a linkage manner across the first opening surface S1 due to the influence of the high-frequency current flowing through the inverter current path B3 can be reduced, and the generation of common mode noise in the common mode current path B2 can be suppressed. In addition, heat generated in the inverter 502 moves to the inverter magnetic shield part 56 side by thermal conduction and is dissipated from the inverter magnetic shield part 56. This makes it possible to cool the inverter 502 by the inverter magnetic shield part 56. The inverter magnetic shield part 56 may be electrically connected to the housing 3.

[0121] According to the power conversion device 900 of the ninth embodiment, the inverter magnetic shield section 56 also functions to cool the inverter 502, making it possible to keep the size of the device small and the cost of the device low.

[0122] In addition, the same effects as those of the eighth embodiment are achieved.

[0123] In a modification particularly related to the power conversion device 900 of the ninth embodiment, a structure can be adopted in which either the covering member 55 or the inverter magnetic shield portion 56 is omitted. In another modification, a cooling structure can be adopted in which a refrigerant flow path through which a cooling medium flows is provided in the inverter magnetic shield portion 56. This makes it possible to improve the cooling effect for cooling the inverter 502.

[0124] (Embodiment 10) 18 and 19, a power conversion device 1000 of the tenth embodiment includes a capacitor module 1001, an inverter 502 connected to the capacitor module 1001 so as to be capable of power conversion, and a conductive housing 3 that houses the capacitor module 1001 and the inverter 502. This power conversion device 1000 differs from the power conversion device 800 of the eighth embodiment only in the relative position between the common mode current path B2 (see FIG. 19) of the capacitor module 1001 and the inverter 502.

[0125] As shown in Fig. 19, in the power conversion device 1000, the inverter 502 has a second opening surface S2 defined by an inverter current path B3 through which a high-frequency current flows. The second opening surface S2 extends along a first opening surface S1 defined by a common-mode current path B2. Here, the capacitor module 1001 and the inverter 502 are arranged such that the first opening surface S1 and the second opening surface S2 do not overlap with each other in a second direction Y that is a linkage direction with respect to the common-mode current path B2. That is, when the power conversion device 1000 is viewed in the second direction Y, the first opening surface S1 and the second opening surface S2 are arranged at a distance from each other in the first direction X and are configured not to overlap with each other.

[0126] The other configurations are the same as those in the eighth embodiment.

[0127] According to the power conversion device 1000 of the tenth embodiment, when a magnetic flux (see solid arrows in FIG. 19) is generated by a high-frequency current flowing through the inverter current path B3 of the inverter 502, it is possible to prevent the magnetic flux from flowing in a linkage manner across the first opening surface S1. As a result, it is possible to suppress the generation of common-mode noise in the common-mode current path B2.

[0128] In addition, the same effects as those of the eighth embodiment are achieved.

[0129] In a modification particularly related to the power conversion device 1000 of the tenth embodiment, a structure in which at least one of the covering member 55 and the inverter magnetic shield part 56 of the power conversion device 900 of the ninth embodiment is added can be adopted. This makes it possible to enhance the effect of suppressing the occurrence of common-mode noise in the common-mode current path B2.

[0130] The present invention is not limited to the exemplary embodiment described above, and various applications and modifications are possible without departing from the scope of the present invention. For example, the following embodiments can be implemented by applying the above-described embodiment.

[0131] Any one of the above-mentioned embodiments 1 to 4 can be combined with any one of the above-mentioned embodiments 5 to 10. This makes it possible to suppress both normal mode noise and common mode noise.

[0132] In the above-described embodiment, a power conversion device for a vehicle is described as an example, but the use of this power conversion device is not limited to vehicles, and it is of course also applicable to power conversion devices mounted on equipment other than vehicles. [Explanation of symbols]

[0133] 1...power supply, 3...casing, 10...capacitor, 10A...first capacitor, 10P, 10N...second capacitor, 11...positive electrode surface, 12...negative electrode surface, 13, 14, 15, 16...outer surface, 17...opposing surface, 18...side surface (outer surface other than the opposing surface), 20...power supply side conductive portion, 21...first positive electrode conductor, 21b, 31b...pair of positive electrode side parallel portions, 22...first negative electrode conductor, 2 2b, 32b...pair of negative pole side parallel running portions, 30...inverter side current conducting portion, 31...second positive pole conductor, 32...second negative pole conductor, 50...power supply side current conducting portion, 50P, 50N...intermediate terminal (intermediate connection portion), 51a, 51b...power supply side parallel running portion, 51P, 51N...first conductor, 52P, 52N...intermediate conductor, 52a, 52b...opposing wiring portion (magnetic shield portion), 53...magnetic shield conductor (magnetic shielding portion), 55...coating member (magnetic shielding portion), 56...inverter magnetic shielding portion (magnetic shielding portion), 61a, 61b...ground side parallel portion, 61P, 61N...second conductor, 62...ground conductor, 62a...ground side parallel portion, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000...power conversion device, 101, 201, 301, 401, 501, 601, 701, 801, 901, 1001...capacitor module, 102, 502...inverter, 502b...opposing surface, B1...capacitor current path, B2...common mode current path, B3...inverter current path, S1...first current path surface, S2...second current path surface, Y...second direction (interlinkage direction)

Claims

1. A capacitor (10); a power supply side conducting portion (20) provided between the capacitor and the power supply (1); an inverter-side current-carrying unit (30) provided between the capacitor and an inverter (102); the power supply side conductive portion has a first positive conductor (21) electrically connected to a positive electrode surface (11) of the capacitor, and a first negative conductor (22) electrically connected to a negative electrode surface (12) of the capacitor, the inverter side conductive portion has a second positive conductor (31) electrically connected to the positive electrode surface of the capacitor, and a second negative conductor (32) electrically connected to the negative electrode surface of the capacitor, at least one of a pair of positive side parallel running portions (21b, 31b) running in parallel such that the current flows in the same direction in the first positive conductor and the second positive conductor, and a pair of negative side parallel running portions (22b, 32b) running in parallel such that the current flows in the same direction in the first negative conductor and the second negative conductor, The capacitor has a plurality of outer surfaces (13, 14, 15, 16) extending between the positive and negative electrode surfaces; At least one of the pair of positive electrode side parallel running portions and the pair of negative electrode side parallel running portions is provided opposite at least one of the plurality of outer surfaces of the capacitor.

2. 2. The capacitor module according to claim 1, wherein the pair of positive electrode side parallel running portions are arranged opposite one of the plurality of outer surfaces of the capacitor, and the pair of negative electrode side parallel running portions are arranged opposite one outer surface other than the outer surface opposite to which the pair of positive electrode side parallel running portions face, and are arranged in a diagonal position relative to the pair of positive electrode side parallel running portions.

3. 2. The capacitor module according to claim 1, wherein at least one of the pair of positive electrode side parallel running portions and the pair of negative electrode side parallel running portions is provided opposite at least two of the plurality of outer surfaces of the capacitor.

4. The capacitor module according to any one of claims 1 to 3, wherein at least one of the pair of positive electrode side parallel running portions and the pair of negative electrode side parallel running portions is arranged to run parallel in a direction perpendicular to a current flow direction from the positive electrode surface to the negative electrode surface of the capacitor.

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