Power conversion device

Abstract

To provide a technique effective for suppressing influence of conduction noise transmitted from an inverter through a conductor.SOLUTION: A capacitor module 501 of a power conversion device 500 includes: a first capacitor 10A for smoothing; second capacitors 10P, 10N for noise removal; first conductors 51P, 51N extending from intermediate connecting units 50P, 50N toward a power supply; second conductors 61P, 61N that electrically connect the second capacitors 10P, 10N and the intermediate connecting units 50P, 50N; and a ground conductor 62 that electrically connects the second capacitors 10P, 10N and a housing 3. Power-supply-side parallel extending units 51a, 51b are provided on the first conductors 51P, 51N. The second conductors 61P, 61N and the ground conductor 62 are provided with ground-side parallel extending units 61a, 61b, 62a that extend in parallel with the power-supply-side parallel extending units 51a, 51b so that an induced current is generated in a direction opposite to a noise current in the power-supply-side parallel extending units 51a, 51b.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to 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 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 supply and a motor. The capacitor module has a smoothing capacitor provided on the inverter side and two noise-removing capacitors provided on the power supply side. The positive side of the power supply and the positive side of the inverter are electrically connected by a positive side conductor, and the negative side of the power supply and the negative side of the inverter are electrically connected by a negative side conductor. The positive side conductor and the negative side conductor have a laminated region where they are laminated together and a non-laminated region where they are not laminated together. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-207780 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-described 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 voltage fluctuations between the power supply lines. However, the parasitic inductance of the noise-removing capacitors can reduce the effectiveness of suppressing voltage fluctuations between the power supply lines. This problem becomes more pronounced, particularly when it is difficult to adopt a structure that requires longer conductors, as power converters have become smaller and denser in recent years.

[0006] The power converter also attempts to suppress conducted noise from the inverter by providing non-laminated regions in the positive and negative conductors to increase parasitic inductance and using a noise-reducing capacitor to dissipate common-mode noise from the housing to ground. However, the effectiveness of the conducted noise suppression is easily affected by the routing of the ground conductor that electrically connects the noise-reducing capacitor to the housing. Depending on the routing of the ground conductor, it may be difficult to achieve the desired conducted noise suppression effect. Furthermore, when smoothing capacitors and noise-reducing capacitors are placed close to each other, noise may worsen due to inductive coupling caused by mutual inductance. In particular, these problems become more pronounced when the routing accuracy of the ground conductor is insufficient due to the broadband noise caused by the high-speed switching of recent power converters.

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

[0008] One aspect of the present invention is The power supply system comprises: 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 (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, and a ground conductor (62) electrically connecting the second capacitor and the housing, wherein the first conductor is provided with a power-source-side parallel running portion (51a, 51b), 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.

[0009] Another aspect of the present invention is The power supply system comprises: 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, intermediate conductors (52P, 52N) electrically connecting the first capacitor and the intermediate connection, second conductors (61P, 61N) electrically connecting the second capacitor and the intermediate connection, and a second conductor (61P, 61N) electrically connecting the second capacitor and the intermediate connection. a power conversion device (500, 600, 700, 800, 900, 1000) including: a ground conductor (62) that electrically connects a capacitor and the housing; and a magnetic shield section (51c, 53, 56) that suppresses a magnetic flux generated by a high-frequency current flowing through a capacitor current path (B1) of the first capacitor from interlinking with and flowing through 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. [Effects of the Invention]

[0010] In one aspect of the power conversion device described above, 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 of a power supply-side conducting part that electrically connects a first smoothing capacitor to a power supply to the power supply side. A second conductor is provided so as to electrically connect a second noise-removing capacitor to the intermediate connection of the power supply-side conducting part. A ground conductor is provided so as to electrically connect the second capacitor to the housing.

[0011] Here, the power-side parallel run portion provided on the first conductor runs parallel to the ground-side parallel run portion provided on at least one of the second conductor and the ground conductor. When a noise current flows through the ground-side parallel run portion from the housing side toward the second capacitor side, an induced voltage is generated in the power-side parallel run portion, causing an induced current to flow. This induced current flows in the opposite direction to the noise current flowing from the power supply side to the power-side parallel run portion, thereby reducing conducted noise on the power supply side.

[0012] In the power conversion device of the above-described alternative embodiment, the capacitor module is provided with a magnetic shielding section. The magnetic shielding section has a function of suppressing magnetic flux generated by high-frequency current flowing through the capacitor current path of the first capacitor from interlinking with the 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 placed close to each other.

[0013] As described above, according to the above-described aspects, it is possible to provide a technique that is effective in suppressing the influence of conduction noise transmitted from the inverter through the conductor.

[0014] In addition, the symbols in parentheses in the claims and the means for solving the problems indicate the correspondence with the specific means described in the embodiments described below, and do not limit the technical scope of the present invention. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is an electrical circuit diagram of a power conversion device according to a first embodiment of the present invention; [Figure 2] FIG. 10 is a perspective view of the periphery of a capacitor of the capacitor module of the first embodiment. [Figure 3] FIG. 10 is a perspective view of the periphery of a capacitor of a capacitor module of a second embodiment. [Figure 4] FIG. 11 is a perspective view of the periphery of a capacitor of a capacitor module of a third embodiment. [Figure 5] FIG. 11 is a perspective view of the periphery of a capacitor of a capacitor module of a fourth embodiment. [Figure 6] 1 is an electrical circuit diagram of a power conversion device according to a first embodiment. [Figure 7] FIG. 1 is a perspective view of a capacitor module according to a first embodiment. [Figure 8] 7 is a diagram for explaining the combined inductance of the conductors of the capacitor module in FIG. 6. [Figure 9] FIG. 8 is a perspective view showing the capacitor module of FIG. 7 housed in a housing. [Figure 10] FIG. 10 is a perspective view of a capacitor module according to a second embodiment. [Figure 11] FIG. 10 is a perspective view of a capacitor module according to a third embodiment. [Figure 12] FIG. 10 is a perspective view of a power conversion device according to a fourth embodiment. [Figure 13] FIG. 13 is a side view of the power converter of FIG. 12. [Figure 14] FIG. 14 is an enlarged side view of a portion of the power converter shown in FIG. [Figure 15] FIG. 15 is a side view showing a modification of the power converter of FIG. [Figure 16] FIG. 10 is a perspective view of a power conversion device according to a fifth embodiment. [Figure 17] FIG. 17 is a side view of the power converter of FIG. [Figure 18] FIG. 10 is a perspective view of a power conversion device according to a sixth embodiment. [Figure 19] FIG. 19 is a side view of the power converter of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of a power conversion device will be described with reference to the drawings. The embodiment is typically suitable for use in an on-board 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.

[0017] In this specification, unless otherwise specified, two mutually perpendicular directions along the positive and negative electrode surfaces of the smoothing capacitors that make up the capacitor module are referred to as the first direction X and the second direction Y, and a direction perpendicular to both the first direction X and the second direction Y is referred to as the third direction Z.

[0018] Furthermore, 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.

[0019] (Reference form 1) 1, a power conversion device 100 of the first embodiment is a device for converting power 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.

[0020] The capacitor module 101 includes a smoothing capacitor 10 on the power supply 1 side, a smoothing capacitor 10 on the inverter 102 side, a power supply side conducting unit 20 provided between the capacitor 10 and the power supply 1, and an inverter side conducting unit 30 provided between the capacitor 10 and the inverter 102. The two capacitors 10, 10 are connected in parallel to the power supply 1.

[0021] The inverter 102 is a semiconductor module having a plurality of semiconductor elements 102a connected to electrodes of any of the three phases (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 the high potential side terminal of the power supply 1 or lower arm semiconductor elements on the negative electrode side electrically connected to the low potential side 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.

[0022] 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." Typically, any semiconductor element such as an IGBT (i.e., insulated gate bipolar transistor) or a MOSFET (i.e., metal-oxide-semiconductor field-effect transistor) is used as the semiconductor elements 102a. The number and connection form of the semiconductor elements 102a are not particularly limited and can be set appropriately as needed.

[0023] 2, the capacitor 10 on the power source 1 side has a substantially 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 substantially parallel to the positive electrode surface 11. Hereinafter, the capacitor 10 on the power source 1 side will be simply referred to as "capacitor 10."

[0024] Capacitor 10 has multiple outer surfaces extending in the third direction X between positive electrode surface 11 and negative electrode surface 12. Each outer surface is an outer surface of capacitor 10 and may be flat, curved, or stepped. The multiple outer surfaces of capacitor 10 include four outer surfaces 13, 14, 15, and 16. Outer surface 13 is the surface of capacitor 10 on one side in the second direction Y. Outer surface 14 is the surface of capacitor 10 on one side in the second direction Y that is parallel to outer surface 13. Outer surface 15 is the surface of capacitor 10 on one side in the first direction X. Outer surface 16 is the surface of capacitor 10 on the other side in the first direction X that is parallel to outer surface 15.

[0025] As shown in Figures 1 and 2, the power supply side conductive part 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.

[0026] The inverter side current-carrying 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.

[0027] 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 can be used instead of the bus bar.

[0028] 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.

[0029] 2, the positive electrode side parallel running structure 41 has 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, which run parallel to each other across a gap 23 so that the current flows in the same 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.

[0030] Similarly, the negative electrode side parallel running structure 42 is a structure in which a pair of negative electrode side parallel running portions 22b, 32b formed by the first negative electrode conductor 22 and the second negative electrode conductor 32 run parallel to each other across a gap 24 so that the current flows in the same 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 positions along the negative electrode surface 12 of the capacitor 10, with the three-direction Z being the plate thickness direction and the second direction Y being the plate width direction.

[0031] It is preferable that the gap 23 in the positive electrode side parallel running structure 41 and the gap 24 in the negative electrode side parallel running structure 42 are both minute gaps of less than 1 mm. The gap 23 and the gap 24 may have the same dimensions or different dimensions.

[0032] In the electric circuit shown in Fig. 1, the inverter 102 acts as a noise source and conducts noise when multiple semiconductor elements 102a perform switching operations. 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 back to the inverter 102 side. This noise current C is bypassed in the capacitor 10 from the positive side to the negative side. 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 caused by the noise current C at this time is called "normal mode noise (differential mode noise)."

[0033] In FIG. 2, the flow of noise current C around the capacitor 10 is indicated by solid or dashed lines with arrows.

[0034] In the first positive conductor 21, the noise current C flows from the one end 21a through the positive side parallel running portion 21b to the power supply 1 side. In the second positive conductor 31, the noise current C flows from the inverter 102 side to the one end 31a through the positive side parallel running portion 31b. In the positive electrode 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 electrode surface 11, the noise current C flows in the opposite direction to the positive side parallel running portions 21b, 31b.

[0035] In the first negative conductor 22, the noise current C flows from the power supply 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 of the first negative conductor 22 to the one end 32a 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.

[0036] 1, if the positive electrode side parallel running structure 41 configured as described above is represented by an electric circuit, where Mp is the mutual inductance between the two conductors 21, 31 and ESL is the parasitic inductance of the capacitor 10, the resulting circuit is a T-shaped circuit equivalent to connecting this mutual inductance Mp to the parasitic inductance ESL with a negative coefficient. With this positive electrode side parallel running structure 41, by running the positive electrode side parallel running portion 21b of the first positive electrode conductor 21 and the positive electrode side parallel running portion 31b of the second positive electrode conductor 31 parallel to each other as described above, the positive electrode side parallel running structure 41 acts to strengthen the magnetic flux generated by the noise current C flowing through the positive electrode side parallel running portions 21b, 31b.

[0037] Similarly, if the negative-side parallel running structure 42 configured as described above is represented by an electric circuit, where Mn is the mutual inductance between the two conductors 22, 32, the resulting circuit is a 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-side parallel running structure 42, by running the negative-side parallel running portion 22b of the first negative conductor 22 and the negative-side parallel running portion 32b of the second negative conductor 32 parallel to each other as described above, the negative-side parallel running structure 42 acts to strengthen the magnetic flux generated by the noise current C flowing through the negative-side parallel running portions 22b, 32b.

[0038] In this case, the total inductance of this capacitor 10 is the value (ESL-Mp-Mn) obtained by subtracting the mutual inductances Mp and 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 and 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. Furthermore, because 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.

[0039] 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 flow direction in the third direction Z, which is the direction of current flow from the positive electrode surface 11 to the negative electrode surface 12 in the capacitor 10. 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 flow direction in the third direction Z. This prevents the magnetic flux generated when a noise current C flows in the capacitor 10 from weakening the magnetic flux generated in the positive electrode side parallel running portions 21b, 31b and the negative electrode side parallel running portions 22b, 32b.

[0040] Note that the term "substantially perpendicular" as used herein 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 perpendicular relationship is slightly deviated from the direction of current flow, that is, the parallel running directions are approximately perpendicular.

[0041] 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 near the capacitor 10, and the second positive conductor 31 and the second negative conductor 32 are electrically connected near the capacitor 10.

[0042] According to the first embodiment described above, it is possible to suppress voltage fluctuations occurring in the capacitor 10 of the capacitor module 101. This makes it possible to suppress the influence of conduction noise transmitted from the inverter 102 through conductors, that is, normal mode noise.

[0043] 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.

[0044] Next, other reference embodiments 2 to 4 related to the above-mentioned reference embodiment 1 will be described with reference to the drawings. In these reference embodiments 2 to 4, the same elements as those in reference embodiment 1 are given the same reference numerals, and the description of these same elements will be omitted.

[0045] (Reference form 2) As shown in FIG. 3, the power converter 200 of the second reference embodiment differs from the capacitor module 101 of the first reference embodiment in the arrangement of the four conductors 21, 22, 31, and 32 in the capacitor module 201.

[0046] The capacitor module 201 has a capacitor 10 having the same structure as that of Reference Example 1. 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. In this case, the side surfaces of the positive electrode side parallel running portion 21b and 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 positioned below the positive electrode surface 11 in the third direction Z and 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.

[0047] 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. In this case, the side surfaces of the negative electrode side parallel running portion 22b and 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 arranged parallel to each other at positions 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.

[0048] The other configurations are the same as those of the first embodiment.

[0049] Because noise current C flows in the positive electrode surface 11 of capacitor 10 in the opposite direction to that of positive electrode side parallel running portions 21b, 31b, when positive electrode side parallel running portions 21b, 31b approach positive electrode surface 11, this hinders the effect of strengthening the magnetic flux generated by noise current C flowing in positive electrode side parallel running portions 21b, 31b. Similarly, because noise current C flows in the opposite direction to that of negative electrode side parallel running portions 22b, 32b when negative electrode side parallel running portions 22b, 32b approach negative electrode surface 12, this hinders the effect of strengthening the magnetic flux generated by noise current C flowing in negative electrode side parallel running portions 22b, 32b.

[0050] Therefore, in Reference Form 2, the pair of positive electrode side parallel running portions 21b, 31b formed by the two conductors 21, 31 are opposed to the outer surface 13 of the capacitor 10, thereby being able to be spaced apart from the positive electrode surface 11. Also, the pair of negative electrode side parallel running portions 22b, 32b formed by the two conductors 22, 32 are opposed to the outer surface 13 of the capacitor 10, thereby being able to be spaced apart from the negative electrode surface 12.

[0051] By arranging the four parallel running portions 21b, 31b, 22b, and 32b of the four conductors 21, 22, 31, and 32 to face the same outer surface 13 of the capacitor 10, when using capacitors 10 of the same shape, it is possible to prevent the effect of strengthening the magnetic flux from being hindered compared to Reference Form 1. It is also possible to prevent the capacitor module 201 from becoming large in size in the third direction Z.

[0052] In addition, the same effects as those of the first embodiment are achieved.

[0053] (Reference form 3) As shown in FIG. 4, the power converter 300 of the third embodiment differs from the capacitor module 201 of the second embodiment in the arrangement of the conductors 22 and 32 in the capacitor module 301.

[0054] In this capacitor module 301, the pair of negative electrode side parallel running portions 22b, 32b that make up 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 that is opposite the outer surface 13 that faces the pair of positive electrode side parallel running portions 21b, 31b that make up the positive electrode side parallel running structure 41. The pair of negative electrode side parallel running portions 22b, 32b are also provided in diagonal positions relative to the pair of positive electrode side parallel running portions 21b, 31b.

[0055] The other configurations are the same as those of the second embodiment.

[0056] 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, which have opposite directions of noise current C flowing, can be spaced apart from each other, thereby preventing 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.

[0057] In addition, the same effects as those of the second embodiment are achieved.

[0058] (Reference form 4) As shown in FIG. 5, the 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 the capacitor module 401.

[0059] 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 disposed opposite the three outer surfaces 13, 15, and 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. Furthermore, a pair of negative electrode side parallel running portions 22b, 32b constituting the negative electrode side parallel running structure 42 are disposed opposite 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 generally 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.

[0060] The other configurations are the same as those of the first embodiment.

[0061] According to the fourth embodiment, the mutual inductance of the pair of positive-side parallel running portions 21b, 31b is larger than when the pair of positive-side parallel running portions 21b, 31b face one or two outer surfaces, thereby enhancing the effect of reducing the combined inductance of the capacitor 10.

[0062] It is preferable to set the distance between the pair of positive electrode side parallel running portions 21b, 31b and the three outer surfaces 13, 15, 16 of capacitor 10 as small as possible, thereby preventing capacitor module 401 from becoming large.

[0063] In addition, the same effects as those of the first embodiment are achieved.

[0064] In modified examples particularly related to the above-mentioned reference form 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.

[0065] 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 configured to have 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 can be applied to only one of the positive electrode side and the negative electrode side.

[0066] (Embodiment 1) 6, the power conversion device 500 of the first 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 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 able to convert power. The housing 3 is typically made of a conductive metal material and is grounded to the ground GND.

[0067] 6 and 7, the capacitor module 501 includes a plurality of first smoothing capacitors 10A connected in parallel to each other on the inverter 502 side, two second noise-removing capacitors 10P and 10N, first conductors 51P and 51N, intermediate conductors 52P and 52N, second conductors 61P and 61N, and a ground conductor 62. The first capacitors 10A are also referred to as "X capacitors," and the second capacitors 10P and 10N are also referred to as "Y capacitors."

[0068] The first conductors 51P and 51N are conductors that extend from intermediate terminals 50P and 50N, which serve as intermediate connection portions between the first capacitor 10A and the power source 1, toward the power source 1 side of the current-carrying unit 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 unit 50, and the first conductor 51N is a conductor on the negative electrode side of the current-carrying unit 50.

[0069] The intermediate conductors 52P and 52N are conductors that electrically connect the first capacitor 10A to the intermediate terminals 50P and 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.

[0070] 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, which electrically connects the intermediate terminals 50P, 50N to the housing 3. The second conductor 61P is the conductor on the positive electrode side of the current-carrying unit 60, and the second conductor 61N is the 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.

[0071] 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.

[0072] 7, these conductors 51P, 51N, 52P, 52N, 61P, and 61N are all made of flat metal members with rectangular cross sections, and are also called “bus bars.” If necessary, metal wiring with a circular or elliptical cross section can be used instead of the bus bars.

[0073] In this embodiment, a portion of the first conductors 51P, 51N runs parallel to the second conductors 61P, 61N and also runs parallel to the ground conductor 62. In this case, the first conductors 51P, 51N are provided with power supply side parallel running portions 51a, 51b. The second conductors 61P, 61N are provided with ground side parallel running portions 61a, 61b running parallel to the power supply side parallel running portions 51a, 51b. The ground conductor 62 is further provided with a ground side parallel running portion 62a running parallel to the power supply side parallel running portions 51a, 51b, and a connection portion 62b extending between the ground side parallel running portion 62a and the housing 3. In other words, the power supply side parallel running portions 51a, 51b extend in the same direction as the ground side parallel running portions 61a, 61b, 62a. The power supply side parallel running portions 51a and 51b and the ground side parallel running portions 61a, 61b, and 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.

[0074] In the electric circuit shown in Figure 6, inverter 502 acts as a noise source and conducts noise. At this time, noise current C leaks via the floating electrostatic capacitance of motor 2 and returns to the power supply line via ground GND. The flow of noise current C is indicated by a solid line with arrows. Because this noise current C flows in the same direction on the positive and negative sides of power supply 1, the conducted noise at this time is called "common mode noise."

[0075] 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.

[0076] Here, if some of the conducted noise conducted from the housing 3 to the ground conductor 62 is conducted to the power supply 1, it can cause a deterioration in the noise environment. Therefore, in this embodiment, the ground-side parallel running portions 61a, 61b, and 62a of the second conductors 61P and 61N and the ground conductor 62 are configured to run parallel to the power-supply-side parallel running portions 51a and 51b so that an induced current D in the opposite direction to the noise current C is generated in the power-supply-side parallel running portions 51a and 51b of the first conductors 51P and 51N. With this configuration, the noise current C flows through the ground-side parallel running portions 61a, 61b, and 62a, causing an induced current in the opposite direction to the noise current C to flow in the power-supply-side parallel running portions 51a and 51b. In FIG. 6, the flow of this induced current D is indicated by a dashed line with an arrow.

[0077] 7, the lower surface of power supply side parallel running portion 51a faces the upper surface of ground side parallel running portion 61a, and the lower surface of power supply side parallel running portion 51b faces the upper surface of ground side parallel running portion 61b. The lower surfaces of power supply side parallel running portions 51a, 51b face the upper surface of ground side parallel running portion 62a. Second capacitor 10P runs parallel to power supply side parallel running portion 51a in the current-carrying direction (first direction X), and second capacitor 10N runs parallel to power supply side parallel running portion 51b in the current-carrying direction (first direction X).

[0078] Preferably, the power supply-side parallel running portions 51a and 51b and the ground-side parallel running portions 61a, 61b, and 62a run parallel to each other so as 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 prevents magnetic flux generated by a relatively large high-frequency current flowing through the first capacitor 10A from disrupting the magnetic flux generated in the power supply-side parallel running portions 51a and 51b and the ground-side parallel running portions 61a, 61b, and 62a. This ensures mutual inductance between the power supply-side parallel running portions 51a and 51b and the ground-side parallel running portions 61a, 61b, and 62a.

[0079] Note that the term "substantially orthogonal" 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 deviated from the direction of current flow in the first capacitor 10A, where the parallel running directions are approximately orthogonal.

[0080] 7, the intermediate conductor 52N has an opposing wiring portion 52b arranged to face the opposing surface 17 of the first capacitor 10A that faces the second capacitors 10P and 10N. This opposing wiring portion 52b is configured as a magnetic shield that suppresses magnetic flux generated by high-frequency current flowing through the capacitor current path of the first capacitor 10A from interlinking with and flowing through the common-mode current path formed by the second capacitors 10P and 10N, the first conductors 51P and 51N, the second conductors 61P and 61N, the ground conductor 62, and the housing 3. This configuration makes it possible to prevent noise deterioration due to the influence of inductive coupling caused by mutual inductance when the first capacitor 10A and the second capacitors 10P and 10N are arranged closely to each other.

[0081] 8, in a capacitor module 501, the combined inductance of the power supply-side parallel running portions 51a and 51b of the first conductors 51P and 51N is denoted as L1. The combined inductance of the second capacitors 10P and 10N, the ground-side parallel running portions 61a, 61b, and 62a of the second conductors 61P and 61N and the ground conductor 62, and the connection portion 62b of the ground conductor 62 is denoted as L2. In this case, a mutual inductance M is formed by the combined inductances L1 and L2 running in parallel.

[0082] Here, when the current flowing through the combined inductance L2 is i, an induced voltage (=M×(di / dt)) is generated in the combined inductance L1, which is the product of the mutual inductance M and the change in current i over time, and an induced current D flows. Because the direction of the flow of this induced current D is opposite to the direction of conduction of the conducted noise caused by the noise current C, common mode noise, which is the conducted noise of the power supply 1, is reduced. This makes it possible to suppress the effects of conducted noise (common mode noise) transmitted from the inverter 502 through the conductor.

[0083] In particular, the capacitor module 501 has a structure in which the ground-side parallel running portions 61a, 61b, and 62a run parallel to the power-side parallel running portions 51a and 51b, and in addition, the second capacitors 10P and 10N run parallel to the power-side parallel running portions 51a and 51b in the current-carrying direction, thereby enhancing the common-mode noise reduction effect.

[0084] On the other hand, if necessary, at least one of the following parallel running structures can be adopted: a parallel running 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 running 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 running 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.

[0085] As shown in FIG. 6, the effect of reducing the conduction noise according to the first embodiment can be evaluated by measuring the conduction noise at a noise evaluation point E set near the power supply 1, for example.

[0086] In the first embodiment described above, as shown in FIG. 9 , the second capacitors 10P, 10N are preferably interposed between the power supply-side parallel running portions 51a, 51b and the ground-side parallel running portions 61a, 61b, 62a and the housing 3. In the third direction Z, the ground-side parallel running portions 61a, 61b, 62a are disposed below the power supply-side parallel running portions 51a, 51b, and the second capacitors 10P, 10N are disposed below the ground-side parallel running portions 61a, 61b, 62a. The second capacitors 10P, 10N are disposed opposite the bottom surface 3a of the housing 3 with a space between them. This prevents the housing 3, which is a conductor, from being placed near the power supply-side parallel running portions 51a, 51b and the ground-side parallel running portions 61a, 61b, 62a, and suppresses a decrease in the mutual inductance M between the combined inductances L1 and L2.

[0087] In addition, as long as the space between the power supply side parallel running sections 51a, 51b and the ground side parallel running sections 61a, 61b, 62a and the housing 3 is large enough 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.

[0088] Next, other embodiments 2 to 6 related to the above-mentioned embodiment 1 will be described with reference to the drawings. In these embodiments 2 to 6, the same elements as those in embodiment 1 are given the same reference numerals, and the description of these same elements will be omitted.

[0089] (Embodiment 2) 10, a power conversion device 600 of the second embodiment differs from that of the first embodiment in that a capacitor module 601 includes a magnetic shielding component 53. The magnetic shielding component 53 is interposed between the first capacitor 10A and the second capacitors 10P and 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.

[0090] The other configurations are the same as those in the first embodiment.

[0091] According to the second embodiment, the magnetic flux generated by the high-frequency current flowing through the first capacitor 10A in the third direction Z (see the arrow in FIG. 10) can be shielded from the second capacitors 10P and 10N by the magnetic shield component 53. This prevents the magnetic flux generated on the first capacitor 10A side from interfering with the magnetic flux generated by the current flowing through the power-side parallel running portions 51a and 51b and the ground-side parallel running portions 61a, 61b, and 62a. As a result, the mutual inductance M can be ensured.

[0092] In addition, the same effects as those of the first embodiment are achieved.

[0093] If the magnetic shielding function of magnetic shielding component 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 component 53 may be omitted as necessary.

[0094] (Embodiment 3) 11, the power conversion device 700 of the third embodiment differs from that of the first 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.

[0095] The other configurations are the same as those in the first embodiment.

[0096] According to the third embodiment, the arrangement of the second capacitors 10P and 10N can be changed as needed.

[0097] In addition, the same effects as those of the first embodiment are achieved.

[0098] (Embodiment 4) 12 , the power converter 800 of the fourth embodiment is a more specific embodiment of the structure related to the opposing wiring portion 52b as a magnetic shield portion provided in the power converter 500 of the first embodiment. The power converter 800 includes a capacitor module 801, an inverter 502 connected to the capacitor module 801 so as to be able to convert power, and a conductive housing 3 that houses the capacitor module 801 and the inverter 502.

[0099] Similar to the capacitor module 501 of embodiment 1, 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 grounding conductor 62, and an opposing wiring portion 52b.

[0100] The ground conductor 62 has a flat ground-side parallel portion 62a whose thickness direction is the third direction Z, 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.

[0101] The opposing wiring portion 52b is formed by a part of the intermediate conductor 52N and is a plate-like portion whose thickness direction is in the first direction X. The opposing wiring portion 52b is arranged to face, in the first direction X, the opposing surface 17 of each first capacitor 10A located on the second capacitor 10P, 10N side. That is, when each first capacitor 10A is viewed from the second capacitor 10P, 10N side, the opposing surface 17 of each first capacitor 10A is shielded by the opposing wiring portion 52b. The opposing wiring portion 52b is configured so 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, outer surfaces 18, which are side surfaces of each of the two first capacitors 10A arranged on the outer side in the second direction Y and are different from the opposing surfaces 17, are exposed.

[0102] 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.

[0103] 13, the 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 facing surface 17 of each first capacitor 10A is disposed within the range of this height H, and its entire surface is shielded from the second capacitors 10P, 10N by the facing wiring portion 52b. The capacitor module 801 has a first opening surface S1 defined by a common-mode current path B2 described below.

[0104] The other configurations are the same as those in the first embodiment.

[0105] 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 and 10N, the first conductors 51P and 51N, the second conductors 61P and 61N, the ground conductor 62, and the housing 3.

[0106] Here, the high-frequency current flowing through the capacitor current-carrying path B1 generates magnetic flux (see the two-dot chain arrow in FIG. 14) around the capacitor current-carrying path B1. 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 with magnetic shielding properties. This prevents the magnetic flux generated by the high-frequency current flowing through the capacitor current-carrying path B1 from interlinking with the common-mode current-carrying path B2.

[0107] Note that "flowing in an interlinked manner" as used herein refers to a state in which the magnetic flux flows while crossing the first opening surface S1, and typically refers to a state in which at least a portion of the magnetic flux flows in a direction normal to the first opening surface S1.

[0108] 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 Fig. 14 through the capacitor current-carrying path B1 and the magnetic flux generated by the high-frequency current flowing upward in Fig. 14 through the opposing wiring portion 52b to cancel each other out. This is therefore effective in further reducing the magnetic flux that links to the common-mode current-carrying path B2 due to the influence of the high-frequency current flowing through the capacitor current-carrying path B1.

[0109] On the other hand, in 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 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 due to electromagnetic induction. Therefore, by adopting a structure in which the opposing wiring portion 52b is disposed opposite the opposing surface 17 as in this embodiment, the amount of magnetic flux that flows in a linkage across the first opening 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 first embodiment) in the common-mode current path B2 can be suppressed.

[0110] In addition, the same effects as those of the first embodiment are achieved.

[0111] 15 , in a modification particularly related to the power converter 800 of the fourth embodiment, in addition to providing an opposing routing portion 52b in the intermediate conductor 52N, an opposing routing portion 52a is provided in the intermediate conductor 52P. The opposing routing portion 52a of the intermediate conductor 52P faces an upper region of the opposing surface 17 of each first capacitor 10A in the third direction Z, and the opposing routing portion 52b of the intermediate conductor 52N faces a remaining lower region of the opposing surface 17 of each first capacitor 10A in the third direction Z. That is, the two intermediate conductors 52P and 52N form opposing routing portions 52a and 52b facing the opposing surface 17 of each first capacitor 10A. In both the opposing routing portion 52a and the opposing routing portion 52b, a 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.

[0112] This configuration also provides the same advantageous effects as the configuration in which only the opposing wiring portion 52b of the intermediate conductor 52N is arranged to face the entire opposing surface 17 of each first capacitor 10A. In another modified example, only the opposing wiring portion 52a of the intermediate conductor 52P may face the entire opposing surface 17 of each first capacitor 10A.

[0113] (Embodiment 5) 16 and 17, a power conversion device 900 of the fifth embodiment includes a capacitor module 901, an inverter 502 connected to the capacitor module 901 so as to be able to convert power, 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 fourth embodiment only in that it includes a covering member 55 and an inverter magnetic shield unit 56.

[0114] 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 among the multiple first capacitors 10A. The covering member 55 functions to suppress 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 with magnetic shielding properties. 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 interlinking with 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.

[0115] In the power conversion device 900, the inverter magnetic shield 56 is provided on an opposing surface 502b of the inverter 502 that faces the common-mode current path B2. The inverter magnetic shield 56 performs two functions. The first function is a magnetic shield function that prevents magnetic flux generated by a high-frequency current flowing through the inverter 502 from interlinking with the common-mode current path B2 of the capacitor module 901. The second function is a cooling function that cools the inverter 502. In other words, the inverter magnetic shield 56 also functions as a cooler that cools the inverter 502. To achieve these two functions, the inverter magnetic shield 56 is made of a material that has magnetic shielding properties and high thermal conductivity.

[0116] The other configurations are the same as those in the fourth embodiment.

[0117] An inverter current path B3 is formed inside the inverter 502, through which a high-frequency current flows from the emitter terminal 54N to the collector terminal 54P via the output terminal 54O. The high-frequency current flowing through the inverter current path B3 generates magnetic flux (see the two-dot chain arrow in FIG. 17 ). The inverter magnetic shield 56 is provided on the opposing surface 502b of the inverter 502. This reduces the amount of magnetic flux that crosses the first opening surface S1 due to the influence of the high-frequency current flowing through the inverter current path B3, thereby suppressing the generation of common-mode noise in the common-mode current path B2. Furthermore, heat generated by the inverter 502 is transferred to the inverter magnetic shield 56 by thermal conduction and dissipated from the inverter magnetic shield 56. This allows the inverter 502 to be cooled by the inverter magnetic shield 56. The inverter magnetic shield 56 may be electrically connected to the housing 3.

[0118] According to the power conversion device 900 of the fifth embodiment, the inverter magnetic shield section 56 also functions to cool the inverter 502, which makes it possible to keep the size of the device small and the cost of the device low.

[0119] In addition, the same effects as those of the fourth embodiment are achieved.

[0120] In a modification particularly related to the power conversion device 900 of the fifth embodiment, a structure can be adopted in which either the covering member 55 or the inverter magnetic shield 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 56. This can improve the cooling effect of cooling the inverter 502.

[0121] (Embodiment 6) 18 and 19, a power conversion device 1000 of the sixth embodiment includes a capacitor module 1001, an inverter 502 connected to the capacitor module 1001 so as to be able to convert power, 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 fourth 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.

[0122] 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. 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, which is the interlinkage direction with respect to the common-mode current path B2. In other words, 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 spaced apart in the first direction X and do not overlap with each other.

[0123] The other configurations are the same as those in the fourth embodiment.

[0124] According to the power conversion device 1000 of the sixth embodiment, when a magnetic flux (see the 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 across the first opening plane S1, thereby suppressing the generation of common-mode noise in the common-mode current path B2.

[0125] In addition, the same effects as those of the fourth embodiment are achieved.

[0126] In a modification particularly related to the power conversion device 1000 of the sixth embodiment, it is also possible to adopt 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 fifth embodiment is added. This makes it possible to enhance the effect of suppressing the occurrence of common-mode noise in the common-mode current path B2.

[0127] The present invention is not limited to the exemplary embodiments 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 embodiments.

[0128] Any one of the above-described reference embodiments 1 to 4 can be combined with any one of the above-described embodiments 1 to 6. This makes it possible to suppress both normal mode noise and common mode noise.

[0129] In the above-described embodiment, a power conversion device for a vehicle is exemplified, but the use of this power conversion device is not limited to vehicles, and it is of course also applicable to power conversion devices installed in equipment other than vehicles. [Explanation of symbols]

[0130] 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 conducting portion, 21...first positive electrode conductor, 21b, 31b...pair of positive electrode side parallel running portions, 22...first negative electrode conductor, 2 2b, 32b...pair of negative pole side parallel running portions, 30...inverter side current-carrying portion, 31...second positive pole conductor, 32...second negative pole conductor, 50...power supply side current-carrying portion, 50P, 50N...intermediate terminal (intermediate connection portion), 51a, 51b...power supply side parallel running portions, 51P, 51N...first conductor, 52P, 52N...intermediate conductor, 52a, 52b...opposing wiring portion (magnetic shield portion), 53...magnetic shield 100,200,300,400,500,600,700,800,900,1000...power converter, 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 plane, S2...second current path plane, Y...second direction (interlinkage direction)

Claims

1. 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 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 the first conductor is provided with a power source side parallel portion (51a, 51b), and at least one of the second conductor and the ground conductor is provided with a ground side parallel portion (61a, 61b, 62a) running parallel to the power source side parallel portion so that an induced current in a direction opposite to that of the noise current is generated in the power source side parallel portion.

2. The power conversion device according to claim 1 , wherein the second capacitor is interposed between the power supply side parallel running portion and the housing, and between the ground side parallel running portion and the housing.

3. 3. The power conversion device according to claim 1, wherein the power supply side parallel running portion and the ground side parallel running portion run parallel to each other so as to be perpendicular to a current flow direction from a positive electrode surface (11) to a negative electrode surface (12) of the first capacitor.

4. The power conversion device according to any one of claims 1 to 3, wherein the capacitor module has a magnetic shield component (53) interposed between the first capacitor and the second capacitor.

5. 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 capacitor (10A) for smoothing, a second capacitor (10P, 10N) for removing noise, a first conductor (51P, 51N) extending from an intermediate connection part (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 part, a second conductor (61P, 61N) electrically connecting the second capacitor and the intermediate connection part, and the second conductor (62P, 62N) electrically connecting the second capacitor and the intermediate connection part. A power conversion device (500, 600, 700, 800, 900, 1000) comprising: a ground conductor (62) electrically connecting a capacitor and the housing; and a magnetic shield section (51c, 53, 56) that suppresses 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.

6. 6. The power conversion device according to claim 5, wherein the intermediate conductor has an opposing arrangement portion (52a, 52b) arranged to face an opposing surface (17) of the first capacitor located on the second capacitor side, and the magnetic shield portion is constituted by the opposing arrangement portion of the intermediate conductor.

7. 7. The power converter according to claim 6, wherein a high frequency current flows through the opposing wiring portion of the intermediate conductor in a direction opposite to a direction of a high frequency current flowing through the capacitor current path.

8. The power conversion device according to claim 6 or 7, wherein the capacitor module has a covering member (55) that covers an outer surface (18) other than the opposing surface of the first capacitor, and the magnetic shield portion is constituted by the opposing wiring portion and the covering member.

9. The power conversion device according to any one of claims 5 to 8, wherein the inverter has an opposing surface (502b) facing the common mode current path, and the opposing surface is provided with an inverter magnetic shield portion (56) that suppresses magnetic flux generated by high frequency current flowing through the inverter from flowing in linkage with the common mode current path of the capacitor module.

10. The power conversion device according to claim 9 , wherein the inverter magnetic shield portion also serves as a cooler for cooling the inverter.

11. the capacitor module has a first opening surface (S1) defined by the common mode current path, the inverter has a second opening surface (S2) defined by an inverter current path (B3) through which a high frequency current flows, the second opening surface extending along the first opening surface, The capacitor module and the inverter are arranged so that the first opening surface and the second opening surface do not overlap each other in the linkage direction (Y) with respect to the common mode current path. A power conversion device as described in any one of claims 5 to 10.

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