Capacitor module and power conversion device

Abstract

An X capacitor (20) has a first capacitor (21) and a second capacitor (22) connected in parallel. A positive-pole conductor (30P) and a negative-pole conductor (30N) intersect. These power supply conductors 30 have: accommodating parts (33N, 33P) accommodating at least a part of the X capacitor (20); terminal parts (31N, 31P); and terminal parts (32N, 32P) on a power converter side. The first capacitor (21) is connected to the terminal parts (31P, 32N). The second capacitor (22) is connected to the terminal parts (31N, 32P). In each of the power supply conductors (30), the terminal part (31P, 31N) is connected to one of the open ends of the accommodating part (33P, 33N), and the terminal part (32P, 32N) is connected to the other one of the open ends. The accommodating parts (33P, 33N) are recessed with respect to the terminal parts (31P, 31N, 32P, 32N).

Description

Capacitor module and power conversion device Cross-reference to Related Applications

[0001] This application is based on Japanese Patent Application No. 2025-45862 filed in Japan on March 19, 2025, and the entire content of the base application is incorporated herein by reference.

[0002] The disclosure in this specification relates to a capacitor module and a power conversion device.

[0003] Patent Document 1 discloses a filter device. The filter device includes a positive electrode wiring, a negative electrode wiring, and an X-capacitor. The X-capacitor has a first capacitor and a second capacitor connected in parallel between the positive electrode wiring and the negative electrode wiring. The positive electrode wiring is connected to the first capacitor and the second capacitor. The negative electrode wiring is connected to the first capacitor and the second capacitor. The positive electrode conductor and the negative electrode conductor cross each other. The content described in the prior art document is incorporated herein by reference as a description of technical elements in the present specification.

[0004] Japanese Unexamined Patent Publication No. 2022-162441

[0005] Since a Wheatstone bridge circuit is formed by the crossing structure of the positive electrode conductor and the negative electrode conductor, it is important to balance the inductance when inserting an X-capacitor to reduce normal mode noise. In Patent Document 1, inductance is secured by providing accommodation portions for accommodating X-capacitors in the positive electrode wiring and the negative electrode wiring, and forming the positive electrode wiring and the negative electrode wiring located at the bottom of the accommodation portions into meandering shapes. However, since inductance of the lead wires of the X-capacitor, the connection portion between the positive electrode conductor and the lead wire, and the connection portion between the negative electrode conductor and the lead wire is large, there is a possibility that the meandering shape described above may be insufficient for achieving balance.

[0006] To increase inductance, it is conceivable to reduce the cross-sectional area of ​​the positive and negative wiring forming the housing section. However, this increases the heat generated by the positive and negative wiring when current flows, thus increasing the thermal impact on the X capacitor. To increase inductance while reducing the thermal impact, it is conceivable to lengthen the positive and negative conductors forming the housing section in the depth direction. However, in the structure of Patent Document 1, if the positive and negative conductors forming the housing section are lengthened in the depth direction, the wiring connected to the X capacitor also becomes longer. Therefore, it is difficult to balance the inductance.

[0007] One of the purposes of this disclosure is to provide a technology that can improve the effectiveness of X capacitors while reducing thermal effects.

[0008] One aspect of the disclosure is a capacitor module connected to a power converter including a switching element, comprising: a power conductor including a positive conductor connected to the DC positive terminal of the power converter and a negative conductor connected to the DC negative terminal of the power converter; and an X capacitor connected to the positive and negative conductors, wherein the X capacitor has a first X capacitor and a second X capacitor connected in parallel between the positive and negative conductors, the positive and negative conductors intersect, and each of the positive and negative conductors has a housing portion with a bottom of a predetermined depth relative to an opening to accommodate at least a portion of the X capacitor, a first terminal portion and a second terminal portion on the power converter side provided at a position away from the first terminal portion, the first X capacitor is connected to the first terminal portion of the positive conductor and the second terminal portion of the negative conductor, the second X capacitor is connected to the second terminal portion of the positive conductor and the first terminal portion of the negative conductor. In both the positive and negative conductors, the first terminal portion is connected to one of the open ends of the housing portion, and the second terminal portion is connected to the other open end of the housing portion, and the housing portion is recessed relative to the first and second terminal portions.

[0009] Another aspect of the disclosure is a power converter comprising: a power converter including a switching element; a capacitor module connected to the power converter; the capacitor module comprising: a power conductor including a positive conductor connected to the DC positive terminal of the power converter; a negative conductor connected to the DC negative terminal of the power converter; and an X capacitor connected to the positive and negative conductors, wherein the X capacitor has a first X capacitor and a second X capacitor connected in parallel between the positive and negative conductors, the positive and negative conductors intersect, and each of the positive and negative conductors has a housing portion with a bottom of a predetermined depth relative to an opening to accommodate at least a portion of the X capacitor, a first terminal portion, and a second terminal portion on the power converter side located away from the first terminal portion, the first X capacitor being connected to the first terminal portion of the positive conductor and the second terminal portion of the negative conductor, the second X capacitor being connected to the second terminal portion of the positive conductor and the first terminal portion of the negative conductor In both the positive and negative conductors, the first terminal portion is connected to one of the open ends of the housing portion, and the second terminal portion is connected to the other open end of the housing portion, and the housing portion is recessed relative to the first and second terminal portions.

[0010] According to the disclosed embodiment, a first terminal portion and a second terminal portion connected to the X capacitor are provided at the open end of the housing portion. The housing portion is recessed relative to the first terminal portion and the second terminal portion. This allows for increased inductance in the path formed between the first and second terminal portions of the positive conductor and the path formed between the first and second terminal portions of the negative conductor, without increasing the inductance of the bypass path formed between the first terminal portion of the positive conductor and the second terminal portion of the negative conductor, including the first X capacitor, and the bypass path formed between the first terminal portion of the negative conductor and the second terminal portion of the positive conductor, including the second X capacitor. In other words, the inductance can be balanced. Therefore, the effect of the X capacitor can be improved while reducing thermal effects.

[0011] The various embodiments disclosed in this specification employ different technical means to achieve their respective objectives. The reference numerals in parentheses in the claims are illustrative in their correspondence with the embodiments described later and are not intended to limit the technical scope. The objectives, features, and effects disclosed in this specification will become clearer by referring to the subsequent detailed description and the accompanying drawings.

[0012] This figure shows an example of a power converter and drive system according to the first embodiment. This is an equivalent circuit diagram of a capacitor module. This is a diagram of a Wheatstone bridge circuit. This is a plan view showing an example of the structure of a capacitor module. This is a perspective view showing the power conductor in the capacitor module shown in Figure 4. This is a diagram for explaining inductance. This is a diagram for explaining inductance. This is a plan view showing another example of the structure of a capacitor module. This is an exploded perspective view corresponding to Figure 8. This is a side view of Figure 8 viewed from the Y1 direction. This is a side view showing another example. This is a side view showing another example. This is a plan view showing another example of a power conductor. This figure shows an example of Y capacitor connection in a capacitor module according to the second embodiment. This is an equivalent circuit diagram of a capacitor module. This is a diagram showing another example of Y capacitor connection. This is an equivalent circuit diagram of a capacitor module. This is a diagram showing another example of an equivalent circuit. This is a diagram showing another example of an equivalent circuit. This is a side view showing an example of Y capacitor arrangement. This is a modified example. This is a side view showing an example of base conductor arrangement. This is an equivalent circuit diagram of a capacitor module. This is a diagram of a Wheatstone bridge circuit. This is a diagram for explaining the propagation path of common-mode noise. This is a side view showing an example of a capacitor module according to the third embodiment.

[0013] Several embodiments will be described below with reference to the drawings. In each embodiment, the same reference numerals are used for corresponding components, and redundant explanations may be omitted. If only a part of the configuration is described in each embodiment, the configuration of other embodiments described earlier can be applied to the other parts of that configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations from multiple embodiments can be partially combined even if not explicitly stated, as long as there are no particular problems with the combination.

[0014] (First Embodiment) The capacitor module and power conversion device equipped with the capacitor module of this embodiment are applied, for example, to a mobile body that uses a rotating electric machine as a drive source. The mobile body is, for example, an electric vehicle such as an electric vehicle (BEV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV), an electric aircraft such as a drone or an electric vertical take-off and landing aircraft (eVTOL), a ship, construction machinery, or agricultural machinery. BEV is an abbreviation for Battery Electric Vehicle. HEV is an abbreviation for Hybrid Electric Vehicle. PHEV is an abbreviation for Plug in Hybrid Electric Vehicle. eVTOL is an abbreviation for electronic Vertical Take-Off and Landing aircraft. Examples of application to vehicles will be described below.

[0015] <Vehicle Drive System> Figure 1 shows an example of a power converter and drive system according to this embodiment. The vehicle drive system 1 includes a DC power supply 2, a motor generator 3, and a power converter 4.

[0016] The DC power supply 2 is a DC voltage source configured to supply DC power. The DC power supply 2 is composed of, for example, a rechargeable secondary battery. The secondary battery is, for example, a lithium-ion battery or a nickel-metal hydride battery. The motor generator 3 is a three-phase AC rotating electric machine. The motor generator 3 functions as the vehicle's driving source, i.e., an electric motor. The motor generator 3 functions as a generator during regeneration. The power converter 4 performs power conversion between the DC power supply 2 and the motor generator 3. The power generated by the motor generator 3 is supplied to, for example, the DC power supply 2 via the power converter 4. This charges the DC power supply 2.

[0017] The drive system 1 may include a power supply switch, such as an SMR (System Main Relay), between the DC power supply 2 and the power converter 4. SMR is an abbreviation for System Main Relay. For example, turning the power supply switch on enables power supply from the DC power supply 2 to the motor generator 3, and turning the power supply switch off cuts off the power supply from the DC power supply 2 to the motor generator 3.

[0018] <Power Conversion Device> Figure 1 shows an example of a power conversion device 4. The illustrated power conversion device 4 includes an inverter 5, a smoothing capacitor 6, and a capacitor module 7. For convenience, the intersection of the positive and negative conductors is omitted in Figure 1.

[0019] The inverter 5 is a DC-AC conversion circuit. The inverter 5 converts a DC voltage to a three-phase AC voltage according to the switching control of the control circuit and outputs it to the motor generator 3. This drives the motor generator 3 to generate a predetermined torque. During regenerative braking of the vehicle, the inverter 5 converts the three-phase AC voltage generated by the motor generator 3 in response to the rotational force from the wheels to a DC voltage according to the switching control of the control circuit and outputs it to the DC bus. In this way, the inverter 5 performs bidirectional power conversion between the DC power supply 2 and the motor generator 3. The inverter 5 is sometimes referred to as a power converter, power conversion module, or power module. Because the inverter 5 has semiconductor elements, that is, switching elements formed on a semiconductor substrate, it is sometimes referred to as a semiconductor module.

[0020] The inverter 5 is equipped with three phase upper and lower arm circuits 10 connected to the P line 8 and N line 9. The P line 8 is the high-potential DC bus (P bus) connected to the positive terminal of the DC power supply 2. The N line 9 is the low-potential DC bus (N bus) connected to the negative terminal of the DC power supply 2. The upper and lower arm circuits 10 are sometimes referred to as legs. The upper and lower arm circuits 10 have an upper arm 10H and a lower arm 10L. The upper arm 10H and the lower arm 10L are connected in series between the P line 8 and the N line 9, with the upper arm 10H facing the P line 8 side.

[0021] The connection point between the upper arm 10H and the lower arm 10L is connected to the corresponding phase winding 3a in the motor generator 3 via the output line 11. Of the upper and lower arm circuits 10, the U-phase upper and lower arm circuit 10U is connected to the U-phase winding 3a via the output line 11. The V-phase upper and lower arm circuit 10V is connected to the V-phase winding 3a via the output line 11. The W-phase upper and lower arm circuit 10W is connected to the W-phase winding 3a via the output line 11.

[0022] The inverter 5 has six arms. Each arm is composed of a switching element 12. The number of switching elements 12 that make up each arm is not particularly limited. There may be one or more. In the case of multiple switching elements 12, the multiple switching elements 12 connected in parallel to each other are driven on and off at the same timing by a common gate drive signal (drive voltage).

[0023] The example switching element 12 is an n-channel type MOSFET. MOSFET is an abbreviation for Metal Oxide Semiconductor Field Effect Transistor. In the upper arm 10H, the drain terminal of the MOSFET is connected to the P line 8. In the lower arm 10L, the source terminal of the MOSFET is connected to the N line 9. The source terminal of the MOSFET in the upper arm 10H and the drain terminal of the MOSFET in the lower arm 10L are interconnected.

[0024] Each MOSFET has a freewheeling diode 13 connected in antiparallel. Diode 13 may be a parasitic diode (body diode) of the MOSFET, or it may be a separate diode. The anode terminal of diode 13 is connected to the source terminal of the corresponding MOSFET, and the cathode terminal is connected to the drain terminal.

[0025] Note that the switching element 12 is not limited to a MOSFET. For example, an IGBT may be used. IGBT is an abbreviation for Insulated Gate Bipolar Transistor. In the case of an IGBT, a freewheeling diode is also connected in antiparallel.

[0026] The smoothing capacitor 6 primarily smooths the DC voltage supplied from the DC power supply 2. The smoothing capacitor 6 is connected to the P line 8 and the N line 9. The positive terminal of the smoothing capacitor 6 is connected to the P line 8 between the DC power supply 2 and the inverter 5. The negative terminal of the smoothing capacitor 6 is connected to the N line 9 between the DC power supply 2 and the inverter 5. The smoothing capacitor 6 is connected in parallel to the upper and lower arm circuit 10.

[0027] The capacitor module 7 reduces high-frequency noise current, i.e., high-frequency noise, associated with the switching operation of the power converter. The example capacitor module 7 reduces high-frequency noise associated with the switching operation of the inverter 5. The capacitor module 7 reduces normal-mode noise. Normal-mode noise is sometimes called differential-mode noise. High frequency refers to, for example, several hundred kHz to several hundred MHz. The capacitor module is sometimes called a filter module or filter device. The capacitor module 7 is electrically connected to the DC positive terminal 5P and the DC negative terminal 5N of the inverter 5. The DC positive terminal 5P and the DC negative terminal 5N are terminals of conductors that form part of the DC busbar in the inverter 5.

[0028] The capacitor module 7 includes an X capacitor 20 connected to the P line 8 and the N line 9. In the case of a cross arrangement (cross-connection), a larger capacitance of the X capacitor 20 enhances the capacitive (C) effect in addition to the inductive (L) effect, thus reducing noise over a wider frequency band. The X capacitor 20 has a first capacitor 21 and a second capacitor 22 connected in parallel between the P line 8 and the N line 9. In the example, the X capacitor 20 is connected to the P line 8 and the N line 9 between the DC power supply 2 and the inverter 5. The capacitances of the first capacitor 21 and the second capacitor 22 may be equal or different. Having equal capacitances makes it easier to balance the inductance. Details of the capacitor module 7 will be described later.

[0029] The power converter 4 may comprise at least a power converter and a capacitor module 7. The illustrated power converter 4 comprises an inverter 5, which is a DC-AC converter, and a capacitor module 7. The X capacitor 20 may be connected to a DC bus between the smoothing capacitor 6 and the DC power supply 2, as illustrated, or to a DC bus between the inverter 5 and the capacitor module 7. The power converter is not limited to the inverter 5. The power converter may be, for example, a DC-DC converter. The power converter 4 may comprise a DC-DC converter and a capacitor module 7. The power converter 4 may comprise an inverter 5, a converter, and a capacitor module 7.

[0030] The capacitor module 7 may include a smoothing capacitor 6 together with the X capacitor 20. The capacitor module 7 may also include a Y capacitor. The capacitor module 7 may also include elements that constitute a filter together with the X capacitor 20, such as a core.

[0031] The power converter 4 may include, for example, a snubber circuit. The power converter 4 may also include a drive circuit for switching elements that constitute the inverter 5, etc. The drive circuit supplies a drive voltage to the gate of the corresponding arm's switching element based on a drive command from the control circuit. The drive circuit drives the corresponding switching element, i.e., turns it on or off, by applying the drive voltage. The drive circuit is sometimes referred to as a driver.

[0032] The power converter 4 may include a control circuit for the switching elements. The control circuit generates drive commands for operating the switching elements and outputs them to the drive circuit. The control circuit generates drive commands based on, for example, torque requests input from a higher-level ECU (not shown) and signals detected by various sensors. ECU is an abbreviation for Electronic Control Unit. Various sensors may include, for example, current sensors, rotation angle sensors, and voltage sensors. The current sensor detects the phase current flowing through the windings 3a of each phase. The rotation angle sensor detects the rotation angle of the rotor of the motor generator 3. The voltage sensor detects the voltage across the smoothing capacitor 6. The control circuit outputs, for example, a PWM signal as a drive command. The control circuit is configured to include, for example, a processor and memory. PWM is an abbreviation for Pulse Width Modulation.

[0033] <Circuit Configuration of Capacitor Module> Figure 2 is an equivalent circuit diagram of the capacitor module. In addition to the X capacitor 20 described above, the capacitor module 7 is equipped with a power supply conductor 30 consisting of a positive conductor 30P and a negative conductor 30N. The power supply conductor 30 forms part of the DC bus. The positive conductor 30P forms part of the P bus, and the negative conductor 30N forms part of the N bus.

[0034] The positive conductor 30P and the negative conductor 30N are crossed. The positive conductor 30P and the negative conductor 30N are connected in a diagonal configuration. Capacitor X 20 is connected to the positive conductor 30P and the negative conductor 30N. The first capacitor 21 and the second capacitor 22 are connected in parallel between the positive conductor 30P and the negative conductor 30N. The positive electrode of the first capacitor 21 is electrically connected to the positive conductor 30P, and the negative electrode of the first capacitor 21 is electrically connected to the negative conductor 30N. The connection point P1 between the first capacitor 21 and the positive conductor 30P and the connection point N2 between the first capacitor 21 and the negative conductor 30N are connected by a bypass path BP1 that includes the first capacitor 21. The inductance L1 of the bypass path BP1 includes at least the parasitic inductance of the bypass path BP1. The inductance L1 may include the equivalent series inductance (ESL) of the first capacitor 21.

[0035] The positive terminal of the second capacitor 22 is electrically connected to the positive conductor 30P, and the negative terminal of the second capacitor 22 is electrically connected to the negative conductor 30N. The connection point P2 between the second capacitor 22 and the positive conductor 30P and the connection point N1 between the second capacitor 22 and the negative conductor 30N are connected by a bypass path BP2 that includes the second capacitor 22. The inductance L2 of the bypass path BP2 includes at least the parasitic inductance of the bypass path BP2. The inductance L2 may also include the equivalent series inductance of the second capacitor 22.

[0036] The inductance L3 of the path NP connecting connection points N1 and N2 includes the parasitic inductance of the portion of the negative conductor 30N corresponding to the connection points N1 and N2. The inductance L4 of the path PP connecting connection points P1 and P2 includes the parasitic inductance of the portion of the positive conductor 30P corresponding to the connection points P1 and P2. Note that connection points P1 and N1 are connection points on the DC power supply 2 side, and connection points P2 and N2 are connection points on the inverter 5 side.

[0037] Figure 3 shows an example of a Wheatstone bridge circuit. As described above, a Wheatstone bridge circuit is formed in the capacitor module 7 to cross the positive conductor 30P and the negative conductor 30N. The Wheatstone bridge circuit is sometimes called a Wheatstone bridge circuit. In Figure 3, connection points P2 and N2 are located diagonally opposite each other, and connection points P1 and N1 are located diagonally opposite each other. Connection points P2 and N2 are located on the high-frequency source side.

[0038] In the example Wheatstone bridge circuit, when the product of impedance Z1 and impedance Z2 is equal to the product of impedance Z3 and impedance Z4, the potential difference (voltage) between connection point P1 and connection point N1 becomes zero. No current flows between connection point P1 and connection point N1, and the impedance Z0 between connection point P1 and connection point N1 becomes zero.

[0039] Furthermore, even if the product of impedance Z1 and impedance Z2 differs by about 50% from the product of impedance Z3 and impedance Z4, normal mode noise can still be reduced. Therefore, it is preferable to balance the impedances so that the difference between the product of impedance Z1 and impedance Z2 and the product of impedance Z4 and impedance Z5 is 50% or less. More preferably, the impedances should be balanced so that the product of impedance Z1 and impedance Z2 and the product of impedance Z4 and impedance Z5 are approximately the same. Approximately the same means that a manufacturing tolerance, for example, a few percent deviation, can be tolerated. Even more preferably, the impedances should be balanced so that the product of impedance Z1 and impedance Z2 and the product of impedance Z4 and impedance Z5 are perfectly the same.

[0040] In the high-frequency range, the value obtained by multiplying the inductance by the frequency corresponds to the impedance. The frequency is the frequency of the current flowing through the conductor. Therefore, in order to reduce normal-mode noise, it is important to balance the value obtained by multiplying inductance L1 and inductance L2 with the value obtained by multiplying inductance L3 and inductance L4. More preferably, it is important to balance the inductances so that the value obtained by multiplying inductance L1 and inductance L2 is approximately equal to the value obtained by multiplying inductance L3 and inductance L4.

[0041] <Capacitor Module Structure> Figure 4 is a plan view showing an example of the structure of a capacitor module. Figure 5 is a perspective view showing the power conductor of the capacitor module shown in Figure 4.

[0042] In the following description, the depth direction of the accommodating portion is defined as the Z direction. The direction perpendicular to the Z direction in which the first X capacitor and the second X capacitor are arranged is defined as the Y direction, and the direction perpendicular to both the Y direction and the Z direction is defined as the X direction. The X direction, the Y direction, and the Z direction are in a mutually perpendicular positional relationship. Unless otherwise specified, a shape viewed in plan from the Z direction, in other words, a shape along the XY plane defined by the X direction and the Y direction, is referred to as a planar shape. A plan view from the Z direction may be simply referred to as a plan view.

[0043] As shown in Figures 3 and 4, the capacitor module 7 includes an X capacitor 20 and a power conductor 30. The X capacitor 20 includes a first capacitor 21 and a second capacitor 22. The first capacitor 21 corresponds to the first X capacitor, and the second capacitor 22 corresponds to the second X capacitor. The first capacitor 21 and the second capacitor 22 are arranged at substantially the same position in the Z direction. The first capacitor 21 and the second capacitor 22 are arranged in the Y direction with a predetermined interval therebetween.

[0044] The X capacitor 20 includes a main body portion 23 and lead terminals 24. The main body portion 23 has a capacitor element 231. The illustrated X capacitor 20 is a film capacitor. The main body portion 23 includes a capacitor element 231 formed by winding or laminating films, an outer case that accommodates the capacitor element 231, and a resin filled in the outer case. The main body portion 23 has a substantially rectangular planar shape with the X direction as the longitudinal direction and the Y direction as the lateral direction. The main body portion 23 has a substantially rectangular parallelepiped shape. The X capacitor 20 is arranged such that the main surface 232 of the main body portion 23 faces the Z direction. One of the main surfaces 232 faces the bottom portion 331 of the accommodating portions 33P and 33N.

[0045] The lead terminal 24 is connected to the capacitor element 231. The lead terminal 24 may be referred to as a lead wire. The lead terminal 24 includes a lead terminal 24P and a lead terminal 24N. The lead terminal 24P is connected to the positive electrode of the capacitor element 231. The lead terminal 24N is connected to the negative electrode of the capacitor element 231. A positive electrode is provided at one end of the capacitor element 231 in the X direction, and a negative electrode is provided at the other end of the capacitor element 231 in the X direction. A part of the lead terminal 24 is covered with an exterior case and resin, and the other part protrudes outside the main body portion 23. The lead terminal 24 extends from the capacitor element 231 in a direction different from the Z direction. The illustrated lead terminal 24 extends in the Y direction. The lead terminals 24P and 24N connected to the same capacitor element 231 are arranged side by side in the X direction at a predetermined interval.

[0046] The first capacitor 21 and the second capacitor 22 are arranged such that surfaces of the respective main body portions 23 opposite to the protruding surface of the lead terminal 24 face each other. The lead terminal 24 of the first capacitor 21 protrudes from a surface opposite to the surface facing the second capacitor 22 and extends in the Y direction. The lead terminal 24 of the second capacitor 22 protrudes from a surface opposite to the surface facing the first capacitor 21 and extends in the Y direction. The lead terminal 24 of the first capacitor 21 and the lead terminal 24 of the second capacitor 22 extend in directions opposite to each other. The first capacitor 21 and the second capacitor 22 are arranged with two-fold symmetry about an axis parallel to the Z direction. The lead terminal 24P is located on the left side when viewed in the first capacitor 21, and is located on the right side when viewed in the second capacitor 22.

[0047] The power conductor 30 includes a positive electrode conductor 30P and a negative electrode conductor 30N as described above. The positive electrode conductor 30P and the negative electrode conductor 30N are formed using a bus bar that is a metal plate. The bus bar may have a substantially uniform thickness over the entire surface, or may be a profiled strip having partially different thicknesses. The illustrated bus bar has a substantially uniform thickness.

[0048] The positive conductor 30P has terminals 31P and 32P and a housing portion 33P. Terminal 31P is the terminal on the DC power supply 2 side, and terminal 32P is the terminal on the inverter 5 side. Terminal 31P is connected to another conductor on the DC power supply 2 side that forms the P busbar. Terminal 32P is connected to another conductor on the inverter 5 side that forms the P busbar. Terminal 32P is electrically connected to the DC positive terminal 5P. The example terminal 31P is provided with a fastening hole 311 for connection to another conductor. Similarly, terminal 32P is provided with a hole 321. Note that the connection method is not limited to fastening. Other connection methods such as welding may be used.

[0049] The housing section 33P is a connecting section that electrically relays terminal sections 31P and 32P. The housing section 33N houses at least a portion of the X capacitor 20 (see Figure 10). The housing section 33P houses at least a portion of the first capacitor 21 and the second capacitor 22, respectively. The housing section 33P has a bottom 331 of a predetermined depth relative to the opening. The housing section 33P closes downward in the Z direction and opens upward.

[0050] Terminal portion 31P is connected to one of the ends of the housing portion 33P in the extending direction, and terminal portion 32P is connected to the other end. Terminal portion 31P is connected to one of the open ends of the housing portion 33P, and terminal portion 32P is connected to the other open end. The housing portion 33P is recessed relative to terminal portions 31P and 32P. Terminal portions 31P and 32P are not folded back from the open end of the housing portion 33P toward the bottom portion 331. Terminal portions 31P and 32P do not extend from the open end of the housing portion 33P toward the bottom portion 331 in the Z direction. In the example, terminal portions 31P and 32P extend from the open end of the housing portion 33P toward the X direction. The thickness direction of terminal portions 31P and 32P is substantially parallel to the Z direction. Terminal portions 31P and 32P are arranged at substantially the same position in the Z direction.

[0051] The housing section 33P has a bottom section 331 and side sections 332 and 333. In the exemplary housing section 33P, the thickness direction of the bottom section 331 is substantially parallel to the Z direction. The bottom section 331 extends obliquely with respect to the X and Y directions. For example, the bottom section 331 extends obliquely at an angle of approximately 45 degrees with respect to the X and Y directions, respectively.

[0052] Side portion 332 is the portion connecting the bottom portion 331 and the terminal portion 31P. Side portion 333 is the portion connecting the bottom portion 331 and the terminal portion 32P. Side portion 332 corresponds to the first side portion, and side portion 333 corresponds to the second side portion. In the illustrated housing portion 33P, the plate thickness direction of side portions 332 and 333 is substantially parallel to the X direction. Side portions 332 and 333 have a bent portion between them and the bottom portion 331 such that the angle they make with the bottom portion 331 is substantially 90 degrees. Side portions 332 and 333 have a bent portion between them and the terminal portions 31P and 32P such that the angle they make with the terminal portions 31P and 32P is substantially 90 degrees.

[0053] In other words, the housing section 33P has a roughly U-shape or a roughly U-shape when viewed from above in the Y direction. The concave shape of the housing section 33P is not particularly limited. For example, the angle between the sides 332, 333 and the bottom 331 may be acute or obtuse. If the angle is approximately 90 degrees, the size of the housing section 33P can be matched to the size of the X capacitor 20. Therefore, the overall size can be reduced. The angle between the sides 332, 333 and the terminal sections 31P, 32P may be acute or obtuse. If the angle is approximately 90 degrees, it is easier to connect to another conductor and to the X capacitor 20.

[0054] The terminal portions 31P and 32P have connecting portions 34P and 35P. The connecting portions 34P and 35P are the connection portions with the X capacitor 20 at the positive conductor 30P. The connecting portion 34P is connected to the main portion of the terminal portion 31P. The thickness direction of the example connecting portion 34P is approximately parallel to the Z direction. The connecting portion 34P branches off from the main portion of the terminal portion 31P and extends toward the lead terminal 24P of the first capacitor 21. The connecting portion 34P extends to a position where it overlaps with the lead terminal 24P of the first capacitor 21. The connecting portion 34P is connected to the lead terminal 24P by welding while supporting the lead terminal 24P. The cross-sectional area of ​​the connecting portion 34P is smaller than the cross-sectional area of ​​the main portion of the terminal portion 31P. The cross-sectional area is the area of ​​the cross-section perpendicular to each extension direction.

[0055] The connecting portion 35P is connected to the main part of the terminal portion 32P. The thickness direction of the illustrated connecting portion 35P is approximately parallel to the Z direction. The connecting portion 35P branches off from the main part of the terminal portion 32P and extends toward the lead terminal 24P of the second capacitor 22. The connecting portion 35P extends to a position where it overlaps with the lead terminal 24P of the second capacitor 22. The connecting portion 35P is connected to the lead terminal 24P by welding while supporting the lead terminal 24P. The cross-sectional area of ​​the connecting portion 35P is smaller than the cross-sectional area of ​​the main part of the terminal portion 32P.

[0056] The basic configuration of the negative electrode conductor 30N is the same as that of the positive electrode conductor 30P. The negative electrode conductor 30N has terminal portions 31N and 32N and a housing portion 33N. Terminal portion 31N is the terminal portion on the DC power supply 2 side, and terminal portion 32N is the terminal portion on the inverter 5 side. Terminal portion 32N is electrically connected to the DC negative pole 5N. In the power supply conductor 30, terminal portions 31P and 31N correspond to the first terminal portion, and terminal portions 32P and 32N correspond to the second terminal portion. The illustrated terminal portions 31N and 32N extend in the X direction from the open end of the housing portion 33N. The thickness direction of terminal portions 31N and 32N is substantially parallel to the Z direction. Terminal portions 31N and 32N are positioned in substantially the same position as terminal portions 31P and 32P in the Z direction.

[0057] The housing section 33N houses at least a portion of the X capacitor 20. The housing section 33N houses at least a portion of the first capacitor 21 and the second capacitor 22, respectively. A terminal section 31N is connected to one of the open ends of the housing section 33N, and a terminal section 32N is connected to the other open end. The housing section 33N is recessed relative to the terminal sections 31N and 32N.

[0058] The housing portion 33N has a bottom portion 331 and side portions 332 and 333. In the exemplary housing portion 33N, the bottom portion 331 extends obliquely with respect to the X and Y directions. The bottom portion 331 extends obliquely, for example, at an angle of approximately 45 degrees with respect to the X and Y directions, respectively. The bottom portion 331 of the positive electrode conductor 30P and the bottom portion 331 of the negative electrode conductor 30N intersect in a plan view. The bottom portion 331 of the negative electrode conductor 30N is arranged to form approximately an X shape in plan with the bottom portion 331 of the positive electrode conductor 30P.

[0059] The side portion 332 connects the bottom portion 331 and the terminal portion 31N. The side portion 333 connects the bottom portion 331 and the terminal portion 32N. In a plan view in the Y direction, the housing portion 33N has the same shape as the housing portion 33P. The illustrated housing portion 33N is roughly U-shaped or U-shaped in a plan view in the Y direction.

[0060] The terminal sections 31N and 32N have connecting sections 34N and 35N. The connecting section 34N is connected to the main part of the terminal section 31N. The connecting section 35N is connected to the main part of the terminal section 32N. The thickness direction of the connecting sections 34N and 35N is substantially parallel to the Z direction. The connecting section 34N branches off from the main part of the terminal section 31N and extends toward the lead terminal 24N of the second capacitor 22. The connecting section 34N is connected to the lead terminal 24N by welding while supporting the lead terminal 24N. The cross-sectional area of ​​the connecting section 34N is smaller than the cross-sectional area of ​​the main part of the terminal section 31N.

[0061] The connecting portion 35N is connected to the main part of the terminal portion 32N. The thickness direction of the illustrated connecting portion 35N is approximately parallel to the Z direction. The connecting portion 35N branches off from the main part of the terminal portion 32N and extends toward the lead terminal 24N of the second capacitor 22. The connecting portion 35N is connected to the lead terminal 24N by welding while supporting the lead terminal 24N. The cross-sectional area of ​​the connecting portion 35N is smaller than the cross-sectional area of ​​the main part of the terminal portion 32N.

[0062] The positive electrode conductor 30P and the negative electrode conductor 30N are insulated and separated by a predetermined distance and / or by an insulating member. In the example power conductor 30, the bottom 331 of the negative electrode conductor 30N is located on the opening side of the bottom 331 of the positive electrode conductor 30P. The negative electrode conductor 30N corresponds to the first conductor, and the positive electrode conductor 30P corresponds to the second conductor. The bottom 331 of the negative electrode conductor 30N has a straddling portion 3311 and ends 3312, 3313. The straddling portion 3311 is the part that straddles the bottom 331 of the positive electrode conductor 30P. A part of the straddling portion 3311 overlaps with the bottom 331 of the positive electrode conductor 30P in a plan view. The straddling portion 3311 is located above the bottom 331 of the positive electrode conductor 30P so as not to contact it.

[0063] End portion 3312 is connected to one of the ends of the straddling portion 3311 in the extending direction, and end portion 3313 is connected to the other end. In the negative electrode conductor 30N, end portion 3312 is connected to the straddling portion 3311 and the side portion 332. End portion 3313 is connected to the straddling portion 3311 and the side portion 333. End portion 3312 corresponds to the first end, and end portion 3313 corresponds to the second end. The bottom portion 331 of the housing portion 33N has a plurality of bends. The straddling portion 3311 has bends near the boundary with ends 3312 and 3313. The number of bends in the bottom portion 331 of the negative electrode conductor 30N is greater than the number of bends in the bottom portion 331 of the positive electrode conductor 30P.

[0064] The ends 3312 and 3313 are located below the portion of the overlapping section 3311 that overlaps the bottom 331 of the positive electrode conductor 30P. In the example overlapping section 3311, the thickness direction of the portion excluding the bent section is approximately parallel to the Z direction. The thickness direction of the ends 3312 and 3313 is approximately parallel to the Z direction. The ends 3312 and 3313 are positioned approximately at the same location as the bottom 331 of the positive electrode conductor P in the Z direction.

[0065] In the capacitor module 7, as shown in Figure 4, the length LY in the Y direction of the bottom portion 331 is longer than the length LX in the X direction of the bottom portion 331. As shown in Figure 5, the minimum value of the cross-sectional area S1 at the bottom portion 331 of the negative electrode conductor 30N is smaller than the minimum value of the cross-sectional area S2 at the side portion 332 and the minimum value of the cross-sectional area S3 at the side portion 333. Similarly, the minimum value of the cross-sectional area at the bottom portion 331 of the positive electrode conductor 30P is smaller than the minimum value of the cross-sectional area at the side portion 332 and the minimum value of the cross-sectional area at the side portion 333.

[0066] Although an example is shown where the negative conductor 30N is placed above the positive conductor 30P, i.e., on the opening side, at the intersection, the configuration is not limited to this. The positive conductor 30P may be placed above the negative conductor 30N at the intersection. Although an example is shown where a part of the X capacitor 20 is placed in the housing portions 33P and 33N such that the main body portion 23 straddles the opening surfaces of the housing portions 33P and 33N in the Z direction, the configuration is not limited to this.

[0067] Figures 6 and 7 are diagrams illustrating inductance. Figure 6 corresponds to Figure 4. Figure 7 corresponds to Figure 5. In the capacitor module 7, the connection part 34P, the first capacitor 21, and the connection part 35N constitute the bypass path BP1 described above. The inductance L1 includes the parasitic inductance of the connection part 34P, the parasitic inductance of the lead terminals 24P and 24N of the first capacitor 21, the parasitic inductance of the connection part 35N, and the inductance of the weld between the connection parts 34P and 35N and the lead terminals 24P and 24N. The inductance L1 may further include the equivalent series inductance of the first capacitor 21.

[0068] Similarly, the connection portion 34N, the second capacitor 22, and the connection portion 35P constitute the bypass path BP2 described above. The inductance L2 includes the parasitic inductance of the connection portion 34N, the parasitic inductance of the lead terminals 24P and 24N of the second capacitor 22, the parasitic inductance of the connection portion 35P, and the inductance of the weld between the connection portions 34N and 35P and the lead terminals 24P and 24N. The inductance L2 may further include the equivalent series inductance of the second capacitor 22.

[0069] Furthermore, the negative conductor 30N constitutes the path NP. The inductance L3 includes the parasitic inductance of the housing portion 33N, specifically the parasitic inductance of the bottom portion 331 and the side portions 332, 333. The inductance L3 may include the parasitic inductance of the terminal portions 31N, 32N from the connection ends with the connecting portions 34N, 35N to the housing portion 33N. The positive conductor 30P constitutes the path PP. The inductance L4 includes the parasitic inductance of the housing portion 33P, specifically the parasitic inductance of the bottom portion 331 and the side portions 332, 333. The inductance L4 may include the parasitic inductance of the terminal portions 31P, 32P from the connection ends with the connecting portions 34P, 35P to the housing portion 33P.

[0070] The cross-sectional areas of the connection parts 34P, 34N, 35P, and 35N that constitute the bypass paths BP1 and BP2 are small, and the cross-sectional areas of the lead terminals 24P and 24N are even smaller. In addition, because conductors with small cross-sectional areas are welded together, the inductances L1 and L2 become large. However, the terminal parts 31P, 31N, 32P, and 32N are connected to the open ends of the corresponding housing parts 33P and 33N, and the housing part 33P is recessed relative to the terminal parts 31P and 32P. This recessed shape allows for the acquisition of inductances L3 and L4 without increasing the inductances L1 and L2, thereby balancing the inductances.

[0071] The capacitor module 7 may include at least an X capacitor 20 having a first capacitor 21 and a second capacitor 22, and a power supply conductor 30 having a positive electrode conductor 30P and a negative electrode conductor 30N. In addition to the X capacitor 20 and the power supply conductor 30, the capacitor module 7 may also include other elements.

[0072] Figure 8 is a plan view showing another example of the structure of a capacitor module. Figure 9 is an exploded perspective view corresponding to Figure 8. Figure 10 is a side view of Figure 8 viewed from the Y1 direction. The capacitor module 7 illustrated in Figures 8 to 10 comprises an X capacitor 20, a power conductor 30, a base 40, an insulating member 50, and a support member 60. The X capacitor 20 and the power conductor 30 are the same as those illustrated in Figures 4 and 5.

[0073] The base 40 is a component for positioning at least some of the other elements of the capacitor module 7 on the support member. The base 40 may provide an insulating function to the support member. The base 40 is, for example, a resin molded body. The base 40 may also be molded with a metal collar or the like as an insert part.

[0074] In this example, the support member is a housing 70. The housing 70 may be the housing of the capacitor module 7 or the housing of the power converter 4. The housing 70 comprises a base 71 and a boss 72. The housing 70 is formed from a metal material such as aluminum. The housing 70 may have side walls connected to the base 71. The boss 72 extends in the Z direction from one surface of the base 71. The boss 72 has a screw hole (not shown) with an opening on its upper surface and a predetermined depth in the Z direction.

[0075] The base 40 comprises a base 41, a fixing part 42, and a terminal block 43. The base 41 supports the power conductor 30 located below the intersection. The base 41 has a bottom wall 411 and side walls 412. The bottom wall 411 has a substantially rectangular shape with the Y direction as its longitudinal direction so as to enclose the bottom 331 and the X capacitor 20. Grooves 413 corresponding to the housing part 33P of the positive electrode conductor 30P are formed in the exemplary bottom wall 411 and side walls 412. The housing part 33P is fitted into the grooves 413. The bottom wall 411 is interposed between the base 71 of the housing 70, which is a support member, and the bottom 331 of the housing part 33P of the positive electrode conductor 30P. The bottom wall 411 supports the bottom 331 of the housing part 33P, and the side walls 412 support the sides 332 and 333. The base 41 is provided with a projection 414 to determine the position of the base 40 and the insulating member 50.

[0076] The fixing portion 42 is the part that fixes the base 40, and by extension the other elements constituting the capacitor module 7, to the housing 70. The fixing portion 42 is connected to both ends of the base 41 in the Y direction. The fixing portion 42 extends in the Y direction away from the base 41. The fixing portion 42 extends in the Z direction toward the openings of the housing portions 33P and 33N. The fixing portion 42 has holes 421 formed in it for fastening and fixing to the housing 70. As shown by the white arrows in Figure 10, the fixing direction of the fixing portion 42 to the housing 70 (support member) is downward in the Z direction. As shown by the solid arrows, the direction of the opening relative to the bottom portion 331, that is, the opening direction of the housing portions 33P and 33N, is upward in the Z direction.

[0077] The fixing portion 42 has two bent portions. The fixing portion 42 has two Y-direction extensions and a Z-direction extension connecting the Y-direction extensions. The upper end 422 of the fixing portion 42 is located above the bottom 331 of the power conductor 30. In Figure 10, the positions in the Z direction are shown with a dashed line. The upper surface position ZL1 of the bottom 331 of the housing portion 33P and the upper surface position ZL2 of the bottom 331 of the housing portion 33N are located below the position ZL3 of the upper end 422.

[0078] The terminal block 43 supports the terminals 32P and 32N and is the part that fixes the terminals 32P and 32N to the conductors (busbars) that form the DC busbar on the inverter 5 side. The example terminals 32P and 32N and the conductors on the inverter 5 side are fastened and fixed to the terminal block 43. The terminal block 43 has a support surface 431 that supports the terminals 32P and 32N. A separation wall 432 is provided on the support surface 431. The separation wall 432 extends in the Z direction from the support surface 431. When fixed with the conductors on the inverter 5 side, the separation wall 432 insulates and separates the terminal 32P side and the terminal 32N side. Note that the base 40 may be configured without the terminal block 43. Terminal blocks may be provided on the terminals 31P and 31N side.

[0079] The insulating member 50 is interposed between the positive electrode conductor 30P and the negative electrode conductor 30N, ensuring electrical insulation between them. The insulating member 50 supports the power supply conductor 30, which is located above it at the intersection. The insulating member 50 is, for example, a molded resin body. The insulating member 50 has a bottom wall 501 and side walls 502. The bottom wall 501 is provided in correspondence with the bottom wall 411. Grooves 503 corresponding to the housing portion 33N of the negative electrode conductor 30N are formed in the bottom wall 501 and the side walls 502. The housing portion 33N is fitted into the grooves 503. Positioning holes 504 are formed in the bottom wall 501 in correspondence with the projection 414. The bottom wall 501 is provided with projections 505 to determine the position of the insulating member 50 and the support member 60.

[0080] The support member 60 supports the X capacitor 20. The support member 60 is positioned in the housing sections 33P and 33N and is placed on the insulating member 50 and the negative electrode conductor 30N. The support member 60 is, for example, a resin molded body. The support member 60 has a base 61. The upper surface of the base 61 is the support surface 611 for the X capacitor 20. Partition walls 62 and 63 are provided on the support surface 611. The partition walls 62 and 63 divide the area where the X capacitor 20 is located into the area of ​​the first capacitor 21 and the area of ​​the second capacitor 22. Partition wall 62 is provided between the first capacitor 21 and the second capacitor 22 in the Y direction. Partition walls 63 are provided at both ends of the support surface 611 in the X direction and are connected to partition wall 62. In plan view, partition walls 62 and 63 form a substantially H shape.

[0081] As described above, the capacitor module 7 is formed by stacking a base 40, a positive electrode conductor 30P, an insulating member 50, a negative electrode conductor 30N, a support member 60, and an X capacitor 20. The insulating member 50 may be molded using the power supply conductor 30 as an insert component. The base 40 and insulating member 50 may be integrally molded using the power supply conductor 30 as an insert component. The base 40, insulating member 50, and support member 60 may be integrally molded using the power supply conductor 30 as an insert component. The capacitor module 7 may comprise an X capacitor 20, a power supply conductor 30, an insulating member 50, and a support member 60.

[0082] Figure 11 is a side view showing another example of a capacitor module. Figure 11 corresponds to Figure 10. In Figure 11, the depth H of the housing section 33P is longer than the length LX in the X direction of the bottom section 331. The depth H is the length in the Z direction from the lower end of the housing section 33P to the upper end of the housing section 33P. Similarly, the depth of the housing section 33N is longer than the length LX.

[0083] Figure 12 is a side view showing another example of a capacitor module. Figure 12 corresponds to Figure 10. The example capacitor module 7 includes a cooler 73. The cooler 73 cools the bottom 331. The cooler 73 is also the housing 70 of the capacitor module 7. Fins 74 are provided on the base 71 of the housing 70. The fins 74 are provided in positions corresponding to the capacitor module 7. The capacitor module 7 further includes a heat conductive member 75. The heat conductive member 75 is interposed between the base 40 and the base 71, and thermally connects the base 40 to the cooler 73. The heat conductive member 75 is sometimes referred to as TIM. TIM is an abbreviation for Thermal Interface Material. GF may also be used as the heat conductive member. GF is an abbreviation for Gap Filler.

[0084] Although not shown in the diagram, in the configuration with the cooler 73, as described above, the ends 3312 and 3313 are positioned closer to the cooler 73 than the straddling portion 3311. In the configuration with the cooler 73, as described above, the minimum cross-sectional area at the bottom portion 331 is smaller than the minimum cross-sectional area at the side portion 332 and the minimum cross-sectional area at the side portion 333. The configuration of the cooler 73 is not limited to the above example. For example, a flow path for the refrigerant may be provided in the base 71. The cooler 73 may be provided in the power converter 4. The cooler 73 may be provided separately from the housing 70.

[0085] Figure 13 is a plan view showing another example of a power conductor. In the example power conductor 30, the minimum value of the cross-sectional area S11 of the housing portion 33N for the negative electrode conductor 30N, whose bottom 331 is closer to the opening, is smaller than the minimum value of the cross-sectional area S12 of the housing portion 33P for the positive electrode conductor 30P, whose bottom 331 is further from the opening. The thicknesses of the positive electrode conductor 30P and the negative electrode conductor 30N are approximately the same. The minimum value of the width W11 of the housing portion 33N is narrower than the minimum value of the width W12 of the housing portion 33P, which is why the minimum value of the cross-sectional area S11 is smaller than the minimum value of the cross-sectional area S12.

[0086] <Summary of the First Embodiment> The capacitor module 7 of this embodiment comprises a positive conductor 30P, a negative conductor 30N, and an X capacitor 20. The X capacitor 20 has a first capacitor 21 (first X capacitor) and a second capacitor 22 (second X capacitor) connected in parallel between the positive conductor 30P and the negative conductor 30N. The positive conductor 30P and the negative conductor 30N are intersecting. Each of the positive conductor 30P and the negative conductor 30N has a housing portion 33P, 33N with a bottom 331 of a predetermined depth relative to the opening to accommodate at least a portion of the X capacitor 20, terminal portions 31P, 31N (first terminal portion), and terminal portions 32P, 32N (second terminal portion) on the power converter side. The first capacitor 21 is connected to terminal portions 31P, 32N, and the second capacitor 22 is connected to terminal portions 31N, 32P. In both the positive conductor 30P and the negative conductor 30N, the terminal portions 31P and 31N are connected to one of the open ends of the corresponding housing portions 33P and 33N, and the terminal portions 32P and 32N are connected to the other open end of the corresponding housing portions 33P and 33N. The housing portions 33P and 33N are recessed relative to the terminal portions 31P, 31N, 32P, and 32N.

[0087] In this way, terminals 31P, 31N, 32P, and 32N connected to the X capacitor 20 are provided at the open ends of the housing sections 33P and 33N. The housing sections 33P and 33N are recessed relative to the terminals 31P, 31N, 32P, and 32N. This allows for increasing the length between terminals 31P and 32P in the positive conductor 30P, and the length between terminals 31N and 32N in the negative conductor 30N, without changing the connection distance between the X capacitor 20 and the terminals 31P, 31N, 32P, and 32N. In other words, the inductance L3 of the path NP and the inductance L4 of the path PP can be increased without increasing the inductance L1 of the bypass path BP1 including the first capacitor 21, or the inductance L2 of the bypass path BP2 including the second capacitor 22. Thus, the inductances can be balanced. As a result, the effect of the X capacitor 20 can be improved while reducing thermal effects.

[0088] Furthermore, since the X capacitor 20 is placed in the housing sections 33P and 33N, the size of the capacitor module 7 can be reduced compared to a configuration in which the entire X capacitor 20 is placed outside the housing sections 33P and 33N.

[0089] As illustrated, the housing sections 33P and 33N may be opened in the opposite direction to the fixing direction of the fixing section 42 to the support member. Note that the opposite direction is not limited to the completely opposite direction, but is sufficient if it is approximately the opposite direction. With this arrangement, the X capacitor 20 is located above the bottom 331 of the housing sections 33P and 33N with respect to the base 71 of the housing 70, which is the support member, making it easier to connect the X capacitor 20 to the power conductor 30.

[0090] As illustrated, in the Z direction, the bottom portion 331 may be positioned below the upper end 422 of the fixing portion 42. The fixing portion 42 is fixed to the boss 72. The height of the boss 72 relative to the base 71 is determined based on the screw depth of the fastening. By positioning the bottom portion 331 below the upper end 422, the dead space created by the fixing structure can be utilized to increase the inductance L3, L4 while making the capacitor module 7 lower in profile.

[0091] As illustrated, the lead terminal 24 may be configured to extend in a direction different from the Z direction. Preferably, it may extend in a direction perpendicular to the Z direction, for example, in the Y direction. This allows the lead terminal 24 and the power conductor 30 to be welded together in the Z direction. In other words, the connection between the lead terminal 24 and the power conductor 30 becomes easier.

[0092] As illustrated, the depth H of the housing sections 33P and 33N may be made longer than the length LX in the X direction of the bottom section 331. The length LX is determined by the length of the X capacitor 20 in the X direction. By increasing the depth H while maintaining a length LX sufficient to accommodate the X capacitor 20, the inductances L3 and L4 can be increased.

[0093] As illustrated, the length LY in the Y direction of the bottom portion 331 may be made longer than the length LX in the X direction of the bottom portion. As mentioned above, the length LX is determined by the length of the X capacitor 20 in the X direction. By increasing the length LY without changing the length LX, the inductances L3 and L4 can be increased.

[0094] As illustrated, the minimum cross-sectional area at the bottom 331 may be smaller than the minimum cross-sectional area at the side 332 (first side) and the minimum cross-sectional area at the side 333 (second side). By reducing the cross-sectional area at the bottom 331, the inductances L3 and L4 can be increased.

[0095] As illustrated, the minimum cross-sectional area of ​​the housing portions 33P and 33N for the positive conductor 30P and the negative conductor 30N may be configured such that the minimum cross-sectional area is smaller on the side closer to the opening than on the side further away from the opening. By making the side further away from the opening longer and reducing the cross-sectional area on the side closer to the opening, the inductances L3 and L4 can be brought closer together, ideally to almost the same value. This makes it easier to balance the inductances L3, L4 with those L1, L2.

[0096] As illustrated, the number of bends in the positive conductor 30P and the negative conductor 30N may be configured such that there are more bends on the side of the bottom 331 closer to the opening than on the side further from the opening. In other words, the bottom 331 may be configured to have more bends on the side of the bottom 331 closer to the opening than on the side further from the opening. This increases the length on the side closer to the opening, bringing the inductances L3 and L4 closer together, ideally to almost the same value.

[0097] As illustrated, the main surface 232 of the X capacitor 20 may be positioned facing the bottom 331. This allows the X capacitor 20 to be moved away from the bottom 331. Therefore, the thermal influence on the X capacitor 20 can be reduced.

[0098] As illustrated, the capacitor element 231 of the X capacitor may be placed between the connection point between the power supply conductor 30 and the lead terminal 24 of the first capacitor 21, and the connection point between the power supply conductor 30 and the lead terminal 24 of the second capacitor 22. By placing the capacitor element 231 inside the connection point in this way, the capacitor module 7 can be made smaller compared to a configuration in which the capacitor element 231 is placed outside the connection point.

[0099] As illustrated, at least in the housing sections 33P and 33N, an insulating member 50 may be provided interposed between the positive conductor 30P and the negative conductor 30N. The presence of the insulating member 50 allows the positive conductor 30P and the negative conductor 30N to be positioned closer together. Thus, the capacitor module 7 can be miniaturized.

[0100] As illustrated, a cooler 73 for cooling the bottom 331 may be provided. The housing sections 33P and 33N increase the inductances L3 and L4, which comes at the cost of increased heat generation due to current flow. By providing the cooler 73, the thermal effects on the X capacitor 20 can be reduced.

[0101] In a configuration that includes a cooler 73, the ends 3312 and 3313 may be positioned closer to the cooler 73 than the straddling portion 3311. The power conductor 30 located above, that is, the power conductor 30 closer to the X capacitor 20, can also be effectively cooled by the cooler 73. This effectively reduces the thermal impact on the X capacitor 20.

[0102] In a configuration that includes a cooler 73, the minimum cross-sectional area at the bottom 331 may be smaller than the minimum cross-sectional area at the side 332 (first side) and the minimum cross-sectional area at the side 333 (second side). By reducing the cross-sectional area at the bottom 331, the inductances L3 and L4 can be increased while the heat generated at the bottom 331 can be effectively cooled by the cooler 73.

[0103] (Second Embodiment) This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be incorporated by reference. In the preceding embodiment, the capacitor module was equipped with an X capacitor. Alternatively, the capacitor module may be equipped with both an X capacitor and a Y capacitor.

[0104] Figure 14 shows an example of a Y-capacitor connection in the capacitor module according to this embodiment. In Figure 14, the Y-capacitor is shown as an equivalent circuit. Furthermore, only the Y-capacitor and its connection symmetrical parts are shown in the capacitor module.

[0105] The capacitor module 7 includes a Y-capacitor 80 in addition to the configuration shown in the prior embodiment (see Figure 8). The fixing portion 42 of the base 40 is electrically connected to the housing 70, which is a support member, when fastened, thereby providing a reference potential (GND). The Y-capacitor 80 is connected to the power conductor 30 and the fixing portion 42 that provides the reference potential. The capacitor module 7 has two fixing portions 42.

[0106] The example capacitor module 7 includes two Y-capacitors 80P connected to a positive conductor 30P and a fixed part 42, and two Y-capacitors 80N electrically connected to a negative conductor 30N and a fixed part 42. One Y-capacitor 80P is connected to one of the fixed parts 42 and the bottom 331 of the positive conductor 30P, and the other Y-capacitor 80P is connected to the other fixed part 42 and the bottom 331 of the positive conductor 30P. One Y-capacitor 80N is connected to one of the fixed parts 42 and the bottom 331 of the negative conductor 30N, and the other Y-capacitor 80N is connected to the other fixed part 42 and the bottom 331 of the negative conductor 30N.

[0107] Figure 15 is an equivalent circuit diagram of the capacitor module 7 shown in Figure 14. The two Y capacitors 80P are connected to the path PP and GND connecting connection points P1 and P2 at different positions. The two Y capacitors 80N are connected to the path NP and GND connecting connection points N1 and N2 at different positions.

[0108] Figure 16 shows another example of Y capacitor connection. Figure 16 shows another example of a capacitor module equipped with Y capacitors. Figure 16 corresponds to Figure 8. In Figure 16, the Y capacitor is shown in an equivalent circuit. In the example capacitor module 7, one Y capacitor 80P is connected to one of the fixed parts 42 and to the connection part 34P of the terminal part 31P, and the other Y capacitor 80P is connected to the other fixed part 42 and to the connection part 35P of the terminal part 32P. One Y capacitor 80N is connected to one of the fixed parts 42 and to the connection part 34N of the terminal part 31N, and the other Y capacitor 80N is connected to the other fixed part 42 and to the connection part 35N of the terminal part 32N.

[0109] Figure 17 is an equivalent circuit diagram of the capacitor module 7 shown in Figure 16. One of the Y capacitors 80P is connected to bypass path BP1 and GND, and the other Y capacitor 80P is connected to bypass path BP2 and GND. One of the Y capacitors 80N is connected to bypass path BP1 and GND, and the other Y capacitor 80N is connected to bypass path BP2 and GND.

[0110] Figures 18 and 19 show alternative examples of equivalent circuits. The capacitor module 7 may include one Y capacitor 80P and one Y capacitor 80N. In Figure 18, the Y capacitor 80P and the Y capacitor 80N are connected to a common GND (fixed part 42). In Figure 19, the GND (fixed part 42) is separated, and the Y capacitor 80P and the Y capacitor 80N are individually connected to GND.

[0111] Figure 20 is a side view showing an example of the arrangement of the Y capacitor. Figure 20 corresponds to Figure 10. The Y capacitor 80 is housed in the housing sections 33P and 33N. The Y capacitor 80 is located between the X capacitor 20 and the bottom section 331 in the Z direction. Alternatively, the Y capacitor 80 may be placed outside the housing sections 33P and 33N. The other configurations are the same as those described in the prior embodiment.

[0112] <Summary of the Second Embodiment> As illustrated, the capacitor module 7 may include a Y-capacitor 80 electrically connected to the power supply conductor 30 and the fixed part 42 that provides a reference potential. A capacitor module 7, and by extension a power converter 4, can be provided that integrates the function of suppressing normal mode noise and the function of suppressing common mode noise.

[0113] As illustrated, the Y capacitor 80 may be placed between the X capacitor 20 and the bottom 331 in the housing sections 33P and 33N. This effectively utilizes the dead space between the X capacitor 20 and the bottom 331, allowing for a smaller size for the capacitor module 7.

[0114] <Modification> The configuration including the Y capacitor 80 can be combined with various configurations shown in the prior embodiment.

[0115] Figure 21 shows a modified example. Figure 21 corresponds to Figure 16. In Figure 21, the Y capacitor is shown in an equivalent circuit. Figure 22 is a side view of the modified example. Figure 22 corresponds to Figure 10. The exemplary capacitor module 7 includes a base conductor 85. The base conductor 85 electrically connects a plurality of fixed parts 42. The exemplary base conductor 85 extends in the Y direction, crosses the housing parts 33P and 33N, and electrically connects the two fixed parts 42. A part of the base conductor 85 is positioned between the X capacitor 20 and the bottom part 331 in the Z direction. The base conductor 85 intersects with the power supply conductor 30. In a plan view, the base conductor 85 intersects with the bottom part 331 of the positive electrode conductor 30P. The base conductor 85 intersects with the bottom part 331 of the negative electrode conductor 30N.

[0116] The Y capacitor 80P has a first capacitor 801P connected to the connection part 34P of terminal part 31P and a second capacitor 802P connected to the connection part 35P of terminal part 32P. The Y capacitor 80N has a first capacitor 801N connected to the connection part 34N of terminal part 31N and a second capacitor 802N connected to the connection part 35N of terminal part 32N. The first capacitors 801P and 801N correspond to the first Y capacitor, and the second capacitors 802P and 802N correspond to the second Y capacitor.

[0117] The first capacitor 801P and the second capacitor 802N are connected near the connection point with one of the fixed portions 42 on the base conductor 85. The first capacitor 801N and the second capacitor 802P are connected near the connection point with the other fixed portion 42 on the base conductor 85.

[0118] Figure 23 is an equivalent circuit diagram of the capacitor module 7 shown in Figure 21. Figure 23 corresponds to Figure 21. The base conductor 85 connects two GNDs. An inductance L5 exists between the connection points B1 and B2 between the base conductor 85 and GND (fixed part 42). The inductance L5 includes the parasitic inductance of the base conductor 85.

[0119] The first capacitor 801P is connected to connection point P1 and connection point B1. An inductance L6 exists in the path connecting connection point P1 and connection point B1. The inductance L6 includes parasitic inductances such as connection point 34P. The inductance L6 may include the equivalent series inductance of the first capacitor 801P. The second capacitor 802P is connected to connection point P2 and connection point B2. An inductance L7 exists in the path connecting connection point P2 and connection point B2. The inductance L7 includes parasitic inductances such as connection point 35P. The inductance L7 may include the equivalent series inductance of the second capacitor 802P.

[0120] The first capacitor 801N is connected to connection part N1 and connection part B2. An inductance L8 exists in the path connecting connection part N1 and connection part B2. The inductance L8 includes parasitic inductance such as connection part 34N. The inductance L8 may include the equivalent series inductance of the first capacitor 801N. The second capacitor 802N is connected to connection part N2 and connection part B1. An inductance L9 exists in the path connecting connection part N2 and connection part B1. The inductance L9 includes parasitic inductance such as connection part 35N. The inductance L9 may include the equivalent series inductance of the second capacitor 802N.

[0121] Figure 24 shows a Wheatstone bridge circuit. As described above, a Wheatstone bridge circuit is formed in the capacitor module 7 to cross the power conductor 30 and the base conductor 85. Figure 24 shows the Wheatstone bridge circuit formed between the positive electrode conductor 30P and the base conductor 85. Connections P2 and B1 are located diagonally opposite each other, and connections P1 and B2 are located diagonally opposite each other. Connections P2 and B1 are located on the high-frequency source side. Although not shown in the figure, a similar Wheatstone bridge circuit is also formed between the negative electrode conductor 30N and the base conductor 85. Specifically, connections N2 and B2 are located diagonally opposite each other, and connections N1 and B1 are located diagonally opposite each other. Connections N2 and B2 are located on the high-frequency source side.

[0122] In the example Wheatstone bridge circuit, when the product of impedance Z4 and impedance Z5 is equal to the product of impedance Z6 and impedance Z7, the potential difference (voltage) between connection point P1 and connection point B2 becomes zero. No current flows between connection point P1 and connection point N2, and the impedance Z10 between connection point P1 and connection point B2 becomes zero. Since the potential difference between connection point P1 and connection point B2 is zero, the potential difference between the positive conductor 30P and the base conductor 85 is approximately zero. Therefore, impedance Z6 can be made approximately zero. Also, impedance Z7 can be made approximately zero. In other words, impedances Z6 and Z7 can be canceled out. Inductances L6 and L7 can be canceled out.

[0123] Even if the product of impedance Z4 and impedance Z5 differs by about 50% from the product of impedance Z6 and impedance Z7, impedances Z6 and Z7 can still be reduced to some extent. Therefore, it is preferable to balance the impedances so that the difference between the product of impedance Z4 and impedance Z5 and the product of impedance Z6 and impedance Z7 is 50% or less. More preferably, the impedances should be balanced so that the product of impedance Z4 and impedance Z5 and the product of impedance Z6 and impedance Z7 are approximately the same. Approximately the same means that a manufacturing tolerance, for example, a few percent deviation, can be tolerated. Even more preferably, the impedances should be balanced so that the product of impedance Z4 and impedance Z5 and the product of impedance Z6 and impedance Z7 are perfectly the same.

[0124] As described above, in the high-frequency range, the value obtained by multiplying the inductance by the frequency corresponds to the impedance. Therefore, in order to reduce common-mode noise, it is important to balance the value obtained by multiplying inductance L4 and inductance L5 with the value obtained by multiplying inductance L6 and inductance L7. More preferably, common-mode noise can be reduced by balancing the inductances so that the value obtained by multiplying inductance L4 and inductance L5 is approximately equal to the value obtained by multiplying inductance L6 and inductance L7.

[0125] Figure 25 is a diagram illustrating the propagation path of common-mode noise. Figure 25 corresponds to Figure 24. Noise currents are indicated by dashed and dotted arrows. Parasitic capacitance exists between the inverter 5 (switching element 12) and metal components such as the housing of the power converter 4. Parasitic capacitance exists between the winding 3a of the motor generator 3 and metal components such as the motor housing. Common-mode noise generated by the operation of the switching element 12 flows, for example, from the inverter 5 through the parasitic capacitance and housing to the body ground (GND). Common-mode noise flows, for example, from the winding 3a through the parasitic capacitance to the body ground.

[0126] The Y capacitor 80 has low impedance in the high-frequency range. For example, the first capacitor 801P and the second capacitor 802P bypass common-mode noise between the positive conductor 30P (P bus) and the body ground. The noise current flows through the path: body ground → connection point B1 of the base conductor 85 → first capacitor 801P → connection point P1 → connection point P2. The noise current flows through the path: body ground → connection point B1 of the base conductor 85 → connection point B2 → second capacitor 802P → connection point P2. By bypassing in this way, common-mode noise can be reduced. The Y capacitor 80P can suppress the flow of noise current to the DC power supply 2 side. The Y capacitor 80P can reduce the noise current loop. The same applies to the Y capacitor 80N.

[0127] (Third Embodiment) This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be used by reference. In the preceding embodiment, the capacitor module was equipped with an X capacitor, or an X capacitor and a Y capacitor. In other words, it was equipped with a capacitor. Alternatively, the capacitor module may be equipped with a core in addition to the capacitor.

[0128] Figure 26 is a circuit diagram showing an example of a capacitor module according to this embodiment. Figure 26 corresponds to Figure 10. The capacitor module 7 includes a core 90. The core 90 is an annular member equipped with a magnetic material. The magnetic material may be, for example, ferrite or an iron-based metal. The core 90 is located outside the housing portions 33P and 33N. The power supply conductor 30 passes through the core 90. In the example capacitor module 7, the terminal portions 31P and 31N pass through the core 90. The core 90 attenuates high-frequency noise and consumes noise energy through magnetic loss, i.e., suppresses noise current. In Figure 26, the core 90 is located on the DC power supply 2 side relative to the housing portions 33P and 33N, but it may also be located on the inverter 5 side. The number of cores 90 is not limited to one. Multiple cores 90 may be provided. Other configurations are the same as those described in the prior embodiment.

[0129] <Summary of the Third Embodiment> As illustrated, the capacitor module 7 may include a core 90 positioned outside the housing sections 33P and 33N, through which the power supply conductor 30 is inserted. By positioning it outside the housing sections 33P and 33N, the functions can be integrated while suppressing disruption of the inductance balance.

[0130] The configuration including the core 90 can be combined with various configurations shown in the prior embodiment.

[0131] (Other Embodiments) The disclosures in this specification and drawings are not limited to the exemplary embodiments. The disclosures include the exemplary embodiments and variations thereof by those skilled in the art. For example, the disclosures are not limited to combinations of parts and / or elements shown in the embodiments. The disclosures are implementable in a variety of combinations. The disclosures may have additional parts that can be added to the embodiments. The disclosures include those in which parts and / or elements of an embodiment have been omitted. The disclosures include substitutions or combinations of parts and / or elements between one embodiment and another. The scope of the disclosed technical areas is not limited to the descriptions of the embodiments. Some of the scope of the disclosed technical areas are indicated by the descriptions of the claims and should be understood to include all modifications within the meaning and scope equivalent to the descriptions of the claims.

[0132] The disclosures in the specification and drawings are not limited by the claims. The disclosures in the specification and drawings encompass the technical ideas described in the claims and extend to a wider and more diverse range of technical ideas than those described in the claims. Therefore, a variety of technical ideas can be extracted from the disclosures in the specification and drawings without being bound by the claims.

[0133] When an element or layer is referred to as “on top of,” “connected to,” “linked to,” or “joined,” it may be directly on top of, connected to, or joined to another element or layer, and there may also be an intervening element or layer. In contrast, when an element is referred to as “directly on top of,” “directly connected to,” “directly linked to,” or “directly joined to” another element or layer, there is no intervening element or layer. Other words used to describe relationships between elements should be interpreted in a similar manner (e.g., “between” vs. “directly between,” “adjacent” vs. “directly adjacent,” etc.). As used in this specification, the term “and / or” includes any combination and all combinations relating to one or more of the enumerated items in question. That is, the statement A and / or B means at least one of A and B.

[0134] Spatially relative terms such as “inside,” “outside,” “back,” “below,” “low,” “above,” and “high” are used here to facilitate descriptions of the relationship between one element or feature and other elements or features, as illustrated. Spatially relative terms may be intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, if the device in the drawing is turned upside down, an element described as “below” or “directly below” another element or feature will be oriented “above” the other element or feature. Thus, the term “below” can encompass both up and down orientations. The device may also be oriented in other directions (it may be rotated 90 degrees or in other directions), and the spatially relative descriptors used in this specification will be interpreted accordingly.

[0135] (Disclosure of Technical Ideas) This specification discloses several technical ideas as described in the following paragraphs. Some paragraphs may be written in a multiple dependent form, where subsequent paragraphs optionally refer to preceding paragraphs. Furthermore, some paragraphs may be written in a multiple dependent form, where they refer to other multiple dependent forms. These paragraphs written in multiple dependent forms define several technical ideas.

[0136] <Technical Concept 1> A capacitor module connected to a power converter (5) including a switching element, comprising: a power conductor (30) including a positive electrode conductor (30P) connected to the DC positive electrode terminal of the power converter and a negative electrode conductor (30N) connected to the DC negative electrode terminal of the power converter; and an X capacitor (20) connected to the positive electrode conductor and the negative electrode conductor, wherein the X capacitor has a first X capacitor (21) and a second X capacitor (22) connected in parallel between the positive electrode conductor and the negative electrode conductor, the positive electrode conductor and the negative electrode conductor intersect, and each of the positive electrode conductor and the negative electrode conductor has a housing portion (33P, 33N) with a bottom portion (331) of a predetermined depth relative to the opening to accommodate at least a part of the X capacitor, a first terminal portion (31P, 31N), and a second terminal portion (32P, 32N) on the power converter side provided at a position away from the first terminal portion. A capacitor module in which the first X capacitor is connected to the first terminal portion of the positive conductor and the second terminal portion of the negative conductor, the second X capacitor is connected to the second terminal portion of the positive conductor and the first terminal portion of the negative conductor, in each of the positive conductor and the negative conductor, the first terminal portion is connected to one of the open ends of the housing, and the second terminal portion is connected to the other open end of the housing, and the housing is recessed relative to the first terminal portion and the second terminal portion.

[0137] <Technical Concept 2> A capacitor module according to Technical Concept 1, comprising a fixing portion (42) for fixing to a support member (70), wherein the housing portion opens in the opposite direction to the fixing direction of the fixing portion to the support member.

[0138] <Technical Concept 3> The capacitor module according to Technical Concept 2, wherein in the depth direction of the housing, the bottom is located below the upper end (422) of the fixing part.

[0139] <Technical Concept 4> The capacitor module according to any one of Technical Concepts 1 to 3, wherein the X capacitor has a capacitor element (231) and a lead terminal (24) connected to the capacitor element, and the lead terminal extends in a direction different from the depth direction of the housing.

[0140] <Technical Concept 5> A capacitor module according to any one of Technical Concepts 1 to 4, wherein the depth of the housing is longer than the length of the bottom in a direction perpendicular to the direction in which the first X capacitor and the second X capacitor are aligned and the direction of the depth of the housing.

[0141] <Technical Concept 6> A capacitor module according to any one of Technical Concepts 1 to 5, wherein, in a plan view of the housing in the depth direction, the length of the bottom in the direction in which the first X capacitor and the second X capacitor are aligned is longer than the length of the bottom in the direction perpendicular to the depth direction and the direction perpendicular to the alignment direction of the housing.

[0142] <Technical Concept 7> The housing portion comprises a bottom portion, a first side portion (332) connecting the bottom portion and the first terminal portion, and a second side portion (333) connecting the bottom portion and the second terminal portion, wherein the minimum cross-sectional area of ​​the bottom portion is smaller than the minimum cross-sectional area of ​​the first side portion and the minimum cross-sectional area of ​​the second side portion, as described in any one of Technical Concepts 1 to 6.

[0143] <Technical Concept 8> The positive electrode conductor and the negative electrode conductor intersect at the bottom, and the minimum value of the cross-sectional area of ​​the housing for the conductor whose bottom is closer to the opening of the housing is smaller than the minimum value of the cross-sectional area of ​​the housing for the conductor whose bottom is further away from the opening of the housing, as described in any one of Technical Concepts 1 to 7.

[0144] <Technical Concept 9> The positive electrode conductor and the negative electrode conductor intersect at the bottom, and the number of bends in the conductor on the side of the positive electrode conductor and the negative electrode conductor whose bottom is closer to the opening of the housing is greater than the number of bends in the conductor on the side of the bottom farther from the opening of the housing is greater, as described in any one of Technical Concepts 1 to 8.

[0145] <Technical Concept 10> A capacitor module according to any one of Technical Concepts 1 to 9, wherein the main surface (232) of the X capacitor faces the bottom.

[0146] <Technical Concept 11> A capacitor module according to any one of Technical Concepts 1 to 10, wherein the capacitor element of the X capacitor is arranged between the connection portion between the positive conductor and the negative conductor and the lead terminal of the first X capacitor, and the connection portion between the positive conductor and the negative conductor and the lead terminal of the second X capacitor.

[0147] <Technical Concept 12> A capacitor module according to any one of Technical Concepts 1 to 11, wherein at least in the housing section, an insulating member (50) is interposed between the positive electrode conductor and the negative electrode conductor.

[0148] <Technical Concept 13> A capacitor module according to any one of Technical Concepts 1 to 6, comprising a cooler (73) for cooling the bottom.

[0149] <Technical Concept 14> The capacitor module according to technical concept 13, wherein the positive electrode conductor and the negative electrode conductor intersect at the bottom, and the first conductor, which is one of the positive electrode conductor and the negative electrode conductor and is the conductor closer to the opening of the housing, has a straddling portion (3311) that straddles the second conductor, which is the other of the positive electrode conductor and the negative electrode conductor, a first end (3312) connected to one of the ends of the straddling portion, and a second end (3313) connected to the other end of the straddling portion, and the first end and the second end are provided in a position closer to the cooler than the straddling portion.

[0150] <Technical Concept 15> The housing portion comprises a bottom portion, a first side portion (332) connecting the bottom portion and the first terminal portion, and a second side portion (333) connecting the bottom portion and the second terminal portion, wherein the minimum cross-sectional area of ​​the bottom portion is smaller than the minimum cross-sectional area of ​​the first side portion and the minimum cross-sectional area of ​​the second side portion, as described in technical concept 13 or technical concept 14.

[0151] <Technical Concept 16> A capacitor module according to any one of Technical Concepts 1 to 15, comprising a fixed part (42) that is fixed to a support member (70) and provides a reference potential, and a Y capacitor (80) that is electrically connected to the power supply conductor and the fixed part.

[0152] <Technical Concept 17> The capacitor module according to technical concept 16, wherein the Y capacitor is arranged between the X capacitor and the bottom in the housing.

[0153] <Technical Concept 18> A capacitor module according to technical concept 16 or technical concept 17, comprising a plurality of fixed parts, a base conductor (85) connecting the plurality of fixed parts, the Y capacitor having a first Y capacitor (801P, 801N) and a second Y capacitor (802P, 802N) connected in parallel between the power supply conductor and the base conductor, a part of the base conductor being positioned between the X capacitor and the power supply conductor, and the base conductor and the power supply conductor intersecting.

[0154] <Technical Concept 19> A capacitor module according to any one of Technical Concepts 1 to 18, comprising a core (90) arranged outside the housing so as to pass the power supply conductor through it.

[0155] <Technical Concept 20> A power conversion device comprising: a power converter (5) including a switching element; a capacitor module (7) connected to the power converter, wherein the capacitor module comprises: a power conductor (30) including a positive electrode conductor (30P) connected to the DC positive electrode terminal of the power converter and a negative electrode conductor (30N) connected to the DC negative electrode terminal of the power converter; and an X capacitor (20) connected to the positive electrode conductor and the negative electrode conductor, wherein the X capacitor has a first X capacitor (21) and a second X capacitor (22) connected in parallel between the positive electrode conductor and the negative electrode conductor, and the positive electrode conductor and the negative electrode conductor intersect. Each of the positive and negative conductors has a housing portion (33P, 33N) with a bottom portion (331) of a predetermined depth relative to the opening to accommodate at least a portion of the X capacitor, a first terminal portion (31P, 31N), and a second terminal portion (32P, 32N) on the power converter side provided at a position separate from the first terminal portion, the first X capacitor being connected to the first terminal portion of the positive conductor and the second terminal portion of the negative conductor, the second X capacitor being connected to the second terminal portion of the positive conductor and the first terminal portion of the negative conductor, in each of the positive and negative conductors, the first terminal portion is connected to one of the opening ends of the housing portion and the second terminal portion is connected to the other opening end of the housing portion, and the housing portion is recessed relative to the first and second terminal portions, in a power converter.

Claims

1. A capacitor module connected to a power converter (5) including a switching element, comprising: a power conductor (30) including a positive electrode conductor (30P) connected to the DC positive terminal of the power converter and a negative electrode conductor (30N) connected to the DC negative terminal of the power converter; and an X capacitor (20) connected to the positive electrode conductor and the negative electrode conductor, wherein the X capacitor has a first X capacitor (21) and a second X capacitor (22) connected in parallel between the positive electrode conductor and the negative electrode conductor, the positive electrode conductor and the negative electrode conductor intersect, and each of the positive electrode conductor and the negative electrode conductor has a housing portion (33P, 33N) with a bottom portion (331) of a predetermined depth relative to the opening to accommodate at least a part of the X capacitor, a first terminal portion (31P, 31N), and a second terminal portion (32P, 32N) on the power converter side provided at a position away from the first terminal portion. A capacitor module in which the first X capacitor is connected to the first terminal portion of the positive conductor and the second terminal portion of the negative conductor, the second X capacitor is connected to the second terminal portion of the positive conductor and the first terminal portion of the negative conductor, in each of the positive conductor and the negative conductor, the first terminal portion is connected to one of the open ends of the housing, and the second terminal portion is connected to the other open end of the housing, and the housing is recessed relative to the first terminal portion and the second terminal portion.

2. The capacitor module according to claim 1, comprising a fixing portion (42) for fixing to a support member (70), wherein the housing portion opens in the direction opposite to the direction in which the fixing portion is fixed to the support member.

3. The capacitor module according to claim 2, wherein in the depth direction of the housing portion, the bottom portion is located below the upper end (422) of the fixing portion.

4. The capacitor module according to claim 1, wherein the X capacitor comprises a capacitor element (231) and a lead terminal (24) connected to the capacitor element, and the lead terminal extends in a direction different from the depth direction of the housing portion.

5. The capacitor module according to claim 1, wherein the depth of the housing is longer than the length of the bottom in a direction perpendicular to the direction in which the first X capacitor and the second X capacitor are aligned and the direction of the depth of the housing.

6. In a plan view of the housing in the depth direction, the length of the bottom in the direction in which the first X capacitor and the second X capacitor are aligned is longer than the length of the bottom in the direction perpendicular to the depth direction and the direction in which the housing is aligned, according to claim 1.

7. The capacitor module according to claim 1, wherein the housing portion has a bottom portion, a first side portion (332) connecting the bottom portion and the first terminal portion, and a second side portion (333) connecting the bottom portion and the second terminal portion, and the minimum cross-sectional area of ​​the bottom portion is smaller than the minimum cross-sectional area of ​​the first side portion and the minimum cross-sectional area of ​​the second side portion.

8. The capacitor module according to claim 1, wherein the positive electrode conductor and the negative electrode conductor intersect at the bottom, and the minimum value of the cross-sectional area of ​​the housing for the conductor whose bottom is closer to the opening of the housing is smaller than the minimum value of the cross-sectional area of ​​the housing for the conductor whose bottom is further away from the opening of the housing.

9. The capacitor module according to claim 1, wherein the positive electrode conductor and the negative electrode conductor intersect at the bottom, and the number of bends in the conductor on the side of the positive electrode conductor and the negative electrode conductor whose bottom is closer to the opening of the housing is greater than the number of bends in the conductor on the side of the conductor whose bottom is further away from the opening of the housing.

10. The capacitor module according to claim 1, wherein the main surface (232) of the X capacitor faces the bottom.

11. The capacitor module according to claim 1, wherein the capacitor element of the X capacitor is arranged between the connection portion between the positive electrode conductor and the negative electrode conductor and the lead terminal of the first X capacitor, and the connection portion between the positive electrode conductor and the negative electrode conductor and the lead terminal of the second X capacitor.

12. The capacitor module according to claim 1, further comprising an insulating member (50) interposed between the positive electrode conductor and the negative electrode conductor in at least the housing portion.

13. The capacitor module according to claim 1, further comprising a cooler (73) for cooling the bottom portion.

14. The capacitor module according to claim 13, wherein the positive electrode conductor and the negative electrode conductor intersect at the bottom, and the first conductor, which is one of the positive electrode conductor and the negative electrode conductor and is the conductor closer to the opening of the housing, has a straddling portion (3311) that straddles the second conductor, which is the other of the positive electrode conductor and the other negative electrode conductor, a first end (3312) connected to one of the ends of the straddling portion, and a second end (3313) connected to the other end of the straddling portion, and the first end and the second end are provided in a position closer to the cooler than the straddling portion.

15. The capacitor module according to claim 13, wherein the housing portion has a bottom portion, a first side portion (332) connecting the bottom portion and the first terminal portion, and a second side portion (333) connecting the bottom portion and the second terminal portion, and the minimum cross-sectional area of ​​the bottom portion is smaller than the minimum cross-sectional area of ​​the first side portion and the minimum cross-sectional area of ​​the second side portion.

16. The capacitor module according to claim 1, comprising a fixed part (42) that is fixed to a support member (70) and provides a reference potential, and a Y capacitor (80) electrically connected to the power conductor and the fixed part.

17. The capacitor module according to claim 16, wherein the Y capacitor is disposed between the X capacitor and the bottom portion in the housing portion.

18. The capacitor module according to claim 16, comprising a plurality of the fixed parts, a base conductor (85) connecting the plurality of fixed parts, the Y capacitor having a first Y capacitor (801P, 801N) and a second Y capacitor (802P, 802N) connected in parallel between the power supply conductor and the base conductor, a part of the base conductor being positioned between the X capacitor and the power supply conductor, and the base conductor and the power supply conductor intersecting.

19. The capacitor module according to claim 1, further comprising a core (90) positioned outside the housing so as to pass the power supply conductor through it.

20. A power conversion device comprising: a power converter (5) including a switching element; and a capacitor module (7) connected to the power converter, wherein the capacitor module comprises: a power conductor (30) including a positive electrode conductor (30P) connected to the DC positive terminal of the power converter and a negative electrode conductor (30N) connected to the DC negative terminal of the power converter; and an X capacitor (20) connected to the positive electrode conductor and the negative electrode conductor, wherein the X capacitor has a first X capacitor (21) and a second X capacitor (22) connected in parallel between the positive electrode conductor and the negative electrode conductor, and the positive electrode conductor and the negative electrode conductor intersect. Each of the positive and negative conductors has a housing portion (33P, 33N) with a bottom portion (331) of a predetermined depth relative to the opening to accommodate at least a portion of the X capacitor, a first terminal portion (31P, 31N), and a second terminal portion (32P, 32N) on the power converter side provided at a position separate from the first terminal portion, the first X capacitor being connected to the first terminal portion of the positive conductor and the second terminal portion of the negative conductor, the second X capacitor being connected to the second terminal portion of the positive conductor and the first terminal portion of the negative conductor, in each of the positive and negative conductors, the first terminal portion is connected to one of the opening ends of the housing portion and the second terminal portion is connected to the other opening end of the housing portion, and the housing portion is recessed relative to the first and second terminal portions, in a power converter.

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