JP2016082745A - Power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the propagation of a noise generated in a switching circuit to a housing while maintaining cooling performance of a cooling unit in a power supply device having the switching circuit.SOLUTION: The power supply device includes: a switching circuit; a cooling unit 30 for cooling the switching circuit; a housing 50 for accommodating the switching circuit and the cooling unit 30; a conductive unit 40 for connecting between the cooling unit 30 and the housing 50; and a member disposed between the cooling unit 30 and the housing 50. The member is formed of at least one of a dielectric having a relative permittivity larger than that of air and an induction member having a relative permeability larger than 1. A parallel resonance circuit is formed between the cooling unit 30 and the housing 50.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply device.

  In an inverter device for supplying and controlling necessary voltages and currents by applying ON and OFF signals to a plurality of semiconductor power switching elements mounted via mounting portions in a grounded casing and varying their conduction times. There is known an inverter device in which a mounting portion made of a high-insulation and high-thermal-conductivity material having a low rate is integrated with a cooling fin and a semiconductor power switching element is mounted on the mounting portion (Patent Document 1).

Japanese Patent Laid-Open No. 9-289889

  However, in the conventional inverter device, since an insulating material is used for the cooling fin, there is a problem that heat conduction is deteriorated and cooling performance is lowered.

  The problem to be solved by the present invention is to suppress the propagation of noise generated in the switching circuit to the housing while maintaining the cooling performance in the power supply device including the switching circuit.

  The present invention includes a casing that accommodates the switching circuit and the cooling unit, a conductor that connects the cooling unit and the casing, and a member that is disposed between the cooling unit and the casing. Is formed of at least one of a dielectric having a relative permittivity greater than air or a derivative having a non-permeability greater than 1, and the parallel resonance circuit is formed between the cooling unit and the housing. Solve.

  Since the present invention is configured so that noise having a desired frequency is difficult to propagate from the cooling unit to the housing by the parallel resonance circuit, it is possible to suppress propagation of noise generated in the switching circuit to the housing.

FIG. 1 is a perspective view of a power converter according to an embodiment of the present invention. FIG. 2 is a sectional view taken along line II-II in FIG. FIG. 3 is a circuit diagram for explaining a connection state of each component of the power conversion device. FIG. 4 is a graph showing impedance characteristics. FIG. 5 is a perspective view of the conductive portion. FIG. 6 is a perspective view of the cooling unit, the support unit, and the housing. FIG. 7 is a graph showing noise characteristics in a predetermined frequency band. FIG. 8 is a cross-sectional view of a power converter according to another embodiment of the present invention. FIG. 9 is a cross-sectional view of a power converter according to another embodiment of the present invention. FIG. 10 is a sectional view taken along line XX in FIG. FIG. 11 is a cross-sectional view of a power converter according to another embodiment of the present invention. FIG. 12 is a cross-sectional view of a power converter according to another embodiment of the present invention. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<< First Embodiment >>
A power supply device according to an embodiment of the present invention will be described. The power supply device is provided in a vehicle, for example, and is used as a device that converts the power of the in-vehicle battery. In addition, below, after mentioning a power converter as an example of a power supply device, an embodiment will be described. The power supply device is not limited to a power conversion device, and may be a device including a circuit that generates high-frequency noise. Further, the power supply device is not limited to the vehicle, and may be provided in another device or system.

  FIG. 1 is a perspective view of the power converter. 2 is a cross-sectional view taken along the line II-II in FIG. The power conversion device 1 includes a power supply circuit 10, an insulating unit 20, a cooling unit 30, a conductive unit 40, a housing 50, and a support unit 60. In FIG. 1, the power supply circuit 10, the insulating unit 20, and the cooling unit 30 are housed in the housing 50 and are not visible from the outside, but are illustrated for explanation. The same applies to the perspective views shown in other embodiments.

  The power supply circuit 10 is a switching circuit that generates high-frequency noise. The power supply circuit is provided inside the housing 50 and has a power module. The power module is a member obtained by modularizing a power semiconductor element (switching element) such as an IGBT. The power semiconductor element switches the switch on and off by a switching signal transmitted from the control circuit. Then, the power module converts the input power by switching on and off of the power semiconductor element.

  As an example of the power supply circuit 10, an inverter is used. When the power conversion device 1 is applied to a vehicle drive system, a battery for supplying DC power is connected to the input side of the inverter. A motor that obtains rotational force from the output power of the inverter is connected to the output side of the inverter. The inverter has a switch group. The switch group includes a switch and a control circuit configured by modularized power semiconductor elements. Then, the switches included in the switch group are switched on and off, and power is converted. At this time, the power module generates noise as the switches included in the switch group are turned on and off. The power supply circuit 10 is not limited to an inverter, and may be, for example, a converter (non-insulated booster circuit), an isolated converter, or the like. The power supply circuit 10 is formed to be a rectangular parallelepiped.

  The insulating unit 20 is provided between the power supply circuit 10 and the cooling unit 30 and is a member for insulating between the power supply circuit 10 and the cooling unit 30. For example, an insulating sheet is used for the insulating unit 20, and the insulating sheet is sandwiched between the power supply circuit 10 and the cooling unit 30.

  The cooling unit 30 is a cooler for cooling the power supply circuit 10. For example, a heat sink is used for the cooling unit 30. The cooling unit 30 is formed of a conductive material such as metal. The power module in the power supply circuit 10 generates heat at a loss point in the circuit. The cooling unit 30 cools the heat generated at the loss point of the power module. The cooling unit 30 is formed to be a rectangular parallelepiped. The longitudinal direction of the cooling unit 30 is the y direction. And the surface along a longitudinal direction among the surfaces of the cooling unit 30 becomes a surface (yz surface of FIG. 1) on which the power supply circuit 10 is placed. Then, the power supply circuit 10, the insulating unit 20, and the cooling unit 30 are arranged so that the bonding surface between the power circuit 10 and the insulating unit 20 and the connection surface between the insulating unit 20 and the cooling unit 30 are parallel to the yz plane. Has been placed.

  The conductive part 40 is constituted by a fastening member such as a bolt, and is a member for connecting the cooling part 30 and the housing 50. The conductive part 40 has a shaft part 41 and a head part 42. A groove (male screw) is provided on a side surface of the cylindrical shaft portion 41. The cooling unit 30, the housing 50, and the support unit 60 are provided with insertion holes. The insertion hole is a hole for inserting the shaft portion 41, and a groove (female screw) is provided on the surface of the insertion hole. When the shaft portion 41 is inserted into the insertion hole, the cooling portion 30, the support portion 60, and the housing 50 are fastened by the conductive portion 40. Thereby, the conductive unit 40 fixes the cooling unit 30 to the housing 50. The conductive unit 40 is not limited to a fastening member, and may be any configuration as long as the cooling unit 30 is fixed to the housing 50 while the support unit 60 is sandwiched between the cooling unit 30 and the housing 50.

  The conductive part 40 is a member having conductivity. Therefore, when the cooling unit 30 is fixed to the housing 50 by the conductive unit 40, the cooling unit 30 and the housing 50 are electrically connected. Further, the conductive portion 40 is inserted into the cooling portion 30 and the housing 50 in such a direction that the direction of the axial center of the shaft portion 41 (the X direction in FIG. 2) is a conduction direction of leakage current. The leakage current is a current that flows from the power supply circuit 10 toward the cooling unit 30. High frequency noise generated in the power supply circuit 10 flows to the cooling unit 30 via the insulating unit 20. At this time, the current flowing through the cooling unit 30 becomes a leakage current. In the present embodiment, the power supply circuit 10 is arranged in the direction along the X axis in FIGS. 1 and 2 and is disposed above the cooling unit 30, so that the leakage current conduction direction is along the X axis. In FIG. 2, the cooling unit 30 and the housing 50 are connected by the two conductive units 40, but the number of the conductive units 40 is not limited to two and may be three or more.

  The housing 50 accommodates the power supply circuit 10, the insulating unit 20, the cooling unit 30, and the support unit 60. The housing 50 is made of metal or the like and has conductivity. Moreover, the housing | casing 50 is formed so that it may become a rectangular parallelepiped shape.

  The support unit 60 is a member that supports the cooling unit 30 in a state where the cooling unit 30 does not contact the housing 50. The support unit 60 is disposed between the cooling unit 30 and the housing 50. The support part 60 is formed of a dielectric having a relative dielectric constant larger than that of air. The support part 60 is formed in a plate shape so as to be along the opposing surface of the cooling part 30 and the opposing surface of the housing 50. The facing surface of the cooling unit 30 is a surface facing the casing 50 among the surfaces of the rectangular parallelepiped cooling unit 30. The facing surface of the housing 50 is a surface on the inner side of the housing 50 that faces the bottom surface of the cooling unit 30.

  Next, a connection state of each component of the power conversion device and a parallel resonance circuit formed between the cooling unit 30 and the housing 50 will be described with reference to FIG. FIG. 3 is a circuit diagram for explaining a connection state of each component of the power conversion device.

  The power supply circuit 10 and the cooling unit 30 are insulated from each other by the insulating unit 20, but a capacitance component is formed between the power supply circuit 10 and the cooling unit 30. Therefore, the noise generated in the power supply circuit 10 propagates to the cooling unit 30 via the coupling capacitance between the power supply circuit 10 and the cooling unit 30.

  Between the cooling unit 30 and the housing 50, an LC resonance circuit in which a capacitive component (Ca) and an inductive component (La) are connected in parallel is formed. A support unit 60 is disposed between the cooling unit 30 and the housing 50, and the support unit 60 is a dielectric having a relative dielectric constant larger than that of air. Therefore, the cooling unit 30 and the housing 50 are capacitively coupled, and a capacitive component (Ca) is formed between the cooling unit 30 and the housing 50. The inductive component (La) is an inductance that the conductive portion 40 has.

  When the impedance Z of the LC resonance circuit is assumed, the impedance is expressed by the following formula (1).

ただし、ωは角周波数であって、ω＝２πｆ_ｒで表される。ｆ_ｒはＬＣ共振回路の共振周波数である。

However, ω is an angular frequency is represented by ω = 2πf _{r. fr} is the resonance frequency of the LC resonance circuit.

From the equation (1), the resonance frequency of the LC resonance circuit is expressed by the following equation (2).

  The impedance characteristic of the LC resonance circuit is represented by the graph of FIG. FIG. 4 is a graph showing the impedance characteristics, where the horizontal axis indicates the frequency and the vertical axis indicates the magnitude of the impedance.

As shown in FIG. 4, the impedance of the LC resonant circuit, the most high at the resonance frequency (f _r), increases at a specific frequency band around the resonance frequency (f _r). Therefore, when the frequency of the leakage current is included in a specific frequency band centered on the resonance frequency (f _r ), the impedance between the cooling unit 30 and the housing 50 is increased, and thus the leakage current is It becomes difficult to flow to the body 50. As shown in the equation (2), the resonance frequency (f _r ) is set by the capacitive component (Ca) and the inductive component (La), and the capacitive component (Ca) and the inductive component (La) are the cooling unit 30 and the conductive unit. 40, the housing 50, and the support 60 can be derived from various parameters.

  Here, parameters for deriving the inductive component (La) and the capacitive component (Ca) will be described with reference to FIGS. FIG. 5 is a perspective view of the conductive portion 40, and FIG. 6 is a perspective view of the cooling portion 30, the support portion 60, and the housing 50.

For ease of explanation, it is assumed that the conductive portion 40 is formed of a rectangular parallelepiped conductor as shown in FIG. Then, as parameters for defining the inductive component (La), the width of the conductive portion 40 is w, the height is H, and the length is L. Further, the magnetic permeability in vacuum is μ ₀ and the non-magnetic permeability is μ _r . The induction component (La) is represented by the following formula (3).

As shown in FIG. 6, as parameters for defining the capacitance component (Ca), the area of the facing surface of the cooling unit 30 and the area of the facing surface of the housing 50 are S, and the facing surface of the cooling unit 30 and the housing The distance between the 50 opposing surfaces is d. Further, the dielectric constant of vacuum is ε ₀ and the relative dielectric constant is ε _r . The capacitance component (Ca) is represented by the following formula (4).

  Of the high frequency noise generated in the power supply circuit 10, the frequency band of the noise to be suppressed is determined. For example, when the power conversion device 1 is provided in a vehicle, the frequency band to be suppressed is set to the radio reception band in order to prevent interference with the in-vehicle radio. Then, the capacitance component (Ca) and the induction component (La) are derived from the equations (1) and (2) so that the resonance frequency (fr) falls within the set frequency band. And a parameter is prescribed | regulated by Formula (3) and Formula (4) so that the derived | led-out capacitance component (Ca) and induction | guidance | derivation component (La) may be satisfy | filled. Thereby, the resonance frequency (fr) is set according to the frequency of the high frequency noise generated in the power supply circuit 10.

  For example, assume that the center frequency of the frequency band of noise to be suppressed is 100 [MHz]. 100 [MHz] is an FM radio reception band, and is a frequency that is required to be regulated by a noise standard defined by, for example, the International Special Committee on Radio Interference (CISPR). When the inductive component (La) of the conductive portion 40 is 10 [nH], the capacitive component (Ca) formed between the cooling portion 30 and the housing 50 is about 25 [pH]. The relative dielectric constant of the support part 60, the area (S) where the cooling part 30 and the casing 50 face each other, and the distance (d) between the cooling part 30 and the casing 50 are approximately 25 for the capacitive component (Ca). By being designed to be [pH], the resonance frequency (fr) is 100 [MHz]. This prevents leakage current from flowing from the cooling unit 30 to the housing 50 in a specific frequency band centered on 100 [MHz]. As a result, propagation of noise generated in the switching circuit to the housing 50 can be suppressed.

  The cooling unit 30 is connected to the housing 50 by the conductive unit 40. Since the heat conduction path from the cooling unit 30 to the housing 50 is connected by metal, the heat resistance of the conduction path is small. Thereby, the power converter device 1 can also maintain cooling performance.

  FIG. 7 is a graph showing noise characteristics in a frequency band from 60 MHz to 140 MHz. In FIG. 7, the horizontal axis represents frequency, and the vertical axis represents noise magnitude in dB. Graph a shows characteristics when the conductive portion 40 and the support portion 60 are not provided, and graph b shows characteristics when the conductive portion 40 and the support portion 60 are provided. As shown in FIG. 7, the leakage current flowing from the cooling unit 30 to the housing 50 can be reduced by 24 dB or more.

  As described above, in the present embodiment, the support portion 60 is formed of a dielectric having a relative dielectric constant larger than that of air, and the support portion 60 is disposed between the cooling portion 30 and the housing 50. A parallel resonant circuit is formed between the cooling unit 30 and the housing 50. Thereby, since impedance can be increased in a desired frequency band, it is possible to suppress leakage of noise generated in the power supply circuit 10 from the cooling unit 30 to the housing 50 while maintaining cooling performance.

  In this embodiment, the resonance frequency of the parallel resonance circuit is set according to the frequency of noise generated in the power supply circuit 10. Thereby, the noise which has a frequency which does not want to leak outside the power converter device 1 among high frequency noises can be suppressed effectively.

  In the present embodiment, a capacitive component is formed between the cooling unit 30 and the housing 50, and the parallel resonant circuit is an LC resonant circuit in which the capacitive component and the inductive component of the conductive unit 40 are connected in parallel. . Thereby, the noise generated in the power supply circuit 10 can be prevented from leaking from the cooling unit 30 to the housing 50.

  The power supply circuit 10 corresponds to the “switching circuit” of the present invention, and the support portion 60 corresponds to the “member” of the present invention.

<< Second Embodiment >>
FIG. 8 is a part of a cross-sectional view of a power converter according to another embodiment of the invention. The cross section shown in FIG. 8 corresponds to the cross section taken along the line II-II in FIG. In this embodiment, a part of structure of a support part differs with respect to 1st Embodiment mentioned above. Other configurations are the same as those in the first embodiment described above, and the description thereof is incorporated.

  The support unit 60 is disposed between the cooling unit 30 and the housing 50. The support portion 60 is made of a derivative having a relative permeability greater than 1. Moreover, the support part 60 is formed so that the relative dielectric constant becomes larger. A plurality of support portions 60 are provided so as to correspond to the plurality of conductive portions 40. One support portion 60 among the plurality of support portions 60 is provided so as to cover a part of the shaft portion 41 of one conductive portion 40. The other support part 60 among the plurality of support parts 60 is provided so as to cover a part of the shaft part 41 of the other conductive part 40.

  A gap 61 is provided between the plurality of support portions 60. The upper surface of the gap 61 is covered with the bottom surface of the cooling unit 30, and the lower surface of the gap 61 is covered with the surface of the housing 50.

  Between the cooling unit 30 and the housing 50, an LC resonance circuit in which a capacitive component (Ca) and an inductive component (La) are connected in parallel is formed. The gap 61 is held between the conductive cooling unit 30 and the housing 50. Therefore, a capacitive component is formed between the cooling unit 30 and the housing 50. Further, since the support portion 60 also functions as a dielectric having a relative dielectric constant larger than that of air, a capacitive component is also generated in a portion that holds the support portion 60. The capacitive component (Ca) is a combination of the capacitive component in the gap 61 and the capacitive component in the support portion 60. The inductive component (La) is an inductance that the support unit 60 has.

  As described above, in the present embodiment, the support portion 60 is formed of a derivative having a relative permeability greater than 1, and the support portion 60 is disposed between the cooling portion 30 and the housing 50. A parallel resonant circuit is formed between the cooling unit and the housing. Thereby, since impedance can be increased in a desired frequency band, it is possible to suppress leakage of noise generated in the power supply circuit 10 from the cooling unit 30 to the housing 50 while maintaining cooling performance.

  In this embodiment, a capacitive component is formed between the cooling unit 30 and the casing 50, and the parallel resonant circuit is an LC resonant circuit in which the capacitive component and the inductive component of the support unit 60 are connected in parallel. . Thereby, the noise generated in the power supply circuit 10 can be prevented from leaking from the cooling unit 30 to the housing 50.

  In the present embodiment, the gap 61 is provided between the cooling unit 30 and the housing 50, so that the support unit 60 is not provided on the entire lower surface of the cooling unit 30. Therefore, when defining the capacitance value (Ca size) required in the parallel resonant circuit, in addition to the thickness of the support portion 60, the area of the portion where the support portion 60 is provided (corresponding to the area S shown in FIG. 6). ), The capacitance value can be adjusted.

  In this embodiment, the support portion 60 is formed of a derivative having a relative permeability greater than 1 and a dielectric having a greater relative permittivity. However, the support portion 60 is formed only of a derivative having a relative permeability greater than 1. It may be formed.

<< Third Embodiment >>
FIG. 9 is a part of a cross-sectional view of a power conversion device according to another embodiment of the invention. 10 is a cross-sectional view taken along line XX of FIG. The cross section shown in FIG. 9 corresponds to the cross section taken along the line II-II in FIG. In this embodiment, the structure of the cooling part 30, the electroconductive part 40, and the support part 60 differs with respect to 1st Embodiment mentioned above. Other configurations are the same as those in the first embodiment described above, and the description thereof is incorporated.

  The cooling unit 30 includes a main body 31 and a plurality of fins 32. The main body 31 is a plate-like member. The plurality of fins 32 are members for increasing the surface area of the cooling unit 30, and are formed so as to extend from the surface (bottom surface) of the main body 31 toward the housing 50. The main body 31 and the plurality of fins 32 are integrally formed of the same metal.

  The conductive portion 40 is configured to be one fin 32. The conductive portion 40 is formed so as to extend from the surface of the main body portion 31 to the housing 50. One end of the conductive portion 40 is connected to the main body portion 31, and the other end of the conductive portion 40 is connected to the housing 50. As shown in FIG. 10, a slit is provided inside the conductive portion 40. By providing a plurality of slits, a plurality of plate-like conductive members along the XY plane are arranged. Thus, the conductive unit 40 also functions as the fins 32 of the cooling unit 30 while electrically connecting the cooling unit 30 and the housing 50.

  Of the plurality of fins 32, the fins 32 other than the conductive portion 40 are not connected to the housing 50, and the end portions of the fins 32 are open ends.

  The support part 60 is formed so as to cover the conductive part 40. The support part 60 is also filled between the slits of the conductive part 40. The support portion 60 is made of a derivative having a relative permeability greater than 1. Moreover, the support part 60 is formed so that a dielectric constant may become larger than air.

  Between the cooling unit 30 and the housing 50, an LC resonance circuit in which a capacitive component (Ca) and an inductive component (La) are connected in parallel is formed. As shown in FIG. 10, slits are provided inside the conductive portion 40, and a support portion 60 is filled between the slits. Since the portion holding the support portion 60 by the conductive portion 40 functions as a capacitor, a capacitance component (Ca) is formed. The inductive component (La) is an inductance that the support unit 60 has.

  As described above, in the present embodiment, the conductive part 40 is configured by the fins 32 of the cooling part 30. Moreover, in this embodiment, the electroconductive part 40 has a slit. Thereby, since impedance can be increased in a desired frequency band, it is possible to suppress leakage of noise generated in the power supply circuit 10 from the cooling unit 30 to the housing 50 while maintaining cooling performance.

  In the present embodiment, a plurality of conductive portions 40 may be provided, and the plurality of conductive portions 40 may be configured by a plurality of fins 32, respectively.

<< 4th Embodiment >>
FIG. 11 is a part of a cross-sectional view of a power converter according to another embodiment of the invention. The cross section shown in FIG. 11 corresponds to the cross section taken along the line II-II in FIG. The present embodiment differs from the first embodiment described above in the configuration of the conductive portion 40 and the support portion 60 and in that the substrate 70 is provided. Other configurations are the same as those in the first embodiment described above, and the description thereof is incorporated. In FIG. 11, for ease of illustration, the conductive portion 40 is represented by a circuit symbol.

  The support unit 60 is a member that supports the cooling unit 30 in a state where the cooling unit 30 does not contact the housing 50. The support unit 60 is disposed between the cooling unit 30 and the housing 50. Note that, unlike the first embodiment, the support portion 60 does not have an insertion hole for inserting the conductive portion 40.

  The substrate 70 is a substrate on which the power supply circuit 10 is mounted. The substrate 70 is formed in a plate shape, and the power supply circuit 10 is mounted on the surface of the substrate 70. Further, an inductor component such as a coil is mounted on the substrate 70. This inductor component becomes the conductive portion 40. One end of the conductive unit 40 is connected to the cooling unit 30, and the other end of the conductive unit 40 is connected to the housing 50. Thus, the conductive portion 40 is configured by an inductor component mounted on the board, and electrically connects the cooling portion 30 and the housing 50.

  As described above, in the present embodiment, the conductive portion 40 is configured by the inductor component mounted on the substrate 70. Thereby, since impedance can be increased in a desired frequency band, it is possible to suppress leakage of noise generated in the power supply circuit 10 from the cooling unit 30 to the housing 50 while maintaining cooling performance. Moreover, the magnitude | size of the induction component (La) of a parallel resonant circuit can be changed by adjusting the parameter of inductor components. Therefore, the impedance in a desired frequency band can be easily increased.

  In the present embodiment, the conductive portion 40 may be configured by a wiring pattern of the substrate 70 instead of the inductor component. The wiring pattern is formed on the surface of the substrate 70. The inductive component (La) of the parallel resonant circuit is the inductance of the wiring pattern. The conductive portion 40 may be configured by a wiring pattern and an inductor component.

<< 5th Embodiment >>
FIG. 12 is a perspective view of a power converter according to another embodiment of the invention. 13 is a cross-sectional view taken along line XIII-XIII in FIG. FIG. 14 is a sectional view taken along line XIV-XIV in FIG. In this embodiment, the structure of the cooling part 30, the electroconductive part 40, and the support part 60 differs with respect to 1st Embodiment mentioned above. Other configurations are the same as those in the first embodiment described above, and the description thereof is incorporated.

  The cooling unit 30 is a water-cooled cooler and includes a pipe 33 and a cover 34. The pipe 33 is a pipe for flowing water and is formed in a cylindrical shape. The pipe 33 is connected between the cooling unit 30 and the housing 50. The pipe 33 is made of metal. Therefore, the pipe 33 is a member that electrically connects the cooling unit 30 and the housing 50. In other words, in the present embodiment, the conductive member that connects the cooling unit 30 and the housing 50 is configured by the pipe 33 instead of the conductive unit 40 of the first embodiment.

  A side surface of the pipe 33 is covered with a cover 34. The cover 34 is formed of a derivative having a relative permeability greater than 1. The cover 34 is formed so that the relative dielectric constant is larger than that of air and larger than that of air. The cover 34 is formed in a cylindrical shape. The cover 34 covers a portion of the pipe 33 between the cooling unit 30 and the housing 50.

  Between the cooling unit 30 and the housing 50, an LC resonance circuit in which a capacitive component (Ca) and an inductive component (La) are connected in parallel is formed. The side surface of the cooling unit 30 and the side surface of the housing 50 are opposed to each other with the air layer interposed therebetween, and function as a capacitor. Further, since the cover 34 also functions as a dielectric having a relative dielectric constant larger than that of air, the portion that holds the cover 34 between the cooling unit 30 and the housing 50 also functions as a capacitor. The capacitive component (Ca) is a combination of these capacitive components. The inductive component (La) is an inductance that the cover 34 has.

  As described above, in the present embodiment, the conductive member (corresponding to the conductive portion of the present invention) that connects the cooling unit 30 and the housing 50 is constituted by a pipe through which water flows. Thereby, since impedance can be increased in a desired frequency band, it is possible to suppress leakage of noise generated in the power supply circuit 10 from the cooling unit 30 to the housing 50 while maintaining cooling performance.

  In the present embodiment, water is used as the refrigerant for cooling the power supply circuit 10, but the refrigerant may be a liquid other than water or a gas.

DESCRIPTION OF SYMBOLS 1 ... Power converter 10 ... Power supply circuit 20 ... Insulating part 30 ... Cooling part 31 ... Main-body part 32 ... Fin 33 ... Piping 34 ... Cover 40 ... Conductive part 41 ... Shaft part 42 ... Head 50 ... Housing 60 ... Support part 61 ... Gap 70 ... Substrate

Claims (8)

A switching circuit;
A cooling unit for cooling the switching circuit;
A housing for housing the switching circuit and the cooling unit;
A conductive part connecting between the cooling part and the housing;
A member disposed between the cooling unit and the housing;
The member is formed of at least one of a dielectric having a relative permittivity greater than air or a derivative having a relative permeability greater than 1.
A power supply apparatus, wherein a parallel resonant circuit is formed between the cooling unit and the housing. The power supply device according to claim 1, wherein
The power supply apparatus according to claim 1, wherein a resonance frequency of the parallel resonance circuit is set according to a frequency of noise generated in the switching circuit. The power supply device according to claim 1 or 2,
The conductive portion has an inductive component;
The parallel resonant circuit is an LC resonant circuit in which the inductive component and the capacitive component are connected in parallel.
The power supply device, wherein the capacitive component is formed between the cooling unit and the housing. The power supply device according to claim 1 or 2,
The member has an inductive component;
The parallel resonant circuit is an LC resonant circuit in which the inductive component and the capacitive component are connected in parallel.
The power supply device, wherein the capacitive component is formed between the cooling unit and the housing. In the power supply device according to any one of claims 1 to 4,
The power supply apparatus according to claim 1, wherein the conductive portion is configured by fins of the cooling portion. In the power supply device according to any one of claims 1 to 5,
The power supply device, wherein the conductive portion has a slit. In the power supply device according to any one of claims 1 to 4,
Equipped with a substrate,
The power supply device according to claim 1, wherein the conductive portion is configured by at least one of a wiring pattern formed on the substrate or an inductor component mounted on the substrate. In the power supply device according to any one of claims 1 to 4,
The cooling unit cools the switching circuit by flowing a refrigerant,
The conductive portion is constituted by a pipe through which the refrigerant flows.
A power supply device characterized by that.

Images