Power conversion device

Abstract

The invention provides a power conversion device. A power conversion device according to the present disclosure is provided with a housing and a power factor improvement circuit module. The housing has formed therein a flow path that travels in one surface. The power factor improvement circuit module includes a cooling plate, a power semiconductor, an electrolytic capacitor, and a resin mold. The cooling plate has thermal conductivity and is formed in a flat plate shape. The power semiconductor is fixed to the first main surface of the cooling plate such that the heat dissipation surface faces the first main surface and can exchange heat with the first main surface, and is electrically connected to the drive substrate. The electrolytic capacitor is disposed on the opposite side of the cooling plate with respect to the power semiconductor, and is electrically connected to the drive substrate. The resin mold is fixed to the first main surface of the cooling plate, is interposed at least between the power semiconductor and the electrolytic capacitor, and defines the position of the power semiconductor. A second main surface opposite to the first main surface of the cooling plate is thermally connected to the housing.

Description

Technical Field

[0001] The present disclosure relates to a power conversion device. Background Art

[0002] Conventionally, there has been a demand for miniaturization of power conversion devices such as chargers mounted on electric vehicles or the like due to limitations on mounting space, for example.

[0003] For example, Patent Document 1 discloses a technology in which a power conversion device is configured to have a power semiconductor, a smoothing capacitor, and a gate drive substrate built into the device, thereby miniaturizing the entire device.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 6749428 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] However, when converting high-current, high-voltage power, the power loss of power semiconductors increases, and the heat generated by the power semiconductors increases. In addition, the waste heat generated by the power semiconductors also has a greater impact on the surrounding area of ​​the power semiconductors, which may cause adverse effects such as thermal degradation of capacitors. In such a situation, when liquid cooling is used as a heat dissipation method, for example, there are cases where a vertical flow path is branched from a horizontal flow path to match the configuration of the power semiconductors. Due to the structure of this flow path, the refrigerant is retained in the flow path, making it impossible to dissipate heat effectively. Therefore, there is room for improvement in heat dissipation from power semiconductors.

[0009] One of the problems to be solved by the present disclosure is to achieve miniaturization of a power conversion device while taking heat dissipation into consideration.

[0010] Solutions for solving problems

[0011] The power conversion device disclosed herein includes a housing and a power factor improvement circuit module. The housing has a flow path formed within a single surface. The power factor improvement circuit module is detachably fixed to the housing. The power factor improvement circuit module includes a cooling plate, a power semiconductor, an electrolytic capacitor, and a resin mold. The cooling plate is thermally conductive and flat. The power semiconductor is fixed to the first main surface of the cooling plate with its heat dissipation surface facing the first main surface and capable of exchanging heat with the cooling plate. The power semiconductor is also electrically connected to a drive substrate. The electrolytic capacitor is positioned on the opposite side of the power semiconductor from the cooling plate, i.e., on the side of the drive substrate, and is electrically connected to the drive substrate. The resin mold is fixed to the first main surface of the cooling plate to define the position of the power semiconductor and is inserted at least between the power semiconductor and the electrolytic capacitor. When the power factor improvement circuit module is fixed to the housing, the second main surface of the cooling plate, which is the back surface of the first main surface, is thermally connected to the housing.

[0012] Effects of the Invention

[0013] According to the present disclosure, it is possible to achieve miniaturization of the power conversion device while taking heat dissipation into consideration. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a diagram showing an example of the configuration of a charging system including a power conversion device equipped with a power factor improvement circuit module according to an embodiment.

[0015] Figure 2 It shows Figure 1 A perspective view of an example of the structure of a power factor improvement circuit module.

[0016] Figure 3 It shows Figure 1 sectional view of an example of the structure of a power factor improvement circuit module. DETAILED DESCRIPTION

[0017] Hereinafter, embodiments of a power factor improvement circuit structure, a power factor improvement circuit module, a power conversion device, a vehicle, and a charging system according to the present disclosure will be described with reference to the accompanying drawings.

[0018] Furthermore, in the description of the present disclosure, components having the same or substantially the same functions as components described in a previous figure are denoted by the same reference numerals, and descriptions thereof may be omitted as appropriate. Furthermore, even when representing identical or substantially identical parts, the dimensions and proportions thereof may differ depending on the figure. Furthermore, for example, to ensure the visibility of the drawings, only the main components are denoted by reference numerals in the description of each drawing, and even components having the same or substantially the same functions as components described in a previous figure may not be denoted by reference numerals.

[0019] Furthermore, in the description of the present disclosure, components having the same or substantially the same functions may be described by adding alphanumeric characters at the end of the reference numerals to distinguish them from each other. Alternatively, when multiple components having the same or substantially the same functions are not distinguished from each other, they may be described collectively by omitting the alphanumeric characters at the end of the reference numerals.

[0020] Figure 1 1 is a diagram showing an example of the configuration of the charging system 1 according to the embodiment. Figure 1 As shown, the charging system 1 includes an AC power source 11, a load 13 and a power conversion device 2. In addition, Figure 1 The following describes an example in which a three-phase AC power source (external power source) as the AC power source 11 and a battery as the load 13 are connected to the power conversion device 2 .

[0021] As an example, the power conversion device 2 according to the embodiment can also be mounted on a vehicle as an onboard charger. For example, the power conversion device 2 can also be an onboard charger that converts AC power supplied from an external single-phase or three-phase AC power source 11 into DC power and supplies the converted DC power to a load 13 mounted on the vehicle. The load 13 can also be, for example, a battery, an inverter, a motor, or various electronic devices. In other words, the power conversion device 2 according to the embodiment can also be implemented as an onboard charger that converts AC power from an external AC power source 11 into DC power and supplies power to a load 13, such as a battery of a vehicle, which is charged using this DC power.

[0022] In addition, as a vehicle, various mobile bodies such as cars, trucks, buses, two-wheeled motor vehicles, electric scooters, etc. can be appropriately utilized, which can be configured to use power from a battery to drive or drive their accessories (electronic devices). As such electronic devices, for example, they can be navigation devices, audio devices, air conditioners, power windows, defoggers, ECUs (Electronic Control Units), GPS (Global Positioning System) modules, vehicle-mounted cameras, etc. In addition, the battery of the vehicle can store power for driving the driving motor (main motor), electronic devices, etc. mounted on the vehicle, and for example, any battery such as a lithium-ion battery, a nickel-metal hydride battery, an all-solid-state battery, etc. can be appropriately utilized. In addition, the power conversion device 2 involved in the embodiment is not limited to being provided in a vehicle, and can also be provided in, for example, an aircraft, a game device, an uninterruptible power supply device, etc.

[0023] The AC power source 11 is, for example, an external power source such as a power source mounted on a fast charging device or a commercial power source. Furthermore, the AC power source 11 is not limited to a single-phase AC power source or a three-phase AC power source (multi-phase AC power source), and a two-phase AC power source (multi-phase AC power source) may also be used. In this embodiment, as the AC power source 11 that supplies AC power to the power conversion device 2, a case where a single-phase or three-phase AC power source 11 can be used is exemplified. That is, in this embodiment, a power conversion device 2 is exemplified that is configured to operate regardless of whether the input of AC power is from a single-phase AC power source 11 or from a three-phase AC power source 11.

[0024] like Figure 1 As shown, the power conversion device 2 is electrically connected to the AC power source 11 via any one of a plurality of power lines L1 to L3, N. In addition, it is assumed that the plurality of power lines L1 to L3, N are electrically connected to the input end of the power conversion device 2, respectively. As an example, the power line L1 is an electric wire through which a single-phase current from a single-phase AC power source 11 flows. As an example, the power line L1 is an electric wire through which, for example, a U-phase (first phase) current from a three-phase AC power source 11 flows. As an example, the power line L2 is an electric wire that is not electrically connected to the single-phase AC power source 11. As an example, the power line L2 is an electric wire through which, for example, a V-phase (second phase) current from a three-phase AC power source 11 flows. As an example, the power line L3 is an electric wire that is not electrically connected to the single-phase AC power source 11. As an example, the power line L3 is an electric wire through which, for example, a W-phase (third phase) current from a three-phase AC power source 11 flows. As an example, the power supply line N is a neutral line, and is electrically connected to the single-phase or three-phase AC power supply 11 and the ground potential.

[0025] like Figure 1As shown, the power conversion device 2 includes a noise filter 4 , a power factor correction (PFC) circuit 5 , and a DC-DC conversion circuit 6 .

[0026] The noise filter 4 is used to suppress (cancel) the noise entering from the AC power supply 11 to the power conversion device 2 and the noise flowing out from the power conversion device 2 to the AC power supply 11. The noise filter 4 is electrically connected to the input end of the power conversion device 2 and the power factor improvement circuit 5 via a plurality of power lines L1 to L3 and N. Figure 1 In the example shown, noise filter 4 includes multiple coils provided on each of power lines L1 to L3 and N. These multiple coils are, for example, common-mode choke coils or normal-mode choke coils. Furthermore, a switch is provided in parallel with the coil provided on power line N. When turned on, this switch short-circuits the input terminal of power converter 2 and power factor correction circuit 5. This switch operates under the control of, for example, a control circuit (not shown) of power converter 2.

[0027] Furthermore, in the noise filter 4, a plurality of X capacitors may be provided between each coil and the input end of the power converter 2. The plurality of X capacitors are electrically connected between each of the power lines L1 to L3 and the power line N (between lines).

[0028] Furthermore, for example, a surge protection resistor may be provided in each of the power lines L1 to L3 after the noise filter 4. The surge protection resistor may be a surge current protection element such as a thermal fuse resistor, a cement resistor, or a thermistor, and suppresses the inrush current from flowing into the power factor improvement circuit 5.

[0029] The power factor improvement circuit 5 rectifies and smoothes the AC voltage from the AC power supply 11 to generate a DC voltage. Figure 1 As shown, power factor correction circuit 5 is electrically connected to noise filter 4 and DC-DC converter circuit 6. Power factor correction circuit 5 includes high-side MOSFETs 51a, 51c, 51e, and 51g, low-side MOSFETs 51b, 51d, 51f, and 51h, and electrolytic capacitors 53a and 53b. MOSFETs 51a to 51h are examples of the multiple power semiconductors of power converter 2.

[0030] MOSFET 51 rectifies the AC voltage from AC power source 11. For example, a simplified equivalent circuit for each MOSFET 51 is constructed using a switch, a capacitor, and a diode. Each MOSFET 51 operates in response to a control signal from the control circuit (not shown) of the power converter 2. For example, in this simplified equivalent circuit, the switch, capacitor, and diode are electrically connected in parallel. For example, in the high-side MOSFET 51, the anode and cathode of the diode are electrically connected to the input side (AC power source 11 side) and output side (load 13 side) of each MOSFET 51, respectively. On the other hand, in the low-side MOSFET 51, the anode and cathode of the diode are electrically connected to the output side and input side of each MOSFET 51, respectively. Each MOSFET 51 switches on and off at timings corresponding to control signals from the control circuit (not shown) of the power converter 2, switching the connection and disconnection of each MOSFET 51. While the switch is off, charge from the AC power source is accumulated in the capacitor, creating a potential difference between the input and output terminals of the capacitor. In addition, in this embodiment, turning on / off the internal switch is expressed as turning on / off the MOSFET 51 .

[0031] The input and output sides of each high-side MOSFET 51 are electrically connected to the coil of the noise filter 4 and the input side of each high-side MOSFET 61 of the DC-DC converter circuit 6, respectively. Furthermore, the input and output sides of each low-side MOSFET 51 are electrically connected to the coil of the noise filter 4 and the input side of each low-side MOSFET 61 of the DC-DC converter circuit 6, respectively.

[0032] MOSFETs 51a and 51b are an example of a pair of power semiconductors associated with power line L1, specifically corresponding to specific phases of the AC power supply 11. Specifically, MOSFETs 51a and 51b rectify the single-phase current flowing through power line L1 from the single-phase AC power supply 11 or, for example, the U-phase (first phase) current flowing through the three-phase AC power supply 11. MOSFETs 51c and 51d are an example of a pair of power semiconductors associated with power line L2, specifically corresponding to phases other than the specific phases of the AC power supply 11. Specifically, MOSFETs 51c and 51d rectify the single-phase current flowing through power line L2 from the single-phase AC power supply 11 or, for example, the V-phase (second phase) current flowing through the three-phase AC power supply 11. MOSFETs 51e and 51f are an example of a pair of power semiconductors associated with power line L3, specifically corresponding to phases other than the specific phases of the AC power supply 11. Specifically, MOSFETs 51e and 51f rectify the single-phase current flowing through power line L3 from a single-phase AC power source 11, or, for example, the W-phase (third phase) current from a three-phase AC power source 11. MOSFETs 51g and 51h are an example of a pair of power semiconductors associated with power line N, i.e., corresponding to the neutral line. Specifically, MOSFETs 51g and 51h form a circuit for returning the single-phase current flowing through power lines L1 to L3 from a single-phase AC power source 11 to the AC power source 11.

[0033] The electrolytic capacitor 53 smoothes the current rectified by the MOSFET 51. The electrolytic capacitor 53 is an output capacitor of the power factor improvement circuit 5. Alternatively, the electrolytic capacitor 53 can be described as an input capacitor of the DC-DC converter circuit 6. Figure 1 Electrolytic capacitors 53a and 53b are exemplified as the electrolytic capacitor 53. The electrolytic capacitors 53a and 53b are electrically connected between the output side (load 13 side) of the high-side MOSFET 51 and the output side (load 13 side) of the low-side MOSFET 51. In addition, the electrolytic capacitors 53a and 53b can be implemented by a single electrolytic capacitor or by three or more electrolytic capacitors. For example, Figure 2 A case where eight electrolytic capacitors 53 are used is exemplified.

[0034] The DC-DC conversion circuit 6 converts the DC voltage generated by the power factor improvement circuit 5 into an AC voltage again, and then rectifies and smoothes it to generate a DC voltage of an arbitrary set voltage. Figure 1As shown, the DC-DC converter circuit 6 is electrically connected to the power factor improvement circuit 5 and the output terminal of the power conversion device 2. The DC-DC converter circuit 6 includes primary-side MOSFETs 61a to 61d, a primary-side coil 63, a transformer 73, secondary-side MOSFETs 81a to 81d, a secondary-side coil 83, and an output capacitor 85. The primary-side coil 63 and the secondary-side coil 83 can each be replaced by the leakage inductance of the transformer 73. Here, the primary-side MOSFETs 61a to 61d are one example of the multiple power semiconductors of the power conversion device 2.

[0035] The primary-side MOSFETs 61a-61d and coil 63 convert the DC voltage from the electrolytic capacitor 53, serving as the input capacitor, into an AC voltage through the switching operation of the MOSFETs 61 under the control of the control circuit (not shown) of the power converter 2. In other words, the primary-side MOSFETs 61a-61d and coil 63 constitute a DC-AC inverter circuit. The simplified equivalent circuit of each MOSFET 61 has the same structure as, for example, each MOSFET 51 of the power factor improvement circuit 5. In the high-side MOSFET 61, the anode and cathode of the diode are electrically connected to the output side (load 13 side) and input side (AC power supply 11 side) of each MOSFET 61, respectively. On the other hand, in the low-side MOSFET 61, the anode and cathode of the diode are electrically connected to the input side and output side of each MOSFET 61, respectively.

[0036] The input side of each high-side MOSFET 61 is electrically connected to the output side of each high-side MOSFET 51 of the power factor improvement circuit 5. Furthermore, the input side of each low-side MOSFET 61 is electrically connected to the output side of each low-side MOSFET 51 of the power factor improvement circuit 5. Furthermore, the output sides of MOSFETs 61a and 61b are electrically connected to one end of the primary side of a transformer 73 via a coil 63. Furthermore, the output sides of MOSFETs 61c and 61d are electrically connected to the other end of the primary side of the transformer 73, that is, the side opposite to the coil 63.

[0037] The transformer 73 is a transformer that transfers energy of a single-phase AC voltage generated by the MOSFETs 61 a to 61 d and the coil 63 on the primary side to the secondary side.

[0038] Secondary-side MOSFETs 81a to 81d and coil 83 rectify the single-phase AC voltage transmitted by transformer 73 through the switching operation of MOSFETs 81 under the control of a control circuit (not shown) of power converter 2. The simplified equivalent circuit of each MOSFET 81 has the same structure as, for example, each MOSFET 51 of power factor improvement circuit 5. In high-side MOSFETs 81, the anode and cathode of the diode are electrically connected to the input side (AC power supply 11 side) and output side (load 13 side) of each MOSFET 61, respectively. On the other hand, in low-side MOSFETs 81, the anode and cathode of the diode are electrically connected to the output side and input side of each MOSFET 81, respectively.

[0039] The input side of MOSFETs 81a and 81b is electrically connected to one end of the secondary side of transformer 73 via coil 83. Figure 1 In the example shown, the output side of each MOSFET 81c and 81d is electrically connected to the other end of the secondary side of the transformer 73, that is, the side opposite to the coil 83. The output side of each of the high-side and low-side MOSFETs 81 is electrically connected to a pair of output terminals of the power conversion device 2.

[0040] Output capacitor 85 smoothes the current rectified by MOSFET 81. Output capacitor 85 is electrically connected between the output side (load 13 side) of high-side MOSFET 81 and the output side (load 13 side) of low-side MOSFET 81. In other words, output capacitor 85 is electrically connected between a pair of output terminals of power converter 2.

[0041] In addition, the control circuit (not shown) of the power conversion device 2 includes, for example, at least one processor and at least one memory, and may also be configured using the hardware structure of a conventional computer. As the processor, for example, a CPU (Central Processing Unit) can be used. The processor, for example, controls the operation of the control circuit in a unified manner by executing a program, thereby realizing the various functions of the control circuit. In addition, the control circuit may realize the various functions of the control circuit by, for example, having the processor load a program stored in a ROM (Read Only Memory) or the like into a RAM (Random Access Memory) and execute the loaded program, or may realize part or all of the functions using a dedicated hardware circuit (such as a semiconductor integrated circuit).

[0042] The control circuit of the power conversion device 2 can also be implemented by a computer such as an ECU (Electronic Control Unit), a DCU (Domain Control Unit) such as a cockpit domain controller (CDC) formed by integrating multiple ECUs, or an OBU (On-Board Unit) installed within the vehicle. Furthermore, the control circuit can transmit and receive information with other ECUs installed in the vehicle and an external power supply (AC power supply 11) connected to the vehicle via an in-vehicle network such as the CAN (Controller Area Network), Ethernet (registered trademark), or USB (Universal Serial Bus) within the vehicle. It can also communicate with information processing devices external to the vehicle via a network such as the Internet.

[0043] like Figure 1 As shown, the power factor improvement circuit 5 and the MOSFET 61 of the DC-DC converter circuit 6 constitute the power factor improvement circuit module 3 according to the embodiment. In other words, the power conversion device 2 according to the embodiment is equipped with a power factor improvement circuit module. Furthermore, the power factor improvement circuit module 3 may also include other circuit components, such as the noise filter 4 and the coil 63.

[0044] Here, a power factor improvement circuit structure of the power factor improvement circuit module 3 according to the present disclosure will be described in detail with reference to the drawings.

[0045] Figure 2 It shows Figure 1 3D is a perspective view of an example of the structure of the power factor improvement circuit module 3 (power factor improvement circuit structure). Figure 2 The external appearance of the power factor improvement circuit module 3 and its vicinity of the power conversion device 2 is shown. Figure 3 It shows Figure 1 2 is a cross-sectional view of an example of the structure of the power factor improvement circuit module 3 (power factor improvement circuit structure). Figure 3 Shown is the observation from the X+ side through the Figure 2 The cross section of the power factor improvement circuit module 3 and its vicinity is obtained by taking the YZ plane of the plurality of fixing members 39c on the X+ side of the relay substrate 32b. Figure 2 and Figure 3 In the figure, part or all of other structures of the power conversion device 2 are omitted.

[0046] like Figure 2 and Figure 3 As shown in FIG. 1 , the power factor improvement circuit module 3 is arranged above the housing 21 of the power conversion device 2 (on the Z+ side). Figure 2 As shown, the power factor improvement circuit module 3 is detachably fixed to the housing 21 by a fixing member 39e such as a screw.

[0047] In addition, if Figure 2 and Figure 3 As shown, the drive substrate 31 is positioned above the power factor improvement circuit module 3 (on the Z+ side). The drive substrate 31 serves as the main substrate of the power conversion device 2. The drive substrate 31 electrically connects various components of the power conversion device 2, either directly or through other components. The drive substrate 31 is removably secured to the support portion 25 of the housing 21 using screws or other fixing members (not shown).

[0048] The drive substrate 31 may be a component of the power factor improvement circuit module 3 or a component of the power conversion device 2 that is external to the power factor improvement circuit module 3 .

[0049] The housing 21 is a flat plate-shaped member extending along the XY plane. Furthermore, the housing 21 is formed, for example, by die-casting and may be made of iron or an alloy. Furthermore, the housing 21 may be formed of other metal materials, as long as it can transfer heat from components such as the power factor improvement circuit module 3 disposed within the housing 21 to the coolant flowing through the flow path 23 within the housing 21.

[0050] In addition, a liquid cooling mechanism using a coolant such as antifreeze as a working fluid is provided in the housing 21. Specifically, Figure 3 As shown, a coolant flow path 23 is formed inside the housing 21. In the housing 21 according to the embodiment, the flow path 23 extends in a direction along the XY plane (e.g., horizontally). In other words, the flow path 23 is formed inside the housing 21 so as to extend within a single plane.

[0051] The flow path 23 may also branch in at least two directions along the XY plane. On the other hand, the flow path 23 involved in the embodiment does not branch in the direction along the Z direction. In other words, in the housing 21 involved in the embodiment, when there is an intersection where the flow paths 23 in at least two directions intersect, each flow path 23 extends from the intersection in the direction along the XY plane, and on the other hand, does not extend in the direction along the Z direction. In this way, the power conversion device 2 involved in the present disclosure can constitute the cooling mechanism of the entire system by the flow path 23 running only in one plane (XY plane).

[0052] The power factor improvement circuit module 3 is thermally connected to the housing 21. Here, thermal connection means being configured to enable heat exchange. Heat transfer between the power factor improvement circuit module 3 and the housing 21 is achieved, for example, by thermal conduction, but other methods may be used in addition to or in place of thermal conduction. Furthermore, heat transfer between the power factor improvement circuit module 3 and the housing 21 may also be achieved via other components.

[0053] In addition, if Figure 2 As shown, other components of the power conversion device 2, such as a transformer 73, are also disposed on the housing 21. The transformer 73 is covered by a housing 75. The housing 75 is formed, for example, of metal and shields electromagnetic noise from the transformer 73. The transformer 73 and the drive substrate 31 are electrically connected, for example, by fixing members 77 such as screws, welding, or the like.

[0054] Generally speaking, in a power conversion device, the transformer 73 is a large component (large part) compared to other components. Therefore, the height (length in the Z direction) of the support portion 25 of the housing 21 that supports the drive substrate 31 is determined so that the transformer 73 is accommodated between the housing 21 and the drive substrate 31. In other words, the height (size in the Z direction) of the power conversion device 2 depends on the distance between the housing 21 and the drive substrate 31 where the transformer 73 exists. In other words, when the distance (size in the Z direction) between the housing 21 and the drive substrate 31 is specified based on the size of large components such as the transformer 73, there is excess height at the configuration position of components other than the large component, that is, at a position different from the large component in the XY direction.

[0055] In this context, the power conversion device 2 according to the present disclosure includes a power factor improvement circuit module 3, which is a modularization of some of the multiple components other than the transformer 73. Furthermore, the power factor improvement circuit module 3 is inserted between the housing 21 and the drive substrate 31, with the spacing between the housing 21 and the drive substrate 31 determined by the transformer 73. In other words, the power factor improvement circuit module 3 according to the present disclosure is configured to be smaller in height (Z direction) than other large components of the power conversion device 2, thereby achieving miniaturization of the power conversion device 2.

[0056] like Figure 2 and Figure 3 As shown, the power factor improvement circuit module 3 further includes relay substrates 32 a and 32 b , an insulating heat dissipation plate 33 , and a resin mold 35 .

[0057] like Figure 3As shown in FIG. 1 , the drive substrate 31 is detachably fixed to the resin mold 35 by fixing members 39 a such as screws. In other words, the resin mold 35 supports the drive substrate 31 .

[0058] The relay substrates 32a and 32b are electrically connected to the drive substrate 31. The relay substrate 32 is provided with a wiring pattern. The relay substrate 32 electrically connects the electrically connected components to the drive substrate 31 via the wiring pattern. For example, some components of the power factor improvement circuit module 3 (power conversion device 2) are electrically connected to the drive substrate 31 via the relay substrate 32. Figure 3 As shown, the relay substrate 32a is detachably fixed to the resin mold 35 by fixing members 39b such as screws. In addition, the relay substrate 32b is detachably fixed to the resin mold 35 by fixing members 39c such as screws. In other words, the resin mold 35 supports each of the relay substrates 32a and 32b.

[0059] Note that the electrical connection between the drive substrate 31 and the relay substrate 32 may be achieved by soldering or by detachable connection via a connector.

[0060] like Figure 2 and Figure 3 As shown, the insulating heat dissipation plate 33 is disposed below (on the Z-side) the resin mold 35. The resin mold 35 is fixed to the surface (first main surface) of the insulating heat dissipation plate 33 on the drive substrate 31 side using fixing means (not shown), such as screws or adhesive. In other words, the resin mold 35 supports the insulating heat dissipation plate 33.

[0061] The insulating heat dissipation plate 33 is a flat plate extending along the XY plane. It has both thermal conductivity (preferably high thermal conductivity) and electrical insulation. Specifically, the insulating heat dissipation plate 33 only needs to be able to transport heat along the thickness direction (Z direction). For example, it can be a metal plate, but non-metallic materials are also acceptable. The insulating heat dissipation plate 33 in this embodiment is an example of a cooling plate.

[0062] An electrically insulating insulating layer is formed on the outer surface of insulating heat sink plate 33. Specifically, an insulating layer is provided between each of MOSFETs 51 and 61 and insulating heat sink plate 33. The insulating layer on the outer surface of insulating heat sink plate 33 can be formed by coating with an electrically insulating material or by providing an electrically insulating sheet-like member on the outer surface. Furthermore, insulating heat sink plate 33 can be a plate-like member formed from a material that is both thermally conductive and electrically insulating.

[0063] At least the side of the insulating heat sink 33 facing the housing 21 (the Z-side) is formed to conform to the shape of the position of the power factor improvement circuit module 3 above the housing 21 (the Z+side). The surface of the insulating heat sink 33 facing the housing 21 (the Z-side) serves as the cooling surface for the power factor improvement circuit module 3. In other words, in the power conversion device 2, the cooling surface of the power factor improvement circuit module 3 extends along the surface (the XY plane) along which the flow path 23 of the housing 21 is provided. In other words, the power factor improvement circuit module 3 is thermally connected to the housing 21 via its cooling surface, allowing heat generated within the module to be dissipated into the housing 21.

[0064] For example, the insulating heat dissipation plate 33 is fixed to the housing 21 by the fixing member 39e, thereby fixing the power factor improvement circuit module 3 to the housing 21. In other words, when the power factor improvement circuit module 3 is fixed to the housing 21, the surface of the insulating heat dissipation plate 33 on the housing 21 side (the second main surface) is thermally connected to the housing 21. Here, the surface of the insulating heat dissipation plate 33 on the housing 21 side is the back surface of the surface of the insulating heat dissipation plate 33 on the resin mold 35 side (the first main surface).

[0065] like Figure 3 As shown, MOSFETs 51 and 61 (power semiconductors) of the power factor improvement circuit 5 and DC-DC converter circuit 6 are arranged on the surface (first main surface) of the insulating heat dissipation plate 33 facing the resin mold 35. Each of the multiple MOSFETs 51 and 61 is secured to the insulating heat dissipation plate 33 using a securing member (not shown) such as an adhesive or adhesive sheet. The securing member may be formed of a material that is at least thermally conductive. Alternatively, the securing member may be electrically insulating, in which case the insulating heat dissipation plate 33 does not need to be electrically insulating.

[0066] The cooling surfaces of the multiple MOSFETs 51 and 61 face the surface of the insulating heat sink 33 on the resin mold 35 side and are thermally connected to the insulating heat sink 33. In other words, the heat dissipation path of the multiple MOSFETs 51 and 61 is a path in the Z direction from the cooling surface to the flow path 23 via the insulating heat sink 33 and the housing 21. In this way, the MOSFETs 51 and 61 are fixed to the surface of the insulating heat sink 33 on the resin mold 35 side in a manner that allows heat exchange between the heat dissipation surface and the insulating heat sink 33.

[0067] Here, if Figure 3 As shown, multiple MOSFETs 51 and 61 are placed flat on the insulating heat dissipation plate 33. Here, placing flat means that the heat dissipation surfaces of the multiple MOSFETs 51 and 61 are arranged on the insulating heat dissipation plate 33 so that they face the surface of the insulating heat dissipation plate 33 on the resin mold 35 side.

[0068] The multiple MOSFETs 51 and 61 are each arranged in the gap 37 formed between the insulating heat dissipation plate 33 and the resin mold 35. In other words, the multiple MOSFETs 51 and 61 are each arranged below (on the Z-side) the electrolytic capacitor 53 via the resin mold 35. For example, the multiple MOSFETs 51 and 61 are each arranged directly below the electrolytic capacitor 53. In other words, the upper side (Z+ side) of each of the multiple MOSFETs 51 and 61 is covered by the resin mold 35. The positions of the multiple MOSFETs 51 and 61 on the insulating heat dissipation plate 33 (for example, the positions in the XY directions) are defined (positioned) by the resin mold 35.

[0069] In addition, the leads 511 and 611 of the plurality of MOSFETs 51 and 61 are electrically connected to the drive substrate 31. Figure 2 and Figure 3 In the illustrated configuration, the leads 511 and 611 of the plurality of MOSFETs 51 and 61 are electrically connected to one of the relay substrates 32 a and 32 b by, for example, soldering.

[0070] By providing the relay substrate 32 in the power factor improvement circuit module 3, some components of the power conversion device 2, such as the MOSFETs 51 and 61 (power semiconductors), can be electrically connected to the drive substrate 31 via the relay substrate 32, thereby increasing the degree of freedom in their placement. For example, when the MOSFETs 51 and 61 are directly connected to the drive substrate 31, the placement of the MOSFETs 51 and 61 is restricted due to the layout of the wiring used for this connection. On the other hand, the power factor improvement circuit module 3 of the present disclosure is indirectly connected to the drive substrate 31 via the relay substrate 32, thereby increasing the degree of freedom in its placement.

[0071] Furthermore, for example, a portion or all of the leads 511 and 611 of each of the plurality of MOSFETs 51 and 61 may be extended in the Z direction to the drive substrate 31. In other words, each of the plurality of MOSFETs 51 and 61 may be electrically connected to the drive substrate 31 without passing through the relay substrate 32. In this case, a portion or all of the relay substrate 32 may not be provided.

[0072] Furthermore, depending on the number and arrangement of the plurality of MOSFETs 51 and 61, either relay substrate 32a or 32b may not be provided. In other words, relay substrate 32 may be a single substrate. Alternatively, relay substrate 32 may be a plurality of substrates, three or more.

[0073] As an example, the relay substrate 32 may be provided on at least one side in the Y direction of the resin mold 35. As an example, the relay substrate 32 may be provided on at least one side in the X direction of the resin mold 35. In other words, the relay substrate 32 may be provided so as to extend from the bottom portion (a portion on the Z-side) of the resin mold 35 toward the drive substrate 31 and cover at least one side surface portion of the electrolytic capacitor 53.

[0074] As an example, the relay substrate 32 may be provided on the bottom portion (a portion on the Z-side) of the resin mold 35, which is inserted at least between the MOSFETs 51 and 61 and the electrolytic capacitor 53. For example, the relay substrate 32 may be provided on the side of each of the plurality of MOSFETs 51 and 61 opposite to the insulating heat sink 33. For example, the relay substrate 32 may be provided between each of the plurality of MOSFETs 51 and 61 and the resin mold 35. For example, the relay substrate 32 may be provided inside the resin mold 35 below the electrolytic capacitor 53 (on the Z-side). In this case, the relay substrate 32 may be housed inside the resin mold 35 or may protrude from the resin mold 35.

[0075] In this manner, by providing the relay substrate 32 on the side of each of the plurality of MOSFETs 51 and 61 opposite to the insulating heat sink 33, the degree of freedom in the arrangement of the plurality of MOSFETs 51 and 61 can be further increased. Furthermore, with this configuration, the relay substrate 32 can reduce the amount of radiant heat (waste heat) from the plurality of MOSFETs 51 and 61 to other components such as the electrolytic capacitor 53.

[0076] In addition, the relay substrate 32 is not limited to a flat substrate, and may also be a substrate with an L-shaped cross section. That is, the relay substrate 32 may also be formed into a shape such as an L-shaped angle (L-shaped angle steel). That is, the relay substrate 32 may also be a substrate having at least one L-shaped cross section supported by at least two of at least one side surface portion and a bottom surface portion of the resin mold 35. The L-shaped relay substrate 32 may be provided over both side surfaces (X direction and Y direction) of the resin mold 35, or may be provided over both the side surface (X direction or Y direction) and the bottom surface (Z-side) of the resin mold 35.

[0077] In addition, on the side of the resin mold 35 opposite to the MOSFETs 51 and 61 (Z+ side), that is, on the Figure 2 and Figure 3 In the illustrated structure, the electrolytic capacitor 53 of the power factor improvement circuit 5 is arranged inside the resin mold 35. In other words, the electrolytic capacitor 53 is arranged on the side of the MOSFETs 51 and 61 opposite to the insulating heat sink 33, that is, on the side close to the drive substrate 31.

[0078] The lead wires 531 of the electrolytic capacitor 53 are electrically connected to the drive substrate 31. For example, the electrolytic capacitor 53 is fixed to the drive substrate 31 by welding or the like, and is supported by the drive substrate 31. As an example, the electrolytic capacitor 53 is arranged so as to be suspended from the drive substrate 31 toward the resin mold 35. Alternatively, the electrolytic capacitor 53 may be held or defined (positioned) relative to the drive substrate 31 by the resin mold 35. Alternatively, the electrolytic capacitor 53 may be supported by the resin mold 35.

[0079] In this manner, the resin mold 35 is inserted at least between the MOSFETs 51 and 61 and the electrolytic capacitor 53, thereby reducing radiant heat from the multiple MOSFETs 51 and 61 to the electrolytic capacitor 53. More specifically, in the power factor improvement circuit module 3 according to the present disclosure, the MOSFETs 51 and 61 and the electrolytic capacitor 53 are covered by the resin mold 35. In other words, in the power factor improvement circuit module 3 according to the present disclosure, the resin mold 35 serves to hold and position the MOSFETs 51 and 61, and to insulate the electrolytic capacitor 53.

[0080] Furthermore, the resin mold 35 is not limited to positioning the MOSFETs 51 and 61 but may also position other components such as the electrolytic capacitor 53. In other words, the resin mold 35 at least defines (positions) the position of each of the MOSFETs 51 and 61.

[0081] Furthermore, the gap 37 between the insulating heat sink 33 and the resin mold 35, or the gap between the resin mold 35 and the electrolytic capacitor 53, can be filled with a heat-dissipating buffer material, such as a gap filler, that has at least heat dissipation properties (thermal conductivity). In other words, a heat-dissipating buffer material, such as a gap filler, can also be used as a heat sink. This can further enhance the heat dissipation performance of the power factor improvement circuit module 3. The gap filler preferably also has electrical insulating properties.

[0082] Furthermore, a reflective or absorptive thermal insulation layer may be formed on the side of the resin mold 35 facing the MOSFETs 51 and 61 to prevent heat transfer to the electrolytic capacitor 53 via the resin mold 35. Furthermore, a reflective thermal insulation layer, for example, may be formed on the outer surface of the electrolytic capacitor 53 to prevent heat transfer from the outside. These thermal insulation layers may be formed, for example, by applying a thermal insulation coating to the outer surface of the resin mold 35. This can further improve the heat dissipation performance of the power factor improvement circuit module 3 or suppress thermal degradation of the electrolytic capacitor 53.

[0083] Furthermore, the power conversion device 2 of the present disclosure is expandable by mounting multiple power factor correction circuit modules 3 in parallel. Specifically, the power conversion device 2 of the present disclosure is expandable by modularizing the power factor correction circuit 5 and the MOSFETs 61 of the DC-DC converter circuit 6. For example, the power conversion device 2 can increase its output (kW) by electrically connecting a number of power factor correction circuit modules 3 in parallel corresponding to the amount of power it converts, i.e., the output (kW) of the DC voltage. This can be achieved by increasing the number of modules.

[0084] As described above, in the power conversion device 2 involved in the present disclosure, the power factor improvement circuit structure required for power conversion is modularized. Specifically, in the power factor improvement circuit module 3 involved in the present disclosure, a plurality of MOSFETs 51 and 61 are respectively placed flat on the insulating heat dissipation plate 33. Therefore, in the housing 21 of the power conversion device 2, the flow path 23 inside it can be formed as a flow path that only travels in the horizontal direction (XY direction), thereby suppressing the retention of the working fluid (coolant). In addition, in the power factor improvement circuit module 3 involved in the present disclosure, the degree of freedom of configuration of the MOSFETs 51 and 61 can be increased by using the relay substrate 32. In addition, by making the power factor improvement circuit module 3 involved in the present disclosure more compact in the height direction compared to large components such as the transformer 73, the overall miniaturization of the power conversion device 2 can be achieved.

[0085] According to at least one embodiment described above, it is possible to achieve miniaturization of the power conversion device while taking heat dissipation into consideration.

[0086] While several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways and can be omitted, replaced, or modified without departing from the spirit of the invention. These embodiments and their variations are included within the scope and spirit of the invention and are also included within the invention set forth in the claims and their equivalents.

[0087] (Note)

[0088] Based on the description of the above embodiments, the following technology is disclosed.

[0089] (1) A power conversion device comprising:

[0090] a housing having a flow path formed inside the housing so as to extend within a single plane; and

[0091] A power factor improvement circuit module is detachably fixed to the housing.

[0092] Wherein, the power factor improvement circuit module has:

[0093] a cooling plate having thermal conductivity and formed in a flat plate shape;

[0094] a power semiconductor fixed to the first main surface of the cooling plate with its heat dissipation surface facing the first main surface and capable of exchanging heat with the cooling plate, and electrically connected to the drive substrate;

[0095] an electrolytic capacitor disposed on a side of the power semiconductor opposite to the cooling plate, that is, on a side close to the drive substrate, and electrically connected to the drive substrate; and

[0096] a resin molded member fixed to the first main surface of the cooling plate, for defining the position of the power semiconductor and interposed at least between the power semiconductor and the electrolytic capacitor;

[0097] In a state where the power factor improvement circuit module is fixed to the housing, the second main surface of the cooling plate, which is the back surface of the first main surface, is thermally connected to the housing.

[0098] (2) The power conversion device according to (1) above, wherein:

[0099] Leads of the power semiconductor extend to the drive substrate.

[0100] (3) The power conversion device according to (1) above, wherein:

[0101] The power factor improvement circuit module further includes a relay substrate electrically connected to the drive substrate.

[0102] The resin mold supports the relay substrate.

[0103] The power semiconductor is electrically connected to the relay substrate and is connected to the drive substrate via the relay substrate.

[0104] (4) The power conversion device according to (3) above, wherein:

[0105] The resin mold has a bottom portion inserted between the power semiconductor and the electrolytic capacitor; and at least one side portion extending from the bottom portion toward the drive substrate to cover the electrolytic capacitor.

[0106] The relay substrate is at least one substrate supported by at least one of the at least one side surface portion and the bottom surface portion of the resin mold.

[0107] (5) The power conversion device according to (4) above, wherein:

[0108] The relay substrate is a substrate having at least one L-shaped cross section and is supported by at least two of the at least one side surface portion and the bottom surface portion of the resin mold.

[0109] (6) The power conversion device according to (3) above, wherein:

[0110] The relay substrate is at least one substrate supported by the bottom portion of the resin mold inserted between the power semiconductor and the electrolytic capacitor.

[0111] (7) The power conversion device according to any one of (1) to (6), wherein:

[0112] The power semiconductor is arranged in a gap between the first main surface of the cooling plate and the resin mold.

[0113] The gap is filled with heat dissipation buffer material.

[0114] (8) The power conversion device according to any one of (1) to (7), wherein:

[0115] The power factor improvement circuit module further includes the drive substrate.

[0116] (9) The power conversion device according to any one of (1) to (8), wherein:

[0117] The power factor improvement circuit modules are provided in a number corresponding to the amount of electric power to be converted.

[0118] (10) The power conversion device according to any one of (1) to (9), wherein:

[0119] A transformer is further provided, the transformer being fixed to the housing and electrically connected to the drive substrate.

[0120] The power factor improvement circuit module is smaller than the transformer in a direction from the housing toward the drive substrate.

[0121] (11) A vehicle comprising:

[0122] The power conversion device according to any one of (1) to (10) above, which converts AC power from an external AC power source into DC power; and

[0123] A battery is charged using the DC power converted by the power conversion device.

Claims

1. A power conversion device comprising: a housing having a flow path formed inside the housing so as to extend within a single plane; and A power factor improvement circuit module is detachably fixed to the housing. in, The power factor improvement circuit module has: a cooling plate having thermal conductivity and formed in a flat plate shape; a power semiconductor fixed to the first main surface of the cooling plate with its heat dissipation surface facing the first main surface and capable of exchanging heat with the cooling plate, and electrically connected to the drive substrate; an electrolytic capacitor disposed on a side of the power semiconductor opposite to the cooling plate, that is, on a side close to the drive substrate, and electrically connected to the drive substrate; as well as a resin molded member fixed to the first main surface of the cooling plate, for defining the position of the power semiconductor and interposed at least between the power semiconductor and the electrolytic capacitor; In a state where the power factor improvement circuit module is fixed to the housing, the second main surface of the cooling plate, which is the back surface of the first main surface, is thermally connected to the housing.

2. The power conversion device according to claim 1, wherein: Leads of the power semiconductor extend to the drive substrate.

3. The power conversion device according to claim 1, wherein: The power factor improvement circuit module further includes a relay substrate electrically connected to the drive substrate. The resin mold supports the relay substrate. The power semiconductor is electrically connected to the relay substrate and is connected to the drive substrate via the relay substrate.

4. The power conversion device according to claim 3, wherein: The resin mold has a bottom portion inserted between the power semiconductor and the electrolytic capacitor; and at least one side portion extending from the bottom portion toward the drive substrate to cover the electrolytic capacitor. The relay substrate is at least one substrate supported by at least one of the at least one side surface portion and the bottom surface portion of the resin mold.

5. The power conversion device according to claim 4, wherein: The relay substrate is a substrate having at least one L-shaped cross section and is supported by at least two of the at least one side surface portion and the bottom surface portion of the resin mold.

6. The power conversion device according to claim 3, wherein: The relay substrate is at least one substrate supported by the bottom portion of the resin mold inserted between the power semiconductor and the electrolytic capacitor.

7. The power conversion device according to claim 1, wherein: The power semiconductor is arranged in a gap between the first main surface of the cooling plate and the resin mold. The gap is filled with heat dissipation buffer material.

8. The power conversion device according to claim 1, wherein: The power factor improvement circuit module further includes the drive substrate.

9. The power conversion device according to any one of claims 1 to 8, wherein: The power factor improvement circuit modules are provided in a number corresponding to the amount of electric power to be converted.

10. The power conversion device according to any one of claims 1 to 8, wherein: A transformer is further provided, the transformer being fixed to the housing and electrically connected to the drive substrate. The power factor improvement circuit module is smaller than the transformer in a direction from the housing toward the drive substrate.

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