Power converter

Abstract

To provide a power conversion device in which a DC-DC converter unit can be easily replaced even when the power conversion device is mounted on a load.SOLUTION: A power conversion device 100 is placed on a load 210 and supplies power to a load 210. The power conversion device 100 includes an inverter unit 10 that converts DC power input from a DC power source 200 into AC power and supplies the AC power to the load 210, and a DC-DC converter unit 30 that converts the voltage of the DC power into a different voltage. The inverter unit 10 and the DC-DC converter unit 30 are stacked in this order from the load 210 side.SELECTED DRAWING: Figure 1

Description

Technical Field

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[0001] This invention relates to a power conversion device, and particularly to a power conversion device including a DC-DC converter section.

Background Art

[0002] Conventionally, a power conversion device including a DC-DC converter section has been known (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a power conversion device including an inverter device, a DC-DC converter (DC-DC converter section), and a housing that houses the inverter device and the DC-DC converter. The inverter device includes a semiconductor module that constitutes an upper arm and a lower arm. The DC-DC converter includes a MOSFET, a high-voltage circuit board on which the MOSFET is mounted, and the like. In Patent Document 1, in the housing, the DC-DC converter and the inverter device are stacked in this order from below.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, in the power conversion device as described in Patent Document 1, the DC-DC converter is a component that is periodically replaced. When the power conversion device of Patent Document 1 is placed above a load, the DC-DC converter is sandwiched between the load and the inverter device. Therefore, there is a problem that the DC-DC converter (DC-DC converter section) cannot be easily replaced.

[0006] This invention was made to solve the above-mentioned problems, and one of its objectives is to provide a power converter that allows for easy replacement of the DC-DC converter section even when the power converter is mounted on a load. [Means for solving the problem]

[0007] To achieve the above objective, a power conversion device according to one aspect of this invention is a power conversion device that is placed on a load and supplies power to the load, comprising: a DC-DC converter unit that converts the voltage of DC power input from a DC power source to a different voltage; a boost converter unit that boosts the DC power input from a DC power source; an inverter unit that converts the DC power boosted by the boost converter unit into AC power and supplies it to the load; a base unit on which the inverter unit, DC-DC converter unit and boost converter unit are arranged; and the inverter unit, DC-DC converter unit, boost converter unit and base unit The inverter unit, base unit, and DC-DC converter unit are stacked in this order from the load side, and both the DC-DC converter unit and the boost converter unit are located on the load side of the base unit and are exposed through the opening of the housing. The DC-DC converter unit is fixed to the base unit by a first fastening member inserted along the direction from the DC-DC converter unit toward the inverter unit, and the housing is... It has a rectangular shape when viewed from the direction opposite to the load, and at least two orthogonal sides of the rectangle have a length shorter than the length of the corresponding side of the load, and the holes of the fixing part are provided so as to protrude outward on the outer circumference of the two sides, The second fastening member is inserted in the same direction as the first fastening member, thereby securing it to the load.

[0008] In a power conversion device according to one aspect of this invention, the inverter section and the DC-DC converter section are stacked in this order from the load side, as described above. As a result, even when the power conversion device is placed on a load, the DC-DC converter section is located on the opposite side from the load, so the DC-DC converter section can be easily replaced. Furthermore, even when the inverter unit and the DC-DC converter unit are housed in a casing, the DC-DC converter unit is exposed through an opening in the casing, allowing for easy replacement of the DC-DC converter unit. Furthermore, since the DC-DC converter unit is located on the opposite side of the base unit from the load, the DC-DC converter unit can be easily replaced even if it is located on the base unit. Furthermore, even when the power conversion device is mounted on a load, the boost converter unit is positioned on the opposite side from the load, allowing for easy replacement of the boost converter unit. Furthermore, even when the housing is fixed to the load by fastening members, the DC-DC converter section is exposed through an opening in the housing, allowing for easy replacement of the DC-DC converter section. Furthermore, the DC-DC converter can be easily replaced simply by releasing the fastening of the fastening members.

[0011] In the power conversion device according to the first aspect described above, preferably, the load includes a motor for an electric vehicle. This allows the DC-DC converter section to be easily replaced even when the power conversion device is mounted on a motor for an electric vehicle.

[0015] In this case, preferably, the boost converter is fixed to the base by fastening members. This allows the boost converter to be easily replaced simply by releasing the fastening of the fastening members. [Effects of the Invention]

[0016] According to the present invention, as described above, even when the power conversion device is mounted on a load, the DC-DC converter section can be easily replaced. [Brief explanation of the drawing]

[0017] [Figure 1] This figure shows a power conversion device according to one embodiment in a state where it is placed on a load. [Figure 2] This is a circuit diagram of a power conversion device according to one embodiment. [Figure 3] This is a perspective view of a power conversion device (excluding the housing) according to one embodiment. [Figure 4]It is an exploded perspective view of a power conversion device (excluding the housing) as viewed from above in accordance with an embodiment. [Figure 5] It is a perspective view of a base portion of a power conversion device as viewed from below in accordance with an embodiment. [Figure 6] It is a side view of a power conversion device (excluding the housing) in accordance with an embodiment.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments embodying the present invention will be described based on the drawings.

[0019] Referring to FIGS. 1 to 6, the configuration of a power conversion device 100 according to an embodiment of the present invention will be described. As shown in FIG. 1, the power conversion device 100 is placed on a load 210. The load 210 includes a motor for an electric vehicle. In this case, the power conversion device 100 is mounted on a vehicle.

[0020] Referring to FIG. 2, the circuit configuration of the power conversion device 100 will be described. The power conversion device 100 includes an inverter section 10. The inverter section 10 converts DC power input from a DC power source 200 into AC power and supplies it to the load 210. A switch 201 is provided between the power conversion device 100 and the DC power source 200.

[0021] The inverter section 10 includes a switching element module 11. The switching element module 11 converts DC power into AC power. The switching element module 11 also includes semiconductor switching elements Q1, Q2, and Q3 that constitute the upper arm, and semiconductor switching elements Q4, Q5, and Q6 that constitute the lower arm.

[0022] The inverter section 10 includes a first inverter section 10a and a second inverter section 10b. The switching element module 11 includes a first switching element module 11a included in the first inverter section 10a and a second switching element module 11b included in the second inverter section 10b. Also, the load 210 includes a first load 210a and a second load 210b. The first inverter section 10a converts the DC power input from the DC power supply 200 into AC power and supplies it to the first load 210a. The second inverter section 10b converts the DC power input from the DC power supply 200 into AC power and supplies it to the second load 210b.

[0023] The power conversion device 100 includes a boost converter section 20. The boost converter section 20 is arranged on the input side of the inverter section 10. The boost converter section 20 boosts the DC power input from the DC power supply 200 and supplies it to the inverter section 10. The boost converter section 20 includes a boost switching element module 21 and a reactor 22. The boost switching element module 21 includes boost switching elements Q11 and Q12. The boost switching elements Q11 and Q12 each constitute an upper arm and a lower arm. Also, the boost converter section 20 includes a capacitor C1. The reactor 22 is provided between the positive side of the DC power supply 200 and the connection point between the boost switching element Q11 and the boost switching element Q12. The capacitor C1 is provided in parallel with the boost switching element Q12.

[0024] The power conversion device 100 includes a capacitor C2 and a resistor R. The capacitor C2 and the resistor R are provided between the boost converter section 20 and the inverter section 10. The capacitor C2 and the resistor R are provided in parallel with each other.

[0025] The power converter 100 includes a DC-DC converter unit 30. The DC-DC converter unit 30 converts the voltage of DC power to a different voltage. Specifically, the DC-DC converter unit 30 steps down the voltage of the DC power input from the DC power supply 200 via the connector 1. The DC-DC converter unit 30 also supplies the stepped-down voltage to the output terminal 2. Note that the DC-DC converter unit 30 is an example of the "DC-DC converter unit" in the claims.

[0026] Next, the structure of the power converter 100 will be described. As shown in Figure 1, the power converter 100 includes, in addition to the inverter unit 10, boost converter unit 20, and DC-DC converter unit 30 described above, a base unit 50 and a housing 70. In this embodiment, the inverter unit 10, base unit 50, and DC-DC converter unit 30 are stacked in this order from the load 210 side. Each component will be described in detail below.

[0027] As shown in Figure 3, the DC-DC converter unit 30 comprises a DC-DC converter element 31 and a DC-DC converter substrate 32 on which the DC-DC converter element 31 is mounted. The DC-DC converter substrate 32 has a flat plate shape. The DC-DC converter element 31 mounted on the DC-DC converter substrate 32 includes a converter switching element 31a, a transformer 31b, a resonant reactor 31c, and a smoothing reactor 31d. The converter switching element 31a is provided on the back side (Z2 side) of the DC-DC converter substrate 32. The transformer 31b, resonant reactor 31c, and smoothing reactor 31d are provided so as to penetrate the DC-DC converter substrate 32.

[0028] As shown in Figure 2, the switching element module 11 houses semiconductor switching elements Q1 to Q6 inside. The semiconductor switching elements Q1 to Q6 are covered by a housing made of resin or the like. As shown in Figure 4, the switching element module 11 has a rectangular shape when viewed from a direction perpendicular to the surface of the switching element module 11.

[0029] As shown in Figure 4, the power converter 100 includes a base 50. The base 50 is flat. The inverter unit 10 and the DC-DC converter unit 30 are arranged on the base 50. The base 50 is made of a metal with relatively high thermal conductivity, such as aluminum. The base 50 has a rectangular shape when viewed from a direction perpendicular to the front surface 50a (Z1 side) and back surface 50b (Z2 side) of the base 50.

[0030] As shown in Figure 4, the base portion 50 includes a cooling channel 51. Furthermore, as shown in Figure 6, the cooling channel 51 has a channel located on the Z1 side within the base portion 50, a channel located on the Z2 side within the base portion 50, and channels located on both the Z1 and Z2 sides.

[0031] In this embodiment, as shown in Figure 4, the DC-DC converter unit 30 is positioned on the side of the base unit 50 opposite to the load 210. Specifically, the DC-DC converter unit 30 is positioned on the Z1-side surface 50a of the base unit 50. The DC-DC converter unit 30 is fixed to the base unit 50 by fastening members 80. Specifically, the DC-DC converter unit 30 is attached to the cover 53 of the base unit 50, which will be described later, by fastening members 80. The cover 53 is provided with bosses 53b that protrude toward the Z1 side. The DC-DC converter unit 30 is attached to the bosses 53b by fastening members 80 via holes 32a provided in the DC-DC converter substrate 32 of the DC-DC converter unit 30. For example, there are multiple bosses 53b. The DC-DC converter substrate 32 on which the DC-DC converter elements 31 are mounted is attached to the base unit 50 so as to follow the surface 50a of the flat base unit 50.

[0032] The first switching element module 11a and the second switching element module 11b are attached to the base portion 50 so as to follow the back surface 50b of the flat base portion 50. Specifically, the first switching element module 11a and the second switching element module 11b are arranged adjacent to each other along the long side direction (X direction) of the first switching element module 11a and the second switching element module 11b. By arranging them in this way, the Y-direction width of the base portion 50 can be shortened, making it possible to miniaturize the power converter 100. The first switching element module 11a and the second switching element module 11b are attached to the base portion 50 by fastening members 80.

[0033] The boost converter unit 20 is mounted on the base unit 50 so as to follow the surface 50a of the flat base unit 50. Specifically, the boost converter unit 20 is mounted on the surface 50a of the base unit 50 that is opposite to the load 210. Furthermore, the boost converter unit 20 is positioned adjacent to the DC-DC converter unit 30 along the longitudinal direction (X direction) of the flat base unit 50.

[0034] Specifically, the boost converter section 20 includes a boost switching element module 21 and a reactor 22. The boost switching element module 21 and the reactor 22 are mounted on the base section 50 so as to follow the surface 50a of the flat base section 50. The DC-DC converter board 32, the reactor 22, and the boost switching element module 21 are mounted on the base section 50 so as to follow the surface 50a of the flat base section 50 and so as to be adjacent to each other. The DC-DC converter board 32, the reactor 22, and the boost switching element module 21 are mounted on the surface 50a of the base section 50 in this order.

[0035] In this embodiment, the reactor 22 and the boost switching element module 21 are fixed to the base portion 50 by fastening members 80. Specifically, the reactor 22 is fixed to the hole 53c of the lid portion 53 of the base portion 50 by fastening members 80 via the hole 22a of the reactor 22. For example, there are multiple holes 22a. The boost switching element module 21 is fixed to the hole 52f of the cooling section body portion 52 of the base portion 50 by fastening members 80 via the hole 21a of the boost switching element module 21. For example, there are multiple holes 21a.

[0036] As shown in Figure 4, the base portion 50 includes a cooling section body portion 52 made of metal in which a cooling channel 51 is formed, and a cover portion 53 made of metal in which the cooling channel 51 is formed together with the cooling section body portion 52. The cover portion 53 includes an opening 53a. The cooling section body portion 52 also includes openings 52a, 52b, and 52c that open to the Z1 side. Furthermore, as shown in Figure 5, the cooling section body portion 52 also includes openings 52d and 52e that open to the Z2 side. The opening 53a of the cover portion 53 is covered by the reactor 22. In detail, the reactor 22 includes a reactor body portion and a cover portion for the reactor 22 made of metal, with the cover portion for the reactor 22 covering the opening 53a of the cover portion 53. Openings 52a and 52b are covered by the cover portion 53. Opening 52c is covered by the boost switching element module 21. In detail, the boost switching element module 21 includes a boost switching element module body and a metal cover for the boost switching element module 21, with the cover for the boost switching element module 21 covering the opening 52c. The openings 52d and 52e are covered by the first switching element module 11a and the second switching element module 11b, respectively. In detail, the first switching element module 11a includes a switching element module 11a body and a metal cover for the first switching element module 11a, with the cover for the first switching element module 11a covering the opening 52d. The same applies to the opening 52e.

[0037] In this embodiment, as shown in Figure 4, the DC-DC converter element 31 includes a converter switching element 31a. The converter switching element 31a is mounted on the side of the DC-DC converter substrate 32 facing the lid 53 (the Z2 side) so as to be in contact with the lid 53 via a heat conductive member 33. That is, the lid 53, the heat conductive member 33, and the converter switching element 31a are stacked in this order. The heat generated from the converter switching element 31a is dissipated to the lid 53 via the heat conductive member 33. The heat conductive member 33 is made of, for example, a ceramic sheet.

[0038] As shown in Figure 6, the cooling liquid that flows out of the cooling channel 51 is cooled by the heat dissipation section 60. The cooling liquid cooled by the heat dissipation section 60 is then pumped by the pump 61 and flows back into the cooling channel 51. The heat dissipation section 60 includes a heat exchanger and is cooled by the outside air. The heat dissipation section 60 is, for example, a radiator. Alternatively, the pump 61 may be placed between the outlet of the cooling channel 51 and the heat dissipation section 60 to pump the cooling liquid before it is heated by the heat dissipation section 60. The cooling liquid can be, for example, water or antifreeze.

[0039] Furthermore, as shown in Figure 6, the inverter unit 10 is located on the back surface 50b of the base unit 50 and is cooled by a cooling liquid flowing on the Z2 side of the base unit 50. Specifically, the first switching element module 11a and the second switching element module 11b are located on the back surface 50b of the base unit 50 and are cooled by a cooling liquid flowing on the Z2 side of the base unit 50.

[0040] Furthermore, the DC-DC converter section 30 is placed on the surface 50a of the base section 50 and is cooled by a cooling liquid flowing on the Z1 side of the base section 50. Specifically, the converter switching element 31a, the transformer 31b, the resonant reactor 31c, the smoothing reactor 31d, the boost switching element module 21, and the reactor 22 are placed on the surface 50a of the base section 50 and are cooled by a cooling liquid flowing on the Z1 side of the base section 50.

[0041] In the DC-DC converter section 30, components are arranged considering the effects of thermal interference from the reactor 22. Specifically, among the converter switching element 31a, transformer 31b, resonant reactor 31c, and smoothing reactor 31d, components with low heat resistance are arranged so as not to be placed near the reactor.

[0042] The DC-DC converter section 30 has components such as fuses, capacitors, and Hall sensor elements mounted on it in addition to the DC-DC converter element 31, and these components dissipate the heat generated by each component to the surface 50a of the base section 50 via a heat dissipation member.

[0043] At least a portion of the DCDC converter section 30 on the reactor 22 side may be covered with a shielding cover to reduce thermal interference from the reactor 22.

[0044] Furthermore, the cooling channel 51 is formed such that the cooling liquid cools the components with higher priority based on thermal resistance, starting with the first switching element module 11a, the second switching element module 11b, the converter switching element 31a, the transformer 31b, the resonant reactor 31c, the smoothing reactor 31d, the boost switching element module 21, and the reactor 22.

[0045] In this embodiment, as shown in Figure 1, the housing 70 houses the inverter unit 10 and the DC-DC converter unit 30. Specifically, the housing 70 houses the inverter unit 10, the boost converter unit 20, the base unit 50, and the DC-DC converter unit 30, and within the housing 70, the inverter unit 10, the base unit 50, and the DC-DC converter unit 30 are stacked in this order in the Z1 direction. The housing 70 is open on the Z1 side, which is opposite to the load 210, and the DC-DC converter unit 30 is exposed through the opening of the housing 70. The boost switching element module 21 and the reactor 22 of the boost converter unit 20 are also exposed through the opening of the housing 70. The housing 70 is fixed to the load 210 by fastening members 80. Specifically, the housing 70 is fixed to the load 210 by fastening members 80 via holes 71 provided on the outer circumference of the housing 70.

[0046] [Effects of this embodiment] In this embodiment, the following effects can be obtained.

[0047] In this embodiment, as described above, the inverter unit 10 and the DC-DC converter unit 30 are stacked in this order from the load 210 side. As a result, even when the power converter 100 is mounted on the load 210, the DC-DC converter unit 30 is located on the opposite side from the load 210, so the DC-DC converter unit 30 can be easily replaced.

[0048] In this embodiment, as described above, the power converter 100 further comprises a housing 70 that houses the inverter unit 10 and the DC-DC converter unit 30. The housing 70 has an opening on the side opposite to the load 210, and the DC-DC converter unit 30 is exposed through the opening in the housing 70. As a result, even when the inverter unit 10 and the DC-DC converter unit 30 are housed in the housing 70, the DC-DC converter unit 30 is exposed through the opening in the housing 70, so the DC-DC converter unit 30 can be easily replaced.

[0049] In this embodiment, as described above, the housing 70 is fixed to the load 210 by fastening members 80. As a result, even when the housing 70 is fixed to the load 210 by fastening members 80, the DC-DC converter unit 30 is exposed through the opening of the housing 70, so the DC-DC converter unit 30 can be easily replaced.

[0050] In this embodiment, as described above, the load 210 includes a motor for an electric vehicle. This allows the DC-DC converter unit 30 to be easily replaced even when the power converter 100 is mounted on the motor for an electric vehicle.

[0051] In this embodiment, as described above, the power converter 100 further includes a base unit 50 on which the inverter unit 10 and the DC-DC converter unit 30 are arranged. The DC-DC converter unit 30 is located on the side of the base unit 50 opposite to the load 210. As a result, since the DC-DC converter unit 30 is located on the side of the base unit 50 opposite to the load 210, the DC-DC converter unit 30 can be easily replaced even when it is located on the base unit 50.

[0052] In this embodiment, as described above, the DC-DC converter unit 30 is fixed to the base unit 50 by a fastening member 80. This allows the DC-DC converter unit 30 to be easily replaced simply by releasing the fastening of the fastening member 80.

[0053] In this embodiment, as described above, the power converter 100 further comprises a base unit 50 on which the inverter unit 10 and the DC-DC converter unit 30 are arranged, and a boost converter unit 20 arranged on the input side of the inverter unit 10, which boosts the DC power input from the DC power supply 200 and supplies it to the inverter unit 10. The boost converter unit 20 is arranged on the side of the base unit 50 opposite to the load 210. As a result, even when the power converter 100 is mounted on the load 210, the boost converter unit 20 is arranged on the side opposite to the load 210, so the boost converter unit 20 can be easily replaced.

[0054] In this embodiment, as described above, the boost converter unit 20 is fixed to the base unit 50 by a fastening member 80. This allows the boost converter unit 20 to be easily replaced simply by releasing the fastening of the fastening member 80.

[0055] [Differentiation] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than by the description of the embodiments above, and further includes all modifications (exceptions) within the meaning and scope equivalent to the claims.

[0056] In the above embodiment, the housing 70 is shown as having an opening on the side opposite to the load 210 (Z1 side), but the present invention is not limited to this. For example, the side of the housing 70 opposite to the load 210 (Z1 side) may be covered with a lid or the like.

[0057] In the above embodiment, an example was shown in which the housing 70 is fixed to the load 210 by fastening members 80, but the present invention is not limited thereto. For example, the housing 70 may be fixed to the load 210 by being fitted onto the load 210.

[0058] In the above embodiment, an example was shown in which the power converter 100 is mounted on a motor for an electric vehicle, but the present invention is not limited to this. For example, the power converter 100 may be mounted on a load other than a motor for an electric vehicle (such as a motor for industrial machinery).

[0059] In the above embodiment, an example was shown in which the inverter unit 10 and the DC-DC converter unit 30 are arranged on a base unit 50 having a cooling channel 51, but the present invention is not limited to this. For example, the inverter unit 10 and the DC-DC converter unit 30 may be arranged on a plate member that does not have a cooling channel 51.

[0060] In the above embodiment, an example was shown in which the DC-DC converter section 30 and the boost converter section 20 are fixed to the base section 50 by fastening members 80, but the present invention is not limited thereto. For example, the DC-DC converter section 30 and the boost converter section 20 may be fixed to the base section 50 by a thermally conductive adhesive.

[0061] In the above embodiment, an example was shown in which the boost converter unit 20 is located on the opposite side (Z1 side) of the base unit 50 from the load 210, but the present invention is not limited to this. For example, the boost converter unit 20 may be located on the load 210 side (Z2 side) of the base unit 50.

[0062] In the above embodiment, an example was shown in which two first inverter units 10a and second inverter units 10b are provided, and two first loads 210a and second loads 210b are provided, but the present invention is not limited thereto. For example, one inverter unit and one load may be provided. [Explanation of Symbols]

[0063] 10 Inverter section 20 Boost Converter Section 30. DC-DC converter section (DC-DC converter section) 50 Base 70 cabinets 80 Fastening members 100 Power converter 210 load 200 DC power supply

Claims

1. A power conversion device that is placed on a load and supplies power to the load, A DC-to-DC converter unit that converts the voltage of DC power input from a DC power supply to a different voltage, A boost converter unit that boosts the DC power input from the DC power supply, An inverter unit that converts the DC power boosted by the boost converter unit into AC power and supplies it to the load, The base portion on which the inverter unit, the DC-DC converter unit, and the boost converter unit are arranged, The enclosure comprises the inverter section, the DC-DC converter section, the boost converter section, and the base section, and is covered on the side opposite to the load by a separately provided lid, which can be opened by removing the lid, The inverter section, the base section, and the DC-DC converter section are stacked in this order from the load side. Both the DC-DC converter section and the boost converter section are located on the side of the base section opposite to the load, and are exposed through the opening of the housing. The DC-DC converter section is fixed to the base section by inserting a first fastening member along the direction from the DC-DC converter section toward the inverter section. The housing has a rectangular shape when viewed from a direction facing the load, and at least two orthogonal sides of the rectangle have a length shorter than the length of the corresponding side of the load, and is fixed to the load by inserting a second fastening member into a hole in a fixing part that protrudes outward on the outer circumference of the two sides, in the same direction as the first fastening member is inserted.

2. The power conversion device according to claim 1, wherein the load includes a motor for an electric vehicle.

3. The power conversion device according to claim 1, wherein the boost converter section is fixed to the base section by a fastening member.

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