Power conversion device

Abstract

A power conversion device is provided with: a first housing in which a semiconductor module for power conversion and a flow path through which a refrigerant for cooling the semiconductor module flows are accommodated; and a strong-current connector that is disposed on the outer periphery of the first housing in which an electronic component connected to the semiconductor module is accommodated, is connected to a strong-current device disposed outside the first housing, and electrically connects the strong-current device and the semiconductor module to each other, and the flow path is disposed so as to pass between the strong-current connector and the electronic component.

Description

Technical Field

[0001] This invention relates to power conversion devices. Background Technology

[0002] JP2013-115903A discloses the following structure: In a power conversion device having a semiconductor module for power conversion and a housing containing a flow path for the refrigerant to cool the semiconductor module, an electronic component (such as a smoothing capacitor) connected to the semiconductor module is disposed adjacent to the flow path in the housing, and the electronic component is cooled. Summary of the Invention

[0003] In JP2013-115903A, a power connector for connecting to high-voltage equipment is mounted on the outer periphery of a housing, electrically connecting the high-voltage equipment and semiconductor modules to each other. However, heat generated by the contact resistance between the high-voltage equipment and the power connector propagates into the housing, causing the ambient temperature inside the housing to rise, making it difficult to improve the reliability (heat resistance) of electronic components.

[0004] Therefore, the object of the present invention is to provide a power conversion device that improves the reliability of electronic components connected to a semiconductor module.

[0005] According to one aspect of the present invention, a power conversion device includes: a first housing housing a semiconductor module for power conversion and a flow path for a refrigerant to cool the semiconductor module; and a high-voltage connector disposed on the outer periphery of the first housing and connected to a high-voltage device disposed outside the first housing, electrically connecting the high-voltage device and the semiconductor module to each other. In this power conversion device, the first housing houses electronic components connected to the semiconductor module. Furthermore, the flow path is configured to pass between the high-voltage connector and the electronic components. Attached Figure Description

[0006] Figure 1 This is an external view of the drive unit of the power conversion device including this embodiment.

[0007] Figure 2 This is a top view of the drive unit of the power conversion device included in this embodiment.

[0008] Figure 3 This is a circuit diagram of the drive unit of the power conversion device included in this embodiment.

[0009] Figure 4 This is a diagram showing the flow path of the refrigerant cycle in the drive unit of the power conversion device included in this embodiment.

[0010] Figure 5 This is a diagram showing the flow path of the refrigerant within the power conversion device of this embodiment.

[0011] Figure 6 yes Figure 5 A-direction view.

[0012] Figure 7 yes Figure 5 View B.

[0013] Figure 8 This is a side view showing a modified example of the refrigerant flow path within the power conversion device of this embodiment.

[0014] Figure 9 This is a top view showing a modified example of the refrigerant flow path within the power conversion device of this embodiment. Detailed Implementation

[0015] [Drive Unit 100]

[0016] Figure 1 This is an external view of the drive unit 100 that includes the power conversion device (inverter 1) of this embodiment. Figure 2 This is a top view of the drive unit 100, which includes the power conversion device (inverter 1) of this embodiment. The drive unit 100 is used, for example, to drive a series hybrid vehicle. The drive unit 100 integrates the inverter 1, drive motor 2, generator motor 3 (which may also be omitted in this invention), reduction mechanism (not shown), and speed-up mechanism (not shown). It should be noted that the generator motor 3 is connected to a generator engine (not shown).

[0017] The drive unit 100 has a first frame 11 for accommodating the inverter 1, a second frame 22 for accommodating the drive motor 2 and the generator motor 3, and a third frame 33 for accommodating the deceleration mechanism and the speed-increasing mechanism. Figure 1 (Not shown in the image).

[0018] The drive motor 2 and the generator motor 3 are configured such that the stator and rotor axes are parallel to each other and, for example, parallel to the left-right direction of the vehicle, and are housed in the second frame 22 in this configuration.

[0019] The drive unit 100 is disposed, for example, in the engine compartment of the vehicle, but the second frame 22 is disposed in a manner that tilts towards the front of the vehicle (in the direction of travel). Therefore, the upper surface of the second frame 22 becomes an inclined surface that tilts towards the front of the vehicle.

[0020] The first frame 11 is mounted on the upper surface (sloping surface) of the second frame 22. The third frame 33 ( Figure 2The third frame 33 is mounted on the left and right sides of the vehicle in the second frame 22. The longitudinal length of the third frame 33 in the vehicle is set to be longer than the longitudinal length of the second frame 22 in the same direction. In addition, the third frame 33 is configured to protrude from the second frame 22 in the longitudinal (front and rear) directions.

[0021] A high-voltage connector 151 and a high-voltage connector 152 are disposed on the upper surface of the first frame 11. The high-voltage connectors 151 and 152 are electrically connected to the DC side of the inverter 1 (semiconductor module 12, semiconductor module 13). The high-voltage connector 151 is connected to the battery 4 (… Figure 3 The high-voltage connector 152 is connected, for example, to the vehicle's air conditioning (not shown).

[0022] The high-voltage connector 151 experiences a temperature rise due to contact resistance with the connector on the battery side, and the high-voltage connector 152 experiences a temperature rise due to contact resistance with the connector on the air conditioner side.

[0023] Therefore, the high-voltage connectors 151 and 152 are disposed at the ends of the upper surface of the first frame 11 and are located at the upper part (uppermost part) of the inclined surface when the first frame 11 is disposed on the inclined surface of the second frame 22.

[0024] Therefore, the high-voltage connectors 151 and 152 are positioned approximately at the top of the drive unit 100, thereby suppressing the rise in ambient temperature of the drive unit 100 (engine compartment) and improving the performance of the electronic components 14 constituting the inverter 1. Figure 4 Reliability (heat resistance), etc.

[0025] In addition, the power connectors 151 and 152 are disposed on the inclined surface of the second frame 22 that is inclined in the direction of vehicle travel. Therefore, when the vehicle is rear-ended by another vehicle, the wall of the engine compartment contacts the second frame 22 before the power connectors 151 and 152. This reduces the possibility of interference between the wall and the power connectors 151 and 152, which could cause them to break or short-circuit.

[0026] Furthermore, the power connectors 151 and 152 are positioned biased at the end of the upper surface of the first frame 11, i.e., on the side of the third frame 33. As described above, the third frame 33 is equipped with at least a reduction mechanism and is positioned to protrude forward and backward from the second frame 22. Therefore, when the vehicle is rear-ended by another vehicle, the walls of the engine compartment, etc., first come into contact with the third frame 33, thereby reducing interference between the walls and the power connectors 151 and 152, and thus reducing the possibility of them being damaged or short-circuited.

[0027] [Circuit Diagram]

[0028] Figure 3 This is a circuit diagram of the drive unit 100 that includes the power conversion device (inverter 1) of this embodiment. Figure 3 As shown, the drive unit 100 includes a drive motor 2, a generator motor 3, an inverter 1 that transmits and receives power between the drive motor 2 and the generator motor 3 and the battery 4 (and the air conditioner), a high-voltage connector 151 that electrically connects the inverter 1 and the battery 4, and a high-voltage connector 152 that electrically connects the inverter 1 and the air conditioner (not shown).

[0029] Inverter 1 includes: a semiconductor module 12 connected to drive motor 2; a smoothing capacitor 141 connected to the DC side of semiconductor module 12; a semiconductor module 13 connected to generator motor 3; a smoothing capacitor 142 connected to the DC side of semiconductor module 13; and a substrate 145 equipped with a gate drive circuit (not shown) that outputs PWM signals to semiconductor module 12 and semiconductor module 13. It should be noted that smoothing capacitor 141 and smoothing capacitor 142 can also be composed of a single smoothing capacitor. Additionally, drive unit 100 includes a current sensor 143 (electronic component 14) for detecting the current between semiconductor module 12 and drive motor 2, and a current sensor 144 (electronic component 14) for detecting the current between semiconductor module 13 and generator motor 3.

[0030] The semiconductor module 12 for the drive motor 2 forms a parallel circuit of two IGBT or other semiconductor elements 121 and a feedback diode 122. A series circuit formed by connecting the two parallel circuits in series is configured as U-phase, V-phase, and W-phase circuits, which are then connected in parallel with the smoothing capacitor 141 and the battery 4. The midpoint UM of the U-phase series circuit is connected to the U-phase of the drive motor 2, the midpoint VM of the V-phase series circuit is connected to the V-phase of the drive motor 2, and the midpoint WM of the W-phase series circuit is connected to the W-phase of the drive motor 2. By inputting a PWM signal to the gate of the semiconductor element 121 constituting the semiconductor module 12, the DC voltage of the battery 4 can be converted to AC voltage and output to the drive motor 2. Furthermore, the regenerative power generated by the drive motor 2 can be converted to DC voltage and used to charge the battery 4.

[0031] A high-voltage connector 151 is provided on the path connecting the smoothing capacitor 141 and the battery 4 to electrically connect the battery 4 and the semiconductor module 12 to each other. A high-voltage connector 152, which is electrically connected to an air conditioner (not shown), is provided in a branch manner between the smoothing capacitor 141 and the high-voltage connector 151.

[0032] The semiconductor module 13 for the generator motor 3 has the same structure as the semiconductor module 12 and is connected to the smoothing capacitor 142. The smoothing capacitor 142 is connected in parallel with the smoothing capacitor 141 relative to the power connector 151 (and the power connector 152).

[0033] In this embodiment, when power is transferred between the battery 4 and the inverter 1, the high-voltage connector 151 heats up, and when the inverter 1 (or the battery 4) supplies power to the air conditioner, the high-voltage connector 152 (and the high-voltage connector 151) heats up.

[0034] [Refrigerant flow path 7]

[0035] Figure 4 This is a diagram showing the refrigerant circulation path 7 of the drive unit 100, which includes the power conversion device (inverter 1) of this embodiment. (See diagram below.) Figure 4 As shown, the drive unit 100 has a flow path 7 for circulating refrigerant (water), and a radiator 5, a circulation pump 6, a semiconductor module 12, a semiconductor module 13, a drive motor 2 (stator), and a generator motor 3 (stator) are arranged in the flow path 7.

[0036] Radiator 5 facilitates heat exchange between the refrigerant and the outside gas, thereby cooling the refrigerant.

[0037] The circulating pump 6 supplies refrigerant cooled by the radiator 5 to semiconductor modules 12 and 13. Figure 4 In this configuration, flow path 7 is configured to supply refrigerant to semiconductor modules 12 and 13 respectively by branching upstream, and then recombining downstream (see reference). Figure 5 However, it can also be configured such that the flow path 7 is set to be wide, and refrigerant is supplied to both semiconductor module 12 and semiconductor module 13 simultaneously (see reference). Figure 9 ).

[0038] The refrigerant, after cooling semiconductor module 12 and semiconductor module 13, flows sequentially through drive motor 2 (stator) and generator motor 3 (stator) to cool drive motor 2 and generator motor 3, and is supplied to heat sink 5.

[0039] Here, the portion of the flow path 7 between the semiconductor module 12 and the semiconductor module 13 and the drive motor 2 is between the electronic components 14 (smoothing capacitor 141, smoothing capacitor 142, current sensor 143, current sensor 144, substrate 145) constituting the inverter 1 and the high-voltage connectors 151 and 152.

[0040] Semiconductor modules 12 and 13 typically have low thermal time constants and generate a lot of heat, thus becoming the initial components supplied with the refrigerant cooled by the heat sink 5. The thermal time constants of the drive motor 2 (stator) and the generator motor 3 (stator) are higher than those of semiconductor modules 12 and 13, thus ensuring adequate cooling even for the refrigerant passing through semiconductor modules 12 and 13.

[0041] [Refrigerant flow path 7 within inverter 1]

[0042] Figure 5 This is a diagram showing the refrigerant flow path 7 within the power conversion device (inverter 1) of this embodiment. Figure 6 yes Figure 5 A-direction view. Figure 7 yes Figure 5 The B-direction view. In the figure, the direction of the short side extension of the first frame 11 is set as the X direction, the direction of the long side extension of the first frame 11 is set as the Y direction, and the thickness direction of the first frame 11 is set as the Z direction. They are orthogonal to each other.

[0043] The inverter 1 is formed by a first frame 11, but a refrigerant (water) flow path 7 is formed inside the first frame 11. In addition, the inverter 1 has a structure that includes a substrate 145, a semiconductor module 12, a semiconductor module 13, and electronic components 14, and is arranged with the mounting surfaces of the semiconductor module 12, semiconductor module 13, and electronic components 14 facing downwards.

[0044] exist Figures 5-7 In the process, when the flow path 7 enters from the short side of the first frame 11 in the +Y direction, it branches in the -X direction when it reaches the position adjacent to the short side of the semiconductor module 13, and branches into a flow path 7a towards the semiconductor module 13 and a flow path 7b towards the semiconductor module 12.

[0045] The flow path 7a extends in the -X direction in contact with the upper surface of the semiconductor module 13, and bends in the +Y direction as it passes through the semiconductor module 13 in the -X direction. The semiconductor module 13 is cooled by the refrigerant flowing in the flow path 7a.

[0046] The flow path 7b extends in the -X direction in contact with the upper surface of the semiconductor module 12. When it passes through the semiconductor module 12 in the -X direction, it merges with the flow path 7a and becomes the flow path 7 again. The semiconductor module 12 is cooled by the refrigerant flowing in the flow path 7b.

[0047] A stepped portion 111 is formed on the upper surface of the first frame 11 constituting the inverter 1, where the portion configuring the high-voltage connector 151 and the high-voltage connector 152 is lower than the other portions.

[0048] The confluenced flow path 7 forms a flow path mimicking the shape of the stepped portion 111 and extends in the +Y direction, protruding from the first frame 11 and toward the drive motor 2 (stator). At this time, the flow path 7 passes between the high-voltage connectors 151 and 152 and the electronic component 14 in the first frame 11. Thus, the flow path 7 can block the heat propagation path from the high-voltage connectors 151 and 152 toward the electronic component 14 and the substrate 145.

[0049] The flow path 7 in the first frame 11 can also be constructed using a tubular component, for example. Alternatively, if the first frame 11 is divided into two parts in the thickness direction, having a base connected to the second frame 22 and housing the semiconductor module 12, semiconductor module 13, and electronic component 14, and a cover connected to the base in a manner covering the upper surface of the base, it can be configured such that a recess (opening) forming the basis for the flow path 7 is formed in the cover, a substrate 145 is housed in the recess, and a sealing member (gasket) is arranged around the recess. When the cover is connected to the base, the cover presses against the sealing member, thereby closing the recess. Furthermore, the portion of the recess that contacts the semiconductor modules 12 and 13 can also be configured such that the semiconductor modules 12 and 13 directly close the recess.

[0050] [A variation of the refrigerant flow path 7 within inverter 1]

[0051] Figure 8 This is a side view showing a modified example of the refrigerant flow path 7 within the power conversion device (inverter 1) of this embodiment. Figure 9 This is a top view showing a modified example of the refrigerant flow path 7 within the power conversion device (inverter 1) of this embodiment.

[0052] In the modified inverter 1, a semiconductor module 12 is stacked on an electronic component 14 (smoothing capacitor 141) mounted on a substrate 145, and a semiconductor module 13 is stacked on an electronic component 14 (smoothing capacitor 142). Furthermore, the refrigerant flow path 7 is set to be wider than the long sides of both semiconductor modules 12 and 13, and when viewed from above (from the Z direction), it contacts the upper surfaces of semiconductor modules 12 and 13 in a manner that covers them. It should be noted that a current sensor 143 (electronic component 14) for detecting the current between semiconductor module 12 and drive motor 2 is disposed adjacent to semiconductor module 12, and a current sensor 144 (electronic component 14) for detecting the current between semiconductor module 13 and generator motor 3 is disposed adjacent to semiconductor module 13. On the other hand, high-voltage connectors 151 and 152 are disposed on the upper surface of the first frame 11, that is, on the opposite side of semiconductor module 12 and semiconductor module 13 in the Z direction, separated by the flow path 7.

[0053] Thus, the flow path 7 can cut off the propagation path of heat from the high-voltage connector 151 (and high-voltage connector 152) toward the semiconductor module 12, semiconductor module 13, and electronic components 14 (smoothing capacitor 141, smoothing capacitor 142, current sensor 143, and current sensor 144).

[0054] [Effects of this implementation method]

[0055] The power conversion device (inverter 1) of this embodiment includes: a first frame 11, which houses a semiconductor module 12 (and a semiconductor module 13) for power conversion and a flow path 7 for circulating refrigerant to cool the semiconductor module 12; a high-voltage connector 151 (and a high-voltage connector 152), which is disposed on the outer periphery of the first frame 11 and connected to a high-voltage device (battery 4) disposed outside the first frame 11, electrically connecting the high-voltage device (battery 4) and the semiconductor module 12 to each other, wherein the first frame 11 houses an electronic component 14 (smoothing capacitor 141, current sensor 143, substrate 145) connected to the semiconductor module 12, and the flow path 7 is configured to pass between the high-voltage connector 151 and the electronic component 14 (smoothing capacitor 141, current sensor 143, substrate 145).

[0056] According to the above structure, the flow path 7 can cut off the heat transfer path from the high-voltage connector 151 to the electronic components 14 (smoothing capacitor 141, current sensor 143, substrate 145). Therefore, the heat received by soldered components such as the electronic components 14 (smoothing capacitor 141, current sensor 143, substrate 145) can be reduced, and the reliability (heat resistance) of the electronic components 14 can be improved.

[0057] In this embodiment, the flow path 7 is configured such that after the refrigerant is supplied to the semiconductor module 12 (and semiconductor module 13), the refrigerant that has passed through the semiconductor module 12 passes between the high-voltage connector 151 and the electronic component 14 (substrate 145).

[0058] According to the above structure, the refrigerant used to cool the semiconductor module 12 (and semiconductor module 13) can efficiently cool the semiconductor module 12 (and semiconductor module 13) without being heated from the high-voltage connector 151.

[0059] In this embodiment, the high-voltage connector 151 (and high-voltage connector 152) is disposed on the upper surface of the first frame 11, and the flow path 7 is disposed at a position closer to the upper surface of the first frame 11 than the semiconductor module 12 (and semiconductor module 13) and the electronic component 14, so as to pass between the high-voltage connector 151 (and high-voltage connector 152) and the semiconductor module 12 (and semiconductor module 13) and the electronic component 14.

[0060] According to the above structure, the portion of the first housing 11 that is heated by the power connector 151 (and power connector 152) is only the portion above the flow path 7, thus suppressing the rise in ambient temperature of the drive unit 100 (engine compartment).

[0061] In this embodiment, the drive device (drive motor 2, generator motor 3) that transmits and receives power between the semiconductor module 12 (and semiconductor module 13) is housed in a second frame 22. The second frame 22 has an inclined surface that is tilted toward the direction of travel of the vehicle. When the first frame 11 is mounted on the inclined surface, the high-voltage connector 151 (and high-voltage connector 152) is disposed at the end of the upper surface of the first frame 11. When the first frame 11 is mounted on the inclined surface, the end is disposed at the upper part of the inclined surface.

[0062] According to the above structure, the high-voltage connector 151 (and high-voltage connector 152) are positioned at approximately the uppermost part of the drive unit 100, thereby suppressing the rise in ambient temperature of the drive unit 100 (engine compartment) and improving the reliability (heat resistance) of the electronic components 14 constituting the inverter 1.

[0063] Inverter 1 converts the power from battery 4 as a DC power source to drive drive motor 2, and also distributes the power from battery 4 to auxiliary units, such as air conditioners (compressors). These DC voltages are connected by wiring harnesses and high-voltage connectors 151 (and 152), but may generate heat depending on the load conditions. In this case, the heat, particularly in the soldered parts inside inverter 1, causes thermal stress, affecting the lifespan of the solder joints. However, in this embodiment, since the high-voltage connectors 151 (and 152), which can be heat sources, are positioned above drive unit 100, this heat is not transferred to the interior of inverter 1 but is transferred to the outside. Furthermore, by positioning the inverter 1 (first frame 11) in the second frame 22 on an inclined surface tilted toward the direction of vehicle travel, in the event of a rear-end collision, the second frame 22 abuts against the rear wall (front bulkhead) of the engine compartment before the power connector 151 (and power connector 152), thus reducing interference between the power connector 151 (and power connector 152) and the wall.

[0064] In this embodiment, the driving device is a drive motor 2. A third frame 33 is installed on the left and right side of the second frame 22 in the vehicle direction. The third frame 33 houses a reduction mechanism (not shown) that transmits the driving force of the drive motor 2 to the drive wheels of the vehicle. The high-voltage connector 151 (and high-voltage connector 152) are installed at this end and are biased towards the third frame 33.

[0065] The third frame 33 is configured to protrude from the second frame 22 in the forward and backward direction. Therefore, according to the above structure, when the vehicle is rear-ended by another vehicle, the walls of the engine compartment and the like first come into contact with the third frame 33. This reduces the interference between the power connectors 151 (and 152) and the wall, thus reducing the possibility of them being damaged or short-circuited.

[0066] The embodiments of the present invention have been described above, but the above embodiments only represent a part of the application examples of the present invention, and the technical scope of the present invention is not limited to the specific structure of the above embodiments. In addition, the above embodiments can be appropriately combined. It should be noted that when the drive unit 100 of this embodiment is applied to an electric vehicle (which does not have an engine but is driven by an electric motor to drive the drive wheels), the drive unit 100 is composed of a drive electric motor 2, an inverter 1 (semiconductor module 12, semiconductor module 13, electronic components 14 (smoothing capacitor 141, smoothing capacitor 142, current sensor 143, current sensor 144, substrate 145)).

Claims

1. A power conversion device comprising: A first housing that houses a semiconductor module for power conversion and a flow path through which a refrigerant that cools the semiconductor module flows; A heavy electric connector that is arranged at an outer periphery of the first housing and to which a heavy electric device arranged outside the first housing is connected, and that electrically connects the heavy electric device and the semiconductor module to each other, characterized in that An electronic component connected to the semiconductor module is housed in the first housing, The flow path is arranged to pass between the heavy electric connector and the electronic component.

2. The power conversion device according to claim 1, characterized in that The flow path is arranged to pass the refrigerant that has passed through the semiconductor module between the heavy electric connector and the electronic component after the refrigerant is supplied to the semiconductor module.

3. The power conversion device according to claim 1, characterized in that The heavy electric connector is arranged at an upper surface of the first housing, The flow path is arranged at a position closer to the upper surface of the first housing than the semiconductor module and the electronic component, and thereby passes between the heavy electric connector and the semiconductor module and the electronic component.

4. The power conversion device according to claim 2 or 3, characterized in that A drive device that performs transmission and reception of electric power with the semiconductor module is housed in a second housing that has an inclined surface inclined toward a traveling direction side of a vehicle, and in a case where the first housing is mounted to the inclined surface, The heavy electric connector is arranged at an end portion of the upper surface of the first housing, The end portion is arranged at an upper portion of the inclined surface when the first housing is mounted to the inclined surface.

5. The power conversion device according to claim 4, characterized in that The drive device is a drive motor, A third housing that houses a reduction mechanism that transmits a driving force of the drive motor to a drive wheel of the vehicle is mounted to a side surface of the second housing in a left-right direction of the vehicle, The heavy electric connector is mounted to a position of the end portion that is biased toward the third housing.

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