Electric power conversion apparatus

Abstract

Provided is an electric power conversion apparatus including: a first enclosure housing a semiconductor module for power conversion and a distribution path for distributing a refrigerant for cooling the semiconductor module; and a high-power connector which is located in the periphery of the first enclosure and connected to a high-power device located outside the first enclosure, and which electrically connects the high-power device and the semiconductor module to each other, wherein the first enclosure houses an electronic component connected to the semiconductor module, and the distribution path is disposed so as to pass between the high-power connector and the electronic component.

Description

Power Conversion Device

[0001] The present invention relates to a power conversion device.

[0002] JP2013-115903A discloses a power conversion device having a housing that houses a semiconductor module for power conversion and a flow path through which a refrigerant for cooling the semiconductor module flows, in which electronic components (smoothing capacitors, etc.) connected to the semiconductor module are arranged adjacent to the flow path within the housing to cool the electronic components.

[0003] In JP2013-115903A, a high-voltage connector that connects to high-voltage equipment is attached to the outer periphery of the housing, and the high-voltage connector electrically connects the high-voltage equipment and the semiconductor module to each other. However, heat generated due to contact resistance between the high-voltage equipment and the high-voltage connector propagates inside the housing, causing the ambient temperature inside the housing to rise, making it difficult to improve the reliability (heat resistance) of the electronic components.

[0004] SUMMARY OF THE INVENTION It is therefore an object of the present invention 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, there is provided a power conversion device including a first housing that houses a semiconductor module for power conversion and a flow path for circulating a coolant for cooling the semiconductor module, and a high-voltage connector that is arranged on the outer periphery of the first housing and is connected to a high-voltage device arranged outside the first housing, electrically connecting the high-voltage device and the semiconductor module. In this power conversion device, the first housing houses electronic components connected to the semiconductor module, and the flow path is arranged to pass between the high-voltage connector and the electronic components.

[0006] FIG. 1 is an external view of a drive unit including a power conversion device of this embodiment. FIG. 2 is a plan view of a drive unit including a power conversion device of this embodiment. FIG. 3 is a circuit diagram of a drive unit including a power conversion device of this embodiment. FIG. 4 is a diagram showing a circulation path through which a refrigerant circulates in a drive unit including a power conversion device of this embodiment. FIG. 5 is a diagram showing a circulation path of a refrigerant in the power conversion device of this embodiment. FIG. 6 is a view seen from an arrow A in FIG. 5. FIG. 7 is a view seen from an arrow B in FIG. 5. FIG. 8 is a side view showing a modified example of the circulation path of a refrigerant in the power conversion device of this embodiment. FIG. 9 is a plan view showing a modified example of the circulation path of a refrigerant in the power conversion device of this embodiment.

[0007] [Drive unit 100] Fig. 1 is an external view of a drive unit 100 including a power conversion device (inverter 1) of this embodiment. Fig. 2 is a plan view of the drive unit 100 including a power conversion device (inverter 1) of this embodiment. The drive unit 100 is used to drive, for example, a series hybrid vehicle. The drive unit 100 integrates an inverter 1, a drive motor 2, a generator motor 3 (which may be omitted in the present invention), a reduction mechanism (not shown), and a speed increase mechanism (not shown). The generator motor 3 is connected to an engine (not shown) for generating electricity.

[0008] The drive unit 100 has a first housing 11 that houses the inverter 1, a second housing 22 that houses the drive motor 2 and the generator motor 3, and a third housing 33 (not shown in Figure 1) that houses the reduction mechanism and the speed increase mechanism.

[0009] The drive motor 2 and the generator motor 3 are arranged so that the axial directions of the stator and rotor are parallel to each other, for example, parallel to the left-right direction of the vehicle, and are housed in the second housing 22 in this arrangement.

[0010] The drive unit 100 is disposed, for example, in the engine compartment of the vehicle, with the second housing 22 inclined toward the front of the vehicle (the direction of travel of the vehicle). Therefore, the upper surface of the second housing 22 is an inclined surface that slopes toward the front of the vehicle.

[0011] The first housing 11 is attached to the upper surface (inclined surface) of the second housing 22. The third housing 33 (FIG. 2) is attached to a side surface of the second housing 22 in the left-right direction of the vehicle. The length of the third housing 33 in the front-rear direction of the vehicle is set to be longer than the length of the second housing 22 in the front-rear direction. The third housing 33 is also arranged to protrude from the second housing 22 in the front-rear direction (forward and rearward).

[0012] A high-voltage connector 151 and a high-voltage connector 152 are disposed on the top surface of the first housing 11. The high-voltage connector 151 and the high-voltage connector 152 are electrically connected to the DC side of the inverter 1 (semiconductor modules 12 and 13). The high-voltage connector 151 is connected to the battery 4 (FIG. 3), and the high-voltage connector 152 is connected to, for example, a vehicle air conditioner (not shown).

[0013] The temperature of the high-voltage connector 151 rises due to contact resistance with the connector on the battery side, and the temperature of the high-voltage connector 152 rises due to contact resistance with the connector on the air conditioner side.

[0014] Therefore, the high voltage connector 151 and the high voltage connector 152 are located at the end of the top surface of the first housing 11, at a position that becomes the uppermost part (topmost part) of the inclined surface when the first housing 11 is placed on the inclined surface of the second housing 22.

[0015] As a result, the high voltage connector 151 and the high voltage connector 152 are positioned at almost the top of the drive unit 100, which suppresses an increase in the ambient temperature of the drive unit 100 (engine room) and improves the reliability (heat resistance) of the electronic components 14 (Figure 4, etc.) that make up the inverter 1.

[0016] Furthermore, since the high-voltage connectors 151 and 152 are arranged on an inclined surface of the second housing 22 that is inclined in the direction of travel of the vehicle, when the vehicle is hit from behind by another vehicle, the wall surface of the engine compartment or the like will hit the second housing 22 before the high-voltage connectors 151 and 152, thereby reducing the chance that the wall surface will interfere with the high-voltage connectors 151 and 152, causing them to be damaged or short-circuited.

[0017] Furthermore, the high-voltage connectors 151 and 152 are located at the end of the top surface of the first housing 11, biased toward the third housing 33. As described above, the third housing 33 is equipped with at least the speed reduction mechanism, and is located so as to protrude in the longitudinal direction from the second housing 22. Therefore, when the vehicle is hit from behind by another vehicle, the wall surface of the engine compartment or the like comes into contact with the third housing 33 first, thereby reducing interference between the wall surface and the high-voltage connectors 151 and 152 and reducing damage or short-circuiting of these connectors.

[0018] [Circuit Diagram] Figure 3 is a circuit diagram of a drive unit 100 including the power conversion device (inverter 1) of this embodiment. As shown in Figure 3, the drive unit 100 includes a drive motor 2, a generator motor 3, an inverter 1 that exchanges power between the drive motor 2 and the generator motor 3 and a battery 4 (and an 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 an air conditioner (not shown).

[0019] The inverter 1 includes a semiconductor module 12 connected to the drive motor 2, a smoothing capacitor 141 connected to the DC side of the semiconductor module 12, a semiconductor module 13 connected to the generator motor 3, a smoothing capacitor 142 connected to the DC side of the semiconductor module 13, and a substrate 145 on which are mounted a gate drive circuit (not shown) that outputs PWM signals to the semiconductor module 12 and the semiconductor module 13. The smoothing capacitors 141 and 142 may be implemented as a single smoothing capacitor. The drive unit 100 also includes a current sensor 143 (electronic component 14) that detects the current between the semiconductor module 12 and the drive motor 2, and a current sensor 144 (electronic component 14) that detects the current between the semiconductor module 13 and the generator motor 3.

[0020] The semiconductor module 12 for the drive motor 2 forms two parallel circuits each consisting of a semiconductor element 121 such as an IGBT and a feedback diode 122, and two parallel circuits are connected in series to form series circuits for the U phase, V phase, and W phase, which are connected in parallel to a smoothing capacitor 141 and the battery 4. A connection midpoint UM of the U-phase series circuit is connected to the U-phase of the drive motor 2, a connection midpoint VM of the V-phase series circuit is connected to the V-phase of the drive motor 2, and a connection 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 gates of the semiconductor elements 121 that constitute the semiconductor module 12, the DC voltage of the battery 4 can be converted into an AC voltage and output to the drive motor 2, and regenerative power generated by the drive motor 2 can be converted into a DC voltage and charged to the battery 4.

[0021] A high-voltage connector 151 that electrically connects the battery 4 and the semiconductor module 12 to each other is arranged in the path connecting the smoothing capacitor 141 and the battery 4, and a high-voltage connector 152 that electrically connects to an air conditioner (not shown) is arranged so as to branch off between the smoothing capacitor 141 and the high-voltage connector 151.

[0022] The semiconductor module 13 for the generator motor 3 has a configuration similar to that of the semiconductor module 12 and is connected to a smoothing capacitor 142. The smoothing capacitor 142 is connected to the high-voltage connector 151 (and the high-voltage connector 152) so as to be in parallel with the smoothing capacitor 141.

[0023] In this embodiment, the high-voltage connector 151 generates heat when power is exchanged between the battery 4 and the inverter 1, and the high-voltage connector 152 (and the high-voltage connector 151) generates heat when the inverter 1 (or the battery 4) supplies power to the air conditioner.

[0024] 4 is a diagram showing the circulation path 7 through which the refrigerant circulates in the drive unit 100 including the power conversion device (inverter 1) of this embodiment. As shown in Fig. 4, the drive unit 100 has the circulation path 7 through which the refrigerant (water) circulates, and the radiator 5, the circulation pump 6, the semiconductor module 12, the semiconductor module 13, the drive motor 2 (stator), and the generator motor 3 (stator) are arranged in the circulation path 7.

[0025] The radiator 5 exchanges heat between the refrigerant and outside air to cool the refrigerant.

[0026] The circulation pump 6 supplies the coolant cooled by the radiator 5 to the semiconductor modules 12 and 13. In Fig. 4, the flow path 7 is configured to branch upstream of the semiconductor modules 12 and 13 to supply the coolant to the semiconductor modules 12 and 13 individually and then merge again downstream of the semiconductor modules 12 and 13 (see Fig. 5), but the flow path 7 may also be configured to be wide so that the coolant is supplied to the semiconductor modules 12 and 13 simultaneously (see Fig. 9).

[0027] The refrigerant that has cooled the semiconductor modules 12 and 13 flows through the drive motor 2 (stator) and the generator motor 3 (stator) in this order to cool the drive motor 2 and the generator motor 3 , and is then supplied to the radiator 5 .

[0028] Here, the portion of the distribution path 7 between the semiconductor modules 12 and 13 and the drive motor 2 passes between the electronic components 14 (smoothing capacitor 141, smoothing capacitor 142, current sensor 143, current sensor 144, board 145) that constitute the inverter 1 and the high-voltage connector 151 and the high-voltage connector 152.

[0029] The semiconductor modules 12 and 13 usually have a low thermal time constant and generate a large amount of heat, and therefore are the first parts to be supplied with the coolant cooled by the radiator 5. The drive motor 2 (stator) and the generator motor 3 (stator) have a higher thermal time constant than the semiconductor modules 12 and 13, and therefore can be sufficiently cooled even by the coolant that has passed through the semiconductor modules 12 and 13.

[0030] [Refrigerant flow path 7 in inverter 1] Fig. 5 is a diagram showing the refrigerant flow path 7 in the power conversion device (inverter 1) of this embodiment. Fig. 6 is a view seen from the arrow A in Fig. 5. Fig. 7 is a view seen from the arrow B in Fig. 5. In the figures, the direction in which the short sides of the first housing 11 extend is the X direction, the direction in which the long sides of the first housing 11 extend is the Y direction, and the thickness direction of the first housing 11 is the Z direction, which are perpendicular to each other.

[0031] The inverter 1 has an outer shape formed by a first housing 11, and a flow path 7 for a refrigerant (water) is formed inside the first housing 11. The inverter 1 includes a substrate 145, semiconductor modules 12 and 13, and electronic components 14, and is arranged so that the mounting surfaces of the semiconductor modules 12, 13, and electronic components 14 face downward.

[0032] 5 to 7, the distribution path 7 enters from the short side of the first housing 11 in the +Y direction, and when it reaches a position adjacent to the short side of the semiconductor module 13, it branches in the -X direction into a distribution path 7a heading toward the semiconductor module 13 and a distribution path 7b heading toward the semiconductor module 12.

[0033] The flow path 7a extends in the −X direction so as to contact the upper surface of the semiconductor module 13, and bends in the +Y direction after passing through the semiconductor module 13. The semiconductor module 13 is cooled by the refrigerant flowing through the flow path 7a.

[0034] The flow path 7b extends in the −X direction so as to contact the upper surface of the semiconductor module 12, and after passing through the semiconductor module 12 in the −X direction, it merges with the flow path 7a and again becomes the flow path 7. The semiconductor module 12 is cooled by the refrigerant flowing through the flow path 7b.

[0035] The upper surface of the first housing 11 constituting the inverter 1 is formed with a step 111 in which the portion where the high-voltage connectors 151 and 152 are arranged is lower than the other portion.

[0036] After merging, the flow path 7 extends in the +Y direction while forming a flow path following the shape of the step portion 111, protrudes from the first housing 11, and heads toward the drive motor 2 (stator). At this time, the flow path 7 passes between the high electric connectors 151 and 152 and the electronic component 14 in the first housing 11. This allows the flow path 7 to block the heat propagation path from the high electric connectors 151 and 152 toward the electronic component 14 and the board 145.

[0037] The flow path 7 in the first housing 11 may be constructed, for example, with a tubular member. Furthermore, when the first housing 11 is divided into two parts in the thickness direction, and has a base part that connects to the second housing 22 and houses the semiconductor modules 12, 13, and electronic components 14, and a lid part that connects to the base so as to cover the top surface of the base, a recess (opening) that serves as the source of the flow path 7 may be formed in the lid part, the substrate 145 may be housed in the recess, and a sealing member (packing) may be disposed around the recess, so that the lid part presses the sealing member when the lid part is connected to the base to close the recess. Furthermore, the semiconductor modules 12 and 13 may directly close the recess at the portions of the recess where they come into contact.

[0038] [Modification of refrigerant flow path 7 in inverter 1] Fig. 8 is a side view showing a modification of the refrigerant flow path 7 in the power conversion device (inverter 1) of this embodiment. Fig. 9 is a plan view showing a modification of the refrigerant flow path 7 in the power conversion device (inverter 1) of this embodiment.

[0039] In the inverter 1 of the modified example, the semiconductor module 12 is stacked on the electronic component 14 (smoothing capacitor 141) mounted on the substrate 145, and the semiconductor module 13 is stacked on the electronic component 14 (smoothing capacitor 142). The refrigerant flow path 7 is set wider than the long sides of the semiconductor module 12 and the semiconductor module 13, and is in contact with the top surfaces of the semiconductor modules 12 and 13 in a manner covering the semiconductor modules 12 and 13 in a plan view (as viewed from the Z direction). A current sensor 143 (electronic component 14) that detects the current between the semiconductor module 12 and the drive motor 2 is disposed adjacent to the semiconductor module 12, and a current sensor 144 (electronic component 14) that detects the current between the semiconductor module 13 and the generator motor 3 is disposed adjacent to the semiconductor module 13. Meanwhile, the high-voltage connectors 151 and 152 are disposed on the top surface of the first housing 11, i.e., on opposite sides of the flow path 7 from the semiconductor modules 12 and 13 in the Z direction.

[0040] This allows the flow path 7 to block the heat propagation path from the high voltage connector 151 (and the high voltage connector 152) to the semiconductor module 12, the semiconductor module 13, and the electronic component 14 (smoothing capacitor 141, smoothing capacitor 142, current sensor 143, current sensor 144).

[0041] [Effects of this embodiment] The power conversion device (inverter 1) of this embodiment includes a first housing 11 that houses semiconductor modules 12 (and semiconductor modules 13) for power conversion and a flow path 7 that circulates a refrigerant that cools the semiconductor modules 12, and a high-voltage connector 151 (and high-voltage connector 152) that is arranged on the outer periphery of the first housing 11 and is connected to a high-voltage device (battery 4) arranged outside the first housing 11 and that electrically connects the high-voltage device (battery 4) and the semiconductor module 12 to each other, in which the first housing 11 houses electronic components 14 (smoothing capacitor 141, current sensor 143, board 145) connected to the semiconductor module 12, and the flow path 7 is arranged to pass between the high-voltage connector 151 and the electronic components 14 (smoothing capacitor 141, current sensor 143, board 145).

[0042] With the above configuration, the heat transfer path from the high-voltage connector 151 to the electronic components 14 (smoothing capacitor 141, current sensor 143, and board 145) can be blocked by the heat flow path 7. This reduces the heat received by solder-mounted components such as the electronic components 14 (smoothing capacitor 141, current sensor 143, and board 145), improving the reliability (heat resistance) of the electronic components 14.

[0043] In this embodiment, the flow path 7 is arranged so that after the refrigerant is supplied to the semiconductor module 12 (and the 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).

[0044] With the above configuration, the coolant that cools the semiconductor module 12 (and the semiconductor module 13 ) can efficiently cool the semiconductor module 12 (and the semiconductor module 13 ) without receiving heat from the high-voltage connector 151 .

[0045] In this embodiment, the high-voltage connector 151 (and the high-voltage connector 152) is arranged on the upper surface of the first housing 11, and the distribution path 7 is arranged on the upper surface side of the first housing 11 closer to the semiconductor module 12 (and the semiconductor module 13) and the electronic component 14, so that the distribution path 7 passes between the high-voltage connector 151 (and the high-voltage connector 152) and the semiconductor module 12 (and the semiconductor module 13) and the electronic component 14.

[0046] With the above configuration, the only part of the first housing 11 that receives heat from the high-voltage connector 151 (and the high-voltage connector 152) is the part above the flow path 7, so that the increase in the ambient temperature of the drive unit 100 (engine room) can be suppressed.

[0047] In this embodiment, the driving equipment (driving motor 2, generator motor 3) that exchanges power with the semiconductor module 12 (and semiconductor module 13) is housed in the second housing 22, the second housing 22 has an inclined surface that slopes toward the direction of travel of the vehicle, and when the first housing 11 is attached to the inclined surface, the high-voltage connector 151 (and high-voltage connector 152) is arranged at the end of the top surface of the first housing 11, and when the first housing 11 is attached to the inclined surface, the end is arranged at the top of the inclined surface.

[0048] With the above configuration, the high-voltage connector 151 (and the high-voltage connector 152) is positioned at almost the top of the drive unit 100, which suppresses an increase in the ambient temperature of the drive unit 100 (engine room) and improves the reliability (heat resistance) of the electronic components 14 that make up the inverter 1.

[0049] The inverter 1 converts the power from the battery 4 as a DC power source to drive the drive motor 2, and also distributes the power from the battery 4 to an auxiliary unit, such as an air conditioner (compressor). These DC voltages are connected via a harness and a high-voltage connector 151 (and a high-voltage connector 152), which may generate heat depending on the load condition. In this case, soldered connections within the inverter 1 are particularly susceptible to heat stress, which may affect the lifespan of the soldered joints. However, in this embodiment, the high-voltage connector 151 (high-voltage connector 152), which can be a heat source, is located above the drive unit 100, so that the heat is transferred to the outside rather than to the inside of the inverter 1. Furthermore, since the inverter 1 (first housing 11) is arranged on an inclined surface in the second housing 22 that is inclined toward the vehicle's traveling direction, if the vehicle is hit from behind, the second housing 22 will abut against the wall surface (dash panel) at the rear of the engine room before the high-voltage connector 151 (and high-voltage connector 152) does, thereby reducing interference between the high-voltage connector 151 (and high-voltage connector 152) and the wall surface.

[0050] In this embodiment, the driving equipment is a driving motor 2, and a third housing 33 that houses a reduction mechanism (not shown) that transmits the driving force of the driving motor 2 to the driving wheels of the vehicle is attached to the side of the second housing 22 in the left-right direction of the vehicle, and the high-voltage connector 151 (and the high-voltage connector 152) is attached to that end at a position biased toward the third housing 33.

[0051] The third housing 33 is disposed so as to protrude in the front-to-rear direction from the second housing 22. Therefore, with the above-described configuration, when the vehicle is hit from behind by another vehicle, the wall surface of the engine compartment or the like comes into contact with the third housing 33 first, thereby reducing interference between the high-voltage connector 151 (and the high-voltage connector 152) and the wall surface, and reducing damage or short-circuiting of these connectors.

[0052] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and the technical scope of the present invention is not intended to be limited to the specific configurations of the above embodiments. Furthermore, the above embodiments can be combined as appropriate. When the drive unit 100 of this embodiment is applied to an electric vehicle (which does not have an engine and drives the drive wheels by a motor), the drive unit 100 is composed of a drive 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, and board 145)).

Claims

1. A first housing containing a semiconductor module for power conversion and a circulation path for circulating a refrigerant to cool the semiconductor module, In a power conversion device, which includes a power connector that is arranged on the outer periphery of the first housing and to which power equipment arranged outside the first housing is connected, and which electrically connects the power equipment and the semiconductor module to each other, The first housing contains electronic components connected to the semiconductor module, The high-voltage connector is located on the upper surface of the first housing. The aforementioned distribution channels are A power conversion device that is positioned to pass between the high-voltage connector and the electronic component, and is positioned on the upper surface side of the first housing above the semiconductor module and the electronic component, thereby passing between the high-voltage connector, the semiconductor module and the electronic component.

2. The aforementioned distribution channels are The power conversion device according to claim 1, wherein the refrigerant is supplied to the semiconductor module, and the refrigerant that has passed through the semiconductor module is arranged to pass between the high-voltage connector and the electronic component.

3. In a case where a drive device that exchanges power with the semiconductor module is housed in a second housing, the second housing has an inclined surface that slopes toward the direction of travel of the vehicle, and the first housing is attached to the inclined surface, The high-voltage connector is located at the end of the upper surface of the first housing. The power conversion device according to claim 1 or claim 2, wherein when the first housing is attached to the inclined surface, the end portion is positioned on the upper part of the inclined surface.

4. The aforementioned drive device is a drive motor, A third housing is attached to the left and right sides of the second housing of the vehicle, housing a reduction mechanism that transmits the driving force of the drive motor to the drive wheels of the vehicle. The power conversion device according to claim 3, wherein the high-voltage connector is attached to the end portion at a position that is biased toward the third housing side.