CN110247538B

CN110247538B - Power conversion device

Info

Publication number: CN110247538B
Application number: CN201910144192.6A
Authority: CN
Inventors: 采女贵宽; 源田太朗; 山田友子
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2018-03-09
Filing date: 2019-02-26
Publication date: 2021-03-19
Anticipated expiration: 2039-02-26
Also published as: JP7079625B2; CN110247538A; JP2019161797A

Abstract

The invention provides a power conversion device capable of improving cooling efficiency. A power conversion device (1) is provided with a power module (21), a reactor (22), a capacitor unit (23), a DC-DC converter (30), a first heat dissipation part (71), and a second heat dissipation part (72). The power module (21) is provided with a first power conversion circuit unit, a second power conversion circuit unit, and a third power conversion circuit unit. The reactor (22) is connected to the third power conversion circuit unit of the power module (21). The reactor (22) and the DC-DC converter (30) are disposed on the side opposite to the power module (21) with respect to the first heat dissipation part (71) in the third direction (D3). The capacitor element (23) is disposed on the opposite side of the second heat sink (72) from the power module (21) in the third direction (D3).

Description

Power conversion device

Technical Field

The present invention relates to a power conversion device.

Background

Conventionally, there is known a vehicle drive unit including a drive device case that houses a generator and a motor, and a power control unit mounted on the drive device case (see, for example, japanese patent application laid-open No. 2016-140198). In this vehicle drive unit, the power control unit includes, in a unit case, 2 inverters connected to the generator and the motor, respectively, a control unit that controls the 2 inverters, a current sensor, and the like.

[ SUMMARY OF THE INVENTION ]

[ problem to be solved by the invention ]

However, in the above-described conventional power conversion device, it is desired to reduce the size of electronic components such as semiconductor elements, capacitors, reactors, and the like constituting the electronic devices such as inverters connected to the generator and the motor, and to reduce the cost required for the structure by efficiently cooling the electronic components.

Disclosure of Invention

The invention aims to provide a power conversion device capable of improving cooling efficiency.

[ MEANS FOR solving PROBLEMS ] A method for solving the problems

(1) A power conversion device according to an aspect of the present invention includes: an element row (for example, each element row PU1, PV1, PW1, PU2, PV2, and PW2 in the embodiment) including a high-side arm element (for example, each transistor UH, VH, and WH in the high-side arm in the embodiment) and a low-side arm element (for example, each transistor UL, VL, and WL in the low-side arm in the embodiment) that transmit/receive electric power to/from a motor (for example, each first motor 12 and second motor 13 in the embodiment); a voltage conversion element (for example, the first transistor S1 and the second transistor S2 in the embodiment) electrically connected to the element row; a first heat dissipation portion (for example, the first heat dissipation portion 71 in the embodiment) and a second heat dissipation portion (for example, the second heat dissipation portion 72 in the embodiment) which are disposed on both sides with the element rows interposed therebetween in a predetermined direction (for example, the third direction D3 in the embodiment), and in which refrigerant flow paths (for example, the

refrigerant flow paths

77 and 90 in the embodiment) through which a refrigerant flows are formed; and a plurality of circuit components (for example, a reactor 22, a capacitor unit 23, and a DC-DC converter 30 in the embodiment) that are arranged on the opposite side of the element row with respect to the first heat dissipation portion and the second heat dissipation portion, respectively, in the predetermined direction, and each of the plurality of circuit components includes a capacitor (for example, the capacitor unit 23 in the embodiment) that is arranged on the opposite side of the element row with respect to the first heat dissipation portion in the predetermined direction, and a reactor (for example, the reactor 22 in the embodiment) that is connected to the voltage conversion element, and the capacitor is arranged on the opposite side of the element row with respect to the second heat dissipation portion in the predetermined direction.

(2) In the power conversion device according to (1) above, the plurality of circuit components may include a voltage converter (e.g., DC-DC converter 30 in the embodiment) capable of stepping down a power supply voltage (e.g., an output voltage of first battery 11 in the embodiment), and the voltage converter may be disposed on the opposite side of the element row with respect to the first heat dissipation portion in the predetermined direction.

(3) In the power converter according to (2) above, the voltage converter may be disposed upstream of the reactor in the refrigerant flow path.

(4) In the power converter according to any one of (1) to (3), the voltage conversion element may have a portion overlapping the reactor when viewed from the predetermined direction.

(5) In the power converter according to (4) above, the capacitor may include a power supply side capacitor (e.g., the first smoothing capacitor 41 in the embodiment) electrically connected to a power supply side connection terminal (e.g., the third bus bar 53 and the negative electrode bus bar NV in the embodiment) of the voltage converting element, and the power supply side capacitor may include a portion overlapping with the voltage converting element and the reactor when viewed from the predetermined direction.

(6) The power conversion device described in (2) or (3) above may include a power supply side capacitor (e.g., the first smoothing capacitor 41 in the embodiment) electrically connected to a power supply side connection terminal (e.g., the third bus bar 53 and the negative bus bar NV in the embodiment) of the voltage conversion element, and the power supply side capacitor may be disposed between the reactor and the voltage converter in a direction (e.g., the first direction D1 in the embodiment) intersecting the predetermined direction.

[ Effect of the invention ]

According to the above (1), since the reactor is disposed on the first heat radiation portion side and the capacitor is disposed on the second heat radiation portion side with respect to the element row, the reactor and the capacitor can be efficiently cooled in addition to the element row, and an increase in size due to the cooling performance of each member can be suppressed.

In the case of (2) above, since the voltage converter and the reactor are disposed on the first heat dissipation portion side with respect to the element row, the capacitor can be efficiently cooled while suppressing a decrease in the area in which the capacitor can be disposed in the second heat dissipation portion.

In the case of (3), the voltage converter that supplies electric power to the low-voltage-system auxiliary devices in the vehicle or the like can be reliably protected by cooling the voltage converter preferentially over the reactor.

In the case of (4), the connection member electrically connecting the voltage conversion element and the reactor can be prevented from becoming long, and the wiring can be efficiently performed.

In the case of (5), the connection member electrically connecting the power supply side capacitor and the voltage conversion element can be prevented from becoming long, and the wiring can be efficiently performed. Further, since the capacitor includes the power supply side capacitor, even when there are a plurality of capacitors, the capacitors can be arranged in a concentrated manner, and an increase in size can be suppressed.

In the case of (6), the connection member electrically connecting the power supply side capacitor to the reactor and the voltage converter can be prevented from becoming long, and wiring can be performed efficiently.

Drawings

Fig. 1 is a side view schematically showing the structure of a power conversion device according to an embodiment of the present invention.

Fig. 2 is a diagram schematically showing the arrangement of a reactor and a DC-DC converter of a power conversion device according to an embodiment of the present invention with respect to a first heat dissipation unit.

Fig. 3 is a perspective view schematically showing a configuration of a part of a power conversion device according to an embodiment of the present invention.

Fig. 4 is a diagram showing a configuration of a part of a vehicle on which a power conversion device according to an embodiment of the present invention is mounted.

Fig. 5 is a side view schematically showing the configuration of a power conversion device according to a first modification of the embodiment of the present invention.

Fig. 6 is a side view schematically showing the configuration of a power conversion device according to a second modification of the embodiment of the present invention.

Fig. 7 is a side view schematically showing the configuration of a power conversion device according to a third modification of the embodiment of the present invention.

Fig. 8 is a side view schematically showing the configuration of a power conversion device according to a fourth modification of the embodiment of the present invention.

Fig. 9 is a perspective view schematically showing a configuration of a part of a power conversion device according to a fifth modification of the embodiment of the present invention.

[ notation ] to show

1 … power conversion device, 10 … vehicle, 11 … battery, 12 … first motor, 13 … second motor, 21 … power module, 22 … reactor (circuit constituting member), 23 … capacitor cell (circuit constituting member, capacitor), 25 … first current sensor, 26 … second current sensor, 27 … third current sensor, 28 … electronic control unit, 29 … gate drive unit, 30 … DC-DC converter (circuit constituting member, voltage converter), 31 … first power conversion circuit portion, 32 … second power conversion circuit portion, 33 … third power conversion circuit portion, 41 … first smoothing capacitor (power source side capacitor), 53 … third bus bar (power source side connecting end), 70 … refrigerant flow path, 71, … first heat dissipation portion, 72 … second heat dissipation portion, 76a … carrying face, 90 … refrigerant, d1 … first direction (predetermined direction), D2 … second direction, D3 … third direction, PV … positive electrode bus bar, NV … negative electrode bus bar (power supply side connection), PU1, PV1, PW1, PU2, PV2, PW2, PS … element row, S1 … first transistor (voltage conversion element), S2 … second transistor (voltage conversion element), transistors (high side element) of UH, VH, WH … high side arm, transistors (low side element) of UL, VL, WL … low side arm.

Detailed Description

Hereinafter, an embodiment of a power converter according to the present invention will be described with reference to the drawings.

The power conversion device of the present embodiment controls the transfer of electric power between the electric motor and the first battery, and controls the voltage drop of the first battery with respect to the second battery. For example, the power converter is mounted on an electric vehicle or the like. The electric vehicle is an electric vehicle, a hybrid vehicle, a fuel cell vehicle, or the like. The electric motor vehicle is driven by taking the first storage battery as a power source. The hybrid vehicle is driven by the first battery and the internal combustion engine as power sources. A fuel cell vehicle is driven by a fuel cell as a power source.

Fig. 1 is a side view schematically showing the structure of a power conversion device 1 according to an embodiment of the present invention. Fig. 2 is a diagram schematically showing the arrangement of the reactor 22 and the DC-DC converter 30 of the power conversion device 1 according to the embodiment of the present invention with respect to the first heat dissipation portion 71. Fig. 3 is a perspective view schematically showing a configuration of a part of the power conversion device 1 according to the embodiment of the present invention. Fig. 4 is a diagram showing a configuration of a part of a vehicle 10 on which the power conversion device 1 according to the embodiment of the present invention is mounted.

< vehicle >

As shown in fig. 4, the vehicle 10 includes a first battery 11(BATT), a first electric motor 12(MOT) for driving and traveling, a second electric motor 13(GEN) for generating electric power, a second battery 14, and auxiliary devices 15, in addition to the power conversion device 1.

The first battery 11 is, for example, a high-voltage battery as a power source of the vehicle 10. The first battery 11 includes a battery case and a plurality of battery modules housed in the battery case. The battery module includes a plurality of battery cells connected in series. The first battery 11 includes a positive electrode terminal PB and a negative electrode terminal NB connected to the dc connector 1a of the power conversion device 1. The positive electrode terminal PB and the negative electrode terminal NB are connected to positive electrode terminals and negative electrode terminals of a plurality of battery modules connected in series in the battery case.

The first electric motor 12 generates a rotational driving force by the electric power supplied from the first battery 11 (power running operation). The second electric motor 13 generates generated electric power by the rotational driving force input to the rotary shaft. Here, the rotational power of the internal combustion engine can be transmitted to the second electric motor 13. For example, the first motor 12 and the second motor 13 are three-phase ac brushless DC motors, respectively. The three phases are U phase, V phase and W phase. The first motor 12 and the second motor 13 are each of an inner rotor type. Each of the

motors

12 and 13 includes: a rotor having permanent magnets for excitation; and a stator having three-phase stator windings for generating a rotating magnetic field for rotating the rotor. The stator windings of the three phases of the first electric motor 12 are connected to the first three-phase connector 1b of the power conversion device 1. The stator windings of the three phases of the second electric motor 13 are connected to the second three-phase connector 1c of the power conversion device 1.

The second battery 14 is, for example, a low-voltage battery that drives auxiliary devices such as in-vehicle devices of the vehicle 10. The second battery 14 is connected to the first battery 11 via a DC-DC converter 30 of the power conversion device 1. The voltage output from the DC-DC converter 30, that is, the voltage obtained by reducing the output voltage of the first battery 11 is applied to the second battery 14.

The auxiliary devices 15 are driven by the voltage output from the second battery 14, that is, the operating voltage of the auxiliary devices 15. The auxiliary devices 15 are, for example, various sensors and electrical equipment.

< Power conversion device >

The power conversion device 1 includes a power module 21(P/M), a reactor 22, a capacitor unit 23, a resistor 24, a first current sensor 25, a second current sensor 26, a third current sensor 27, an electronic control unit 28(MOT GEN ECU), a gate drive unit 29(G/D VCU ECU), and a DC-DC converter 30.

The power module 21 includes a first power conversion circuit unit 31, a second power conversion circuit unit 32, and a third power conversion circuit unit 33. The first power conversion circuit unit 31 is connected to the three-phase stator windings of the first electric motor 12 via the first three-phase connector 1 b. The first power conversion circuit unit 31 converts the direct-current power input from the first battery 11 via the third power conversion circuit unit 33 into three-phase alternating-current power. The second power conversion circuit unit 32 is connected to the three-phase stator windings of the second electric motor 13 via the second three-phase connector 1 c. The second power conversion circuit unit 32 converts the three-phase ac power input from the second electric motor 13 into dc power. The dc power converted by the second power conversion circuit unit 32 can be supplied to at least one of the first battery 11 and the first power conversion circuit unit 31.

Each of the first power conversion circuit unit 31 and the second power conversion circuit unit 32 includes a bridge circuit formed by a plurality of switching elements connected in a bridge. For example, the switching element is a Transistor such as an igbt (insulated Gate Bipolar Transistor) or a MOSFET (Metal Oxide semiconductor Field Effect Transistor). For example, in the bridge circuit, paired high-side and low-side arm U-phase transistors UH and UL, paired high-side and low-side arm V-phase transistors VH and VL, and paired high-side and low-side arm W-phase transistors WH and WL are respectively bridge-connected.

The transistors UH, VH, and WH of the high-side arm are connected to the positive bus PI via a collector to form the high-side arm. In each phase, each positive electrode bus bar PI of the high-side arm is connected to the positive electrode bus bar 50p of the capacitor unit 23.

The transistors UL, VL, and WL in the low-side arm are connected to the negative bus bar NI through the emitter, thereby forming the low-side arm. In each phase, each negative electrode bus bar NI of the low side arm is connected to the negative electrode bus bar 50n of the capacitor unit 23.

In each phase, the emitter of each transistor UH, VH, WH of the high-side arm is connected to the collector of each transistor UL, VL, WL of the low-side arm at a connection point TI.

The first bus bar 51 forming the connection point TI in each phase of the first power conversion circuit unit 31 is connected to the first input/output terminal Q1. The first input/output terminal Q1 is connected to the first three-phase connector 1 b. The connection point TI of each phase of the first power conversion circuit unit 31 is connected to the stator winding of each phase of the first motor 12 via the first bus bar 51, the first input/output terminal Q1, and the first three-phase connector 1 b.

The second bus bar 52 forming the connection point TI in each phase of the second power conversion circuit unit 32 is connected to the second input/output terminal Q2. The second input/output terminal Q2 is connected to the second three-phase connector 1 c. The connection point TI of each phase of the second power conversion circuit unit 32 is connected to the stator winding of each phase of the second electric motor 13 via the second bus bar 52, the second input/output terminal Q2, and the second three-phase connector 1 c.

The bridge circuit includes diodes connected in a forward direction from an emitter to a collector between collectors of the transistors UH, UL, VH, VL, WH, and WL.

The first power conversion circuit unit 31 and the second power conversion circuit unit 32 switch the pair of transistors of each phase on (on)/off (off) based on gate signals, which are switching commands input from the gate drive unit 29 to the gates of the transistors UH, VH, WH, UL, VL, and WL, respectively. The first power conversion circuit unit 31 converts the dc power input from the first battery 11 via the third power conversion circuit unit 33 into three-phase ac power, sequentially commutates the current to the three-phase stator windings of the first electric motor 12, and energizes the ac U-phase current, V-phase current, and W-phase current to the three-phase stator windings. The second power conversion circuit unit 32 converts the three-phase ac power output from the three-phase stator windings of the second electric motor 13 into dc power by on (on)/off (off) driving of the transistor pairs of each phase in synchronization with the rotation of the second electric motor 13.

The third power conversion circuit unit 33 is a Voltage Control Unit (VCU). The third power conversion circuit unit 33 includes switching elements of a pair of high-side arm and low-side arm. For example, the third power conversion circuit unit 33 includes a first transistor S1 of a high-side arm and a second transistor S2 of a low-side arm.

The first transistor S1 has a collector connected to the positive electrode bus bar PV to form a high-side arm. The positive bus bar PV of the high-side arm is connected to the positive bus bar 50p of the capacitor unit 23. The second transistor S2 has an emitter connected to the negative electrode bus bar NV to form a low-side arm. The negative bus bar NV of the lower side arm is connected to the negative bus bar 50n of the capacitor unit 23. Negative electrode bus bar 50n of capacitor unit 23 is connected to negative electrode terminal NB of first battery 11. The emitter of the first transistor S1 of the high side arm is connected to the collector of the second transistor S2 of the low side arm. The third power conversion circuit unit 33 includes a diode connected between the collector and the emitter of each of the first transistor S1 and the second transistor S2 in the forward direction from the emitter to the collector.

The third bus bar 53 forming a connection point of the first transistor S1 of the high side arm and the second transistor S2 of the low side arm is connected to the reactor 22. Both ends of the reactor 22 are connected to a connection point between the first transistor S1 and the second transistor S2 and the positive electrode terminal PB of the first battery 11. The reactor 22 includes a coil and a temperature sensor for detecting the temperature of the coil. The temperature sensor is connected to the electronic control unit 28 through a signal line.

The third power conversion circuit unit 33 switches the pair of transistors on (on)/off (off) based on a gate signal that is a switching command input from the gate drive unit 29 to the gates of the first transistor S1 and the second transistor S2.

The third power conversion circuit unit 33 alternately switches between a first state in which the second transistor S2 is set to on (conducting) and the first transistor S1 is set to off (disconnecting), and a second state in which the second transistor S2 is set to off (disconnecting) and the first transistor S1 is set to on (conducting) during boosting. In the first state, a current flows sequentially to the positive terminal PB of the first battery 11, the reactor 22, the second transistor S2, and the negative terminal NB of the first battery 11, and the reactor 22 is excited by a direct current to store magnetic energy. In the second state, an electromotive force (induced voltage) is generated between both ends of the reactor 22 due to a change in magnetic flux caused by interruption of the current flowing through the reactor 22. The induced voltage due to the magnetic energy accumulated in the reactor 22 is superimposed on the battery voltage, and a boosted voltage higher than the voltage between the terminals of the first battery 11 is applied between the positive electrode bus PV and the negative electrode bus NV of the third power conversion circuit unit 33.

The third power conversion circuit unit 33 alternately switches between the second state and the first state during regeneration. In the second state, current flows sequentially to the positive electrode bus bar PV of the third power conversion circuit unit 33, the first transistor S1, the reactor 22, and the positive electrode terminal PB of the first battery 11, and the reactor 22 is excited by direct current to store magnetic energy. In the first state, an electromotive force (induced voltage) is generated between both ends of the reactor 22 due to a change in magnetic flux caused by interruption of the current flowing through the reactor 22. The induced voltage due to the magnetic energy accumulated in the reactor 22 is stepped down, and a stepped-down voltage lower than the voltage between the positive bus bar PV and the negative bus bar NV of the third power conversion circuit unit 33 is applied between the positive terminal PB and the negative terminal NB of the first battery 11.

The capacitor unit 23 includes a first smoothing capacitor 41, a second smoothing capacitor 42, and a noise filter 43.

The first smoothing capacitor 41 is connected between the positive electrode terminal PB and the negative electrode terminal NB of the first battery 11. The first smoothing capacitor 41 smoothes voltage fluctuations that occur in the switching operation of the first transistor S1 and the second transistor S2 between on and off during regeneration of the third power conversion circuit unit 33.

The second smoothing capacitor 42 is connected between the positive electrode bus bar PI and the negative electrode bus bar NI of each of the first power conversion circuit unit 31 and the second power conversion circuit unit 32, and between the positive electrode bus bar PV and the negative electrode bus bar NV of the third power conversion circuit unit 33. The second smoothing capacitor 42 is connected to the plurality of positive and negative bus bars PI and NI, and the positive and negative bus bars PV and NV via the positive and

negative bus bars

50p and 50 n. The second smoothing capacitor 42 smoothes voltage fluctuations that occur in the on/off switching operation of each of the transistors UH, UL, VH, VL, WH, WL of the first power conversion circuit unit 31 and the second power conversion circuit unit 32. The second smoothing capacitor 42 smoothes voltage variation caused by the on/off switching operation of the first transistor S1 and the second transistor S2 when the third power conversion circuit unit 33 is boosted.

The noise filter 43 is connected between the positive electrode bus bar PI and the negative electrode bus bar NI of each of the first power conversion circuit unit 31 and the second power conversion circuit unit 32, and between the positive electrode bus bar PV and the negative electrode bus bar NV of the third power conversion circuit unit 33. The noise filter 43 includes 2 capacitors connected in series. The connection point of the 2 capacitors is connected to the body ground of the vehicle 10 or the like.

The resistor 24 is connected between the positive electrode bus bar PI and the negative electrode bus bar NI of each of the first power conversion circuit unit 31 and the second power conversion circuit unit 32, and between the positive electrode bus bar PV and the negative electrode bus bar NV of the third power conversion circuit unit 33.

The first current sensor 25 is disposed on the first bus bar 51 that constitutes the connection point TI of each phase of the first power conversion circuit unit 31 and is connected to the first input/output terminal Q1, and detects the currents of the U-phase, the V-phase, and the W-phase. The second current sensor 26 is disposed on the second bus bar 52 that constitutes the connection point TI of each phase of the second power conversion circuit unit 32 and is connected to the second input/output terminal Q2, and detects the currents of the U-phase, the V-phase, and the W-phase. The third current sensor 27 is disposed on the third bus bar 53 that constitutes a connection point of the first transistor S1 and the second transistor S2 and is connected to the reactor 22, and detects a current flowing through the reactor 22.

The first current sensor 25, the second current sensor 26, and the third current sensor 27 are connected to an electronic control unit 28 through signal lines, respectively.

The electronic control unit 28 controls the operations of the first motor 12 and the second motor 13, respectively. For example, the electronic control unit 28 is a software functional unit that functions by a processor such as a cpu (central Processing unit) executing a predetermined program. The software function unit is an ecu (electronic Control unit) having a processor such as a CPU, a rom (read Only memory) for storing a program, a ram (random Access memory) for temporarily storing data, and an electronic circuit such as a timer. At least a part of the electronic control unit 28 may be an integrated circuit such as an lsi (large Scale integration). For example, the electronic control unit 28 executes feedback control or the like using the current detection value of the first current sensor 25 and the current of the current target value corresponding to the torque command value for the first electric motor 12 to generate a control signal input to the gate drive unit 29. For example, the electronic control unit 28 generates a control signal to be input to the gate drive unit 29 by executing feedback control or the like using the current detection value of the second current sensor 26 and a current of a current target value corresponding to a regeneration command value for the second electric motor 13. The control signal is a signal indicating timing for driving the transistors UH, VH, WH, UL, VL, and WL of the first power conversion circuit unit 31 and the second power conversion circuit unit 32 to be turned on (on)/off (off). For example, the control signal is a pulse width modulated signal or the like.

The gate drive unit 29 generates gate signals for driving the transistors UH, VH, WH, UL, VL, and WL of the first power conversion circuit unit 31 and the second power conversion circuit unit 32 to be actually turned on (on)/off (off) based on the control signals received from the electronic control unit 28. For example, the gate driving unit 29 generates a gate signal by performing amplification, level shift, and the like of a control signal.

The gate driving unit 29 generates gate signals for driving the first transistor S1 and the second transistor S2 of the third power conversion circuit unit 33 to be turned on (on)/off (off). For example, the gate driving unit 29 generates a gate signal having a duty ratio corresponding to a step-up voltage command at the time of step-up of the third power conversion circuit unit 33 or a step-down voltage command at the time of regeneration of the third power conversion circuit unit 33. The duty cycle is the ratio of the first transistor S1 and the second transistor S2.

The DC-DC converter 30 includes a first positive bus bar 60p1 and a first negative bus bar 60n1 that are connected to the positive terminal PB and the negative terminal NB of the first battery 11 via the DC connector 1 a. The DC-DC converter 30 includes a second positive bus bar 60p2 and a second negative bus bar 60n2 connected to the positive terminal and the negative terminal of the second battery 14.

The DC-DC converter 30 may be disposed in the same unit as other components constituting the power conversion device 1, for example, the power module 21, or may be disposed outside the unit in which other components constituting the power conversion device 1 are disposed.

As shown in fig. 3, in each of the first power conversion circuit unit 31, the second power conversion circuit unit 32, and the third power conversion circuit unit 33 of the power module 21, the switching elements of the high-side arm and the low-side arm that form a pair form an element row.

In the first power conversion circuit unit 31, the high-side and low-side arm U-phase transistors UH and UL form an element array PU1, the high-side and low-side arm V-phase transistors VH and VL form an element array PV1, and the high-side and low-side arm W-phase transistors WH and WL form an element array PW 1.

In the second power conversion circuit unit 32, the high-side and low-side arm U-phase transistors UH and UL form an element array PU2, the high-side and low-side arm V-phase transistors VH and VL form an element array PV2, and the high-side and low-side arm W-phase transistors WH and WL form an element array PW 2.

In the third power conversion circuit unit 33, the first transistor S1 of the high-side arm and the second transistor S2 of the low-side arm form an element row PS.

In each of the element rows PU1, PV1, PW1, PU2, PV2, PW2, and PS, the switching elements of the high-side arm and the switching elements of the low-side arm are arranged in a second direction D2 orthogonal to the predetermined first direction D1, for example.

The 3 element rows PU1, PV1, and PW1 of the first power conversion circuit unit 31, the 3 element rows PU2, PV2, and PW2 of the second power conversion circuit unit 32, and the 1 element row PS of the third power conversion circuit unit 33 are sequentially arranged in the predetermined first direction D1. The 3 element rows PU1, PV1, and PW1 of the first power conversion circuit unit 31 are sequentially arranged in the first direction D1, and the 3 element rows PU2, PV2, and PW2 of the second power conversion circuit unit 32 are sequentially arranged in the first direction D1.

As shown in fig. 1 and 3, the power conversion device 1 includes a first heat dissipation portion 71(W/J) and a second heat dissipation portion 72(W/J) sandwiching the power module 21 from both sides, 2 joints 73, and 4 sealing members 74 in a third direction D3 orthogonal to a predetermined first direction D1 and a second direction D2. For example, the third direction D3 is the thickness direction of the power module 21.

The first heat dissipation portion 71 and the second heat dissipation portion 72 are provided with a heat dissipation case 75 and a heat dissipation plate 76, respectively.

The heat radiation case 75 is formed in a rectangular box shape, for example. A refrigerant flow path 77 through which a refrigerant flows is formed in the heat radiation housing 75. The refrigerant flow path 77 is formed by a wall portion defining a groove in the heat radiation housing 75. The refrigerant flow path 77 of the first heat dissipation portion 71 communicates with a refrigerant supply port 75a and a refrigerant discharge port 75b formed in the heat dissipation case 75 of the first heat dissipation portion 71. The refrigerant supply port 75a and the refrigerant discharge port 75b are formed in, for example, 2 non-adjacent corners out of 4 corners of the heat radiation case 75.

A refrigerant supply pipe 78 for supplying a refrigerant from the outside and a refrigerant discharge pipe 79 for discharging the refrigerant to the outside are connected to the first heat dissipation portion 71. The internal flow path of the refrigerant supply pipe 78 communicates with the refrigerant supply port 75 a. The internal flow path of the refrigerant discharge tube 79 communicates with the refrigerant discharge port 75 b.

The heat dissipation casing 75 of each of the first heat dissipation portion 71 and the second heat dissipation portion 72 has, for example, a first flow path 77a and a second flow path 77b as the refrigerant flow path 77, and the first flow path 77a and the second flow path 77b branch in parallel between positions facing the refrigerant supply port 75a and the refrigerant discharge port 75b, respectively, when viewed in the third direction D3. When viewed from the third direction D3, the first flow path 77a extends in the first direction D1 so as to overlap with the switching elements of the high-side arms of the element rows PU1, PV1, PW1, PU2, PV2, PW2, and PS, for example. The second flow path 77b extends in the first direction D1 so as to overlap with the switching elements of the low-side arms of the element arrays PU1, PV1, PW1, PU2, PV2, PW2, and PS, for example, when viewed from the third direction D3.

In the heat dissipation case 75, a surface facing the opposite side of the power module 21 constitutes a mounting surface 75A on which circuit components other than the power module 21 are mounted. The circuit components in the power conversion device 1 are, for example, a reactor 22, a capacitor unit 23, a DC-DC converter 30, and the like.

The heat sink 76 is formed in a plate shape having substantially the same size as the heat dissipation case 75, for example. Heat sink 76 is connected to a wall portion of heat sink case 75, and closes an opening end of the groove to seal refrigerant flow path 77. In 2 corners of heat dissipation plate 76, which are not adjacent to each other, 2 through holes 76a are formed to communicate with refrigerant supply port 75a and refrigerant discharge port 75b of heat dissipation case 75 in a facing manner.

In the heat sink 76, a surface facing the opposite side to the heat sink case 75 constitutes a mounting surface 76A on which the power module 21 is mounted. The heat sink 76 includes a plurality of fins that function as heat sinks on a surface 76B opposite the mounting surface 76A in the thickness direction (i.e., the third direction D3). In a state where the heat sink 76 is assembled to the heat sink case 75, a plurality of fins are arranged in the refrigerant flow path 77.

For example, the joint portion 73 is disposed at a position facing the refrigerant supply port 75a and the refrigerant discharge port 75b, respectively, when viewed from the third direction D3. The joint portion 73 has a through hole 73a communicating with the refrigerant supply port 75a or the refrigerant discharge port 75b in the third direction D3.

The sealing member 74 is disposed between the heat dissipation plate 76 and the joint portion 73. The sealing member 74 has a through hole 74a formed therein, which communicates with the through hole 76a of the heat radiating plate 76 and the through hole 73a of the joint 73 in the third direction D3. The sealing member 74 seals the space between the heat radiating plate 76 and the joint 73 so as to connect and seal the through hole 76a of the heat radiating plate 76 and the through hole 73a of the joint 73.

As shown in fig. 1 and 2, the reactor 22 and the DC-DC converter 30 are formed so that the sizes thereof in at least one of the first direction D1, the second direction D2, and the third direction D3 are substantially the same. For example, the reactor 22 and the DC-DC converter 30 are formed in substantially the same shape, and the reactor 22 and the DC-DC converter 30 are formed in substantially the same size in the first direction D1, the second direction D2, and the third direction D3.

The reactor 22 and the DC-DC converter 30 are disposed on the mounting surface 75A of the heat dissipation case 75 of the first heat dissipation portion 71. That is, the reactor 22 and the DC-DC converter 30 are disposed on the side opposite to the power module 21 with respect to the first heat sink 71 in the third direction D3.

In the mounting surface 75A of the first heat sink member 71, the reactor 22 and the DC-DC converter 30 are arranged in the first direction D1. The DC-DC converter 30 is disposed on the upstream side of the refrigerant flow path 77 with respect to the reactor 22, for example.

When viewed from the third direction D3, the element row PS of the third power conversion circuit unit 33 of the power module 21 and the reactor 22 have a portion overlapping each other.

The capacitor unit 23 is disposed on the mounting surface 75A of the heat dissipation case 75 of the second heat dissipation portion 72. That is, the capacitor element 23 is disposed on the opposite side of the second heat sink member 72 from the power module 21 in the third direction D3.

In the mounting surface 75A of the second heat sink member 72, the first smoothing capacitor 41(C1) and the second smoothing capacitor 42(C2) of the capacitor unit 23 are arranged in the first direction D1, for example. When viewed from the third direction D3, the first smoothing capacitor 41 and the element row PS and the reactor 22 of the third power conversion circuit unit 33 of the power module 21 have portions overlapping each other.

The circuit board 81(G/D) on which the gate driver unit 29 is mounted is disposed on the side opposite to the second heat sink portion 72 with respect to the capacitor unit 23 in, for example, the third direction D3. When viewed from the third direction D3, the circuit board 81 has at least a portion overlapping with the power module 21.

The power module 21 and the circuit board 81(G/D) are connected by a gate signal line 82. For example, the signal line 82 is formed in a pin shape. The signal line 82 is drawn from, for example, the mutually opposing surfaces of the power module 21 and the circuit board 81 in the third direction D3, and extends between the power module 21 and the circuit board 81 in parallel with the third direction D3.

As described above, according to the power conversion device 1 of the present embodiment, since the reactor 22 and the DC-DC converter 30 are mounted on the first heat dissipation portion 71 and the capacitor unit 23 is mounted on the second heat dissipation portion 72, the capacitor unit 23, the reactor 22, and the DC-DC converter 30 can be efficiently cooled in addition to the power module 21. This can prevent the plurality of circuit components of the power conversion device 1 from becoming large due to the cooling performance.

In addition, the degree of freedom in the arrangement of the capacitor elements 23 in the second heat sink member 72 can be increased, and the size of the region in which the capacitor elements 23 can be arranged can be relatively large. This can suppress occurrence of problems such as a case where the connection member (for example, each of the positive electrode bus bars PI, 50p, PV, each of the negative electrode bus bars NI, 50n, NV, and the third bus bar 53, etc.) electrically connecting the capacitor break unit 23 and each of the element rows PU1, PV1, PW1, PU2, PV2, PW2, and PS of the power module 21 becomes long, a case where the length of the connection member becomes nonuniform depending on the position, and a case where the inductance of the connection member locally increases.

Further, since the capacitor unit 23 includes a plurality of capacitors (i.e., the first smoothing capacitor 41 and the second smoothing capacitor 42), the plurality of capacitors can be collectively and integrally arranged in the second heat dissipating portion 72, and an increase in size of the capacitor unit 23 can be suppressed. This can prevent the signal line 82 interconnecting the power module 21 and the circuit board 81(G/D) disposed with the capacitor unit 23 interposed therebetween in the third direction D3 from becoming long. Further, by suppressing an increase in the length of the signal line 82, an increase in electromagnetic noise entering the signal line 82 can be suppressed, and an increase in inductance of the signal line 82 can be suppressed.

Further, since the second heat sink portion 72 is disposed between the power module 21 and the circuit board 81, electromagnetic noise from the power module 21 toward the circuit board 81 can be shielded.

Further, since the sizes of the reactor 22 and the DC-DC converter 30 in the first direction D1, the second direction D2, and the third direction D3 are formed substantially the same, the reactor 22 and the DC-DC converter 30 can be efficiently arranged in the first heat dissipation portion 71, and the size increase of the power conversion device 1 can be suppressed.

Further, when viewed from the third direction D3, the first smoothing capacitor 41, the element row PS of the third power conversion circuit unit 33, and the reactor 22 have portions overlapping each other, and thus, the length of the connecting members electrically connected to each other can be suppressed from becoming long, and wiring can be efficiently performed.

The reactor 22 and the DC-DC converter 30 are mounted in the first heat sink portion 71 on the upstream side of the second heat sink portion 72 in the flow path of the coolant in the first heat sink portion 71 and the second heat sink portion 72, and therefore, the cooling is performed preferentially over the capacitor unit 23, and the size can be reduced.

Further, by mounting the DC-DC converter 30 on the first heat dissipation portion 71 and cooling the DC-DC converter 30 in the first heat dissipation portion 71 in priority over the reactor 22, the DC-DC converter 30 that supplies electric power to the low-voltage-system auxiliary devices 15 can be reliably protected.

Hereinafter, modifications of the embodiment will be described.

In the above-described embodiment, the circuit board 81(G/D) on which the gate drive unit 29 is mounted is disposed so as to be stacked on the capacitor unit 23 in the third direction D3, but is not limited thereto.

Fig. 5 is a side view schematically showing the configuration of a power conversion device 1 according to a first modification of the embodiment of the present invention. As shown in fig. 5, in the power conversion device 1 of the first modification, the circuit board 81 is arranged in the first direction D1 with the power modules 21. The circuit board 81 includes, for example, a first circuit board 81a and a second circuit board 81 b. The first circuit board 81a and the second circuit board 81b are disposed so as to sandwich the power module 21 from both sides in the first direction D1.

The signal lines 82 connecting the power module 21 to the first circuit board 81a and the second circuit board 81b are drawn from, for example, the facing surfaces of the power module 21 and the first circuit board 81a and the second circuit board 81b facing each other in the first direction D1, and extend parallel to the first direction D1 between the power module 21 and the first circuit board 81a and the second circuit board 81 b.

According to the first modification, it is possible to suppress an increase in the inductance of the signal line 82 while suppressing an increase in electromagnetic noise entering the signal line 82 while suppressing a case where the signal line 82 connecting the power module 21 and the circuit board 81 is long.

In the above-described embodiment, the power converter 1 may include the shielding member 83 for shielding the signal line 82 connecting the power module 21 and the circuit board 81 from the high-voltage circuit component.

Fig. 6 is a side view schematically showing the configuration of a power conversion device 1 according to a second modification of the embodiment of the present invention. As shown in fig. 6, the power conversion device 1 of the second modification includes a shield member 83 between the power module 21 and the circuit board 81 and between the signal line 82 and the capacitor unit 23 in the first direction D1. The shield member 83 is, for example, a plate-like member formed of a metal material.

The signal line 82 is drawn from, for example, an end face of the power module 21 in the first direction D1 and a surface of the circuit board 81 facing the capacitor unit 23 in the third direction D3. The signal line 82 is, for example, led out from the power module 21 in the first direction D1, and then bent in the third direction D3 to extend toward the circuit board 81.

According to the second modification, since the shield member 83 shields the signal line 82 from the capacitor unit 23 which is relatively high in voltage, it is possible to suppress an increase in electromagnetic noise entering the signal line 82.

In the above-described embodiment, the flow rates of the refrigerant in the first heat sink portion 71 and the second heat sink portion 72 may be set to different flow rates depending on the circuit components to be cooled, and the like.

Fig. 7 is a side view schematically showing the configuration of a power conversion device 1 according to a third modification of the embodiment of the present invention. As shown in fig. 7, in the power conversion device 1 of the third modification, the thickness of the first heat sink portion 71 is formed larger than the thickness of the second heat sink portion 72, and thus the flow rate of the refrigerant in the first heat sink portion 71 is set larger than the flow rate of the refrigerant in the second heat sink portion 72.

According to the third modification, the reactor 22 and the DC-DC converter 30 are cooled preferentially over the capacitor unit 23, and thus the size can be reduced.

In the above-described embodiment, the first smoothing capacitor 41(C1) and the second smoothing capacitor 42(C2) of the capacitor unit 23 are mounted on the mounting surface 75A of the second heat sink member 72, but the present invention is not limited thereto.

Fig. 8 is a side view schematically showing the configuration of a power conversion device 1 according to a fourth modification of the embodiment of the present invention. As shown in fig. 8, in the power conversion device 1 of the fourth modification example, the second smoothing capacitor 42 is mounted on the mounting surface 75A of the second heat dissipation portion 72, and the first smoothing capacitor 41 is mounted on the mounting surface 75A of the first heat dissipation portion 71. On the mounting surface 75A of the first heat sink member 71, the first smoothing capacitor 41 is disposed, for example, between the reactor 22 and the DC-DC converter 30. The reactor 22, the first smoothing capacitor 41, and the DC-DC converter 30 are arranged in series in the first direction D1.

According to the fourth modification, it is possible to suppress the length of the connecting member that electrically connects the first smoothing capacitor 41 to the reactor 22 and the DC-DC converter 30 from becoming long, and it is possible to efficiently perform wiring.

In the above-described embodiment, the refrigerant flow path 77 in each of the first heat radiating unit 71 and the second heat radiating unit 72 is formed to cool the switching elements of the high-side arm and the switching elements of the low-side arm in parallel for each of the element rows PU1, PV1, PW1, PU2, PV2, PW2, and PS, but the present invention is not limited thereto.

Fig. 9 is a perspective view schematically showing a configuration of a part of a power conversion device 1 according to a fifth modification of the embodiment of the present invention. As shown in fig. 9, in the power module 21 of the power conversion device 1 according to the fifth modification, the 3 element rows PU1, PV1, and PW1 of the first power conversion circuit unit 31 and the 3 element rows PU2, PV2, and PW2 of the second power conversion circuit unit 32 are sequentially arranged in the first direction D1 so that the same-phase element rows are arranged in the second direction. The element row PS of the third power conversion circuit unit 33 is arranged in the vicinity of the first power conversion circuit unit 31 and the second power conversion circuit unit 32 in the first direction D1 with the first transistor S1 of the high-side arm and the second transistor S2 of the low-side arm arranged in the second direction.

The power conversion device 1 includes the first heat sink portion 71(W/J) and the second heat sink portion 72(W/J) of the power module 21 sandwiched from both sides, 1

joint portion

73, and 2 sealing members 74 in the third direction D3.

The heat radiation case 75 is formed in a rectangular box shape, for example. A refrigerant flow path 90 through which a refrigerant flows is formed in the heat radiation housing 75. The refrigerant flow path 90 is formed by a plurality of wall portions defining a groove in the heat radiation housing 75. The refrigerant flow path 90 of the first heat dissipation portion 71 communicates with a refrigerant supply port 75a and a refrigerant discharge port 75b formed in the heat dissipation case 75 of the first heat dissipation portion 71. The refrigerant supply port 75a and the refrigerant discharge port 75b are formed, for example, in 2 corners adjacent to each other in the second direction D2 among 4 corners of the heat radiation housing 75.

For example, a third flow path 91 and a fourth flow path 92, and a plurality of branch flow paths 93 are formed as the refrigerant flow paths 90 in the heat dissipation case 75 of each of the first heat dissipation portion 71 and the second heat dissipation portion 72, the third flow path 91 and the fourth flow path 92 extend in the first direction D1 from positions facing the refrigerant supply port 75a and the refrigerant discharge port 75b, respectively, when viewed from the third direction D3, and the plurality of branch flow paths 93 branch between the third flow path 91 and the fourth flow path 92 and extend in the second direction D2. In the refrigerant flow path 90 of the first heat radiating portion 71, the third flow path 91 communicates with the refrigerant supply port 75a, and the fourth flow path 92 communicates with the refrigerant discharge port 75 b.

The plurality of branch channels 93 are 3

branch channels

93u, 93v, and 93w corresponding to the three phases of the first power conversion circuit unit 31 and the second power

conversion circuit unit

32, and 1 branch channel 93s corresponding to the third power conversion circuit unit 33. When viewed from the third direction D3, the branch flow passage 93U extends in the second direction D2 so as to overlap the U-phase element rows PU1 and PU 2. When viewed from the third direction D3, the branch flow path 93V extends in the second direction D2 so as to overlap with the V-phase element rows PV1 and PV 2. The branch flow passage 93W extends in the second direction D2 so as to overlap with the W-phase element rows PW1 and PW2 when viewed from the third direction D3. The branch flow path 93S extends in the second direction D2 so as to overlap with the first transistor S1 and the second transistor S2 of the element row PS when viewed from the third direction D3.

A surface of the heat dissipation case 75 facing the opposite side of the power module 21 constitutes a mounting surface 75A on which circuit components other than the power module 21 are mounted. The circuit components in the power conversion device 1 are, for example, a reactor 22, a capacitor unit 23, a DC-DC converter 30, and the like.

The heat sink 76 is formed in a plate shape having substantially the same size as the heat dissipation case 75, for example. Heat radiation plate 76 is connected to a wall portion of heat radiation housing 75, and closes an opening end of the groove to seal refrigerant flow passage 90. 2 through holes 76a communicating with refrigerant supply port 75a and refrigerant discharge port 75b of heat radiation case 75 in a manner facing each other are formed in 2 corners adjacent to each other in second direction D2 among 4 corners of heat radiation plate 76.

A surface of heat sink 76 facing the opposite side to heat sink case 75 constitutes a mounting surface 76A on which power module 21 is mounted. The heat sink 76 includes a plurality of fins that function as heat sinks on a surface 76B opposite the mounting surface 76A in the thickness direction (i.e., the third direction D3). In a state where the heat dissipation plate 76 is assembled to the heat dissipation case 75, the plurality of fins are arranged in the refrigerant flow path 90.

For example, the joint portion 73 is disposed at a position facing the refrigerant supply port 75a and the refrigerant discharge port 75b, respectively, when viewed from the third direction D3. The joint portion 73 is formed with through holes 73a communicating with the refrigerant supply port 75a and the refrigerant discharge port 75b in the third direction D3.

According to the fifth modification, an increase in the temperature gradient of the refrigerant between the upstream side and the downstream side of the refrigerant flow path 90 can be suppressed. In addition, in each of the first electric motor 12 and the second electric motor 13, it is possible to perform uniform cooling while suppressing an increase in the difference in cooling performance between the phases.

In the above-described embodiment, the power converter 1 is mounted on the vehicle 10, but is not limited thereto, and may be mounted on another device.

In the above-described embodiment, the power converter 1 includes the first power conversion circuit unit 31 and the second power conversion circuit unit 32 that control the transfer of electric power to and from the 2 motors, i.e., the first motor 12 and the second motor 13, but is not limited to this. The power conversion apparatus 1 may also control 1 or more motors.

In the above-described embodiment, the power converter 1 controls the transfer of electric power between the first electric motor 12 for driving and the second electric motor 13 for generating electric power, but is not limited thereto. For example, the power converter 1 may control another motor such as a pump driving motor provided in an electric compressor of an air conditioner or the like.

The embodiments of the present invention are presented as examples, and are not intended to limit the scope of the invention. These embodiments can be implemented in other various ways, and various omissions, substitutions, and changes can be made without departing from the spirit of the invention. These embodiments and modifications are included in the invention described in the claims and the equivalent scope thereof as in the case of the scope and gist of the invention.

Claims

1. A power conversion device is characterized by comprising:

an element row including a high-side arm element and a low-side arm element that transmit and receive electric power to and from the motor;

a voltage conversion element electrically connected to the element row;

a circuit board connected to the element row by a signal line;

a first heat radiating portion and a second heat radiating portion which are disposed on both sides with the element rows interposed therebetween in a predetermined direction and in which a refrigerant flow path through which a refrigerant flows is formed; and

a plurality of circuit components disposed on the opposite side of the element row with respect to the first heat sink member and the second heat sink member in the predetermined direction,

a plurality of the circuit components include a capacitor and a reactor connected to the voltage conversion element,

the reactor is disposed on the opposite side of the element row with respect to the first heat dissipation portion in the predetermined direction,

the capacitor is arranged on the side opposite to the element row with respect to the second heat sink member in the predetermined direction,

the circuit board is disposed on a side opposite to the second heat sink portion with respect to the capacitor in the predetermined direction.

2. The power conversion apparatus according to claim 1,

a plurality of the circuit components include a voltage converter capable of stepping down a power supply voltage,

the voltage converter is disposed on the opposite side of the element row with respect to the first heat sink portion in the predetermined direction.

3. The power conversion apparatus according to claim 2,

the voltage converter is disposed upstream of the reactor in the refrigerant flow path.

4. The power conversion apparatus according to any one of claims 1 to 3,

the voltage conversion element has a portion overlapping with the reactor when viewed from the predetermined direction.

5. The power conversion apparatus according to claim 4,

the capacitor includes a power supply side capacitor electrically connected to a power supply side connection terminal of the voltage conversion element,

the power supply side capacitor has a portion overlapping with the voltage conversion element and the reactor when viewed from the predetermined direction.

6. The power conversion apparatus according to claim 2 or 3,

the power conversion device includes a power supply side capacitor electrically connected to a power supply side connection terminal of the voltage conversion element,

the power supply side capacitor is disposed between the reactor and the voltage converter in a direction intersecting the predetermined direction.