Power conversion device

Abstract

To provide a power conversion device comprising a heat-exchanger capable of adjusting temperature of not only a switching element but constituent components in the power conversion device.SOLUTION: A power conversion device comprises a case 5, a plate-like semiconductor module 18 for which a switching element included in a power conversion circuit is provided, a smooth capacitor 15, and a heat-exchanger 30. The heat-exchanger 30 comprises a first passage 34 and a second passage 35 arranged in parallel on both sides of the semiconductor module 18 in a thickness direction thereof. The heat-exchanger 30 that receives a heat-exchange medium from an inlet makes the heat-exchange medium flow along both sides of the semiconductor module 18 and then discharges the heat-exchange medium from an outlet. An inlet distance L40a between an inlet 31 and the smooth capacitor 15 is set shorter than an outlet distance L40b between an outlet 38 and the smooth capacitor 15.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The disclosure herein relates to power conversion devices. [Background technology]

[0002] Patent Document 1 discloses a power conversion device. The power conversion device includes a plurality of switching elements and a cooler for cooling them. The cooler of the power conversion device is required to have an appropriate capacity that is neither too large nor too small. The contents of the prior art document are incorporated by reference as explanations of the technical elements in this specification. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6806276 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above respects and in other respects not mentioned, further improvements are required in heat exchangers for power converters.

[0005] One object disclosed herein is to provide a power conversion device equipped with a heat exchanger that can adjust the temperature of components of the power conversion device other than just the switching elements. [Means for solving the problem]

[0006] The power conversion device disclosed herein comprises a case (5) that houses a power conversion circuit, a plate-shaped semiconductor module (18) that provides switching elements included in the power conversion circuit, a smoothing capacitor (15) that smoothes the power in the power conversion circuit, and a heat exchanger (30) that dissipates heat from the semiconductor module to a heat exchange medium, the heat exchanger including an inlet (31) for introducing the heat exchange medium from the outside to the inside of the case, an outlet (38) for discharging the heat exchange medium from the inside to the outside of the case, a first passage (34) and a second passage (35) arranged in parallel on both sides in the thickness direction of the semiconductor module, and a passage partition member (40) that partitions a heat exchange passage that receives the heat exchange medium from the inlet, flows the heat exchange medium along both sides of the semiconductor module, and then discharges the heat exchange medium from the outlet, and an inlet distance (L40a) between the inlet and the smoothing capacitor is set shorter than an outlet distance (L40b) between the outlet and the smoothing capacitor.

[0007] According to the disclosed power conversion device, heat from the semiconductor module is dissipated to the heat exchange medium. The temperature of the heat exchange medium rises due to heat exchange with the semiconductor module. As a result, the temperature of the heat exchange medium near the outlet is higher than the temperature of the heat exchange medium near the inlet. The inlet distance between the inlet and the smoothing capacitor is set shorter than the outlet distance between the outlet and the smoothing capacitor. This allows the smoothing capacitor to dissipate heat to the heat exchange medium near the inlet. Because the heat exchange medium near the inlet is at a relatively low temperature, a high heat dissipation effect can be expected.

[0008] The various embodiments disclosed in this specification employ different technical means to achieve their respective objectives. The reference numerals in parentheses in the claims and in this section are intended to exemplify the correspondence with the following embodiments and are not intended to limit the technical scope. The objectives, features, and advantages disclosed in this specification will become more apparent by reference to the following detailed description and the accompanying drawings. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a circuit diagram of a power conversion device according to a first embodiment. [Figure 2] FIG. 2 is a plan view of the power conversion device. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 3 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 2 is a cross-sectional view showing an example of a heat exchange member. [Figure 7] FIG. 2 is a cross-sectional view showing an example of a heat exchange member. DETAILED DESCRIPTION OF THE INVENTION

[0010] Several embodiments will be described with reference to the drawings. In several embodiments, functionally and / or structurally corresponding and / or associated parts may be designated by the same reference numerals or reference numerals that differ in the hundredth or more digits. For corresponding and / or associated parts, reference may be made to the descriptions of other embodiments.

[0011] First embodiment FIG. 1 is a circuit diagram of a power conversion device 2 according to a first embodiment. The power conversion device 2 provides a power system in a power system 1 of a vehicle. In this embodiment, the vehicle is a vehicle that travels on land. The vehicle is an electric vehicle powered by a rotating electric machine that provides running power using electricity. The vehicle may additionally include an internal combustion engine that provides running power using fuel. The vehicle is also called a hybrid vehicle, a plug-in hybrid vehicle, a battery-electric vehicle, etc. The vehicle may be a ship that travels on water, an aircraft that travels through the air, or a spacecraft in outer space.

[0012] The power system 1 includes a power conversion device 2. The power conversion device 2 is electrically connected to and disposed between a battery 3 and a rotating electric machine 4. The power conversion device 2 provides bidirectional conversion or unidirectional conversion between direct current and alternating current. Furthermore, the power conversion device 2 provides DC power regulation and / or AC power regulation. The power conversion device 2 provides DC-AC conversion, converting DC power supplied from the battery 3 into AC power and supplying it to the rotating electric machine 4. Furthermore, the power conversion device 2 provides ACDC conversion, converting AC power supplied from the rotating electric machine 4 into DC power and charging the battery 3.

[0013] The power system 1 includes a battery 3. The battery 3 is a DC power source. In this embodiment, the battery 3 is a secondary battery that can be charged and discharged. The DC power source can be any of a variety of batteries, such as a lead-acid battery, a lithium-ion battery, or a nickel-cadmium battery. Furthermore, the DC power source may include a fuel cell.

[0014] The power system 1 includes a rotating electric machine 4. An example of the rotating electric machine 4 is an electric motor. Another example of the rotating electric machine 4 is a generator motor (MG). An example of the rotating electric machine 4 is an AC rotating electric machine. An example of the rotating electric machine 4 is a polyphase AC rotating electric machine. In this embodiment, the rotating electric machine 4 is a three-phase AC rotating electric machine.

[0015] The power conversion device 2 includes a case 5. The case 5 is a container that houses a power conversion circuit 10 that provides the power conversion device 2. The case 5 is made of a metal such as aluminum, or a resin. In this embodiment, the case 5 is made of a metal that has excellent thermal conductivity.

[0016] The case 5 includes a DC input / output unit 6 and an AC input / output unit 7. The DC input / output unit 6 is used for connection between the battery 3 and the power conversion circuit 10. The AC input / output unit 7 is used for connection between the rotating electric machine 4 and the power conversion circuit 10.

[0017] The power conversion circuit 10 includes a plurality of circuit components. The plurality of circuit components includes a plurality of conductors. The plurality of conductors includes a plurality of coated electric wires and a plurality of bus bars. The bus bars are conductive pieces suitable for applications in which a large current is carried. For example, the bus bars are provided by copper plates. The drawing illustrates a plurality of bus bars. The plurality of bus bars includes a positive bus bar 11 and a negative bus bar 12 for DC power. The plurality of bus bars includes a plurality of AC power bus bars 13 for AC power. The plurality of circuit components includes a plurality of passive elements and / or a plurality of active elements.

[0018] The plurality of circuit components includes a filter circuit 14 (FLT). The filter circuit 14 includes an inductance and a capacitor.

[0019] The multiple circuit components include a smoothing capacitor 15 (CAP). The smoothing capacitor 15 may be provided as a single capacitor element or as a capacitor module in which multiple capacitor elements are connected. The smoothing capacitor 15 is housed in a case 5. The smoothing capacitor 15 smoothes the power in the power conversion circuit 10. The smoothing capacitor 15 and the case 5 are thermally coupled. This thermal coupling allows heat to be transferred from the smoothing capacitor 15 to the case 5.

[0020] The multiple circuit components include an inverter circuit 16 (INV). The inverter circuit 16 provides an AC-DC converter bridge circuit. The inverter circuit 16 includes multiple switching elements 17 (SW). The switching elements 17 can be implemented by various power elements such as IGBT elements or power MOSFET elements. In this embodiment, the switching elements 17 are implemented by IGBT elements. The switching elements 17 are made of semiconductors. The semiconductors can be implemented by wide-band semiconductors such as SiC (silicon carbide), GaN (gallium nitride), or Ga2O3 (gallium oxide).

[0021] The inverter circuit 16 has multiple switching arms for multi-phase power. In the illustrated embodiment, the inverter circuit 16 has three switching arms 16u, 16v, and 16w for three-phase power. Each switching arm includes a switching element 17 that provides an upper arm and a switching element 17 that provides a lower arm.

[0022] The inverter circuit 16 includes a plurality of semiconductor modules 18. In the illustrated embodiment, one semiconductor module 18 provides one switching arm. In the illustrated embodiment, the inverter circuit 16 includes a plurality of semiconductor modules 18 for multi-phase power. In the illustrated embodiment, the inverter circuit 16 includes three semiconductor modules 18 for three-phase power. In the illustrated embodiment, one semiconductor module 18 includes at least two switching elements 17. Alternatively, one semiconductor module 18 may be configured to include one switching element 17. The semiconductor modules 18 are plate-shaped. The semiconductor modules 18 provide the switching elements 17 included in the power conversion circuit 10.

[0023] The semiconductor module 18 includes a metal lead frame and one or more switching elements 17 mounted on the lead frame. The lead frame provides multiple power terminals and multiple signal terminals. The semiconductor module 18 includes a resin material that encases at least the switching elements. By molding the resin material, the semiconductor module 18 has an overall appearance that can be described as a flat plate. As a result, the semiconductor module 18 can be characterized by an outer peripheral surface that extends around the entire periphery and two side surfaces that extend on both sides in the thickness direction. The multiple power terminals and multiple signal terminals extend outward from the outer peripheral surface. The two side surfaces of the semiconductor module 18 provide heat exchange surfaces for the primary heat transfer.

[0024] From another perspective, the power conversion circuit 10 includes a plurality of semiconductor modules 18. The plurality of semiconductor modules 18 provide switching circuits in the power conversion circuit 10. In the illustrated embodiment, each of the plurality of switching arms 16u, 16v, and 16w in the inverter circuit 16 is provided by a semiconductor module 18. Alternatively or in addition to this, the power conversion circuit 10 may include a converter circuit. The semiconductor module 18 may provide the switching circuit of the converter circuit.

[0025] The multiple circuit components include a control circuit 20 for the power conversion circuit 10. The control circuit 20 includes a sensor circuit that observes a variable physical quantity in the power conversion circuit 10. In the illustrated embodiment, the sensor circuit includes a current sensor module 21 (CS) that detects a current value in the power conversion circuit 10. The current sensor module 21 detects multiple current values ​​in the power conversion circuit 10. The current sensor module 21 is disposed in the power conversion circuit 10 to detect power input and output. The current sensor module 21 detects, for example, a current value of each phase between the power conversion circuit 10 and the rotating electric machine 4. The current sensor module 21 outputs an electrical signal indicating the detected current value. The current sensor module 21 can be provided by one or multiple blocks. The sensor circuit may include a temperature detection circuit that detects the temperature of the power conversion circuit 10.

[0026] The control circuit 20 further includes a control circuit module 22 (CNT). The control circuit module 22 electrically adjusts an adjustable variable quantity of the power conversion circuit 10. The control circuit module 22 includes a drive circuit that provides a drive signal for at least the inverter circuit 16. The control circuit module 22 may further include a control unit implemented by a microcomputer circuit including at least one processor. In the illustrated embodiment, the control circuit module 22 controls, for example, the inverter circuit 16 to adjust the observed value detected by the current sensor module 21 to a target value.

[0027] The control unit in this specification may also be referred to as an Electronic Control Unit (ECU). The control unit is provided by (a) an algorithm in the form of multiple logics called if-then-else format, or (b) an algorithm in the form of a trained model tuned by machine learning, for example, a neural network. The control unit is provided by a control system including at least one computer. The control system may include multiple computers linked by a data communication device. The computer includes at least one processor that is hardware (a hardware processor). The hardware processor may be provided by the following (i), (ii), or (iii):

[0028] (i) A hardware processor may be at least one processor core that executes a program stored in at least one memory. In this case, a computer is provided with at least one memory and at least one processor core. The processor core is called a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a RISC-CPU, etc. Memory is also called a storage medium. Memory is a non-transitory, tangible storage medium that non-temporarily stores "programs and / or data" that can be read by a processor. Storage media are provided by semiconductor memory, magnetic disks, optical disks, etc. Programs may be distributed independently or as storage media on which the programs are stored.

[0029] (ii) A hardware processor may be a hardware logic circuit. In this case, a computer is provided by a digital circuit including a large number of programmed logic units (gate circuits). The digital circuit is also called a logic circuit array, for example, ASIC: Application-Specific Integrated Circuit, FPGA: Field Programmable Gate Array, SoC: System on a Chip, PGA: Programmable Gate Array, CPLD: Complex Programmable Logic Device, etc. The digital circuit may include a memory that stores programs and / or data. A computer may be provided by an analog circuit. A computer may be provided by a combination of digital and analog circuits.

[0030] (iii) The hardware processor may be a combination of (i) and (ii) above. (i) and (ii) may be located on different chips or on a common chip. In these cases, the part (ii) is also called an accelerator.

[0031] 2 is a plan view of the power conversion device 2. The case 5 accommodates a plurality of bus bars 11, 12, and 13, a filter circuit 14, a smoothing capacitor 15, a semiconductor module 18 for the inverter circuit 16, a current sensor module 21, and a terminal block 23 for the AC input / output unit 7.

[0032] The case 5 further houses a heat exchanger 30. The heat exchanger 30 is a heat exchange member that adjusts the temperature of the power conversion device 2 to an appropriate temperature range. The heat exchanger 30 adjusts the temperature of the components of the power conversion circuit 10 so that the components do not reach an undesirably high temperature. In this respect, the heat exchanger 30 is also called a cooler. The heat exchanger 30 mainly adjusts the temperature of the semiconductor module 18. The heat exchanger 30 dissipates heat from the semiconductor module 18 to a heat exchange medium. The heat exchanger 30 uses a liquid as the heat exchange medium for temperature adjustment. The heat exchange liquid is provided by an antifreeze liquid whose main component is water. Alternatively, the heat exchange medium may be provided by oil, gas, or the like.

[0033] FIG. 2 illustrates the width direction WD and depth direction DD of the power conversion device 2. In FIG. 2, the direction perpendicular to the paper surface is the height direction HD. The width direction WD, depth direction DD, and height direction HD correspond to three axes in a Cartesian coordinate system. Furthermore, FIGS. 3, 4, and 5 illustrate the width direction WD and height direction HD. The height direction HD is also called the thickness direction and the stacking direction.

[0034] 2 exemplarily illustrates one semiconductor module 18. The heat exchanger 30 is thermally coupled to multiple semiconductor modules 18. For example, multiple semiconductor modules 18 for three-phase power may be arranged in sequence along the directions of flows F34 and F35 described below. In this case, the temperature of the multiple semiconductor modules 18 is regulated by the heat exchanger 30.

[0035] The heat exchanger 30 is formed by a passage dividing member 40. The passage dividing member 40 may include a portion of the case 5. The passage dividing member 40 divides and forms a passage for the heat exchange medium. The multiple members included in the passage dividing member 40 are fluid-tightly connected. The passage includes at least a first passage 34 and a second passage 35. The first passage 34 and the second passage 35 are arranged in parallel on both sides in the thickness direction of the semiconductor module 18.

[0036] The passage dividing member 40 has an inlet member 40a and an outlet member 40b. The inlet member 40a provides an inlet pipe for introducing the heat exchange medium from the outside to the inside of the case 5. The outlet member 40b provides an outlet pipe for discharging the heat exchange medium from the inside to the outside of the case 5. The inlet member 40a and the outlet member 40b provide a passage connecting the inside and outside of the case 5. The inlet member 40a and the outlet member 40b are arranged on the side walls of the case 5 so as to penetrate the side walls. The position of the inlet member 40a in the height direction HD and the position of the outlet member 40b in the height direction HD overlap with each other in the width direction WD. In other words, the position of the inlet member 40a in the height direction HD and the position of the outlet member 40b in the height direction HD are approximately the same. The inlet member 40a and the outlet member 40b are arranged apart from each other in the width direction WD. The distance between the inlet member 40a and the smoothing condenser 15 in the width direction WD is called the inlet distance L40a. The distance between the outlet member 40b and the smoothing condenser 15 in the width direction WD is called the outlet distance L40b. The inlet distance L40a is shorter than the outlet distance L40b.

[0037] The passages include an inlet passage 31, an inlet gallery 32, and an inlet-side connecting passage 33. The inlet passage 31 introduces a heat exchange medium from the outside to the inside of the case 5. The inlet gallery 32 is also called an inlet common passage. The inlet gallery 32 receives the heat exchange medium from the inlet passage 31. The passages include a first passage 34 and a second passage 35 arranged in parallel on both sides in the thickness direction of the semiconductor module 18.

[0038] The first passage 34 is arranged as a first layer on one side in the thickness direction of the semiconductor module 18. The second passage 35 is arranged as a second layer on the other side in the thickness direction of the semiconductor module 18. The entrance gallery 32 is arranged as a third layer in a layer different from the first and second layers. The third layer is arranged on the opposite side of the second layer from the first layer. In other words, the first, second, and third layers are arranged in parallel in this order in the thickness direction of the semiconductor module 18. The entrance side connecting passage 33 is fluidly connected to the entrance gallery 32. The entrance gallery 32 may be fluidly connected directly to the second passage 35. The entrance side connecting passage 33 fluidly connects the first passage 34 and the second passage 35 on the entrance sides of the first passage 34 and the second passage 35.

[0039] As a result, the heat exchange medium flows from the inlet passage 31 via the inlet gallery 32. Furthermore, the heat exchange medium flows from the inlet gallery 32 via the inlet-side connecting passage 33 to both the first passage 34 and the second passage 35. The flow of the heat exchange medium in the first passage 34 is illustrated by arrow F34. The flow of the heat exchange medium in the second passage 35 is illustrated by arrow F35. The flows F34 and F35 flow along both sides of the semiconductor module 18, respectively, to dissipate heat from the semiconductor module 18. The passages receive the heat exchange medium from the inlet, flow the heat exchange medium along both sides of the semiconductor module 18, and then discharge the heat exchange medium from the outlet.

[0040] The passages include an outlet-side connecting passage 36, an outlet gallery 37, and an outlet passage 38. The outlet-side connecting passage 36 fluidly connects the first passage 34 and the second passage 35 on the outlet side of the first passage 34 and the second passage 35. The outlet-side connecting passage 36 is fluidly connected to the outlet gallery 37. The outlet gallery 37 may be fluidly connected directly to the second passage 35. The outlet gallery 37 is also called an outlet common passage. The outlet gallery 37 is also called a third passage. The outlet gallery 37 is a guide passage that guides the heat exchange medium toward the outlet passage 38. In this embodiment, the heat exchange passage includes the outlet gallery 37 (third passage) that joins the heat exchange medium downstream of the first passage 34 and the second passage 35 and discharges it to the outlet passage 38.

[0041] If the first passage 34 is the first layer and the second passage 35 is the second layer, the exit gallery 37 is located on the third layer. The exit gallery 37 extends in the depth direction DD from the exit-side connecting passage 36 toward the exit passage 38. The exit gallery 37 is located so as to bypass the entrance gallery 32 and the entrance passage 31 in the width direction WD. Compared to the entrance gallery 32, the exit gallery 37 extends along the depth direction DD while meandering slightly toward the width direction WD.

[0042] From another perspective, the exit gallery 37 (third passage) is arranged such that the first passage 34 and the second passage 35 are stacked in the height direction HD. This height direction HD is also referred to as the stacking direction. The exit gallery 37 is arranged to protrude outward from the stacking range of the first passage 34 and the second passage 35 in the width direction WD, which intersects with the stacking direction. In the embodiment shown in FIG. 2, the stacking range of the first passage 34 and the second passage 35 is the range surrounded by the dashed dotted line. In addition, the exit gallery 37 is arranged to reach the exit passage 38 via the outside of the stacking range of the first passage 34 and the second passage 35.

[0043] As a result, the heat exchange medium flows from both the first passage 34 and the second passage 35 through the outlet-side connecting passage 36 and the outlet gallery 37. The flow of the heat exchange medium in the outlet gallery 37, i.e., the third passage, is illustrated by arrow F37. The extent of the outlet gallery 37 is illustrated by a two-dot chain line. The heat exchange medium flows from the outlet gallery 37 to the outlet passage 38.

[0044] The passage partition member 40 partitions the heat exchange passages. The heat exchange passages receive a heat exchange medium from an inlet, flow the heat exchange medium along both sides of the semiconductor module 18, and then discharge the heat exchange medium from an outlet. The passage partition member 40 includes a plurality of members arranged in a stacked manner. The stacking direction is the thickness direction of the semiconductor module 18, which is the main target of heat exchange. The passage partition member 40 partitions the above-mentioned passages 32, 33, 34, and 37 between the plurality of members. Note that the passage partition member 40 may further include additional stacked members. For example, the passage partition member 40 may additionally include sealing members that seal the heat exchange medium between the plurality of members.

[0045] 3 shows cross sections of the inlet gallery 32 and the inlet-side connecting passage 33. The first passage 34, the second passage 35, and the outlet gallery 37 have different flow path shapes in the flow direction of the heat exchange medium. This difference in shape allows the first passage 34 and the second passage 35 to exhibit high heat exchange performance.

[0046] The passage has a plurality of cross-sectional areas with respect to the cross-sectional area of the flow path in the flow direction of the heat exchange medium. This cross-sectional area is the maximum flow path cross-sectional area in the indicated passage. The first passage 34 has a first flow path cross-sectional area A34. The second passage 35 has a second flow path cross-sectional area A35. The inlet gallery 32 has an inlet gallery cross-sectional area A32. The outlet gallery 37 has an outlet gallery cross-sectional area A37. The outlet gallery cross-sectional area A37 is also referred to as the third flow path cross-sectional area. The first flow path cross-sectional area A34, the second flow path cross-sectional area A35, and the third flow path cross-sectional area A37 are different from each other. The first flow path cross-sectional area A34 and the second flow path cross-sectional area A35 can be set to satisfy A35 > A34 or A35 = A34. In the second passage 35, it is desirable to provide a higher heat exchange performance than the first passage 34.

[0047] The first flow path cross-sectional area A34 is set smaller than the third flow path cross-sectional area A37 (A34 < A37). The second flow path cross-sectional area A35 is set smaller than the third flow path cross-sectional area A37 (A35 < A37). Such a difference in the flow path cross-sectional area realizes a high flow velocity of the heat exchange medium in the first passage 34 and the second passage 35 and exhibits a high heat exchange performance.

[0048] The passage partitioning member 40 includes a first member 41, a second member 42, a third member 43, and a fourth member 44. The first member 41 and the second member 42 are stacked and arranged on one side in the thickness direction of the semiconductor module 18. In the illustrated embodiment, the first member 41 and the second member 42 are arranged in this order above the semiconductor module 18. The first member 41 and the second member 42 are stacked. The first member 41 and the second member 42 partition and form the first passage 34 therebetween. The first member 41 and the second member 42 provide a first passage forming member for forming the first passage 34.

[0049] The third member 43 and the fourth member 44 are arranged in a stacked manner on the other side in the thickness direction of the semiconductor module 18. In the illustrated embodiment, the third member 43 and the fourth member 44 are arranged in this order on the lower side of the semiconductor module 18. The third member 43 and the fourth member 44 are stacked. The third member 43 and the fourth member 44 define and form the second passage 35 therebetween. The third member 43 and the fourth member 44 provide a second passage forming member for forming the second passage 35.

[0050] A gap 51 is defined between the second member 42 and the third member 43. The gap 51 provides a gap for accommodating the semiconductor module 18. The gap 51 maintains the second member 42 and the semiconductor module 18 in contact with each other, and at the same time maintains the third member 43 and the semiconductor module 18 in contact with each other. The width of the gap 51 in the height direction HD corresponds to the dimension of the semiconductor module 18 in the thickness direction.

[0051] The inlet-side connecting member 45a fluidly connects the first passage 34 and the second passage 35. The inlet-side connecting member 45a is provided by an annular member 45 having a plurality of openings. The inlet-side connecting member 45a is one of the members that fluidly connects the first passage 34 and the second passage 35. The inlet-side connecting member 45a provides a distribution passage that distributes the heat exchange medium from the outlet gallery 32 to the first passage 34 and the second passage 35. The inlet-side connecting member 45a is also called a distribution passage member.

[0052] The passage dividing member 40 includes a fifth member 46 as a case wall of the case 5. The fifth member 46 is provided by the case bottom wall of the case 5. The fourth member 44 and the fifth member 46 are disposed on the other side in the thickness direction of the semiconductor module 18. In the illustrated embodiment, the fourth member 44 and the fifth member 46 are disposed in this order below the semiconductor module 18. The fourth member 44 and the fifth member 46 are disposed in a stacked manner. The fourth member 44 and the fifth member 46 define and form the entrance gallery 32 therebetween. The fourth member 44 and the fifth member 46 define and form the exit gallery 37 therebetween.

[0053] From another perspective, the fourth member 44 defines both the second passage 35 and the inlet gallery 32. The fourth member 44 defines both the second passage 35 and the outlet gallery 37. The fourth member 44 defines the second passage 35, the inlet gallery 32, and the outlet gallery 37. The fourth member 44 defines the second passage 35 on the side facing the semiconductor module 18. At the same time, the fourth member 44 defines the inlet gallery 32 and the outlet gallery 37 on the opposite side facing away from the semiconductor module 18. The fourth member 44 is also called a heat sink member because it performs multiple functions for heat exchange.

[0054] The fifth member 46 provides the case bottom wall of the case 5. The fifth member 46 has a recess 52 recessed from the inside of the case 5 toward the outside of the case 5. The fifth member 46 has the recess 52 recessed toward one side in the stacking direction of the first passage 34 and the second passage 35. The smoothing capacitor 15 is disposed in the recess 52. By being disposed in the recess 52, the smoothing capacitor 15 is disposed biased toward one side in the stacking direction.

[0055] The smoothing capacitor 15 is thermally coupled to the fifth member 46, i.e., the bottom wall of the case, at the recess 52. This thermal relationship enables the smoothing capacitor 15 to dissipate heat from the smoothing capacitor 15 to the fifth member 46, i.e., the bottom wall. A heat transfer member 53 is disposed between the smoothing capacitor 15 and the fifth member 46. The heat transfer member 53 enables excellent heat transfer from the smoothing capacitor 15 to the fifth member 46. The heat transfer member 53 is a sheet made of a material with a good thermal conductivity. The heat transfer member 53 is provided by, for example, a gel material, a rubber material, or a resin material.

[0056] The thermal coupling relationship between the heat exchange medium in the first passage 34 and the smoothing condenser 15 is slightly weakened by disposing the smoothing condenser 15 in the recess 52. The thermal coupling relationship between the heat exchange medium in the second passage 35 and the smoothing condenser 15 is also slightly weakened by disposing the smoothing condenser 15 in the recess 52. Meanwhile, by accommodating the smoothing condenser 15 in the recess 52, the fifth member 46 relatively strengthens the thermal coupling relationship between the heat exchange medium in the inlet gallery 32 and the smoothing condenser 15. Similarly, by accommodating the smoothing condenser 15 in the recess 52, the fifth member 46 relatively strengthens the thermal coupling relationship between the heat exchange medium in the outlet gallery 37 and the smoothing condenser 15. As a result, heat from the smoothing condenser 15 is more easily transferred to the heat exchange medium in the inlet gallery 32 and / or the heat exchange medium in the outlet gallery 37.

[0057] 3 shows a circuit board 24 on which the control circuit 20 is mounted. The current sensor module 21 is electrically connected to the circuit board 24. The signal terminal of the semiconductor module 18 is connected to the circuit board 24.

[0058] 4 shows a cross section of the semiconductor module 18. Heat from the semiconductor module 18 is dissipated to the heat exchange medium via the passage partition member 40. On one side in the thickness direction of the semiconductor module 18, for example the upper side, the heat from the semiconductor module 18 is dissipated to the heat exchange medium via the second member 42 and the first heat exchange member 47. On the other side in the thickness direction of the semiconductor module 18, for example the lower side, the heat from the semiconductor module 18 is dissipated to the heat exchange medium via the third member 43 and the second heat exchange member 48.

[0059] In Figure 4, the shape of the exit gallery 37 is shown by dashed and solid lines. The exit gallery 37 moves from the center, indicated by the dashed line, to a leftward position, indicated by the solid line, as it moves from the back of the page to the front of the page. The shape of the exit gallery 37 can be clearly understood by comparing Figures 2 and 3.

[0060] In FIG. 4 , the current sensor module 21 is disposed on the fourth member 44. The fourth member 44 and the current sensor module 21 are thermally coupled. As a result, the current sensor module 21 dissipates heat to the heat exchange medium of the outlet gallery 37 through the fourth member 44. In this embodiment, the current sensor module 21 is another circuit component constituting the power conversion circuit 10. The current sensor module 21 provides another component disposed to dissipate heat to the heat exchange medium of the outlet gallery 37, i.e., the third passage, through the fourth member 44. According to this embodiment, the heat exchanger 30 can be used to adjust the temperature of the current sensor module 21.

[0061] In FIG. 5, the outlet side connecting member 45b fluidly connects the first passage 34 and the second passage 35. The outlet side connecting member 45b is provided by an annular member 45 having a plurality of openings. The outlet side connecting member 45b is one of the members that fluidly connects the first passage 34 and the second passage 35. The outlet side connecting member 45b provides a collecting passage that collects the heat exchange medium from the first passage 34 and the second passage 35 to the outlet gallery 37. The outlet side connecting member 45b is also called a collecting passage member.

[0062] 3 and 4, a first heat exchange member 47 is disposed between the first member 41 and the second member 42. The first heat exchange member 47 is disposed inside the first passage 34. The first heat exchange member 47 promotes heat exchange between the heat exchange medium and the heat exchange member. In the illustrated embodiment, the first heat exchange member 47 promotes heat exchange between the heat exchange medium and the first member 41, and simultaneously promotes heat exchange between the heat exchange medium and the second member 42.

[0063] A second heat exchange member 48 is disposed between the third member 43 and the fourth member 44. The second heat exchange member 48 is disposed inside the second passage 35. The second heat exchange member 48 facilitates heat exchange between the heat exchange medium and the heat exchange member. In the illustrated embodiment, the second heat exchange member 48 facilitates heat exchange between the heat exchange medium and the third member 43 and simultaneously facilitates heat exchange between the heat exchange medium and the fourth member 44.

[0064] 4, an elastic member 49 is schematically illustrated. The heat exchanger 30 includes the elastic member 49. The elastic member 49 is provided as one of the passage dividing members 40. The elastic member 49 presses a plurality of members including the first member 41, together with the semiconductor module 18, toward the fourth member 44. The elastic member 49 presses the passage dividing member 40 against both sides of the semiconductor module 18. This achieves high heat transfer performance between the semiconductor module 18 and the passage dividing member 40.

[0065] 6 shows an example of the first heat exchange member 47. The first heat exchange member 47 is provided by an inner fin disposed between the first member 41 and the second member 42. The inner fin can be provided by, for example, an aluminum or stainless steel corrugated fin.

[0066] 7 shows an example of the second heat exchange member 48. The second heat exchange member 48 is provided by inner fins that are integrally formed on the inner surface of the third member 43 using a material that is continuous with the third member 43. The inner fins can be provided by, for example, pin fins or plate fins that are made of a material that is continuous with the third member 43.

[0067] According to this embodiment, a power conversion device 2 is provided. In the power conversion device 2, heat from the semiconductor module 18 is dissipated to a heat exchange medium. The temperature of the heat exchange medium rises due to heat exchange with the semiconductor module 18. As a result, the temperature of the heat exchange medium near the outlet member 40b of the heat exchanger 30 is higher than the temperature of the heat exchange medium near the inlet member 40a. The inlet distance L40a between the inlet member 40a and the smoothing condenser 15 is set shorter than the outlet distance L40b between the outlet member 40b and the smoothing condenser 15. Therefore, the smoothing condenser 15 can dissipate heat to the heat exchange medium near the inlet member 40a. Since the temperature of the heat exchange medium near the inlet member 40a is relatively low, a high heat dissipation effect can be expected.

[0068] Other embodiments In the above embodiment, the first passage 34 is defined by stacking the first member 41 and the second member 42. Alternatively, the first passage 34 may be defined by a cylindrical member and cover members on both ends of the cylindrical member. Similarly, the second passage 35 is defined by stacking the third member 43 and the fourth member 44. Alternatively, the second passage 35 may be defined by a cylindrical member and cover members on both ends of the cylindrical member.

[0069] In the above embodiment, the entrance gallery 32 is defined by stacking the fourth member 44 and the fifth member 46. Alternatively, the entrance gallery 32 may be defined by a cylindrical member thermally coupled to at least one or both of the fourth member 44 and the fifth member 46. Similarly, the exit gallery 37 is defined by stacking the fourth member 44 and the fifth member 46. Alternatively, the exit gallery 37 may be defined by a cylindrical member thermally coupled to at least one or both of the fourth member 44 and the fifth member 46.

[0070] In the above embodiment, the fluid connection between the entrance gallery 32 and the first passage 34 and the fluid connection between the entrance gallery 32 and the second passage 35 are provided by the entrance-side connecting member 45a. Alternatively, at least one or both of the fluid connection between the entrance gallery 32 and the first passage 34 and the fluid connection between the entrance gallery 32 and the second passage 35 may be provided by a direct connection between the passages. Similarly, the fluid connection between the first passage 34 and the exit gallery 37 and the fluid connection between the second passage 35 and the exit gallery 37 are provided by the exit-side connecting member 45b. Alternatively, at least one or both of the fluid connection between the first passage 34 and the exit gallery 37 and the fluid connection between the second passage 35 and the exit gallery 37 may be provided by a direct connection between the passages.

[0071] The disclosure in this specification and drawings, etc. is not limited to the exemplified embodiments. The disclosure encompasses the exemplified embodiments and variations thereon by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and / or elements shown in the embodiments. The disclosure can be implemented in various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure encompasses the omission of parts and / or elements from the embodiments. The disclosure encompasses the substitution or combination of parts and / or elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. Some disclosed technical scopes are defined by the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the claims.

[0072] The disclosure in the specification, drawings, etc. is not limited by the claims. The disclosure in the specification, drawings, etc. encompasses the technical ideas described in the claims, and extends to more diverse and broader technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure in the specification, drawings, etc. without being bound by the claims.

[0073] (Disclosure of technical ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be written in a multiple dependent form, with the subsequent clause referring to the preceding clause as an alternative. Furthermore, some clauses may be written in a multiple dependent form, referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0074] (Technical thought 1) a case (5) for accommodating a power conversion circuit; a plate-shaped semiconductor module (18) that provides a switching element included in the power conversion circuit; a smoothing capacitor (15) that smoothes the power in the power conversion circuit; a heat exchanger (30) that dissipates heat from the semiconductor module to a heat exchange medium; The heat exchanger comprises: a passage partition member (40) that partitions a heat exchange passage including an inlet (31) for introducing the heat exchange medium from the outside to the inside of the case, an outlet (38) for discharging the heat exchange medium from the inside to the outside of the case, a first passage (34) and a second passage (35) that are arranged in parallel on both sides in the thickness direction of the semiconductor module, and that receives the heat exchange medium from the inlet, flows the heat exchange medium along both sides of the semiconductor module, and then discharges the heat exchange medium from the outlet; The power conversion device, wherein an inlet distance (L40a) between the inlet and the smoothing capacitor is set shorter than an outlet distance (L40b) between the outlet and the smoothing capacitor.

[0075] (Technical thought 2) The power conversion device according to Technical Idea 1, wherein the heat exchange passage includes a third passage (37) that joins the heat exchange medium downstream of the first passage and the second passage and discharges it to the outlet.

[0076] (Technical Thought 3) The power conversion device according to Technical Idea 2, wherein the third passage protrudes outside the stacking range of the first passage and the second passage in a width direction (WD) intersecting the stacking direction (HD) of the first passage and the second passage, and is arranged so as to reach the outlet via the outside of the stacking range.

[0077] (Technical Thought 4) The passage partition member is a first member (41) and a second member (42) arranged in a stacked manner on one side of the semiconductor module, defining and forming the first passage between them; a third member (43) and a fourth member (44) arranged in a stacked manner on the other side of the semiconductor module, and defining and forming the second passage between them; an inlet-side connecting member (45a) that fluidly connects the first passage and the second passage at the inlet sides of the first passage and the second passage; an outlet side connecting member (45b) that fluidly connects the first passage and the second passage at the outlet side of the first passage and the second passage; The power conversion device according to Technical Idea 2 or Technical Idea 3, further comprising a case wall (46) that is arranged in a stacked manner with the fourth member and that partitions and forms the third passage between them.

[0078] (Technical Thought 5) The power conversion device described in Technical Idea 4, wherein the case wall and the fourth member (44) are connected to the inlet, define and form an inlet gallery (32) that receives the heat exchange medium from the inlet and is fluidly connected to the inlet side connecting member (45a).

[0079] (Technical Thought 6) The case wall has a recess (52) that is recessed toward one side of the stacking direction (HD) of the first passage and the second passage, The smoothing capacitor is disposed in the recess, and is biased toward one side in the stacking direction, The power conversion device according to Technical Idea 4 or 5, wherein the smoothing capacitor and the case wall are thermally coupled in the recess.

[0080] (Technical Thought 7) A power conversion device described in any one of Technical Ideas 2 to 6, wherein, with respect to the flow path cross-sectional area in the flow direction of the heat exchange medium, the first flow path cross-sectional area (A34) of the first passage, the second flow path cross-sectional area (A35) of the second passage, and the third flow path cross-sectional area (A37) of the third passage are different from each other.

[0081] (Technical Thought 8) A power conversion device according to Technical Idea 7, wherein the first flow path cross-sectional area (A34) is set smaller than the third flow path cross-sectional area (A37), and the second flow path cross-sectional area (A35) is set smaller than the third flow path cross-sectional area (A37).

[0082] (Technical Thought 9) The heat exchanger comprises: a first heat exchange member (47) disposed inside the first passage and promoting heat exchange between the heat exchange medium and the passage partition member; The power conversion device according to any one of Technical Ideas 2 to 8, further comprising a second heat exchange member (48) disposed inside the second passage and promoting heat exchange between the heat exchange medium and the passage partition member.

[0083] (Technical Thought 10) Furthermore, other circuit components (21) constituting the power conversion circuit include: A power conversion device according to any one of Technical Ideas 4 to 6, further comprising another circuit component arranged to dissipate heat to the heat exchange medium in the third passage via the fourth member. [Explanation of symbols]

[0084] 1 power system, 2 power conversion device, 3 battery, 4 rotating electric machine, 5 case, 6 DC input / output section, 7 AC input / output section, 10 power conversion circuit, 11 positive bus bar, 12 negative bus bar, 13 AC power bus bar, 14 filter circuit, 15 smoothing capacitor, 16 inverter circuit, 17 switching element, 18 semiconductor module, 20 control circuit, 21 current sensor module, 22 control circuit module, 23 terminal blocks, 24 circuit boards, 30 heat exchanger, 31 inlet passage, 32 inlet gallery, 33 Inlet side connecting passage, 34 First passage, 35 Second passage, 36 Exit side connecting passage, 37 Exit gallery, 38 Exit passage, 40 passage partition member, 40a inlet member, 40b outlet member, 41 first member, 42 second member, 43 third member, 44 fourth member, 45a inlet side connecting member, 45b outlet side connecting member, 46 sixth member, 47 First heat exchange member, 48 Second heat exchange member, 49 Elastic member, 51 gap, 52 recess, 53 heat transfer member, A32 inlet gallery cross-sectional area, A34 first flow path cross-sectional area, A35 Second flow passage cross-sectional area, A37 Exit gallery cross-sectional area, F34, F35 flow, L40a inlet distance, L40b outlet distance, HD height direction (stacking direction), WD width direction, DD depth direction.

Claims

1. a case (5) for accommodating a power conversion circuit; a plate-shaped semiconductor module (18) that provides a switching element included in the power conversion circuit; a smoothing capacitor (15) for smoothing the power in the power conversion circuit; a heat exchanger (30) that dissipates heat from the semiconductor module to a heat exchange medium, The heat exchanger comprises: the heat exchange passage includes an inlet (31) for introducing the heat exchange medium from the outside to the inside of the case, an outlet (38) for discharging the heat exchange medium from the inside to the outside of the case, a first passage (34) and a second passage (35) arranged in parallel on both sides in the thickness direction of the semiconductor module, and a passage partition member (40) for partitioning a heat exchange passage that receives the heat exchange medium from the inlet, flows the heat exchange medium along both sides of the semiconductor module, and then discharges the heat exchange medium from the outlet; A power conversion device in which an inlet distance (L40a) between the inlet and the smoothing capacitor is set shorter than an outlet distance (L40b) between the outlet and the smoothing capacitor.

2. The power conversion device according to claim 1, wherein the heat exchange passages include a third passage (37) that joins the heat exchange medium downstream of the first passage and the second passage and discharges the heat exchange medium to the outlet.

3. 3. The power conversion device according to claim 2, wherein the third passage is arranged to protrude outside a stacking range of the first passage and the second passage in a width direction (WD) intersecting a stacking direction (HD) of the first passage and the second passage, and to reach the outlet via outside the stacking range.

4. The passage partition member is a first member (41) and a second member (42) arranged in a stacked manner on one side of the semiconductor module, and defining and forming the first passage between them; a third member (43) and a fourth member (44) arranged in a stacked manner on the other side of the semiconductor module, and defining and forming the second passage between them; an inlet side connecting member (45a) that fluidly connects the first passage and the second passage at the inlet side of the first passage and the second passage; an outlet side connecting member (45b) that fluidly connects the first passage and the second passage at the outlet side of the first passage and the second passage; The power conversion device according to claim 2 or 3, further comprising a case wall (46) that is arranged in a stacked manner with the fourth member and that partitions and forms the third passage between them.

5. The power conversion device of claim 4, wherein the case wall and the fourth member (44) define and form an inlet gallery (32) that is in communication with the inlet, receives the heat exchange medium from the inlet, and is fluidly connected to the inlet side connecting member (45a).

6. The case wall has a recess (52) that is recessed toward one side of the stacking direction (HD) of the first passage and the second passage, The smoothing capacitor is disposed in the recess, and is biased toward one side in the stacking direction, The power conversion device according to claim 4 , wherein the smoothing capacitor and the case wall are thermally coupled in the recess.

7. 4. The power conversion device according to claim 2, wherein, with respect to the flow path cross-sectional areas in the flow direction of the heat exchange medium, a first flow path cross-sectional area (A34) of the first passage, a second flow path cross-sectional area (A35) of the second passage, and a third flow path cross-sectional area (A37) of the third passage are different from each other.

8. The power conversion device according to claim 7, wherein the first flow path cross-sectional area (A34) is set smaller than the third flow path cross-sectional area (A37), and the second flow path cross-sectional area (A35) is set smaller than the third flow path cross-sectional area (A37).

9. The heat exchanger comprises: a first heat exchange member (47) disposed inside the first passage and promoting heat exchange between the heat exchange medium and the passage partition member; 4. The power conversion device according to claim 2, further comprising a second heat exchange member (48) disposed inside the second passage and promoting heat exchange between the heat exchange medium and the passage partition member.

10. Furthermore, other circuit components (21) constituting the power conversion circuit, The power conversion device according to claim 4 , further comprising another circuit component arranged to radiate heat to the heat exchange medium in the third passage via the fourth member.

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