JP2011066199A - Power controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve cooling performance of a power controller while suppressing an increase in load on a supply source for a refrigerant. <P>SOLUTION: The power controller 10 includes substrates 15a, 15b having mounting surfaces where a plurality of elements 21 are mounted, respectively, and disposed so that surfaces on the opposite sides from the mounting surfaces may face each other, a cooling flow passage 22 formed in a cooling tube 20 to which the substrates 15a, 15b are joined and connected to an unillustrated pump configured to supply the refrigerant for exchanging heat with the elements 21, and a thermal expansion material 23 disposed in the cooling flow passage 22, the thermal expansion material 23 thermally expanding as the temperature of the refrigerant rises to reduce the flow passage sectional area of the cooling flow passage 22 to increase the flow velocity of the refrigerant. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power control apparatus.

  Conventionally, this type of power control device is an inverter device or the like used in a hybrid vehicle or the like, and includes a substrate on which a power semiconductor element such as an IGBT (Insulated Gate Bipolar Transistor) is mounted and a housing to which the substrate is bonded. An apparatus is proposed that includes a refrigerant flow path formed inside a body and fins that are arranged in the refrigerant flow direction along the refrigerant flow direction and define the refrigerant flow path (see, for example, Patent Document 1). ). In this power control device, a cooling performance is achieved by providing a protrusion or a hole penetrating the side surface of the fin on the side surface of the fin disposed near the power semiconductor element that is a heating element to promote the generation of turbulent flow of the refrigerant. Has improved.

JP 2008-288330 A

  By the way, as another method for improving the cooling performance in the power control apparatus as described above, the flow rate of the refrigerant is increased in order to quickly replace the refrigerant that has exchanged heat with the semiconductor element that is a heating element. It is possible. However, since the flow resistance in the refrigerant flow path increases as the refrigerant flow rate increases, the pump load, that is, the discharge pressure required for the pump increases, thereby increasing the power consumption of the pump and increasing the size of the pump. There is a possibility that it will be necessary to make it.

  The main purpose of the power control apparatus of the present invention is to improve the cooling performance while suppressing an increase in the load of the refrigerant supply source.

  The power control apparatus of the present invention employs the following means in order to achieve the main object described above.

The power control apparatus according to the present invention includes at least one substrate on which a plurality of power control elements are mounted, and the substrate connected to a refrigerant supply source and capable of heat exchange between the refrigerant and the element. A power control device provided with a cooling flow path provided in the vicinity of
The cooling channel contains a thermal expansion material, and the thermal expansion of the thermal expansion material is used to change the flow rate of the refrigerant in the previous cooling channel without changing the flow rate of the refrigerant from the supply source. The flow rate changing means for increasing is arranged.

  In the power control apparatus of the present invention, the flow rate changing means for increasing the flow rate of the refrigerant in the cooling flow path using the thermal expansion of the thermal expansion material without changing the flow rate of the refrigerant from the supply source is disposed in the cooling flow path. Is done. Thereby, when the temperature of the element is high, the flow rate of the refrigerant in the cooling channel can be increased, so that it is possible to improve the cooling performance by quickly circulating the refrigerant in the cooling channel. Further, when the temperature of the element is high, the temperature of the refrigerant also rises due to heat exchange with the element and the viscosity of the refrigerant decreases, so that even if the flow rate of the refrigerant is increased, the flow resistance in the cooling flow path increases, that is, An increase in the load of the refrigerant supply source can be suppressed. When the temperature of the element is low, the flow rate of the refrigerant in the cooling channel does not increase as when the temperature of the element is high. Therefore, the flow resistance in the cooling channel is increased, that is, the load of the refrigerant supply source is increased. Can be suppressed. Therefore, in the power control apparatus of the present invention, it is possible to improve the cooling performance while suppressing an increase in the load of the refrigerant supply source.

  The flow rate changing means may be a means for reducing the cross-sectional area of the cooling flow path in response to a rise in the temperature of the refrigerant, or a bag made of a stretchable material, and enclosed in the bag And a fluid having a thermal expansion coefficient equal to or greater than a predetermined value. The flow velocity changing means has a first slope and a first member disposed in the cooling channel, a second slope parallel to the first slope of the first member, and the second slope. And a second member disposed in the previous cooling channel so as to contact the first slope, and the thermal expansion material includes the first slope and the second slope according to a temperature change of the refrigerant. The first member and the second member may be arranged so as to move relative to each other in opposite directions in a state in which they are in contact with each other. Alternatively, the flow rate changing means includes a first member disposed in the cooling flow path so as to extend in the flow direction of the refrigerant, and one end rotatably supported by the first member. A closing member capable of closing a part of the cooling flow path; and a second member disposed so as to contact both the first member and the closing member, wherein the thermal expansion material is a temperature of the refrigerant. The first member and the second member may be arranged so as to move relative to each other according to the change. Further, the cooling flow path is partitioned into a plurality of passages extending in the refrigerant flow direction, and the flow rate changing means is connected to the thermal expansion material and the plurality of the flow rate changing means are thermally expanded by the thermal expansion material. It may include a valve body capable of closing at least one of the passages.

(A) And (b) is a schematic diagram which shows the principal part of the electric power control apparatus 10 which concerns on one Example of this invention. (A) And (b) is a schematic diagram which shows the principal part of the electric power control apparatus 10B which concerns on the modification of this invention. (A) And (b) is a schematic diagram which shows the principal part of 10 C of electric power control apparatuses which concern on the modification of this invention. (A) And (b) is a schematic diagram which shows the principal part of power control apparatus 10D which concerns on the modification of this invention. (A) And (b) is a schematic diagram which shows the principal part of the electric power control apparatus 10E which concerns on the modification of this invention.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIGS. 1A and 1B are schematic views showing the main part of a power control apparatus 10 according to one embodiment of the present invention. The power control apparatus 10 is used for controlling a motor mounted on, for example, a hybrid vehicle or an electric vehicle, and has a mounting surface on which a plurality of elements 21 including switching elements (for example, semiconductor elements such as IGBT) are mounted. In order to exchange heat with the element 21 while being formed inside the cooling pipe 20 to which the substrates 15a and 15b are disposed so that the surfaces opposite to the mounting surface face each other and the substrates 15a and 15b are bonded to each other. A cooling flow path 22 connected to a pump (not shown) that supplies the refrigerant, and a thermal expansion material 23 that is disposed in the cooling flow path 22 and that thermally expands as the temperature of the refrigerant rises. The thermal expansion material 23 is fixed, for example, near the center of the cooling channel 22 in the vertical direction in the figure. Here, the thermal expansion material 23 may be formed of a metal material such as aluminum or magnesium, or may be an elastic material such as rubber or a resin, as long as it expands in response to a temperature rise of the refrigerant. It may be formed of a material. The arrows in FIGS. 1A and 1B indicate the flow direction of refrigerant in the cooling flow path 22 and the magnitude of the flow velocity. In the embodiment, the power control apparatus 10 includes two opposing substrates 15a and 15b. However, the power control device 10 may include one or three or more substrates.

  In the power control device 10 configured as described above, when a current is passed through the element 21, the element 21 generates heat, and the heat generated from the element 21 flows through the cooling channels 20 through the substrates 15 a and 15 b and the cooling pipe 20. By conducting heat to the refrigerant flowing through the inside 22, heat exchange is performed between the element 21 and the refrigerant, and the element 21 is cooled. On the other hand, the refrigerant that has exchanged heat with the element 21 rises in temperature according to the amount of heat received from the element 21 and raises the temperature of the surrounding refrigerant by heat transfer or the like. Accordingly, when the element 21 generates a relatively small amount of heat, the temperature of the refrigerant flowing in the vicinity of the substrates 15a and 15b does not increase so much, so that the thermal expansion material 23 is in the state before thermal expansion shown in FIG. It will be in the state of thermal expansion. On the other hand, when the heat generation amount of the element 21 is relatively large, the temperature of the refrigerant flowing in the vicinity of the substrates 15a and 15b increases as the heat generation amount of the element 21 increases, and as shown in FIG. , 15b, the thermal expansion material 23 is thermally expanded in response to the temperature rise of the refrigerant. Thereby, the flow path cross-sectional area of the cooling flow path 22 decreases as the temperature of the refrigerant increases, and the flow velocity of the refrigerant flowing in the vicinity of the substrates 15a and 15b is before the thermal expansion of the thermal expansion material 23 shown in FIG. It increases compared to the state of. When the element 21 is cooled and sufficiently cooled, the temperature of the refrigerant flowing in the vicinity of the substrates 15a and 15b decreases, and the thermal expansion material 23 is in a state before thermal expansion shown in FIG. In the expanded state, the cross-sectional area of the channel and the flow rate of the refrigerant in the vicinity of the substrates 15 a and 15 b in the cooling channel 22 are the same as or similar to those before the thermal expansion of the thermal expansion material 23.

  As described above, in the power control apparatus 10 according to the embodiment, the thermal expansion material 23 that thermally expands in accordance with the temperature rise of the refrigerant and decreases the cross-sectional area of the cooling flow path 22 is provided in the cooling flow path 22. Be placed. Thereby, when the temperature of the element 21 is high, the flow rate of the refrigerant in the cooling flow path 22 can be increased. Therefore, it is possible to quickly circulate the refrigerant in the cooling flow path 22 and improve the cooling performance. Further, when the temperature of the element 21 is high, the temperature of the refrigerant also rises due to heat exchange with the element 21 and the viscosity of the refrigerant decreases. Therefore, even if the flow rate of the refrigerant is increased, the channel resistance in the cooling channel 22 Increase, that is, an increase in pump load can be suppressed. When the temperature of the element 21 is low, the flow rate of the refrigerant in the cooling flow path 22 does not increase as when the temperature of the element is high. Therefore, the flow resistance in the cooling flow path 22 is increased, that is, the pump load is increased. Can be suppressed. Therefore, in the power control apparatus 10 of the embodiment, it is possible to improve the cooling performance while suppressing an increase in the load on the pump.

  FIGS. 2A and 2B are schematic views showing the main part of a power control apparatus 10B according to a modification. In addition, in order to avoid duplicate description, the same code | symbol is attached | subjected about the structure same as the structure of the power control apparatus 10 of the above-mentioned Example among the structures of the power control apparatus 10B, and the detailed description is abbreviate | omitted. The power control apparatus 10B shown in the figure includes a thermal expansion material 24 instead of the thermal expansion material 23 in the power control apparatus 10 described above. The thermal expansion material 24 is cooled by a bag body 24a formed of a stretchable material such as an elastic material such as rubber or a resin material, and enclosed in the bag body 24a and having a thermal expansion coefficient equal to or greater than a predetermined value. A thermal expansion fluid 24b that can expand the bag body 24a in accordance with the temperature rise of the refrigerant in the flow path 22.

  In the power control device 10B configured as described above, as in the power control device 10 described above, when a current is passed through the element 21, the element 21 generates heat, and heat exchange is performed between the element 21 and the refrigerant. Is called. When the amount of heat generated by the element 21 is relatively small, the temperature of the refrigerant flowing in the vicinity of the substrates 15a and 15b does not rise so much, so that the thermal expansion material 24 is in the state before thermal expansion shown in FIG. It will be in the state. On the other hand, when the element 21 generates a relatively large amount of heat, as shown in FIG. 2B, the larger the amount of heat generated by the element 21, the more thermally expanded fluid sealed in the bag body 24a of the thermal expansion material 24. 24b receives heat from the refrigerant through the bag body 24a and thermally expands to expand the bag body 24a, thereby increasing the volume of the thermal expansion material 24 as a whole. Thereby, the flow path cross-sectional area of the cooling flow path 22 decreases as the temperature of the refrigerant increases, and the flow rate of the refrigerant flowing in the vicinity of the substrates 15a and 15b is before the thermal expansion of the thermal expansion material 24 shown in FIG. It increases compared to the state of. When the element 21 is cooled and sufficiently cooled, the temperature of the refrigerant flowing in the vicinity of the substrates 15a and 15b decreases, and the thermal expansion material 24 is in the state before thermal expansion shown in FIG. In the expanded state, the flow path cross-sectional area and the flow rate of the refrigerant in the vicinity of the substrates 15 a and 15 b in the cooling flow path 22 are the same as or similar to those before the thermal expansion of the thermal expansion material 24. Therefore, also in the power control apparatus 10B of a modified example in which the thermal expansion material 24 that is thermally expanded in accordance with the temperature rise of the refrigerant and decreases the cross-sectional area of the cooling flow path 22 is disposed in the cooling flow path 22. The same effects as those of the power control apparatus 10 can be obtained.

  FIGS. 3A and 3B are schematic diagrams illustrating a main part of a power control apparatus 10C according to a modification. In addition, in order to avoid duplicate description, the same code | symbol is attached | subjected about the structure same as the structure of the power control apparatus 10 of the above-mentioned Example among the structures of 10 C of power control apparatuses, and the detailed description is abbreviate | omitted. A power control device 10 </ b> C shown in the figure includes a flow rate changing mechanism 30 instead of the thermal expansion material 23 in the power control device 10 described above. The flow rate changing mechanism 30 is thermally expanded in accordance with the rise in the temperature of the refrigerant, and the movable members 31 and 32 disposed in the cooling channel 22 so that the longitudinal direction thereof substantially coincides with the channel direction of the cooling channel 22. Thermal expansion materials 33a and 33b and a fixing member 34 for fixing one end of each of the thermal expansion materials 33a and 33b in the cooling flow path 22 are included. Here, the thermal expansion materials 33a and 33b are formed of a metal material such as aluminum or magnesium, for example, in the same manner as the thermal expansion material 23 of the power control device 10 described above, and the body expands in response to the temperature rise of the refrigerant. It expands or linearly expands.

  The movable member 31 is substantially L-shaped, and includes a first slope 311 formed at one end, a second slope 312 formed at the other end side so as to be parallel to the first slope 311, and a first slope 311. A surface 313 extending in the longitudinal direction between the inclined surface 311 and the second inclined surface 312 and a vertical surface 314 formed to be orthogonal to the longitudinal direction of the movable member 31 behind the second inclined surface. The movable member 32 has the same shape as the movable member 31, and includes a first slope 321 formed at one end, and a second slope 322 formed at the other end so as to be parallel to the first slope 321. And a surface 323 extending in the longitudinal direction between the first inclined surface 321 and the second inclined surface 322, and a vertical surface 324 formed behind the second inclined surface 322 so as to be orthogonal to the longitudinal direction of the movable member 32. The movable member 31 and the movable member 32 are configured such that the first inclined surface 311 of the movable member 31 and the second inclined surface 322 of the movable member 32 come into contact with each other, and the first inclined surface 321 of the movable member 32 and the second inclined surface 312 of the movable member 31. Are arranged near the center in the vertical direction in the drawing in the cooling channel 22 so that the surfaces 313 and 323 are in contact with each other. The other end of the thermal expansion material 33 a is fixed to the vertical surface 314 of the movable member 31, and the other end of the thermal expansion material 33 b is fixed to the vertical surface 324 of the movable member 32.

  In the power control device 10C configured as described above, when the amount of heat generated by the element 21 is relatively small, the temperature of the refrigerant flowing in the vicinity of the substrates 15a and 15b does not increase so much. The state before thermal expansion shown in (a) or a state where thermal expansion has occurred slightly is achieved, and the movable member 31 and the movable member 32 maintain the state in which the surface 313 and the surface 323 are in contact with each other. On the other hand, when the temperature of the refrigerant flowing in the vicinity of the substrates 15 a and 15 b rises as the amount of heat generated by the element 21 increases, the thermal expansion materials 33 a and 33 b thermally expand and the thermal expansion material 33 a becomes perpendicular to the movable member 31. A force is applied to the surface 314 in the same direction as the flow of the refrigerant, and the thermal expansion member 33b applies a force to the vertical surface 324 of the movable member 32 in the direction opposite to the flow of the refrigerant. As shown in FIG. 3B, the movable members 31 and 32 that have received the force from the thermal expansion members 33a and 33b come into contact with the first inclined surface 311 and the second inclined surface 322, and the first inclined surface 321 and the second inclined surface 321. The surface of the movable member 31 is relatively moved in the opposite direction with the inclined surface 312 in contact with the inclined surface 312, so that the area of the surface defined by the vertical surface 314 of the movable member 31 and the first inclined surface 321 of the movable member 32 is movable. The area of the surface defined by the vertical surface 324 of the member 32 and the first inclined surface 311 of the movable member 31 is increased. Thereby, the cross-sectional area of the cooling flow path 22 decreases as the temperature of the refrigerant increases, and the flow rate of the refrigerant flowing in the vicinity of the substrates 15a and 15b increases. When the element 21 is cooled and the temperature is lowered, the temperature of the refrigerant flowing in the vicinity of the substrates 15a and 15b is lowered, and the thermal expansion materials 33a and 33b are in the state before thermal expansion shown in FIG. In addition, the movable members 31 and 32 are in the state shown in FIG. 3A or in a state close thereto, and the flow path cross-sectional area and the flow rate of the refrigerant in the vicinity of the substrates 15a and 15b in the cooling flow path 22 are also the thermal expansion material 33a. , 33b is the same as or similar to that before thermal expansion. Therefore, a modified example in which the flow rate changing mechanism 30 that reduces the channel cross-sectional area of the cooling channel 22 using the thermal expansion materials 31a and 31b that thermally expands in response to the temperature rise of the refrigerant is disposed in the cooling channel 22. Also in the power control apparatus 10C, the same effects as those of the power control apparatus 10 described above can be obtained. The movable members 31 and 32 are not limited to the substantially L-shaped members as shown in the present embodiment, and may have at least one pair of inclined surfaces that come into contact with each other. Further, either one of the movable members 31 and 32 may be fixed in the cooling flow path 22 and the other may be movable with respect to the one.

  FIGS. 4A and 4B are schematic views showing the main part of a power control apparatus 10D according to a modification. In addition, in order to avoid duplication description, the same code | symbol is attached | subjected about the structure same as the structure of the power control apparatus 10 of the above-mentioned Example among the structures of power control apparatus 10D, and the detailed description is abbreviate | omitted. The power control device 10D shown in the figure includes a flow rate changing mechanism 40 instead of the flow rate changing mechanism 30 in the power control device 10C described above. The flow rate changing mechanism 40 has a first member 41 disposed in the cooling flow path 22 so as to extend in the flow direction of the refrigerant, and a base end that is rotatably supported by the first member 41 and is cooled. A plurality of blocking members 42 that can block a part of the flow path 22 are fixed in the cooling flow path 22 and both the first member 41 and the free end of the corresponding blocking member 42 are in contact with each other. A plurality of second members 43 to be arranged, a thermal expansion material 44 whose one end is fixed to the first member 41 and thermally expands in response to a temperature rise of the refrigerant, and the other end of the thermal expansion material 44 are connected to the cooling flow path 22. And a fixing member 45 to be fixed inside. Here, the thermal expansion material 44 is formed of, for example, a metal material such as aluminum or magnesium in the same manner as the thermal expansion material 23 of the power control device 10 described above. It is linearly expanded.

  In the power control device 10D configured as described above, when the amount of heat generated by the element 21 is relatively small, the temperature of the refrigerant flowing in the vicinity of the substrates 15a and 15b does not increase so much. The state before the thermal expansion shown in (a) or a state where the thermal expansion is slightly performed is maintained, and the second member 43 of the flow velocity changing mechanism 40 keeps the state in contact with the free end portion of the closing member 42. On the other hand, when the temperature of the refrigerant flowing in the vicinity of the substrates 15a and 15b rises as the amount of heat generated by the element 21 increases, the thermal expansion material 44 thermally expands to the same temperature as the refrigerant flow at one end of the first member 41. Apply force in the direction. As shown in FIG. 4B, the first member 41 that receives the force from the thermal expansion material 44 moves in the same direction as the flow direction of the refrigerant with respect to each fixing member 43, and moves the first member 41. Accordingly, each closing member 42 is opened so as to be spread over the second member 43, that is, to close a part of the cooling flow path 22. Thereby, the cross-sectional area of the cooling flow path 22 decreases as the temperature of the refrigerant increases, and the flow rate of the refrigerant flowing in the vicinity of the substrates 15a and 15b increases. When the element 21 is cooled and cooled, the temperature of the refrigerant flowing in the vicinity of the substrates 15a and 15b decreases, and the thermal expansion material 44 is in a state before or slightly expanded as shown in FIG. The first member 41 and the closing member 42 are in the state shown in FIG. 4A or in a state close thereto, and the cross-sectional area of the channel and the flow rate of the refrigerant in the vicinity of the substrates 15a and 15b in the cooling channel 22 are also thermally expanded. It is the same as or similar to that before the thermal expansion of 44. Therefore, the electric power of the modified example in which the flow rate changing mechanism 40 that reduces the cross-sectional area of the cooling flow path 22 using the thermal expansion material 44 that thermally expands in response to the temperature rise of the refrigerant is disposed in the cooling flow path 22. In the control device 10D, the same effects as those of the power control device 10 and the like described above can be obtained. In the present embodiment, the second member 43 is fixed in the cooling flow path 22 and the first member 41 and the closing member 42 move together. However, the proximal end of the closing member 42 is cooled. The first member 41 and the second member 43 may be integrally moved while being supported rotatably in the flow path 22.

  FIGS. 5A and 5B are schematic views showing the main part of a power control apparatus 10E according to a modification. In addition, in order to avoid duplication description, the same code | symbol is attached | subjected about the structure same as the structure of the power control apparatus 10 of the above-mentioned Example among the structures of the power control apparatus 10E, and the detailed description is abbreviate | omitted. In the power control device 10D shown in the figure, the cooling flow path 22 is divided into three passages 22a, 22b, and 22c that extend in the refrigerant flow direction. The power control device 10 </ b> D includes a flow rate changing mechanism 50. The flow rate changing mechanism 50 includes a valve body 51 that can close the passage 22b, a thermal expansion material 52 that has one end fixed to the valve body 51 and that thermally expands in response to an increase in the temperature of the refrigerant, and the valve body 51 includes the passage 22b. And a fixing member 53 that fixes the other end of the thermal expansion material 52 in the cooling flow path 22 so as to be separated from the inlet. Here, the thermal expansion material 52 is formed of, for example, a metal material such as aluminum or magnesium, similarly to the thermal expansion material 23 of the power control device 10 described above. It is linearly expanded.

  In the power control device 10E configured as described above, when the amount of heat generated by the element 21 is relatively small, the temperature of the refrigerant flowing in the vicinity of the substrates 15a and 15b does not increase so much. The valve body 51 is kept away from the inlet of the passage 22b. On the other hand, when the temperature of the refrigerant flowing in the vicinity of the substrates 15a and 15b rises as the element 21 generates heat, the thermal expansion material 52 thermally expands and applies force to the valve body 51 in the same direction as the refrigerant flow. . As shown in FIG. 5B, the valve body 51 receiving the force from the thermal expansion material 52 moves to the inlet of the passage 22b and finally closes the passage 22b. As a result, the flow path cross-sectional area of the cooling flow path 22 decreases and the flow rate flowing through the passages 22a and 22c increases, so the flow rate of the refrigerant flowing near the substrates 15a and 15b increases. Further, when the element 21 is cooled and cooled, the temperature of the refrigerant flowing in the vicinity of the substrates 15a and 15b does not increase so much, so that the thermal expansion material 52 is in the state before thermal expansion shown in FIG. 5B, the valve body 51 is opened as shown in FIG. 5A, the passage 22b is opened, and the flow path cross-sectional area and the flow velocity of the refrigerant in the vicinity of the substrates 15a and 15b in the cooling flow path 22 are obtained. Is substantially the same as that before the thermal expansion of the thermal expansion material 52. Therefore, the electric power of the modified example in which the flow velocity changing mechanism 50 that reduces the cross-sectional area of the cooling flow path 22 using the thermal expansion material 52 that thermally expands in response to the temperature rise of the refrigerant is disposed in the cooling flow path 22. In the control device 10E, the same effect as that of the power control device 10 and the like described above can be obtained.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention is applicable to the power control device manufacturing industry.

  10 Power control device, 15a, 15b Substrate, 20 Cooling pipe, 21 Element, 22 Cooling flow path, 22a, 22b, 22c Passage, 23, 24, 33a, 33b, 44, 52 Thermal expansion material, 24a Bag body, 24b Heat Expansion fluid, 30, 40, 50 Flow rate changing mechanism, 31, 32 Movable member, 34, 45, 53 Fixed member, 41 First member, 42 Closure member, 43 Second member, 51 Valve body.

Claims (1)

At least one substrate on which a plurality of power control elements are mounted and a cooling flow connected to the coolant supply source and provided near the substrate so as to allow heat exchange between the coolant and the device A power control device comprising a road,
The cooling channel contains a thermal expansion material, and the thermal expansion of the thermal expansion material is used to change the flow rate of the refrigerant in the previous cooling channel without changing the flow rate of the refrigerant from the supply source. A power control device in which a flow velocity changing means for increasing is arranged.

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