Power conversion device

Abstract

To provide a power conversion device in which a temperature difference between semiconductor elements located at different height positions is reduced.SOLUTION: A power conversion device 1 includes a plurality of semiconductor elements 11 and heat sinks 13. Each heat sink 13 has a heat reception plate 12, a plurality of heat pipes 21 provided on the heat reception plate, and a plurality of fin plates 22 provided on the plurality of heat pipes. The plurality of heat sinks 13 are arranged in a vertical direction. At least a part of the plurality of fin plates of upper-side heat sinks among the plurality of heat sinks is disposed in positions not overlapped with the plurality of fin plates of heat sinks below the upper-side heat sinks in the vertical direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to a power conversion device. [Background technology]

[0002] A technology using a power conversion device in a railway vehicle or the like is known. Such a power conversion device is composed of semiconductor elements, a cooler for cooling the semiconductor elements, and other electrical equipment. Coolers are broadly classified into forced circulation liquid cooling systems using pumps or the like, forced air cooling systems using fans or blowers, and natural air cooling systems using only a heat sink. When selecting a cooling system, natural air cooling systems are often preferred from the viewpoints of low cost, low noise, energy saving, and maintenance-free operation.

[0003] For example, in a power conversion device that uses multiple semiconductor devices, a natural-cooling cooler includes a heat receiving plate on which the semiconductor devices are mounted, a heat pipe mounted on the heat receiving plate, and a heat sink with multiple plate-shaped fins mounted on the heat pipe. The natural-cooling cooler dissipates heat generated by the semiconductor devices through the fins of the heat sink. At this time, the heat dissipation from the fins increases the ambient temperature around the fins, creating an upward air current, allowing for efficient heat dissipation from the fins.

[0004] In such power converters, it is necessary to minimize the temperature difference between the semiconductor elements. However, in power converters using natural air-cooling coolers, the heat sinks are arranged vertically, so the upper heat sinks are cooled by air warmed by the heat dissipation from the lower heat sinks. Therefore, in a power converter, the temperature rise of the semiconductor elements increases toward the top, which can lead to a temperature difference between the upper and lower semiconductor elements. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-86742 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a power conversion device that can reduce the temperature difference between semiconductor elements located at different heights. [Means for solving the problem]

[0007] The power conversion device includes a plurality of semiconductor elements and a plurality of heat sinks. The heat sink includes a heat receiving plate, a heat pipe provided on the heat receiving plate, and a plurality of plate-shaped fin plates provided on the heat pipe. The plurality of heat sinks are arranged in the vertical direction. At least some of the fin plates of an upper heat sink among the plurality of heat sinks are arranged in positions that do not overlap in the vertical direction with the fin plates of a lower heat sink of the upper heat sink. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view schematically showing the configuration of a power conversion device according to a first embodiment. [Figure 2] FIG. 10 is a perspective view schematically showing the configuration of a power conversion device according to a second embodiment. [Figure 3] FIG. 10 is a perspective view schematically showing the configuration of a power conversion device according to a third embodiment. [Figure 4] FIG. 10 is a perspective view schematically showing the configuration of a power conversion device according to a fourth embodiment. [Figure 5] FIG. 10 is a perspective view schematically showing the configuration of a power conversion device according to a fifth embodiment. [Figure 6] FIG. 10 is a perspective view schematically showing the configuration of a power conversion device according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The configuration of a power conversion device 1 according to an embodiment will be described below with reference to Fig. 1. Fig. 1 is a perspective view that schematically shows the configuration of a power conversion device 1 according to a first embodiment.

[0010] The power conversion device 1 is used, for example, in railway vehicles such as electric locomotives, etc. The power conversion device 1 converts DC power supplied from an overhead line via a pantograph, for example, into AC power.

[0011] 1, the power conversion device 1 includes a plurality of semiconductor elements 11 and a plurality of heat sinks 13. The plurality of heat sinks 13 of the power conversion device 1 form a natural air-cooling type cooler that cools the plurality of semiconductor elements 11.

[0012] One or more semiconductor elements 11 are arranged on each heat receiving plate 12. Preferably, multiple semiconductor elements 11 are arranged on each heat receiving plate 12 so that the temperature difference between the multiple heat receiving plates 12 due to the heat generated by the semiconductor elements 11 arranged on each heat receiving plate 12 is uniform. The heat sinks 13 are arranged in a vertical line and each include a heat receiving plate 12, a heat pipe 21, and a plurality of fin plates 22 fixed to the heat pipes 21.

[0013] The heat receiving plates 12 are arranged in a vertical direction. In this embodiment, the vertical direction is the direction along the direction of gravity, in other words, the up-down direction. In this embodiment, three heat receiving plates 12 are provided. The heat receiving plates 12 are arranged in the railway vehicle with the pair of main surfaces with the largest areas of the heat receiving plates 12 aligned along the vertical direction. One or more semiconductor elements 11 are fixed to one of the main surfaces of the heat receiving plates 12.

[0014] The heat pipes 21 are arranged in a row at predetermined intervals, for example, in the vertical direction and in the horizontal direction perpendicular to the vertical direction. The heat pipes 21 are formed, for example, in the shape of a cylinder extending in one direction and closed at both ends. The heat pipes 21 extend in a direction perpendicular to the main surface direction (vertical direction) of the heat reception plate 12, and one end is fixed integrally to the heat reception plate 12.

[0015] The heat pipe 21 is, for example, a sealed container with a capillary structure on the inner wall, and a working fluid is sealed in the internal space. When one end of the heat pipe 21 is heated, the working fluid evaporates, and the evaporated working fluid moves to the low-temperature section at the other end and condenses. The condensed working fluid then flows back to the one end via the capillary structure.

[0016] The fin plate 22 is fixed to the heat pipe 21 with the main surface of the fin plate 22 aligned in a direction perpendicular to the extension direction of the heat pipe 21. In other words, the fin plate 22 is fixed to the heat pipe 21 aligned along the heat reception plate 12. The multiple fin plates 22 are fixed at predetermined intervals to the ends of the multiple heat pipes 21 opposite to the ends to which the heat reception plate 12 is fixed. For example, the multiple fin plates 22 are arranged at equal intervals. The number of multiple fin plates 22 provided on each of the multiple heat sinks 13 may be the same or different.

[0017] In the multiple heat sinks 13 thus configured and arranged in the vertical direction, at least some of the multiple fin plates 22 of the upper heat sink 13 among the adjacent heat sinks 13 are positioned so as not to overlap vertically with the multiple fin plates 22 of the heat sink 13 located adjacent to the lower side of the upper heat sink 13.

[0018] Next, we will explain a specific example of the power conversion device 1. As shown in Fig. 1, the power conversion device 1 includes three heat sinks 13 arranged side by side in the vertical direction. A plurality of semiconductor elements 11 are fixed to each heat receiving plate 12 of the heat sink 13.

[0019] Hereinafter, of the three heat sinks 13 arranged vertically, the heat sink 13 located at the top in the vertical direction will be referred to as the upper heat sink 13, the heat sink 13 located at the bottom in the vertical direction will be referred to as the lower heat sink 13, and the heat sink 13 located in the center in the vertical direction, i.e., below the upper heat sink 13 and above the lower heat sink 13, will be referred to as the center heat sink 13.

[0020] 1, the three heat sinks 13 are arranged in positions in the vertical direction such that the fin plates 22 do not overlap. The fin plates 22 of the upper heat sink 13 are closer to the heat receiving plate 12 than the fin plates 22 of the central heat sink 13 and the fin plates 22 of the lower heat sink 13. The fin plates 22 of the lower heat sink 13 are farther from the heat receiving plate 12 than the fin plates 22 of the upper heat sink 13 and the fin plates 22 of the central heat sink 13. For example, the three heat sinks 13 each have the same number of fin plates 22.

[0021] According to the power conversion device 1 configured in this manner, the installation position of the fin plate 22 installed on the heat sink 13 differs depending on the vertical position of the heat sink 13, thereby reducing the impact of the rise in ambient temperature caused by the lower heat sink 13 on the upper heat sink 13.

[0022] Specifically, when the semiconductor element 11 generates heat, the heat sink 13 transfers the heat from the semiconductor element 11 to the multiple fin plates 22 via the heat receiving plate 12 and the multiple heat pipes 21, and then dissipates the heat at the multiple fin plates 22. At this time, an ascending air current is generated at the multiple fin plates 22, causing air to flow from below the multiple fin plates 22 to above. However, the central heat sink 13 and the upper heat sink 13 are positioned offset from the lower heat sink 13. This prevents the air heated by the lower heat sink 13 from moving to the central heat sink 13 and the upper heat sink 13 located above. This allows each heat sink 13 to achieve optimal cooling performance without being affected by the heat of the lower heat sink 13. In other words, the difference in cooling performance among the multiple heat sinks 13 depending on their vertical position can be reduced.

[0023] Therefore, even if the power conversion device 1 has multiple heat sinks 13 arranged vertically as a natural air-cooling type cooler, it can reduce the temperature of the semiconductor element 11 located at the top and can also reduce the temperature difference between the semiconductor elements 11 provided on the heat receiving plates 12 at different heights.

[0024] As described above, the power conversion device 1 according to the first embodiment can reduce the temperature of the upper semiconductor element 11 and can also reduce the temperature difference between the semiconductor elements 11 mounted on the heat receiving plate 12 at different positions in the height direction.

[0025] The power converter 1 is not limited to the above-described embodiment. That is, the power converter 1 may be configured such that the fin plates 22 of adjacent heat sinks 13 at different heights are arranged in positions where at least a portion of the fin plates 22 do not overlap. Examples of power converters 1 according to other embodiments will be described below with reference to Figs. 2 to 6.

[0026] Fig. 2 is a perspective view schematically showing the configuration of a power conversion device 1 according to a second embodiment. As shown in Fig. 2, the power conversion device 1 includes a plurality of semiconductor elements 11 and three heat sinks 13. Each of the three heat sinks 13 includes a heat receiving plate 12, a heat pipe 21, and the same number of fin plates 22. Adjacent heat sinks 13 are arranged in positions where the fin plates 22 partially overlap in the vertical direction, i.e., where the fin plates 22 partially overlap in the extension direction of the heat pipes 21.

[0027] In the power conversion device 1 of the second embodiment configured in this manner, since some of the multiple fin plates 22 adjacent to each other above and below do not overlap, the impact of the rise in ambient temperature caused by the lower heat sink 13 in the vertical direction on the upper heat sink 13 can be reduced.

[0028] The power conversion device 1 according to the second embodiment described above can reduce the temperature of the upper semiconductor element 11 and can also reduce the temperature difference between semiconductor elements 11 located at different heights.

[0029] FIG. 3 is a perspective view schematically illustrating the configuration of a power conversion device 1 according to a third embodiment. As shown in FIG. 3, the power conversion device 1 includes a plurality of semiconductor elements 11 and three heat sinks 13. Each of the three heat sinks 13 includes a heat receiving plate 12, a heat pipe 21, and a plurality of fin plates 22, each having a different number. For example, the upper heat sink 13 has the greatest number of fin plates 22, and the lower heat sink 13 has the fewest number of fin plates 22. In other words, the three heat sinks 13 have different numbers of fin plates 22, with the number decreasing from the upper heat sink 13 to the lower heat sink 13.

[0030] Furthermore, some of the multiple fin plates 22 of the upper heat sink 13 are arranged in positions that overlap, in the vertical direction, with all of the multiple fin plates 22 of the central heat sink 13. Furthermore, the multiple fin plates 22 of the lower heat sink 13 are arranged in positions that do not overlap, in the vertical direction, with the multiple fin plates 22 of the central heat sink 13, and overlap with some of the multiple fin plates 22 of the upper heat sink 13.

[0031] That is, the multiple fin plates 22 of the upper heat sink 13 are arranged in positions where they overlap with the multiple fin plates 22 of the central heat sink 13 and the multiple fin plates 22 of the lower heat sink 13, but the fin plates 22 of the central heat sink 13 are not arranged between the multiple fin plates 22 of the lower heat sink 13. In addition, the multiple fin plates 22 of the central heat sink 13 are arranged closer to the heat receiving plate 12 than the multiple fin plates 22 of the lower heat sink 13.

[0032] In the power conversion device 1 according to the third embodiment configured as described above, the upper heat sink 13 has the greatest number of fin plates 22, and the lower the heat sink 13, the fewer the number of fin plates 22. Therefore, the cooling performance of the upper heat sink 13 is higher than that of the central heat sink 13 and the lower heat sink 13.

[0033] Furthermore, the distances between the multiple fin plates 22 of the central heat sink 13 and the multiple fin plates 22 of the lower heat sink 13 and the multiple fin plates 22 of the upper heat sink 13 are different. That is, some of the multiple fin plates 22 of the upper heat sink 13 are not adjacent to the multiple fin plates 22 of the adjacent central heat sink 13, but overlap with the multiple fin plates 22 of the lower heat sink 13 in the vertical direction with a gap between them. This reduces the effect of an ambient temperature rise caused by a lower heat sink 13 on the heat sink 13 above it in the vertical direction.

[0034] The power conversion device 1 according to the third embodiment described above can reduce the temperature of the upper semiconductor element 11 and can also reduce the temperature difference between semiconductor elements 11 located at different heights.

[0035] FIG. 4 is a perspective view schematically illustrating the configuration of a power conversion device 1 according to a fourth embodiment. As shown in FIG. 4, the power conversion device 1 includes a plurality of semiconductor elements 11 and three heat sinks 13. Each of the three heat sinks 13 includes a heat receiving plate 12, a heat pipe 21, and a different number of fin plates 22. For example, the upper heat sink 13 has the greatest number of fin plates 22, and the lower the heat sink 13, the fewer the number of fin plates 22. That is, the three heat sinks 13 have different numbers of fin plates 22, decreasing from the upper heat sink 13 to the lower heat sink 13. The three heat sinks 13 are positioned so that the fin plates 22 do not overlap in the vertical direction.

[0036] In the power conversion device 1 according to the fourth embodiment configured as described above, the fin plates 22 adjacent to each other in the vertical direction do not overlap, so that it is possible to reduce the influence of an ambient temperature rise caused by a lower heat sink 13 in the vertical direction on the upper heat sink 13. Furthermore, by increasing the number of fin plates 22 of the upper heat sink 13 where the ambient temperature is relatively high, it is possible to improve the cooling performance of the fin plates 22 of the upper heat sink 13.

[0037] The power conversion device 1 according to the fourth embodiment described above can reduce the temperature of the upper semiconductor element 11 and can also reduce the temperature difference between the semiconductor elements 11 located at different heights.

[0038] FIG. 5 is a perspective view schematically illustrating the configuration of a power conversion device 1 according to a fifth embodiment. As shown in FIG. 5, the power conversion device 1 includes a plurality of semiconductor elements 11 and three heat sinks 13. Each of the three heat sinks 13 includes a heat receiving plate 12, a heat pipe 21, and a plurality of fin plates 22, each having a different number. For example, the upper heat sink 13 has the greatest number of fin plates 22, and the lower heat sink 13 has the fewest number of fin plates 22. That is, the three heat sinks 13 have different numbers of fin plates 22, with the number decreasing from the upper heat sink 13 to the lower heat sink 13.

[0039] Furthermore, some of the fin plates 22 of the upper heat sink 13 overlap all of the fin plates 22 of the central heat sink 13, and some of the fin plates 22 of the middle heat sink 13 overlap all of the fin plates 22 of the lower heat sink 13. For example, in three heat sinks 13, the fin plates 22 overlap in the vertical direction at the end of the heat pipe 21 opposite the heat receiving plate 12.

[0040] In the power conversion device 1 according to the fifth embodiment configured as described above, the upper heat sink 13 has the greatest number of fin plates 22, and the lower the heat sink 13, the fewer the number of fin plates 22. Therefore, the cooling performance of the upper heat sink 13 is higher than that of the central heat sink 13 and the lower heat sink 13.

[0041] Furthermore, the upper heat sink 13 and the central heat sink 13 have a plurality of fin plates 22 that do not partially overlap with the plurality of fin plates 22 of other heat sinks 13. This reduces the effect of an ambient temperature rise caused by a lower heat sink 13 in the vertical direction on the heat sink 13 above.

[0042] The power conversion device 1 according to the fifth embodiment described above can reduce the temperature of the upper semiconductor element 11 and can also reduce the temperature difference between the semiconductor elements 11 located at different heights.

[0043] FIG. 6 is a perspective view schematically illustrating the configuration of a power converter 1 according to a sixth embodiment. As shown in FIG. 6, the power converter 1 includes a plurality of semiconductor elements 11 and three heat sinks 13. Each of the three heat sinks 13 includes a heat receiving plate 12, a heat pipe 21, and a different number of fin plates 22. For example, the upper heat sink 13 has the greatest number of fin plates 22, and the lower the heat sink 13, the fewer the number of fin plates 22. That is, the three heat sinks 13 have different numbers of fin plates 22, decreasing from the upper heat sink 13 to the lower heat sink 13. The three heat sinks 13 are arranged such that some of the fin plates 22 overlap vertically.

[0044] In the power conversion device 1 according to the sixth embodiment configured as described above, the fin plates 22 adjacent to each other in the vertical direction do not partially overlap, which reduces the effect of an ambient temperature rise caused by a lower heat sink 13 on the upper heat sink 13 in the vertical direction. Furthermore, by increasing the number of fin plates 22 of the upper heat sink 13 where the ambient temperature is relatively high, the cooling performance of the fin plates 22 of the upper heat sink 13 can be improved.

[0045] The power conversion device 1 according to the sixth embodiment described above can reduce the temperature of the upper semiconductor element 11 and can also reduce the temperature difference between the semiconductor elements 11 located at different heights.

[0046] Furthermore, the power conversion device 1 is not limited to the several embodiments described above. For example, the power conversion device 1 according to the first, second, fourth, and sixth embodiments described above may be used in an upside-down position.

[0047] In the above example, the power conversion device 1 is configured to have three heat sinks 13, but the number of heat sinks 13 is not limited to three. That is, the number of heat sinks 13 can be set appropriately as long as it is two or more.

[0048] It is also possible to use a combination of a plurality of the above-described power conversion devices 1. For example, when a plurality of power conversion devices 1 are used, it is preferable to use them arranged side by side in the horizontal direction.

[0049] In addition, in order to improve the cooling performance of the upper heat sink 13, the power conversion device 1 of the above-mentioned third embodiment may be configured so that the number of fin plates 22 is increased and the fin plate 22 at the tip side of the heat pipe 21 does not overlap with the fin plate 22 of the lower heat sink 13 in the vertical direction.

[0050] Furthermore, by appropriately selecting or combining the techniques of the above-described multiple embodiments, the power conversion device 1 can adjust the cooling performance of the multiple heat sinks 13 at different height positions based on the heat generation amount of the semiconductor elements 11 provided on the heat receiving plates 12 at different height positions. That is, the power conversion device 1 can set the cooling performance of the heat sink 13 suitable for the semiconductor elements 11 by appropriately setting the number of fin plates 22 of the heat sink 13, whether or not the fin plates 22 overlap in the vertical direction (height direction) of the multiple heat sinks 13, and the number of overlapping fin plates 22, thereby reducing the temperature difference between the semiconductor elements 11 at different height positions.

[0051] Any of the power conversion devices configured as described above can reduce the temperature difference between semiconductor elements located at different heights.

[0052] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0053] 1...power conversion device, 11...semiconductor element, 12...heat receiving plate, 13...heat sink, 21...heat pipe, 22...fin plate

Claims

1. A plurality of semiconductor elements; a plurality of heat sinks arranged in the vertical direction, each heat sink having a plurality of heat receiving plates arranged in the vertical direction on which the semiconductor elements are provided, a heat pipe provided on the heat receiving plate, and a plurality of plate-shaped fin plates provided on the heat pipe; Equipped with A power conversion device in which at least some of the fin plates of the upper heat sink among the plurality of heat sinks are positioned in a position that does not overlap in the vertical direction with the fin plates of the lower heat sink of the upper heat sink.

2. The power conversion device according to claim 1 , wherein none of the plurality of fin plates of the heat sink on the upper side overlaps with the plurality of fin plates of the heat sink on the lower side in the vertical direction.

3. The power conversion device according to claim 1 , wherein some of the fin plates of the upper heat sink overlap some or all of the fin plates of the lower heat sink in the vertical direction.

4. The power conversion device according to claim 1 , wherein the plurality of heat sinks have the same number of the plurality of fin plates.

5. The power conversion device according to claim 1 , wherein the plurality of heat sinks have different numbers of the plurality of fin plates.

6. The power conversion device according to claim 5 , wherein the number of the plurality of fin plates of the heat sink on the upper side is greater than the number of the plurality of fin plates of the heat sink on the lower side.

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