ELECTRONIC DEVICE WITH A CAPACITOR UNIT
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- MITSUBISHI ELECTRIC CORP
- Filing Date
- 2021-05-10
- Publication Date
- 2026-07-23
Smart Images
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Abstract
Description
Technical area
[0001] The present disclosure relates to a capacitor unit and an electronic device. Technological background
[0002] Electronic devices, such as power conversion devices that convert input power and supply the resulting power to a load, may include a capacitor unit with a large capacitance. Patent Literature 1 describes an example of such an electronic device. A vehicle drive controller described in Patent Literature 1 includes a capacitor unit installed in the center of a housing for smoothing power. Citation listPatent literature
[0003] Patent Literature 1: Unexamined Japanese Patent Application Publication No. 2013-163503 Summary of the inventionTechnical problem
[0004] Heat generated in the capacitor unit during power supply is dissipated into the air inside the electronic device housing. In addition to the capacitor unit, the electronic device housing houses heating elements, such as switching elements, which can increase the temperature of the air inside the housing. The large-capacity capacitor unit generates a large amount of heat and thus may not be sufficiently cooled due to the rising temperature inside the housing. This could increase the internal temperature of the capacitor unit, or more specifically, the temperature of the capacitor elements within the capacitor unit.
[0005] If a capacitor element is a film capacitor, the film for the capacitor element should have an allowable temperature that is higher than the maximum temperature achievable by the capacitor element. The temperature of the capacitor element rises when a large amount of current flows through the capacitor element. This could limit the amount of current flowing through the capacitor elements if the allowable temperature of the film is not sufficiently high. In other words, this means that the capacitor unit could have design limitations, including the allowable temperature of the film in the capacitor elements and the current flowing through the capacitor elements, due to a temperature rise in the capacitor elements housed in the package.This is not limited to power supply devices including a large capacity capacitor unit, but could occur in any electronic devices including a capacitor unit that might fail to sufficiently cool the capacitor unit.
[0006] In response to the above circumstances, it is an object of the present disclosure to provide a capacitor unit and an electronic device including the capacitor unit having a smaller temperature rise in capacitor elements. Solution to the problem
[0007] To achieve the above-mentioned object, a condenser unit according to one aspect of the present disclosure comprises a plurality of condenser elements and one or more heat transfer members. The one or more heat transfer members are located adjacent to at least one condenser element of the plurality of condenser elements. The one or more heat transfer members internally dissipate heat absorbed by at least one condenser element of the plurality of condenser elements. Advantageous effects of the invention
[0008] The condenser unit according to the above-mentioned aspect of the present disclosure allows heat generated in the plurality of condenser elements to be dissipated within the heat transfer members. The condenser elements are thus cooled, resulting in a smaller temperature rise. Short description of the drawings Fig. 1 illustrates a block diagram of an electronic device according to an embodiment; Fig. 2 illustrates a front view of a capacitor unit according to the embodiment; Fig. Figure 3 is a cross-sectional view of the capacitor unit according to the embodiment taken along a line III-III when viewed in the direction indicated by the arrows in Fig. 2 is specified; Fig. 4 is a diagram of a capacitor element in the embodiment; Fig. 5 illustrates a cross-sectional view of the capacitor unit according to the embodiment; Fig. 6 illustrates a rear view of the capacitor unit according to the embodiment; Fig. 7 illustrates a cross-sectional view of the electronic device according to the embodiment; Fig. 8 is a front view of a capacitor unit according to a first modification of the embodiment; Fig. 9 is a plan view of a capacitor unit according to a second modification of the embodiment; and Fig. 10 illustrates a cross-sectional view of an electronic device according to a modification of the embodiment. Description of the embodiments
[0009] A capacitor unit and an electronic device according to one or more embodiments of the present disclosure are described in detail below with reference to the drawings. In the figures, the same reference numerals denote the same or equivalent components.
[0010] Examples of the electronic device include a power conversion device mounted on a railway vehicle, which converts direct current (DC) power supplied from a DC power source into three-phase alternating current (AC) power and supplies the AC power to an electric motor. An electronic device 1 according to Embodiment 1 is described below using the power conversion device as an example.
[0011] The electronic device 1, which is Fig. 1 receives DC power from a power source not illustrated, or more specifically, from a current collector that receives power supplied from a substation through a power supply line. The power supply line is, for example, an overhead line or a third rail. The current collector is, for example, a stork's beak or a bus shoe. The electronic device 1 converts the DC power supplied from the current collector into three-phase AC power and supplies the three-phase AC power resulting from the conversion to a load 51. In the embodiment, the electronic device 1 is a three-level inverter, and the load 51 is a three-phase induction motor.
[0012] The electronic device 1 includes a positive terminal 1a connected to the current collector, a negative terminal 1b grounded, a capacitor unit 11 charged with power supplied from the current collector, and a power converter 12 that converts DC power supplied from the current collector through the capacitor unit 11 into three-phase AC power. Preferably, the positive terminal 1a is electrically connected to the current collector with, for example, a contactor or a filter reactor. The capacitor unit 11 includes a first capacitor C1 and a second capacitor C2. The first capacitor C1 and the second capacitor C2 are connected in series.
[0013] The power converter 12 includes a pair of primary terminals electrically connected to the positive terminal 1a and the negative terminal 1b. A terminal between the pair of primary terminals is connected to a connection point between the first capacitor C1 and the second capacitor C2, which are connected in series. The power converter 12 includes three secondary terminals corresponding to the U, V, and W phases of the three-phase AC power and is connected to the corresponding input terminals of the load 51. The power converter 12 includes a plurality of switching elements controlled by a controller (not shown). The switching elements are, for example, insulated-gate bipolar transistors (IGBTs). The power converter 12 converts power through a switching operation controlled by the controller, which switches the switching elements between on and off.More specifically, this means that the power converter 12 converts the DC power input through the primary terminals into three-phase AC power to be supplied to the load 51 and outputs the three-phase AC power through the secondary terminals.
[0014] The condenser unit 11 with a smaller internal temperature rise is described below. As shown in the Fig. 2 and in the Fig. 3, which is a cross-sectional view along a line III-III in Fig. 2, the condenser unit 11 comprises a plurality of condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d and heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c that internally dissipate heat absorbed by the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d. The internal temperature of the condenser unit 11 refers more specifically to the temperature of each of the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d. Fig. 2 and Fig. 3, a Z-axis represents a vertical direction, and a Y-axis extends parallel to major surfaces of the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d. An X-axis is orthogonal to the Y and Z axes.
[0015] The capacitor unit 11 further includes a first busbar 23a electrically connected to the positive electrodes of the capacitor elements 21a, 21b, 21c, and 21d, and a first busbar 33a electrically connected to the positive electrodes of the capacitor elements 31a, 31b, 31c, and 31d. The first busbars 23a and 33a are plates made of a conductive material, such as copper or aluminum.
[0016] The capacitor unit 11 further includes a second bus bar 23b electrically connected to the negative electrodes of the capacitor elements 21a, 21b, 21c, and 21d, and a second bus bar 33b electrically connected to the negative electrodes of the capacitor elements 31a, 31b, 31c, and 31d. The second bus bars 23b and 33b are plates made of a conductive material, such as copper or aluminum. The capacitor unit 11 further includes a first terminal 24a electrically connected to the first bus bar 23a, a first terminal 34a electrically connected to the first bus bar 33a, a second terminal 24b electrically connected to the second bus bar 23b, and a second terminal 34b electrically connected to the second bus bar 33b.
[0017] The condenser unit 11 further comprises an insulating member 25 which at least partially covers the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c and 31d, and the heat transfer members 22a, 22b, 22c, 32a, 32b and 32c.
[0018] The components of the capacitor unit 11 are described in detail below. As in Fig. As illustrated in Figure 2, the capacitor elements 21a, 21b, 21c, and 21d are arranged in a row with the main surfaces facing each other. More specifically, this means that the capacitor elements 21a, 21b, 21c, and 21d are arranged in an X-direction with the main surfaces facing orthogonal to the X-axis. Similarly, the capacitor elements 31a, 31b, 31c, and 31d are arranged in a row with the main surfaces facing each other. More specifically, this means that the capacitor elements 31a, 31b, 31c, and 31d are arranged in an X-direction with the main surfaces facing in the direction orthogonal to the X-axes.
[0019] The capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d have the same structure. The structure of the capacitor element 21a will thus be described with reference to Fig. 4 described.
[0020] The capacitor element 21a is a film capacitor comprising a film 41c on which a positive electrode 41a is located, and a film 41d on which a negative electrode 41b is located. The films 41c and 41d overlap each other and are wound around the central axis to form the capacitor element 21a. The film 41c is a plastic film onto which a metal, such as aluminum or zinc, is evaporated to form the positive electrode 41a. Similarly, the film 41d is a plastic film onto which a metal, such as aluminum or zinc, is evaporated to form the negative electrode 41b.
[0021] The capacitor element 21a has one end as a positive terminal and the other end as a negative terminal in the direction along the central axis of the capacitor element 21a. In the example of Fig. 4, the capacitor element 21a has the upper end as the positive terminal and the lower end as the negative terminal. In the example of Fig. 2 and Fig. 3, the capacitor element 21a has the upper end in the Z direction as the positive terminal of the capacitor element 21a and the lower end in the Z direction as the negative terminal of the capacitor element 21a.
[0022] The heat transfer members 22a, 22b, 22c, 32a, 32b and 32c are each located adjacent to at least one of the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c and 31d to internally dissipate heat transferred from at least one of the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c and 31d.
[0023] The heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c are each preferably located between two of the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d that are adjacent to one another. Also, the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c are each preferably located adjacent to another of the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d.
[0024] In the embodiment, the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c are located between two of the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d that are adjacent to each other at different positions. Specifically, the heat transfer member 22a is located between the capacitor elements 21a and 21b to internally dissipate heat absorbed by the capacitor elements 21a and 21b. The heat transfer member 22b is located between the capacitor elements 21b and 21c to internally dissipate heat absorbed by the capacitor elements 21b and 21c. The heat transfer member 22c is located between the capacitor elements 21c and 21d to internally dissipate heat absorbed by the capacitor elements 21c and 21d.
[0025] Similarly, heat transfer member 32a is located between capacitor elements 31a and 31b to internally dissipate heat absorbed by capacitor elements 31a and 31b. Heat transfer member 32b is located between capacitor elements 31b and 31c to internally dissipate heat absorbed by capacitor elements 31b and 31c. Heat transfer member 32c is located between capacitor elements 31c and 31d to internally dissipate heat absorbed by capacitor elements 31c and 31d.
[0026] The heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c are each preferably a plate having at least one major surface in contact with at least one of the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d. Contacting here includes direct contact and indirect contact. In the embodiment, the heat transfer member 22a is a plate having one major surface in contact with the capacitor element 21a and the other major surface in contact with the capacitor element 21b. The heat transfer member 22b is a plate having one major surface in contact with the capacitor element 21b and the other major surface in contact with the capacitor element 21c. The heat transfer member 22c is a plate having one major surface in contact with the capacitor element 21c and the other major surface in contact with the capacitor element 21d.
[0027] Similarly, the heat transfer member 32a is a plate with one major surface in contact with the condenser element 31a and the other major surface in contact with the condenser element 31b. The heat transfer member 32b is a plate with one major surface in contact with the condenser element 31b and the other major surface in contact with the condenser element 31c. The heat transfer member 32c is a plate with one major surface in contact with the condenser element 31c and the other major surface in contact with the condenser element 31d.
[0028] The heat transfer member 22a, which is a plate in contact with the condenser elements 21a and 21b, allows heat from the condenser elements 21a and 21b to be transferred more efficiently to the heat transfer member 22a and the condenser elements 21a and 21b to be cooled more efficiently. The same applies to the heat transfer members 22b, 22c, 32a, 32b, and 32c. The condenser unit 11 thus has a smaller internal temperature rise.
[0029] The heat transfer members 22a, 22b, 22c, 32a, 32b and 32c could be formed from a highly thermally conductive material, or for example from a metal such as copper or aluminum.
[0030] As described above, the heat transfer members 22a, 22b, 22c, 32a, 32b and 32c enable heat generated in the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c and 31d to be transferred to the heat transfer members 22a, 22b, 22c, 32a, 32b and 32c and dissipated within the heat transfer members 22a, 22b, 22c, 32a, 32b and 32c. The heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c further increase the efficiency of heat transfer from the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d to the outer surface of the condenser unit 11, thereby reducing the temperature difference between the outer surface of the condenser unit 11 and the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d. Thus, the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d exhibit a smaller internal temperature rise, whereas the outer surface of the condenser unit 11 exhibits a temperature rise.
[0031] The heat dissipated within the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c as described above also allows the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d to exhibit smaller temperature fluctuations. In other words, this means that the maximum temperature of the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d is lower.
[0032] The first busbar 23a, which is in contact with the vertically upper ends of the capacitor elements 21a, 21b, 21c, and 21d, is electrically connected to the positive electrodes 41a of the capacitor elements 21a, 21b, 21c, and 21d. Similarly, the first busbar 33a, which is in contact with the vertically upper ends of the capacitor elements 31a, 31b, 31c, and 31d, is electrically connected to the positive electrodes 41a of the capacitor elements 31a, 31b, 31c, and 31d.
[0033] The second busbar 23b, which is in contact with the vertically lower ends of the capacitor elements 21a, 21b, 21c, and 21d, is electrically connected to the negative electrodes 41b of the capacitor elements 21a, 21b, 21c, and 21d. Similarly, the second busbar 33b, which is in contact with the vertically lower ends of the capacitor elements 31a, 31b, 31c, and 31d, is electrically connected to the negative electrodes 41b of the capacitor elements 31a, 31b, 31c, and 31d.
[0034] The first terminal 24a is attached to the first busbar 23a with an unillustrated fastening device while in contact with the first busbar 23a. This electrically connects the first terminal 24a to the first busbar 23a. The first terminal 34a is attached to the first busbar 33a with an unillustrated fastening device while in contact with the first busbar 33a. This electrically connects the first terminal 34a to the first busbar 33a.
[0035] Similarly, the second terminal 24b is attached to the second busbar 23b with an unillustrated fastener while in contact with the second busbar 23b. This electrically connects the second terminal 24b to the second busbar 23b. The second terminal 34b is attached to the second busbar 33b with an unillustrated fastener while in contact with the second busbar 33b. This electrically connects the second terminal 34b to the second busbar 33b.
[0036] The capacitor elements 21a, 21b, 21c, and 21d, the first bus bar 23a, the second bus bar 23b, the first terminal 24a, and the second terminal 24b described above are included in the first capacitor C1. The first terminal 24a serves as a positive terminal of the first capacitor C1. The second terminal 24b serves as a negative terminal of the first capacitor C1. The first terminal 24a is electrically connected to the positive terminal 1a and the power converter 12 with a bus bar (not shown). The second terminal 24b is electrically connected to the power converter 12 and the second capacitor C2 with a bus bar (not shown).
[0037] The capacitor elements 31a, 31b, 31c, and 31d, the first bus bar 33a, the second bus bar 33b, the first terminal 34a, and the second terminal 34b described above are included in the second capacitor C2. The first terminal 34a serves as a positive terminal of the second capacitor C2. The second terminal 34b serves as a negative terminal of the second capacitor C2. The first terminal 34a is electrically connected to the power converter 12 and the first capacitor C1 with a bus bar (not shown). The second terminal 34b is electrically connected to the negative terminal 1b and the power converter 12 with a bus bar (not shown).
[0038] The insulating member 25 is formed of a resin such as epoxy, urethane, or silicone. The insulating member 25 insulates the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d and the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c from each other. In the embodiment, the insulating member 25 at least partially covers the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d and the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c. In other words, the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d and the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c are at least partially encapsulated by the insulating member 25. This fixes the positions of the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c relative to the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d.
[0039] In the embodiment, the insulating member 25 covers the first busbars 23a and 33a and the second busbars 23b and 33b, and covers the first terminals 24a and 34a and the second terminals 24b and 34b, with the first terminals 24a and 34a and the second terminals 24b and 34b at least partially exposed. This fixes the positions of the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d, the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c, the first busbars 23a and 33a, the second busbars 23b and 33b, the first terminals 24a and 34a, and the second terminals 24b and 34b relative to each other. When the first terminals 24a and 34a and the second terminals 24b and 34b are at least partially exposed, the busbars can be electrically connected to the first terminals 24a and 34a and the second terminals 24b and 34b.
[0040] In order to form the insulating member 25 covering the components of the capacitor unit 11 as described above, an unillustrated case accommodating the components of the capacitor unit 11 is filled with, for example, an epoxy resin, and the cured resin is removed from the case.
[0041] To increase cooling performance, as in Fig. 5, the condenser unit 11 is preferably thermally connected to the heat transfer members 22a, 22b, 22c, 32a, 32b and 32c and further includes a cooling device 26 that dissipates heat transferred from the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c and 31d through the heat transfer members 22a, 22b, 22c, 32a, 32b and 32c. Fig. Figure 5 shows a cross-sectional view of the capacitor unit 11 along the same line as in Fig. 3.
[0042] The cooling device 26 includes a heat-absorbing block 27 thermally connected to the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c, and a heat dissipator 28 that dissipates heat transferred from the heat-absorbing block 27. The insulating member 25 is attached to one main surface 27a of the heat-absorbing block 27. The heat dissipator 28 is attached to the other main surface 27b of the heat-absorbing block 27. The heat-absorbing block 27, which is thermally connected to the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c, allows heat to be transferred from the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d to the heat-absorbing block 27 through the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c. The heat-absorbing block 27 is preferably formed from a highly thermally conductive material, such as a metal such as copper or aluminum.
[0043] The heat-absorbing block 27 is preferably in contact with the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c. In the embodiment, the insulating member 25 covers the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c, exposing the end surfaces of the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c that are closer to the cooling device 26. The insulating member 25 is attached to the cooling device 26, with the end surfaces of the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c in direct contact with the cooling device 26. The insulating member 25 is attached to the heat-absorbing block 27 in the cooling device 26 with, for example, a fastening device not shown.
[0044] The heat-absorbing block 27, which is in contact with the end surfaces of the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c, allows heat from the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c to be transferred directly to the heat-absorbing block 27, thereby increasing heat transfer efficiency. This allows the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d to be cooled more efficiently. The condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d can thus exhibit a smaller temperature rise.
[0045] The heat dissipation device 28 dissipates heat transferred from the heat-absorbing block 27 to ambient air. Heat transferred from the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d to the heat-absorbing block 27 through the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c is dissipated by the heat dissipation device 28 to ambient air to cool the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d. In the embodiment shown in Fig. As illustrated in Figure 6, the heat dissipation device 28 comprises a plurality of fins having main surfaces parallel to a YZ plane. More specifically, this means that the heat dissipation device 28 is preferably formed from a highly thermally conductive material, for example, a metal, such as copper or aluminum.
[0046] As in Fig. As illustrated in Figure 7, the electronic device 1 accommodates the capacitor unit 11 having the above-mentioned structure and the power converter 12 within a housing. More specifically, this means that the electronic device 1 comprises a housing 13 that accommodates the capacitor unit 11 and the power converter 12, and a power converter cooling device 14 that cools the power converter 12. To simplify the illustration of the components of the power converter 12, Fig. 7 illustrates several switching elements SW alone and does not illustrate other components of the power converter 12, such as the positive terminal 1a, the negative terminal 1b, busbars connected to the positive terminal 1a and the negative terminal 1b, and terminals and busbars connected to the load 51.
[0047] The components of the electronic device 1 are described in detail below. The housing 13 has openings 13a and 13b. In the embodiment, the openings 13a and 13b are located in different areas.
[0048] The condenser unit 11 is housed in the housing 13. The cooling device 26 in the condenser unit 11 closes the opening 13a, with a portion of the cooling device 26 being exposed outside the housing 13 through the opening 13a. When the opening 13a is closed with a portion of the cooling device 26, air outside the housing 13 containing dust, moisture, and other foreign matter is less likely to flow into the housing 13 through the opening 13a. More specifically, this means that the heat-absorbing block 27 closes the opening 13a from inside the housing 13, with the heat-dissipating device 28 being exposed outside the housing 13. The heat-dissipating device 28, which is exposed outside the housing 13, thus dissipates heat transferred from the heat-absorbing block 27 to air outside the housing 13. The capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c and 31d are thus cooled.The temperature of air outside the housing 13 is lower than the temperature of the air inside the housing 13. The condenser unit 11 thus has a higher cooling capacity than a condenser unit that dissipates heat to air inside a housing.
[0049] The power converter cooling device 14 includes a heat-absorbing block 15 to which a plurality of switching elements SW are attached, and a heat-dissipating device 16 that dissipates heat transferred from the switching elements SW through the heat-absorbing block 15. The switching elements SW are attached to one main surface 15a of the heat-absorbing block 15, or more specifically, to the surface facing the interior of the housing 13. The power converter 12 includes, for example, six switching elements SW arranged two-dimensionally on the main surface 15a of the heat-absorbing block 15. The heat-dissipating device 16 is attached to the other main surface 15b of the heat-absorbing block 15, or more specifically, to the surface facing the exterior of the housing 13. The heat-absorbing block 15 is preferably formed of a highly thermally conductive material, for example, a metal such as copper or aluminum.
[0050] The power converter cooling device 14 having the above-mentioned structure is housed in the casing 13 to close the opening 13b, with a portion of the power converter cooling device 14 being exposed outside the casing 13 through the opening 13b. When the opening 13b is closed with a portion of the power converter cooling device 14, air outside the casing 13, which contains dust, moisture, and other foreign matter, is less likely to flow into the casing 13 through the opening 13b. Specifically, the heat-absorbing block 15 closes the opening 13b from inside the casing 13, with the heat dissipator 16 being exposed outside the casing 13. The heat dissipation device 16, which is exposed outside the housing 13, thus dissipates heat transferred from the switching elements SW through the heat-absorbing block 15 to an air outside the housing 13.The switching elements SW are thus cooled.
[0051] The heat dissipation device 16 comprises a plurality of fins having main surfaces parallel to an XY plane. The electronic device 1, which is mounted on a rail vehicle with a Y-axis aligned with the direction of travel of the rail vehicle, allows air to flow between the fins on the heat dissipation device 16 as the vehicle moves. The switching elements SW are thus cooled more efficiently.
[0052] A laminate busbar 17 electrically connects the capacitor unit 11 and the power converter 12. Specifically, the laminate busbar 17 includes a stack of insulating layers and a conductive layer for electrically connecting the first terminals 24a and 34a and the second terminals 24b and 34b to the corresponding switching elements SW. The laminate busbar 17 is attached to the first terminals 24a and 34a, the second terminals 24b and 34b, and the switching elements SW with fastening devices (not shown).
[0053] When electric power is supplied to the electronic device 1 having the above-mentioned structure, or more specifically, when the electronic device 1 is electrically connected to the current collector, a current flows into the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d, so that heat is generated in the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d. The heat generated in the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d is transferred to the heat-absorbing block 27 in the cooling device 26 through the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c. The heat transferred to the heat-absorbing block 27 is dissipated to air outside the housing 13 either through the heat dissipation device 28 attached to the heat-absorbing block 27 or through the housing 13 in contact with the heat-absorbing block 27.This cools the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c and 31d, and the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c and 31d have a smaller temperature rise.
[0054] During operation of the power converter 12, the switching elements SW generate heat when they are turned on and off. The heat generated in the switching elements SW is transferred to the heat-absorbing block 15. The heat transferred to the heat-absorbing block 15 is dissipated by the heat dissipation device 16 to the air outside the housing 13. The switching elements SW are thus cooled.
[0055] As described above, heat generated in the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d and in any of the switching elements SW is dissipated to the air outside the housing 13. The air inside the housing 13 thus experiences a smaller temperature rise. The capacitor unit 11 thus experiences a smaller internal temperature rise, and the switching elements SW also experience a smaller temperature rise.
[0056] In the condenser unit 11 according to the embodiment described above, heat generated in the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d is transferred to the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c and dissipated within the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c. This reduces the temperature difference between the outer surface of the condenser unit 11 and the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d. The capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c and 31d thus have a smaller temperature rise.
[0057] As described above, the heat dissipated within the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c also allows the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d to exhibit less temperature fluctuation. In other words, this means that the maximum temperature of the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d is lower.
[0058] For the condenser unit 11 including the cooling device 26, heat generated in the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d is transferred to the cooling device 26 through the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c and dissipated from the cooling device 26. This cools the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d more efficiently, and the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d exhibit an even smaller temperature rise.
[0059] The degree of deterioration of the films 41c and 41d depends on the temperature of the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d and on the potential gradient in the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d. Specifically, as the temperature or potential gradient in the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d increases, the service life of the films 41c and 41d decreases.
[0060] As described above, the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d, which exhibit a smaller temperature rise, can have a longer service life. The capacitor elements with substantially the same service life can have a higher potential gradient. In other words, this means that, with substantially the same service life, a larger voltage can be applied to the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d, or that the films 41c and 41d can be thinner. In other words, this means that the capacitor unit 11 has increased design freedom.
[0061] A larger voltage could be applied to the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d to increase the capacitance of the capacitor unit 11. The thinner films 41c and 41d can reduce the size of the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d, or in other words, the size of the capacitor unit 11.
[0062] Embodiments of the present disclosure are not limited to the embodiments described above.
[0063] The number of capacitor elements in the capacitor unit 11 is not limited to the number of capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d in the above example, but may be any number. In the embodiment, the capacitor unit 11 includes two capacitor groups, or the first capacitor C1 and the second capacitor C2, but it may include any number of capacitor groups. For example, the capacitor unit may include only the first capacitor C1, or it may include a third capacitor in addition to the first capacitor C1 and the second capacitor C2.
[0064] The structure of capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d is not limited to the structure in the example given above. In one example, capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d could be film capacitors made of a metal foil.
[0065] The heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c could be provided in any number and in any shape, allowing for the internal dissipation of heat generated in the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d. In one example, the condenser unit 11 could comprise a single flat plate heat transfer member. In another example, the condenser unit 11 could comprise rod-shaped heat transfer members 29a, 29b, 29c, 35a, 35b, and 35c, as shown in Fig. 8. The heat transfer members 29a, 29b, 29c, 35a, 35b, and 35c are each located adjacent to at least one of the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d to internally dissipate heat transferred from at least one of the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d. For the condenser unit 11 included in the cooling device 26, the heat transfer members 29a, 29b, 29c, 35a, 35b, and 35c transfer heat transferred from at least one of the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d to the cooling device 26.
[0066] The heat transfer members 29a, 29b, 29c, 35a, 35b, and 35c are each preferably located between two of the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d that are adjacent to one another. Also, the heat transfer members 29a, 29b, 29c, 35a, 35b, and 35c are preferably located adjacent to another of the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d.
[0067] As in Fig. 8, the heat transfer members 29a, 29b, 29c, 35a, 35b and 35c are preferably located between two of the condenser elements 21a, 21b, 21c, 21d, 31a, 31b, 31c and 31d that are adjacent to each other in different positions.
[0068] In another example, heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c could be U-shaped plates or U-shaped bars. In another example, heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c could be plates that include an internal channel containing a coolant. The same applies to heat transfer members 29a, 29b, 29c, 35a, 35b, and 35c.
[0069] The heat transfer members 22a, 22b, 22c, 32a, 32b, 32c, 29a, 29b, 29c, 35a, 35b, and 35c could be located differently than in the above examples. In one example, in addition to the positions described above, the heat transfer member could be adjacent to the capacitor element 21d alone, or more specifically, adjacent to the surface of the capacitor element 21d facing the positive X direction. In another example, the heat transfer member could be located between the first busbar 23a and the surface of the capacitor element 21a facing the negative X direction.
[0070] The heat transfer members 22a, 22b, 22c, 32a, 32b, 32c, 29a, 29b, 29c, 35a, 35b and 35c could be completely covered by the insulating member 25.
[0071] The heat transfer members 22a, 22b, 22c, 32a, 32b, 32c, 29a, 29b, 29c, 35a, 35b, and 35c could be in contact with the cooling device 26. In another example, a member that reduces thermal contact resistance, such as a heat-dissipating layer, grease, or other thermal interface material (TIM), could be located between the heat-absorbing block 27 in the cooling device 26 and the heat transfer members 22a, 22b, 22c, 32a, 32b, 32c, 29a, 29b, 29c, 35a, 35b, and 35c.
[0072] The material of the heat transfer members 22a, 22b, 22c, 32a, 32b, 32c, 29a, 29b, 29c, 35a, 35b, and 35c is not limited to metals, but could be any metal capable of internally dissipating heat. In one example, each of the heat transfer members 22a, 22b, 22c, 32a, 32b, 32c, 29a, 29b, 29c, 35a, 35b, and 35c could be an anisotropic heat transfer member formed, for example, from graphite. In another example, each of the heat transfer members 22a, 22b, 22c, 32a, 32b, 32c, 29a, 29b, 29c, 35a, 35b, and 35c could be a member formed from multiple materials, such as a shell material made of different metals.
[0073] The method for fixing the positions of the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c relative to the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d is not limited to encapsulation with the insulating member 25, but may be any method. When the electronic device 1 is to be mounted on a railway vehicle, the heat transfer members 22a, 22b, 22c, 32a, 32b, and 32c are preferably fixed using a method that ensures that the positions relative to the capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c, and 31d remain tightly fixed during vibrations from a running railway vehicle.
[0074] The cooling device 26 could have any shape that can dissipate transferred heat. As shown in Fig. 9, portions of the heat transfer members 22a, 22b, and 22c could extend through the heat-absorbing block 27 to serve as heat dissipation devices. Similarly, portions of the heat transfer members 32a, 32b, and 32c could extend through the heat-absorbing block 27 to serve as heat dissipation devices. Fig. 9 could further comprise a heat dissipation device 28 similar to the heat dissipation device of Fig. 5 include.
[0075] The heat sink 28 could have any shape capable of dissipating heat transferred from the heat-absorbing block 27. In one example, the fins of the heat sink 28 could be modified into any shape suitable for airflow around the heat sink 28. In another example, the heat sink 28 could include a plurality of rod-shaped protrusions. In another example, the heat sink 28 could include a heat pipe or plate including an internal channel containing a coolant.
[0076] The cooling device 26 could be located differently than in the above example. More specifically, this means that the cooling device 26 could be located inside the housing 13 instead of outside the housing 13. In this case, as in Fig. 10, the cooling device 26 is preferably located in a position within the housing 13 into which air flows from outside the housing 13. An electronic device 1 in Fig. 10 is described below, which refers to differences in structures compared to the electronic device 1 of the Fig. 7 focused.
[0077] The electronic device 1 includes a partition 18 that divides an interior space of the housing 13 into a first space 19a that allows less air to flow in from outside the housing 13, and a second space 19b that allows air to flow in from outside the housing 13. The housing 13 has a plurality of openings 13c in the surface facing the second space 19b, and air from outside the housing 13 flows into the second space 19b through the openings 13c.
[0078] The partition 18 includes an opening 18a. The cooling device 26 closes the opening 18a with a portion located in the second space 19b. When the opening 18a is closed with a portion of the cooling device 26, air outside the housing 13, which contains dust, moisture, and other foreign matter, is less likely to flow into the first space 19a through the opening 18a. More specifically, this means that the heat-absorbing block 27 closes the opening 18a from inside the first space 19a, with the heat-dissipating device 28 exposed to the second space 19b. The heat-dissipating device 28, exposed to the second space 19b, dissipates heat transferred from the heat-absorbing block 27 to air flowing into the second space 19b from outside the housing 13. The capacitor elements 21a, 21b, 21c, 21d, 31a, 31b, 31c and 31d are thus cooled.
[0079] In another example, the openings 13a and 13b, which are in Fig. 7, could be located in the same area of the housing 13, and the switching elements SW could be thermally connected to the cooling device 26. In other words, this means that the capacitor unit 11 and the switching elements SW could be cooled with a common cooling device. In this case, the main surfaces 27a and 27b of the heat-absorbing block 27 could be dimensioned to accommodate the switching elements SW in addition to the insulating member 25.
[0080] The insulating member 25 may be fixed to the heat-absorbing block 27 by any method. In one example, the insulating member 25 may be bonded to the heat-absorbing block 27 with an adhesive.
[0081] The electronic device 1, which is Fig. 7, the capacitor unit 11 could comprise the Fig. 3. In this case, the insulating member 25 could be attached to the inner surface of the housing 13, the opening 13a shown in Fig. 7, is closed with the insulating member 25. Similarly, the electronic device 1 shown in Fig. 10, comprise the capacitor unit 11, which in Fig. 3. In this case, the insulating member could be attached to the partition 18, with the opening 18a shown in Fig. 10 is illustrated, is closed with the insulating member.
[0082] The electronic device 1 is not limited to a three-stage power conversion device, but could be any device including the capacitor unit 11. In one example, the electronic device 1 could be a rectifier. The electronic device 1 can be mounted on any moving body, such as an automobile, a ship, or an aircraft, in addition to a rail vehicle.
[0083] The load 51 is not limited to a three-phase induction motor, but could be any device that consumes power supplied by the electronic device 1. The load 51 is, for example, an air conditioner or a lighting device.
[0084] The foregoing describes some exemplary embodiments for illustrative purposes. Although the foregoing discussion has presented specific embodiments, those skilled in the art will recognize that changes in form and detail could be made without departing from the broad spirit and scope of the invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. This detailed description, therefore, is not to be taken in a limiting sense, and the scope of the invention is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled. List of reference symbols 1 Electronic device 1a Positive connection 1b Negative connection 11 Capacitor unit 12 power converters 13 housings 13a, 13b, 13c, 18a opening 14 Power converter cooling device 15, 27 Heat-absorbing block 15a, 15b, 27a, 27b Main area 16, 28 Heat dissipation device 17 Laminate busbar 18 partitions 19a First Room 19b Second Room 21a, 21b, 21c, 21d, 31a, 31b, 31c, 31d capacitor element 22a, 22b, 22c, 29a, 29b, 29c, 32a, 32b, 32c, 35a, 35b, 35c heat transfer element 23a, 33a First busbar 23b, 33b Second busbar 24a, 34a First connection 24b, 34b Second connection 25 Insulating element 26 Cooling device 41a Positive electrode 41b Negative electrode 41c, 41d slide 51 Last C1 First capacitor C2 Second capacitor SW switching element QUOTES CONTAINED IN THE DESCRIPTION
[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature
[0000] JP 2013163503
[0003]
Claims
[1] Capacitor unit comprising: a plurality of capacitor elements; and one or more heat transfer members located adjacent to at least one capacitor element of the plurality of capacitor elements and configured to internally dissipate heat received by the at least one capacitor element of the plurality of capacitor elements. [2] The capacitor unit according to claim 1, further comprising: an insulating member for fixing a position of the one or more heat transfer members relative to the plurality of capacitor elements by covering at least a part of each of the one or more heat transfer members and the plurality of capacitor elements. [3] The condenser unit of claim 1 or 2, wherein each of the one or more heat transfer members is a plate having at least one major surface in contact with the at least one condenser element of the plurality of condenser elements. [4] A condenser unit according to claim 1 or 2, wherein each of the one or more heat transfer members is a rod in contact with the at least one condenser element of the plurality of condenser elements. [5] A condenser unit according to any one of claims 1 to 4, wherein the one or more heat transfer members comprise a plurality of heat transfer members, each located adjacent to a different condenser element of the plurality of condenser elements. [6] Capacitor unit according to one of claims 1 to 5, further comprising: a cooling device thermally connected to the one or more heat transfer members and configured to dissipate heat transferred from the plurality of condenser elements through the one or more heat transfer members. [7] The condenser unit of claim 6, wherein each of the one or more heat transfer members is located between two adjacent condenser elements of the plurality of condenser elements, and each of the one or more heat transfer members transfers heat received from the two adjacent condenser elements to the cooling device. [8] A condenser unit according to claim 6 or 7, wherein the one or more heat transfer members are in contact with the cooling device. [9] Capacitor unit according to one of claims 6 to 8, wherein the cooling device includes a heat-absorbing block thermally connected to the one or more heat transfer members, and a heat dissipation device for dissipating heat transferred from the heat-absorbing block. [10] An electronic device comprising: the capacitor unit according to any one of claims 1 to 9. [11] Electronic device comprising: the capacitor unit according to one of claims 6 to 8; a power converter for converting power supplied from a power source through the capacitor unit into power to be supplied to a load and for outputting the power resulting from conversion; and a housing that houses the capacitor unit and the power converter, wherein the cooling device in the condenser unit dissipates heat transferred from the plurality of condenser elements through the one or more heat transfer members to air outside the housing. [12] The electronic device of claim 11, further comprising: a partition dividing an interior space of the housing into a first space and a second space, the first space accommodating the capacitor unit and the power converter and preventing air from flowing in from outside the housing, the second space allowing air to flow in from outside the housing, wherein the cooling device in the condenser unit closes an opening in the partition, wherein a portion of the cooling device is exposed to the second space through the opening. [13] The electronic device according to claim 11, wherein the cooling means in the capacitor unit closes an opening in the housing, a portion of the cooling means being exposed outside the housing through the opening. [14] Electronic device according to one of claims 11 to 13, further comprising: a power converter cooling device for dissipating heat transferred from the power converter to air outside the housing.