Power Conversion Equipment

Abstract

To provide a small-sized power conversion device.SOLUTION: A power conversion device comprises a semiconductor module, a capacitor, and a cooler. The semiconductor module includes a semiconductor element for power conversion, and an input terminal conducted with the semiconductor element is disposed on a module surface. The capacitor includes a capacitor surface in which a capacitor terminal is disposed, and which is opposed to the module surface. The cooler is disposed between the semiconductor module and the capacitor. A connection member electrically connects the input terminal and the capacitor terminal.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a power conversion device. [Background technology]

[0002] Patent Document 1 discloses a power conversion device that includes a plurality of semiconductor modules that house semiconductor elements for power conversion and other electric devices. The power conversion device also includes a plurality of coolers that cool the plurality of semiconductor modules and the electric devices. The plurality of semiconductor modules and the plurality of coolers are stacked alternately one by one. The other electric devices are also in contact with the coolers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-141540 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the power conversion device of Patent Document 1, the terminals of the semiconductor module extend in a direction intersecting the stacking direction of the semiconductor module and the cooler. In addition, there is wasted space around the connection member that electrically connects the terminals of the semiconductor module to other devices. Therefore, the power conversion device of Patent Document 1 requires a large space to be housed. This specification provides a small-sized power conversion device. [Means for solving the problem]

[0005] The power conversion device disclosed in this specification includes a semiconductor module, a capacitor, and a cooler. The semiconductor module has a semiconductor element for power conversion, and an input terminal electrically connected to the semiconductor element is arranged on a surface of the module. The capacitor has a capacitor surface on which a capacitor terminal is arranged and which faces the surface of the module. The cooler is arranged between the semiconductor module and the capacitor. The connection member electrically connects the input terminal and the capacitor terminal.

[0006] In the power conversion device disclosed in this specification, a semiconductor module, a cooler, and a capacitor are stacked, and the input terminal of the semiconductor module faces the cooler, and the capacitor terminal also faces the cooler. Therefore, there is no wasted space around the terminals. In addition, since the connection member that electrically connects the input terminal and the capacitor terminal can be arranged along the cooler, there is no wasted space around the connection member. According to the technology disclosed in this specification, a small-sized power conversion device can be realized. Since the connection member does not protrude from the stack of the semiconductor module, the cooler, and the capacitor, the power conversion device disclosed in this specification can be accommodated in a space-efficient manner, for example, in the front compartment of an electric vehicle.

[0007] The cooler has a groove or hole penetrating from the semiconductor module side to the capacitor side, and the groove or hole may overlap with the input terminal when viewed from the stacking direction of the semiconductor module, the cooler, and the capacitor. This allows the cooler to concentrate on cooling the semiconductor element.

[0008] The holes or grooves in the cooler may be filled with an insulating material, which can reliably ensure insulation between the connection members and the cooler. Also, the semiconductor module and the capacitor may be fixed to the cooler.

[0009] When viewed from the stacking direction of the semiconductor module, the cooler, and the capacitor, the semiconductor element is preferably disposed in the center of the semiconductor module, and the groove or hole is disposed on the outside of the semiconductor element. By disposing the semiconductor element in the center and positioning the groove or hole through which the connection member passes on the outside of the semiconductor element, the effect of the hole or groove on the cooling efficiency (cooling efficiency for the semiconductor element) can be suppressed.

[0010] The input terminal may include a positive input terminal and a negative input terminal, and the capacitor terminal may include a positive capacitor terminal and a negative capacitor terminal. The connection member may include a positive connection member that electrically connects the positive input terminal and the positive capacitor terminal, and a negative connection member that electrically connects the negative input terminal and the negative capacitor terminal. In this case, it is preferable that the positive connection member and the negative connection member overlap. The magnetic field generated in the positive connection member and the magnetic field generated by the negative connection member are offset, and the inductance of the connection member is reduced. If a part of the positive connection member and a part of the negative connection member overlap, the effect of reducing inductance can be expected.

[0011] The semiconductor elements included in the semiconductor module may include six switching elements that constitute a three-phase AC inverter. In this case, it is preferable that the output terminals of the three-phase AC inverter are disposed on the surface of the module, and an output member that is electrically connected to the output terminals is disposed on the cooler. There is no wasted space around the output terminals, and the size of the power conversion device can be further reduced.

[0012] Details and further improvements of the technology disclosed in this specification are described in the following "Forms for Carrying Out the Invention". [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a schematic configuration diagram of a circuit of a power conversion device. [Diagram 2] 1 is a perspective view of a power conversion device according to a first embodiment. [Diagram 3] 1 is an exploded perspective view of a power conversion device according to a first embodiment; [Figure 4] FIG. 2 is a plan view of the power conversion device. [Diagram 5] 5 is a cross-sectional view of the power conversion device taken along line VV in FIG. 4. [Figure 6] FIG. 11 is a perspective view of a cooler of a power conversion device according to a second embodiment. [Figure 7] FIG. 11 is a perspective view of a connection member of a power conversion device according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] (First embodiment) A power converter 2 of a first embodiment will be described with reference to the drawings. FIG. 1 shows a schematic configuration diagram of the power converter 2. The power converter 2 includes a semiconductor module 10, a capacitor 20, and a cooler 30. The semiconductor module 10 includes six switching elements 14. The six switching elements 14 are a type of semiconductor element. The six switching elements 14 form an inverter circuit. The semiconductor module 10 converts DC power input to the input terminals (positive input terminal 12a and negative input terminal 12b) into AC power, and outputs it from the output terminal 13. Hereinafter, for convenience of explanation, the positive input terminal 12a and the negative input terminal 12b may be collectively referred to as the input terminals 12.

[0015] A capacitor 20 is connected to the input terminal 12. The capacitor 20 has a positive capacitor terminal 21a and a negative capacitor terminal 21b. The positive capacitor terminal 21a and the positive input terminal 12a are connected by a positive connection member 41, and the negative capacitor terminal 21b and the negative input terminal 12b are connected by a negative connection member 42. For convenience of explanation, the positive capacitor terminal 21a and the negative capacitor terminal 21b may be collectively referred to as the capacitor terminals 21 below. A DC power supply (not shown) is connected to the capacitor terminal 21 through a bus bar 90. Power from the DC power supply is supplied to the semiconductor module 10 through the bus bar 90 and the connection members (the positive connection member 41 and the negative connection member 42).

[0016] The semiconductor module 10 (switching element 14) and the capacitor 20 generate heat. The power conversion device 2 includes a cooler 30 that cools the semiconductor module 10 and the capacitor 20. The cooler 30 is in contact with the semiconductor module 10 and the capacitor 20.

[0017] Fig. 2 shows the external appearance of the power conversion device 2, and Fig. 3 shows an exploded view of the power conversion device 2. For convenience of explanation, the +Z direction of the coordinate system in the figure is defined as "up".

[0018] The semiconductor module 10, the cooler 30, and the capacitor 20 are stacked in this order. In other words, the cooler 30 is disposed between the semiconductor module 10 and the capacitor 20. The semiconductor module 10 is fixed to the cooler 30 with a screw 91, and the capacitor 20 is fixed to the cooler 30 with a screw 92. The semiconductor module 10 (switching element 14) is cooled by the upper surface of the cooler 30, and the capacitor 20 is cooled by the lower surface of the cooler 30.

[0019] The semiconductor module 10 is plate-shaped and has six switching elements 14 mounted therein. In Figures 2 and 3, two switching elements are denoted by the reference numeral 14, and the reference numerals for the remaining switching elements are omitted. An input terminal 12 and an output terminal 13 are arranged on a bottom surface 10a of the semiconductor module 10.

[0020] Capacitor 20 includes a capacitor element 22, a positive capacitor terminal 21a, and a negative capacitor terminal 21b. Positive capacitor terminal 21a is disposed on an upper surface 20a of capacitor 20, and negative capacitor terminal 21b is disposed on a lower surface of capacitor 20.

[0021] The cooler 30 has coolant ports 31a and 31b on its side surface. A coolant is supplied from the coolant port 31a. The supplied coolant spreads inside the cooler 30 and cools the semiconductor module 10 and the condenser 20. After absorbing heat from the semiconductor module 10 and the condenser 20, the coolant is discharged from the coolant port 31b.

[0022] The cooler 30 has grooves 32, 33 that penetrate from the semiconductor module 10 side to the capacitor 20 side. The groove 32 is disposed at a position facing the input terminal 12. A positive electrode connection member 41 and a negative electrode connection member 42 are fixed to the input terminal 12. The positive electrode connection member 41 electrically connects the positive electrode input terminal 12a of the semiconductor module 10 and the positive electrode capacitor terminal 21a of the capacitor 20. The negative electrode connection member 42 electrically connects the negative electrode input terminal 12b and the negative electrode capacitor terminal 21b.

[0023] The groove 32 is filled with an insulating material 51. The positive electrode connection member 41 and the negative electrode connection member 42 are bent into a U shape so as to fit along the insulating material 51. The positive electrode capacitor terminal 21a is disposed on the upper surface of the capacitor 20, and the positive electrode connection member 41 fits along three surfaces of the insulating material 51. Since the negative electrode capacitor terminal 21b is disposed on the lower surface of the capacitor 20, the negative electrode connection member 42 extends downward beyond the positive electrode connection member 41.

[0024] The groove 33 is disposed at a position facing the output terminal 13. An output member 43 is fixed to the output terminal 13. The groove 33 is filled with an insulating material 52. The output member 43 is bent in an L shape so as to fit along two sides of the insulating material 52. The output terminal 13 faces the cooler 30, and although it cannot be seen from the outside of the power conversion device 2, the L-shaped output member 43 is exposed to the side of the power conversion device 2. The output member 43 is fixed to the cooler 30 together with the insulating material 52. In other words, the output member 43 and the insulating material 52 are part of the cooler 30.

[0025] Fig. 4 shows a plan view of the power conversion device 2. Fig. 4 corresponds to a view seen from the stacking direction of the semiconductor module 10, the cooler 30, and the capacitor 20. In Fig. 4 as well, the reference numeral 14 is given to two switching elements, and the reference numerals are omitted for the remaining switching elements.

[0026] The cooler 30 has grooves 32 and 33, and as described above, when viewed from the stacking direction, groove 32 overlaps with input terminal 12, and groove 33 overlaps with output terminal 13. Groove 32 is filled with insulating material 51, and groove 33 is filled with insulating material 52. Furthermore, when viewed from the stacking direction, six switching elements 14 are disposed in the center of the semiconductor module 10, and input terminal 12 and output terminal 13 are disposed outside the switching elements 14.

[0027] FIG. 5 shows a cross section of the power converter 2 taken along the line VV in FIG. 4. FIG. 5 shows a cross section of the power converter 2 cut along a plane passing through the positive electrode connecting member 41. The cooler 30 is hollow inside, and a coolant flows through the hollow. As can be seen from FIG. 5, the cooler 30 faces the switching element 14, but grooves 32 and 33 are provided in the range facing the input terminal 12 and the output terminal 13. The cooler 30 is concentrated in the range facing the switching element 14, and can efficiently cool the switching element 14. In other words, since the insulating materials 51 and 52 are out of the range facing the switching element 14, the influence of the insulating materials 51 and 52 on the cooling of the switching element 14 can be suppressed.

[0028] The input terminal 12 and the output terminal 13 are provided on the lower surface 10a of the semiconductor module 10, and the positive capacitor terminal 21a is provided on the upper surface 20a of the capacitor 20. The lower surface 10a of the semiconductor module 10 and the upper surface 20a of the capacitor 20 face each other, and the cooler 30 is sandwiched between them. The positive connection member 41 that electrically connects the positive input terminal 12a and the positive capacitor terminal 21a extends along the cooler 30 (along the insulating material 51 of the cooler 30), and there is no wasted space around the positive connection member 41. In FIG. 5, the negative connection member 42 is drawn with a virtual line. The negative capacitor terminal 21b is disposed on the lower surface of the capacitor 20, and the negative connection member 42 extends along the cooler 30 and the capacitor 20. There is also no wasted space around the negative connection member 42. The power conversion device 2 is small in size because no wasted space is generated around the connection members 41 and 42. Moreover, the output member 43 also extends along the cooler 30 (insulating material 52), and there is no wasted space around the output member 43. The layout of the output member 43 also contributes to making the power conversion device 2 smaller in size.

[0029] The semiconductor module 10 is plate-shaped, and the cooler 30 and the capacitor 20 are flat. The semiconductor module 10, the cooler 30, and the capacitor 20 are stacked so that their wide surfaces face each other, and therefore the power converter 2 has an approximately rectangular parallelepiped appearance. Furthermore, the connection members (positive electrode connection member 41 and negative electrode connection member 42) and the output member 43 are arranged along the cooler 30, and the members do not protrude from the rectangular parallelepiped shape of the power converter 2. Since the appearance of the power converter 2 including the connection members 41, 42 and the output member 43 is approximately a rectangular parallelepiped, no wasted space is generated in the space for accommodating the power converter 2.

[0030] An insulating material 51 is disposed between the connection members 41, 42 and the cooler 30, and an insulating material 52 is disposed between the output member 43 and the cooler 30. The insulating material 51 enhances insulation between the connection members 41, 42 and the cooler 30. The insulating material 52 enhances insulation between the output member 43 and the cooler 30.

[0031] (Second embodiment) A power converter of the second embodiment will be described. In the power converter of the second embodiment, the shape of the cooler 130 is different from that of the cooler 30 of the power converter 2 of the first embodiment. A perspective view of the cooler 130 is shown in FIG. 6. Devices other than the cooler 130 are not shown. The cooler 130 has a hole 132 instead of the groove 32 of the first embodiment. The hole 132 penetrates from the semiconductor module 10 side to the capacitor 20 side. A connection member that electrically connects the input terminal and the capacitor terminal passes through the hole 132. The hole is filled with an insulating material. The power converter of the second embodiment is also small in size. In the power converter of the second embodiment, the connection member is not exposed, so safety is high.

[0032] (Third embodiment) A power converter of the third embodiment will be described. The power converter of the third embodiment differs from the embodiments in the positive electrode connection member and the negative electrode member. Fig. 7 shows a perspective view of the positive electrode connection member 141 and the negative electrode connection member 142. Devices other than the positive electrode connection member 141 and the negative electrode connection member 142 are omitted from the illustration.

[0033] The positive electrode connection member 141 has a flat piece 141a, and the negative electrode connection member 142 has a flat piece 142a. The positive electrode connection member 141 and the negative electrode connection member 142 overlap with an insulating plate 143 sandwiched therebetween. The piece 141a of the positive electrode connection member 141 overlaps with the negative electrode connection member 142, and the piece 142a of the negative electrode connection member 142 overlaps with the positive electrode connection member 141. The pieces 141a and 142a expand the overlapping range of the positive electrode connection member 141 and the negative electrode connection member 142. The direction of the current flowing through the positive electrode connection member 141 and the direction of the current flowing through the negative electrode connection member 142 are opposite to each other. The currents flowing in the opposite directions in the overlapping range cancel out the magnetic fields generated by those currents, reducing the inductance of both connection members. A portion of the positive electrode connecting member 141 and a portion of the negative electrode connecting member 142 overlap with each other, thereby reducing the inductance between them.

[0034] The following points should be noted regarding the technology of the embodiment. The switching element 14 of the embodiment corresponds to an example of a semiconductor element. The technology disclosed in this specification can be applied to a power conversion device including a semiconductor element other than the switching element 14.

[0035] Although specific examples of the present invention have been described above in detail, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful. [Explanation of symbols]

[0036] 2: Power conversion device 10: Semiconductor module 12: Input terminal 13: Output terminal 14: Switching element 20: Capacitor 21: Capacitor terminal 30, 130: Cooler 32, 33: Groove 41, 141: Positive electrode connecting member 42, 142: Negative electrode connecting member 43: Output member 51, 52: Insulating material

Claims

1. a semiconductor module having a semiconductor element for power conversion, the semiconductor element being electrically connected to an input terminal disposed on a surface of the module; a capacitor having a capacitor surface on which capacitor terminals are disposed and facing the module surface; a cooler disposed between the semiconductor module and the condenser; a connection member electrically connecting the input terminal and the capacitor terminal; It is equipped with the semiconductor module, the cooler, and the capacitor are stacked, the cooler has a groove penetrating from the semiconductor module side to the capacitor side, and when viewed from a stacking direction of the semiconductor module, the cooler, and the capacitor, the groove, the input terminal, and the capacitor terminal overlap each other; The groove is filled with an insulating material; the connection member is bent into a U-shape along the insulating material, one end of the U-shape is connected to the input terminal and the other end is connected to the capacitor terminal, and the bottom of the U-shape is disposed so as to face the bottom of the groove across the insulating material. Power conversion equipment.

2. The power conversion device according to claim 1 , wherein the semiconductor element is disposed in a center of the semiconductor module when viewed from the stacking direction, and the groove is disposed outside the semiconductor element.

3. The power conversion device according to claim 1 , wherein the semiconductor module and the capacitor are fixed to the cooler.

4. The input terminals include a positive input terminal and a negative input terminal, the capacitor terminals include a positive capacitor terminal and a negative capacitor terminal; the connection member includes a positive connection member that electrically connects the positive input terminal and the positive capacitor terminal, and a negative connection member that electrically connects the negative input terminal and the negative capacitor terminal, The power conversion device according to claim 1 , wherein the positive electrode connecting member and the negative electrode connecting member overlap each other.

5. The semiconductor device includes six switching devices that configure a three-phase AC inverter, an output terminal of the three-phase AC inverter is disposed on a surface of the module; The power conversion device according to claim 1 , wherein an output member electrically connected to the output terminal is disposed in the cooler.

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