Capacitor and power conversion device

Abstract

To reduce the number of components in a power conversion device that requires a ferrite core to reduce manufacturing costs and improve ease of assembly.SOLUTION: A capacitor 1 includes a hollow circular capacitor body 10. A hollow circular ferrite core 3 is provided in a hollow portion 14 of the capacitor body 10 coaxially with the capacitor body 10. The capacitor body 10 includes terminal portions 13P and 13N for P and N poles connected to a semiconductor module 4. The terminal portions 13P and 13N are exposed from the surface of the capacitor body 10 near the hollow portion 14 and protrude toward the axis of the capacitor body 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a capacitor structure. [Background technology]

[0002] A power conversion device, such as an in-vehicle inverter device, is equipped with switching elements such as IGBTs (insulated gate bipolar transistors). The inverter device needs to be equipped with a ferrite core to cut external noise and noise generated by the switching elements. The ferrite core is attached to a bus bar connected to a P-pole and N-pole terminal portion, which is an input portion for DC power from the battery of the inverter device, for example. Patent Document 1 is a prior art example of attaching a ferrite core to a bus bar of an inverter device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-98678 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-119874 [Patent Document 3] Japanese Patent Application Laid-Open No. 2013-197486 Summary of the Invention [Problem to be solved by the invention]

[0004] The ferrite core and other components of the power conversion device, such as the capacitors in Patent Documents 2 and 3, exist as independent components, so the ferrite core needs to be attached to the bus bar in consideration of the space available for arranging the various components of the power conversion device.

[0005] On the other hand, the capacitors in Patent Documents 2 and 3 have a special shape with a hollow portion.

[0006] In view of the above circumstances, an object of the present invention is to reduce the number of parts of a power converter that requires a ferrite core, thereby reducing manufacturing costs and improving assembly ease. [Means for solving the problem]

[0007] Therefore, one aspect of the present invention is a capacitor having a hollow circular capacitor body, in which a hollow circular ferrite core is provided coaxially with the capacitor body in the hollow portion of the capacitor body.

[0008] In one aspect of the present invention, in the capacitor, the capacitor body has terminal portions for a P pole and an N pole that are connected to electrical components, and the terminal portions for the P pole and the N pole are exposed from the surface near the hollow portion of the capacitor body and protrude toward the axis of the capacitor body.

[0009] In one aspect of the present invention, in the capacitor, the electrical component is a semiconductor module of a three-phase power conversion device, and three terminal portions for the P pole and N pole are arranged along the periphery of the hollow portion of the capacitor body portion corresponding to the three phases.

[0010] In one aspect of the present invention, in the capacitor, bus bars connected to the electrical component and the P-pole and N-pole terminal portions are inserted into the ferrite core.

[0011] In one aspect of the present invention, in the condenser, a cooler is disposed between the condenser body and the electrical component.

[0012] One aspect of the present invention is a power conversion device including the above-described capacitor. [Effects of the Invention]

[0013] According to the present invention, the number of parts of a power converter that requires a ferrite core can be reduced, thereby reducing manufacturing costs and improving assembly efficiency. [Brief explanation of the drawings]

[0014] [Figure 1] (a) is a perspective view of a capacitor according to one embodiment of the present invention; (b) is a plan view of the capacitor; and (c) is a side view of the capacitor. [Figure 2] FIG. 1A is a perspective view of a capacitor according to an embodiment of the present invention in which a semiconductor module is disposed, FIG. 1B is a plan view of the capacitor, and FIG. 1C is a side view of the capacitor. [Figure 3] FIG. 1A is a plan view of a condenser according to an embodiment of the present invention in which a cooler is disposed, and FIG. 1B is a side view of the condenser. [Figure 4] FIG. 1 is a circuit diagram of an inverter device for use in a vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] A capacitor 1 according to one embodiment of the present invention shown in FIG. 1 is applied to, for example, an in-vehicle three-phase inverter device 2, which is one aspect of a power conversion device shown in FIG.

[0017] The capacitor 1 has a hollow circular capacitor body 10. A hollow circular ferrite core 3 is provided in a hollow portion 14 of the capacitor body 10 so as to be coaxial with the capacitor body 10.

[0018] The capacitor body 10 has a hollow cylindrical resin case 11 that houses a capacitor element (not shown), and a potting portion 12 that is formed by filling the resin case 11 with a sealing resin. The potting portion 12 has a pair of terminal portions 13P, 13N for the P and N poles that are connected to the capacitor element. The terminal portions 13P, 13N are exposed from the surface near the periphery of the hollow portion of the capacitor body 10 and protrude toward the axis of the capacitor body 10.

[0019] Three terminal portions 13P, 13N are arranged along the periphery of the hollow portion of the capacitor body 10 corresponding to the three phases (U phase, V phase, W phase) of the inverter device 2. As shown in Fig. 2, power card-type semiconductor modules 4U, 4V, 4W corresponding to the U phase, V phase, and W phase of the inverter device 2, respectively, are connected to the terminal portions 13P, 13N of the U phase, V phase, and W phase as electrical components of the inverter device 2.

[0020] As shown in Fig. 4, the semiconductor modules 4U, 4V, and 4W are equipped with upper arms 41 and lower arms 42 each made of an IGBT. The collector terminal 4P of the upper arm 41, which is the P-pole terminal of the semiconductor modules 4U, 4V, and 4W, is connected to the P-pole terminal portion 13P of the capacitor 1, as shown in Fig. 2. Similarly, the emitter terminal 4N of the lower arm, which is the N-pole terminal of the semiconductor modules 4U, 4V, and 4W, is connected to the N-pole terminal portion 13N of the capacitor 1.

[0021] An input bus bar P inserted into the hollow portion of the ferrite core 3 is fastened by a fastener to the collector terminal 4P and terminal portion 13P of the semiconductor module 4U. Similarly, an input bus bar N inserted into the hollow portion 30 of the ferrite core 3 is fastened by a fastener to the emitter terminal 4N and terminal portion 13N of the semiconductor module 4U. A discharge resistor 7 is connected to the input bus bars P and N.

[0022] The three P-pole terminal portions 13P of the capacitor 1 corresponding to the semiconductor modules 4U, 4V, and 4W are electrically connected by a capacitor element inside the resin case 11. Similarly, the three N-pole terminal portions 13N of the capacitor 1 are also electrically connected by the capacitor element. Therefore, when the input bus bars P and N are connected to the collector terminal 4P and the emitter terminal 4N of any one of the semiconductor modules 4, power from the battery is also supplied to the other two semiconductor modules 4.

[0023] Output terminals 43 of semiconductor modules 4U, 4V, 4W are connected to output bus bars 5U, 5V, 5W, which are connected to three-phase motor 5 in Fig. 4. Furthermore, a Hall current detector 6 is attached to each of output bus bars 5U, 5V, 5W.

[0024] According to the above-described capacitor 1, the ferrite core 3 is integrally and coaxially provided in the hollow portion 14 of the capacitor 1, so that the ferrite core 3 can be attached to the input bus bars P, N without considering the space required for arranging the ferrite core 3 within the inverter device 2. This reduces the number of parts of the inverter device 2 that require the ferrite core 3, thereby reducing manufacturing costs and improving assembly efficiency.

[0025] In particular, the terminal portions 13P, 13N are exposed from the surface near the hollow portion of the capacitor body 10 and protrude toward the axis of the capacitor body 10, thereby shortening the distance between the input bus bars P, N inserted through the ferrite core 3, the capacitor 1, and the semiconductor modules 4U, 4V, 4W. This makes it possible to electrically connect the input bus bars P, N to the capacitor 1 and the semiconductor modules 4U, 4V, 4W in a space-saving manner, thereby shortening the input bus bars P, N and downsizing the inverter device 2.

[0026] Furthermore, multiple terminal portions 13P, 13N can be arranged along the periphery of the hollow portion of the capacitor body 10 depending on the number of semiconductor modules 4 in a single-phase or three-phase power converter. Therefore, the capacitor 1 of this embodiment can be applied not only to the three-phase inverter device 2 in Fig. 2 but also to a power converter equipped with a DC capacitor, for example, a single semiconductor module 4 in a single-phase inverter device. Furthermore, the capacitor 1 is not limited to the above-mentioned power card type, but can also be applied to semiconductor modules of other specifications.

[0027] Furthermore, when the input bus bars P, N are inserted into the ferrite core 3, they can be connected to the collector terminal 4P and emitter terminal 4N of the semiconductor modules 4U, 4V, 4W and the terminal portions 13P, 13N of the capacitor body 10. This improves the workability of connecting the input bus bars P, N, the semiconductor modules 4U, 4V, 4W, and the capacitor 1.

[0028] 3, a cooler 8 consisting of a heat sink for cooling the semiconductor modules 4U, 4V, and 4W may be disposed between the capacitor body 10 and the semiconductor modules 4U, 4V, and 4W. A refrigerant is circulated and supplied to the cooler 8 via pipes 81 and 82. According to this embodiment, not only the semiconductor modules 4U, 4V, and 4W but also the upper surface of the capacitor 1 can be cooled, thereby improving the reliability of the power conversion device including the capacitor 1 and the semiconductor modules 4U, 4V, and 4W. [Explanation of symbols]

[0029] 1...capacitor, 10...capacitor body, 11...resin case, 12...potting portion, 13P...terminal portion for P pole, 13N...terminal portion for N pole, 14...hollow portion 2...Inverter device, 3...ferrite core, 30...hollow section 4, 4U, 4V, 4W...semiconductor module, 41...upper arm, 42...lower arm, 4P...collector terminal, 4N...emitter terminal 5...Motor, 5U, 5V, 5W...Output bus bar 6...Hall current detector 7...Discharge resistor 8...Cooler, 81,82...Piping P, N...Input busbar

Claims

1. a hollow circular capacitor body; a ring-shaped ferrite core provided coaxially with the capacitor body in the hollow portion of the capacitor body, through which an electric component and a bus bar connected to the capacitor body are inserted; and the capacitor body includes P-pole and N-pole terminal portions connected to the electrical component via the bus bar, The terminal portions for the P pole and the N pole are exposed from the surface of the capacitor body near the hollow portion and protrude toward the axial center of the capacitor body. A capacitor characterized by:

2. the electrical component is a semiconductor module of a three-phase power converter, The terminal portions for the P pole and the N pole are arranged in three in number along the periphery of the hollow portion of the capacitor body, corresponding to the three phases. The capacitor according to claim 1 ,

3. 3. The capacitor according to claim 1, further comprising a cooler disposed between the capacitor body and the electrical component.

4. A power conversion device comprising the capacitor according to any one of claims 1 to 3.

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