JP2024043987A - Condenser cooling structure and power conversion device - Google Patents

Abstract

[Problem] The aim is to miniaturize the capacitor and simplify the cooling structure by improving the cooling performance of the capacitor elements. [Solution] A capacitor cooling structure 1 has a capacitor module 3 in which a plurality of capacitor elements 2 arranged in parallel are molded in a capacitor case 30, and a case 12 of the power conversion device 10 that houses the capacitor module 3 as a component of the power conversion device 10. A recess 31 is formed in the bottom of the capacitor case 30 of the capacitor module 3 along the length direction of the capacitor elements 2 in correspondence with the space between adjacent capacitor elements 2. A protrusion 13 that fits into the recess 31 of the capacitor case 30 is provided on the inner surface of the case 12 of the power conversion device 10. [Selected Figure] Figure 1

Description

The present invention relates to a capacitor cooling structure.

As an example of a capacitor cooling structure, such as the case-molded capacitor of Patent Document 1, heat from the capacitor module is dissipated through the bottom of a case that houses the capacitor module, which is made up of multiple capacitor elements.

The capacitor cooling structure disclosed in Patent Document 2 dissipates heat from the capacitor module through the surface of the case of the power conversion device that houses the capacitor module.

Japanese Patent Application Publication No. 2013-55095 JP2019-41482A

The polypropylene film of film capacitors used as smoothing capacitors in power conversion devices such as inverters has a low upper limit temperature for use, so cooling is required if the temperature inside the capacitor becomes high.

The capacitor cooling structures of Patent Documents 1 and 2 cover the bottom of a capacitor case 30 of a capacitor module 3 equipped with a plurality of capacitor elements 2 as shown in FIG. Heat is dissipated through the If the condenser module 3 is insufficiently cooled by natural cooling alone, a water-cooling type cooling mechanism is applied to the condenser case 30 and the case 12.

However, the water-cooled cooling structure hinders miniaturization and cost reduction of capacitors and power converters equipped with the same.

In view of the above, the present invention aims to simplify the capacitor cooling structure and reduce the size of the capacitor by improving the cooling performance of the capacitor element.

Therefore, one aspect of the present invention includes a capacitor module in which a plurality of capacitor elements arranged in parallel are molded in a capacitor case, and a case of the power converter that houses the capacitor module as a component of the power converter. The capacitor cooling structure has a capacitor cooling structure in which the inner surface of the case is provided with a protrusion that fits into a recess of the capacitor case corresponding to between the adjacent capacitor elements.

In one aspect of the present invention, in the capacitor cooling structure, the protrusion is made of the same material as the capacitor case.

In one aspect of the present invention, in the capacitor cooling structure, the protrusion is made of resin or metal.

In one aspect of the present invention, in the capacitor cooling structure, a thermally conductive sheet is disposed between the recess and the protrusion.

One aspect of the present invention is a power conversion device having the above-mentioned capacitor cooling structure.

The present invention improves the cooling performance of the capacitor element, simplifies the capacitor cooling structure, and reduces the size of the capacitor.

1 is a cross-sectional view of a condenser cooling structure according to one embodiment of the present invention. FIG. 1 is a cross-sectional view of a conventional condenser cooling structure. FIG. 2 is a basic circuit diagram of a power conversion device to which the capacitor cooling structure of FIG. 1 is applied.

The following describes an embodiment of the present invention with reference to the drawings.

A capacitor cooling structure 1 that is one embodiment of the present invention shown in FIG. It has 12.

The capacitor module 3 is applied, for example, as a capacitor C connected to the power module 11 of the power conversion device 10 in FIG. It is housed in a case 12.

As shown in the figure, the capacitor module 3 is formed by storing, for example, three capacitor elements 2 in parallel in a capacitor case 30 and then molding them. The bottom of the capacitor case 30, which is placed on the inner surface of the case 12 of the power conversion device 10, has recesses 31 formed along the length of the capacitor elements 2 corresponding to the spaces between adjacent capacitor elements 2.

The capacitor element 2 is formed by winding a pair of metallized films, one or both sides of which are metal-deposited, facing each other through the dielectric film, and has a straight body portion 20 with oval-shaped end faces. Electrodes (not shown) are formed on both end faces of this straight body portion 20.

The capacitor element 2 is housed in a capacitor case 30 with the connection terminal P1 of the busbar P connected to the electrode on one end surface and the connection terminal N1 of the busbar N connected to the electrode on the other end surface, and is then molded with epoxy resin or the like.

A protrusion 13 that fits into the recess 31 of the capacitor case 30 is provided on the inner surface (for example, the bottom inner surface) of the case 12 of the power converter 10 . The protrusion 13 is fixed to the inner surface of the case 12 with adhesive. The material of the protrusion 13 may be the same well-known resin or metal as the capacitor case 30. Further, a thermally conductive sheet 4 is appropriately placed between the recess 41 and the protrusion 13. As the thermally conductive sheet 4, a well-known thermally conductive resin is applied.

According to the capacitor cooling structure 1 described above, the protrusion 13 in the case 12 of the power converter 10 fits into the recess 31 of the capacitor case 30, so that the heat of the capacitor element 2 is transferred to the case through the protrusion 13. 12, and the capacitor element 2 is cooled.

In particular, since the gap between the recess 31 of the capacitor case 30 and the inner surface of the case 12, where the heat of the capacitor element 2 tends to accumulate, is sealed by the protrusion 13, the cooling efficiency of the capacitor element 2 is increased.

Furthermore, since the protrusion 13 is made of the same material as the capacitor case 30, the heat transfer effect from the capacitor element 2 to the case 12 via the protrusion 13 is enhanced, and the cooling effect of the capacitor element 2 is further improved. . Further, by disposing the heat conductive sheet 4 between the protrusion 13 and the recess 31, the heat transfer effect is further enhanced.

The above-described condenser cooling structure 1 enhances the cooling effect of the capacitor element 2 without the need for a water-cooling structure, making it possible to simplify the condenser cooling structure. This makes it possible to miniaturize and increase the density of a condenser having multiple capacitor elements 2, thereby enabling the miniaturization of the condenser cooling structure 1 and the power conversion device 10 equipped with the same.

DESCRIPTION OF SYMBOLS 1... Capacitor cooling structure 2... Capacitor element, 20... Straight body part 3... Capacitor module, 30... Capacitor case, 31... Recessed part 4... Thermal conductive sheet P, N... Bus bar, P1, N1... Connection terminal 10... Power conversion Device, 11...Power module, 12...Case, 13...Protrusion

Claims (5)

a capacitor module in which a plurality of capacitor elements arranged in parallel are molded in a capacitor case;
a case for the power conversion device that houses the capacitor module as a component of the power conversion device;
having
a capacitor cooling structure, characterized in that an inner surface of the case is provided with a protrusion that fits into a recess of the capacitor case corresponding to a space between adjacent capacitor elements. 2. The capacitor cooling structure according to claim 1, wherein the protrusion is made of the same material as the capacitor case. 2. The capacitor cooling structure according to claim 1, wherein the protrusion is made of resin or metal. The condenser cooling structure according to claim 1, characterized in that a thermally conductive sheet is disposed between the recess and the protrusion. A power conversion device having the capacitor cooling structure according to claim 1 .

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