US-12626861-B2 - Capacitor unit and electronic device

US12626861B2US 12626861 B2US12626861 B2US 12626861B2US-12626861-B2

Abstract

A capacitor unit includes 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. The one or more heat transfer members internally dissipate heat received from at least one capacitor element of the plurality of capacitor elements.

Inventors

Hirokazu Takabayashi
Takahiro Masuyama
Yuji Shirakata

Assignees

MITSUBISHI ELECTRIC CORPORATION

Dates

Publication Date: 20260512
Application Date: 20210510

Claims (2)

1 . An electronic device, comprising: a capacitor unit comprising: a plurality of capacitor elements arranged in a row with main surfaces thereof facing one another; 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 from the at least one capacitor element of the plurality of capacitor elements; a first busbar extending in a direction in which the plurality of capacitor elements are arranged, and electrically connected to positive electrodes of the plurality of capacitor elements; a second busbar extending in the direction in which the plurality of capacitor elements are arranged, and electrically connected to negative electrodes of the plurality of capacitor elements; a first terminal electrically connected to the positive electrodes of the plurality of capacitive elements; a second terminal electrically connected to the negative electrodes of the plurality of capacitive elements; and a heat receiving block thermally connected to the one or more heat transfer members; a power converter to convert power supplied from a power supply through the capacitor unit to power to be supplied to a load and output the power resulting from conversion; a housing accommodating the capacitor unit and the power converter; and a power converter cooler to dissipate heat transferred from the power converter to air outside the housing, wherein portions of the one or more heat transfer members extend through the heat-receiving block in a direction orthogonal to the direction in which the plurality of capacitor elements are arranged, and dissipate heat transferred from the at least one capacitor element of the plurality of capacitor elements to the air outside the housing, the heat-receiving block included in the capacitor unit closes a first opening in the housing with portions of the one or more heat transfer members exposed outside the housing through the first opening, and the power converter cooler closes a second opening on a surface different from the surface on which the first opening is formed with a portion of the power converter cooler being exposed outside the housing through the second opening.
2 . An electronic device, comprising: a capacitor unit comprising: a plurality of capacitor elements arranged in a row with main surfaces thereof facing one another; 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 from the at least one capacitor element of the plurality of capacitor elements; a first busbar extending in a direction in which the plurality of capacitor elements are arranged, and electrically connected to positive electrodes of the plurality of capacitor elements; a second busbar extending in the direction in which the plurality of capacitor elements are arranged, and electrically connected to negative electrodes of the plurality of capacitor elements: a first terminal electrically connected to the positive electrodes of the plurality of capacitive elements; a second terminal electrically connected to the negative electrodes of the plurality of capacitive elements; and a heat receiving block thermally connected to the one or more heat transfer members; a power converter to convert power supplied from a power supply through the capacitor unit to power to be supplied to a load and output the power resulting from conversion; a housing accommodating the capacitor unit and the power converter; a power converter cooler to dissipate heat transferred from the power converter to air outside the housing; and a partition dividing an internal space of the housing into a first space and a second space, the first space accommodating the capacitor unit and the power converter and suppressing air flowing in from outside the housing, the second space allowing air flowing in from outside the housing, wherein portions of the one or more heat transfer members extend through the heat-receiving block in a direction orthogonal to the direction in which the plurality of capacitor elements are arranged, and dissipate heat transferred from the at least one capacitor element of the plurality of capacitor elements to the air outside the housing, the heat-receiving block included in the capacitor unit closes an opening in the partition, with a portion of a cooler being exposed to the second space through the opening, the cooler being formed with portions of the one or more heat transfer members extending through the heat-receiving block, and the power converter cooler closes an opening in the housing with a portion of the power converter cooler being exposed outside the housing through the opening.

Description

TECHNICAL FIELD The present disclosure relates to a capacitor unit and an electronic device. BACKGROUND ART Electronic devices such as power conversion apparatuses that convert input power and supply the power resulting from the conversion 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 for smoothing power installed in the center of a housing. CITATION LIST Patent Literature Patent Literature 1: Unexamined Japanese Patent Application Publication No. 2013-163503 SUMMARY OF INVENTION Technical Problem Heat generated in the capacitor unit during energization is dissipated to air inside the housing of the electronic device. The housing for the electronic device accommodates heating elements such as switching elements, in addition to the capacitor unit, which may increase the temperature of the air inside the housing. The capacitor unit with a large capacitance generates a large amount of heat, and thus may not be cooled sufficiently due to the rising temperature in the housing. This may increase the internal temperature of the capacitor unit, or more specifically, the temperature of capacitor elements in the capacitor unit. For a capacitor element being a film capacitor, the film for the capacitor element is to have an allowable temperature higher than the maximum temperature reachable by the capacitor element. The temperature of the capacitor element rises as a larger amount of current flows through the capacitor element. This may limit the amount of current flowing through the capacitor elements when the allowable temperature of the film is not sufficiently high. In other words, the capacitor unit may 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 increase in the capacitor elements accommodated in the housing. This is not limited to power supply devices including a capacitor unit with a large capacitance, but may occur to any electronic devices including a capacitor unit that may fail to cool the capacitor unit sufficiently. In response to the above circumstances, an objective of the present disclosure is to provide a capacitor unit and an electronic device including the capacitor unit with a smaller temperature increase in capacitor elements. Solution to Problem To achieve the above objective, a capacitor unit according to an aspect of the present disclosure includes a plurality of capacitor elements and one or more heat transfer members. The one or more heat transfer members are located adjacent to at least one capacitor element of the plurality of capacitor elements. The one or more heat transfer members internally dissipate heat received from at least one capacitor element of the plurality of capacitor elements. Advantageous Effects of Invention The capacitor unit according to the above aspect of the present disclosure allows heat generated in the plurality of capacitor elements to be dispersed inside the heat transfer members. The capacitor elements are thus cooled, which results in a smaller temperature increase. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a block diagram of an electronic device according to an embodiment; FIG. 2 is a front view of a capacitor unit according to the embodiment; FIG. 3 is a cross-sectional view of the capacitor unit according to the embodiment taken along line HI-III as viewed in the direction indicated by the arrows in FIG. 2; FIG. 4 is a diagram of a capacitor element in the embodiment; FIG. 5 is a cross-sectional view of the capacitor unit according to the embodiment; FIG. 6 is a rear view of the capacitor unit according to the embodiment; FIG. 7 is 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 top view of a capacitor unit according to a second modification of the embodiment; and FIG. 10 is a cross-sectional view of an electronic device according to a modification of the embodiment. DESCRIPTION OF EMBODIMENTS A capacitor unit and an electronic device according to one or more embodiments of the present disclosure are described below in detail with reference to the drawings. In the figures, the same reference signs denote the same or equivalent components. Examples of the electronic device include a power conversion apparatus mounted on a railway vehicle that converts direct current (DC) power supplied from a DC power source to 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 apparatus as an example. The electronic device 1 illustrated in FIG. 1 receives DC power from an unillustrated power source, or more