JP2006210561A - Capacitor cooling structure and power converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling structure of capacitor 1 for enabling reduction in size of a power converter. <P>SOLUTION: A flat type aluminum electrolytic capacitor 1 fully exposing a metal case is arranged any side down, this capacitor 1 is supported with an insulating plate 2 including an aperture 201 provided at the center, a heat radiating sheet 3 is held using this aperture 201, and the bottom surface of the capacitor 1 is pressurized in contact with a heat sink 4. The heat sink 4 is provided with a projected part for compressing the heat radiation sheet 3 to the predetermined thickness and the capacitor 1 is tightened to the heat sink 4 with a fixing tool 5 and bolts 61, 62. The power converter can be reduced in size through effective cooling process by compressing the heat radiating sheet 3 formed of a soft insulating material with the projected part 401 of the heat sink 4, and realizing simultaneously reliable insulation and high heat conductivity between the capacitor 1 and heat sink 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cooling structure for a smoothing capacitor for a power converter and a power converter.

A ripple current flows in proportion to the output current of the inverter in the capacitor used for smoothing the voltage of the power converter. Inside the capacitor, a loss is generated according to the ripple current, and the value is obtained by I ² R where I is the capacitor ripple current and R is the equivalent series resistance value of the capacitor. In general, since the resistance value R increases in inverse proportion to the capacitor capacity, the smaller the capacitor, the greater the loss that occurs.

  In the case of a general power conversion device, heat generated in the capacitor is radiated from the capacitor element → the capacitor case → the sleeve → the capacitor fixing base → the power conversion device case. In order to increase the heat dissipation efficiency, it was necessary to improve the capacitor fixing base by making it thicker and thicker. In addition, when a plurality of capacitors are mounted, there is a problem that the temperature of the capacitor located at the center rises.

  In order to solve this problem, Patent Document 1 proposes a structure in which fins are provided in a capacitor case to effectively dissipate heat generated inside the capacitor.

JP 2002-15950 A (Overall)

  However, with this structure, the heat inside the capacitor can be efficiently radiated to the outside of the capacitor, but since the heat is radiated to the internal space of the power converter, the internal temperature of the power converter is increased, and finally In addition, the temperature of the capacitor is increased. In addition, since the insulation of the capacitor is not taken into consideration, there is a problem that it cannot be used for the application to a high voltage power converter of several tens [V] or more.

  The objective of this invention is providing the cooling structure of the capacitor which can cool effectively the capacitor used for a power converter device with a comparatively small structure.

  Another object of the present invention is to provide a miniaturized power converter that can effectively cool and downsize the capacitor, electronic component, and / or semiconductor module of the power converter.

  In a preferred embodiment of the present invention, a horizontally laid capacitor is supported by an insulating plate (insulator) having an opening at the center. Next, the opening of the insulating plate is closed with a heat radiating sheet, and a heat sink having a convex portion for compressing the heat radiating sheet is applied and fixed from below the insulating plate and the heat radiating sheet.

  Here, preferably, an overlap with the insulating plate is provided at the end of the heat dissipation sheet.

  In another desirable embodiment of the present invention, a case 9 is provided in which the electronic component of the power converter is mounted on the anti-capacitor side of the heat sink and the semiconductor module is mounted below the capacitor.

  According to a preferred embodiment of the present invention, a capacitor can be provided with a high heat dissipation structure, and the capacitor can be miniaturized.

  According to another preferred embodiment of the present invention, the capacitor, the electronic component, and / or the semiconductor module of the power conversion device can be effectively cooled, and the power conversion device can be reduced in size.

  Other objects and features of the present invention will become apparent in the description of the embodiments described below.

Example 1:
The capacitor cooling structure according to the first embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

  FIG. 1 is a schematic mounting structure diagram of a capacitor in a power conversion device according to Embodiment 1 of the present invention, and FIG. 2 is an exploded view thereof. In the figure, reference numeral 1 denotes a flat aluminum electrolytic capacitor with a metal case exposed, and is hereinafter referred to as a capacitor for short. The capacitor 1 is supported on the insulating plate 2 in a lying state. The insulating plate 2 is made of a resin material having high hardness, supports the load of the capacitor 1, and has an opening 201 at its center, that is, at the bottom of the capacitor 1. The heat radiating sheet 3 is sandwiched so as to close the opening 201, the heat sink 4 is applied from below, and the fixing tool 5 and the bolts 61 and 62 are fastened. The heat-dissipating sheet 3 is flexible with no hardness, but uses a material having high insulation and thermal conductivity. The heat sink 4 is provided with a convex portion 401 at a portion in contact with the heat radiating sheet 3, and the heat radiating sheet 3 is compressed in the state of FIG. 1 fastened with bolts 61 and 62. The heat sink 4 serves to release the heat of the capacitor 1 to the outside by flowing cooling water in the vicinity not shown.

  Here, the heat generated in the capacitor is effectively radiated from the capacitor element → the heat radiation sheet → the heat sink.

  According to the first embodiment, the heat radiating sheet 3 having high thermal conductivity is used on the bottom surface of the capacitor 1, and the heat radiating sheet 3 is compressed by the opening 201 of the insulating plate 2 and the convex portion 401 of the heat sink 4. The thermal conductivity from 1 to the heat sink 4 can be sufficiently reduced. Therefore, the capacitor 1 is effectively cooled, and the heat can be dissipated to the outside through a coolant such as cooling water of the heat sink 4.

  In addition, since the aluminum electrolytic capacitor 1 with the sleeve without the metal case is pressed against the heat radiating sheet 3 as it is, more effective cooling can be expected.

  In the first embodiment, the aluminum electrolytic type is used for the capacitor 1, but it can also be applied to other capacitors such as a film and a ceramic.

  Further, it can be applied to electronic parts other than capacitors, resistors, inductors, transformers, and the like.

Example 2:
Next, Embodiment 2 of the present invention will be described with reference to FIGS.

  FIG. 3 is a schematic mounting structure diagram of a capacitor in the power conversion device according to the second embodiment of the present invention, and FIG. 4 is an exploded view thereof. In the figure, the same functional parts as those in the first embodiment shown in FIGS. The difference from the first embodiment is that a heat dissipation sheet 3 that is wider than the opening 201 of the insulating plate 2 is used as shown in FIG. Next, the heat sink 4 is provided with a concave portion 402 on the outer peripheral portion of the central convex portion 401. If these are fastened by the fixture 5 and the bolts 61 and 62 in the same manner as in the first embodiment, the end portion of the heat radiation sheet 3 overlaps the lower side of the edge portion of the insulating plate 2 as shown in FIG. Can be completely blocked. In this way, by letting the end portion of the heat dissipation sheet 3 be under the edge portion of the insulating plate 2, high insulation performance can be exhibited.

  According to the second embodiment, the gap between the insulating plate 2 and the heat radiating sheet 3 can be completely closed, and high insulation performance can be exhibited. Therefore, a power converter for high voltage of several tens [V] or more can be used in a capacitor. A high heat dissipation structure can be provided.

Example 3:
Next, Embodiment 3 of the present invention will be described with reference to FIG.

  FIG. 5 is a schematic mounting structure diagram of the capacitor in the power converter according to the third embodiment of the present invention. In the figure, the same function parts as those in FIGS. The difference from the second embodiment is that a recess 202 is provided on the lower surface side of the edge portion along the opening 201 of the insulating plate 2, and the end portion of the heat radiation sheet 3 enters the recess 202 on the lower surface side of the edge portion of the insulating plate 2. That is, it is configured to overlap with the insulating plate 2.

  Also in the third embodiment, the gap between the insulating plate 2 and the heat radiating sheet 3 can be completely blocked, and high insulation performance can be exhibited. Therefore, a high heat dissipation structure is provided for the capacitor also in the power converter for high voltage. Can do. Further, according to the third embodiment, it is easy to provide the depression 202 in the insulating plate 2, and it is not necessary to process the uneven portion of the heat sink 4 as in the second embodiment, and a heat sink having the same structure as that in the first embodiment is used. Since it can be used, there exists an effect which the process becomes easy.

Example 4:
Next, Embodiment 4 of the present invention will be described with reference to FIG.

  FIG. 6 is a schematic mounting structure diagram of a capacitor in the power conversion device according to the fourth embodiment of the present invention. In the figure, the same function parts as those in FIGS. The difference from the third embodiment is that a recess 203 is provided on the upper surface side of the edge portion along the opening 201 of the insulating plate 2, and the end portion of the heat radiation sheet 3 uses the recess 203 on the upper surface side of the edge portion of the insulating plate 2. Thus, the insulating plate 2 is overlaid.

  Also in the fourth embodiment, the gap between the insulating plate 2 and the heat radiating sheet 3 can be completely closed, and high insulation performance can be exhibited. Therefore, a high heat dissipation structure is provided for the capacitor also in the power converter for high voltage. Can do. Also in the fourth embodiment, it is easy to provide the recess 203 in the insulating plate 2, and it is not necessary to process the uneven portion of the heat sink 4 as in the second embodiment, and the heat sink having the same structure as in the first and third embodiments. Therefore, there is an effect that the processing is simplified.

  Furthermore, since the heat dissipation sheet 3 can be put on the insulating plate 2 and fastened, workability during assembly is improved.

Example 5:
Next, Embodiment 5 of the present invention will be described with reference to FIGS.

  FIG. 7 is a schematic mounting structure diagram of a capacitor in a power converter according to a fifth embodiment of the present invention, and FIG. 8 is a perspective view of the capacitor with a resin case. The same functional parts as those in FIGS. The difference from the second embodiment of FIGS. 3 and 4 is that the insulating plate 2 that supports the capacitor 1 is omitted, and instead the resin case 7 protects the capacitor. Here, the resin case 7 is provided with an opening 701 on the bottom surface of the capacitor 1. The resin case 7 may be a sleeve provided with an opening.

  For example, in the case of a high voltage of 300 [V] or higher, the capacitor 1 may be placed in a resin case 7 or a sleeve instead of being exposed for insulation and protection. In such a case, as in the present embodiment, an opening 701 is provided in the resin case 7 or the sleeve, and the opening 701 is used to remove the heat dissipation sheet 3 from the capacitor 1 as in the previous embodiments. Thus, a high heat dissipation structure to the heat sink 4 can be provided.

  According to this embodiment, the insulating plate 2 in the previous embodiments is not necessary, and the resin case 7 is present. Therefore, the fixture 51 is sufficient to be an easily rounded square shape.

Example 6:
Next, Embodiment 6 of the present invention will be described with reference to FIG.

  FIG. 9 is a side view illustrating a schematic structure of a power conversion device according to Embodiment 6 of the present invention. The same functional parts as those in FIGS. In the sixth embodiment, the semiconductor module 10 is mounted on the lower part of the case 9 of the power converter, and the cooling water 11 is led to the bottom of the case 9. The capacitor 1 is disposed above the semiconductor module 10, and further, a controller 8 such as a circuit board or component of the power converter is mounted thereon.

  The cooling structure from the lower part of the capacitor 1 is basically the same as that of the fifth embodiment of FIG. 7, and heat is radiated to the heat radiation sheet 31 and the heat sink 41 using the opening 701 of the resin case 7.

  The difference is that the resin case 7 is provided with an opening 702 above the capacitor 1, and the heat radiation sheet 32 and the heat sink 42 are mounted thereon so that the heat of the capacitor 1 can be dissipated up and down. Further, by mounting the controller 8 such as a circuit board or a component on the upper heat sink 42, both the capacitor 1 and the controller 8 can be cooled.

  The heat generated in the capacitor 1 is dissipated from the heat sinks 41 and 42 through the case 9 of the power converter to the cooling water 11 and is dissipated outside the power converter.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic attachment structure figure of the capacitor in the power converter device by Example 1 of this invention. The exploded view of FIG. The schematic attachment structure figure of the capacitor in the power converter by Example 2 of the present invention. FIG. 4 is an exploded view of FIG. 3. The schematic attachment structure figure of the capacitor in the power converter by Example 3 of the present invention. The schematic attachment structure figure of the capacitor in the power converter by Example 4 of the present invention. The schematic attachment structure figure of the capacitor in the power converter by Example 5 of the present invention. The perspective view of the capacitor | condenser with a resin case in FIG. The side view explaining schematic structure of the power converter device by Example 6 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Capacitor, 2 ... Insulating plate, 201 ... Opening part of insulating plate, 202, 203 ... Indentation of insulating plate, 3, 31, 32 ... Radiation sheet, 4, 41, 42 ... Heat sink, 401 ... Convex part of heat sink, 402 ... concave portion of heat sink, 5 ... fixing means (fixing tool), 61, 62 ... bolt, 7 ... resin case, 701, 702 ... opening of resin case, 8 ... controller, 9 ... case of power converter, 10 ... Semiconductor module of power converter, 11 ... cooling water.

Claims (11)

  A capacitor lying down, supporting the capacitor, an insulating plate having an opening at the center of the bottom surface of the capacitor, a heat dissipation sheet closing the opening of the insulating plate, and a lower portion of the insulating plate and the heat dissipation sheet A capacitor cooling structure comprising: a heat sink that is positioned and has a convex portion that compresses the heat dissipation sheet; and a fixing means that fixes the capacitor to the heat sink.   2. The capacitor cooling structure according to claim 1, wherein the capacitor is a flat aluminum electrolytic capacitor with a metal case exposed.   A heat radiation comprising a capacitor lying down, an insulating plate that supports the capacitor and has an opening at the center of the bottom surface of the capacitor, and a highly thermally conductive insulating material that covers the opening by overlapping with an edge of the insulating plate. A capacitor comprising: a sheet; a heat sink located under the insulating plate and the heat radiating sheet; and a convex portion that compresses the heat radiating sheet; and a fixing unit that fixes the capacitor to the heat sink. Cooling structure.   The capacitor cooling structure according to claim 3, wherein the heat dissipation sheet is configured to overlap the lower side of the edge of the insulating plate and close the opening.   5. The insulating plate according to claim 4, wherein the insulating plate includes a recess on a lower surface side of an opening edge portion thereof, and the heat dissipation sheet is configured to overlap the insulating plate at a recess on the lower surface side of the edge portion of the insulating plate. Capacitor cooling structure.   The capacitor cooling structure according to claim 3, wherein the heat dissipation sheet is configured to overlap with an upper side of an edge portion of the insulating plate and close the opening.   The insulating plate according to claim 6, wherein the insulating plate includes a recess on an upper surface side of an opening edge thereof, and the heat dissipation sheet is configured to overlap the insulating plate at a recess on the upper surface side of the edge portion of the insulating plate. Capacitor cooling structure.   In any one of Claims 1-7, in the state which fixed the said capacitor to the said heat sink by the said fixing means, the said heat dissipation sheet has the high thermal conductivity by which the part which contacts a capacitor was compressed thinner than the other part A capacitor cooling structure comprising an insulating material.   A capacitor lying down, an insulating resin case that encloses the upper and lower surfaces of the capacitor and having an opening at the center of the bottom surface of the capacitor, a heat dissipation sheet that closes the opening of the insulating resin case, the insulating resin case, A cooling structure for a capacitor, comprising: a heat sink having a convex portion that abuts the heat radiating sheet from below and compresses the heat radiating sheet; and a fixing unit that fixes the capacitor to the heat sink.   A capacitor that is laid down, an insulating plate that is in contact with the upper surface and / or lower surface of the capacitor and has an opening at the center of the upper surface and / or lower surface of the capacitor, and a heat dissipation sheet that closes the opening of the insulating plate, The insulating plate and the heat dissipation sheet are mounted on the anti-capacitor side of the heat sink, the heat sink having a convex portion for compressing the heat dissipation sheet, the fixing means for fixing the capacitor to the heat sink, and the heat sink. A power conversion device comprising an electronic component of a power converter.   The power conversion device according to claim 10, further comprising a case in which a semiconductor module is mounted below the capacitor.

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