JP2012064794A - Power converter and power converter for railroad vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight main circuit structure of a power converter which suppresses stress transmitted to electrode terminals 10 of a case mold type capacitor 100 as with a conventional power converter, reduces the number of components placed around the electrode terminals 10, and is easily assembled.SOLUTION: Electrode terminals 10 and conductor bars 2 are fastened to an electric insulative structure 30 which is incorporated into a case mold type capacitor 100 and fixed to a frame 4 of a power converter.

Description

  The present invention relates to a power converter obtained by improving the structure of a main circuit portion of a power converter, and more particularly to a power converter for a railway vehicle.

  In general, a main circuit of a power converter for railway vehicles has a configuration in which a semiconductor element, a filter capacitor, and a snubber circuit are connected by a conductor bar. As a filter capacitor, a small-sized and large-capacitance capacitor is often used as described in Patent Document 1 (Japanese Patent Laid-Open No. 2007-67063), in which small-capacitance capacitor elements are connected in parallel. A case mold type capacitor 100 as shown in FIG.

  FIG. 3 shows the structure of the main circuit portion of such a power converter in the prior art. The case mold type capacitor 100 includes capacitor elements having positive and negative poles in the vertical direction connected in parallel at the electrode terminals 10. Further, the outside is sandwiched between resin cases 12 and 12 and resin molded. In FIG. 3, although individual capacitor elements are not shown, a range 11 in which the capacitor elements are mounted is shown. Both poles of the capacitor element are subjected to a metallicon process, and the electrode terminal 10 is soldered thereto. In order to prevent the capacitor element from being destroyed by heat, the electrode terminal 10 is a thin metal plate having a thickness of about 0.3 mm so that it can be soldered in a short time. The electrode terminal 10 is drawn to the end of the case mold type capacitor 100 and is connected to a conductor bar 2 of a metal plate described later (shown in FIGS. 1 and 2 but not shown in FIG. 3 of the conventional example). It is the composition which becomes. That is, the plate-like conductor bar 2 is connected to the thin metal plate-like electrode terminal 10. For this reason, when the conductor bar 2 vibrates during traveling of the vehicle, an excessive displacement stress may be applied to the electrode terminal 10 connected to the conductor bar 2 to be destroyed.

  Normally, in a power converter for a railway vehicle, the conductor bar 2 made of a metal plate needs to be a flat plate having a relatively large area. This is because power converters for railway vehicles have high currents and voltages unlike automobiles, etc., so it is necessary to increase the area of conductor bars arranged in parallel to reduce the influence of the generated electromagnetic field. There is. In this way, in power converters for railway vehicles, an inevitable measure against vibration of the conductor bar in parallel with the large and heavy positive and negative electrodes is an important point of the main circuit structure.

  Therefore, as a measure for increasing the strength against vibration of the electrode terminal 10, structures as shown in FIGS. 4 and 5 are conceivable. 4 is a perspective view in the same direction as the case mold type capacitor 100 of FIG. 3, and FIG. 5 is a view of a cross section passing through the electrode terminal 10 and the fastener 52 of FIG.

  As shown in FIG. 4, the countermeasure is to sandwich the electrode terminal 10 across the metal holding plates 8 and 8 that are thicker than the electrode terminal 10, and to fix the metal holding plates 8 and 8 to an electrically insulating structure. It was fixed to the body 34 with a fastener 58, and this electrically insulating structure 34 was fixed to the frame 4 of the power converter by the fastener 54. In other words, as shown in FIG. 5, the conductor bar 2 is fastened together with the holding plate 8 to the electrode terminal 10 by the metal fastener 52. Note that the conductor bar 2 is not shown in FIG. Such a case mold type capacitor 100 is arranged so that a cylindrical electrically insulating structure 31 is sandwiched between cases 12, and the frame 4 passes through a fixing hole 54 in a through hole of the electrically insulating structure 31. It is fixed to. With such a configuration, the displacement stress transmitted from the vibrating conductor bar 2 to the electrode terminal 10 can be suppressed by the suppression plate 8.

JP 2007-67063 A

  However, in such a configuration, the number of parts around the electrode terminal 10 of the case mold type capacitor 100 such as the holding plate 8 and the electrically insulating structure 34 is large, and the number of man-hours during assembly and maintenance increases. Cannot be resolved. Further, the weight around the electrode terminal 10 also increases, and there remains a problem that such a member is not desired to be provided in the moving body.

  An object of the present invention is to provide a power converter that significantly suppresses the stress transmitted to the electrode terminal 10 of the case mold type capacitor 100 by vibration from the conductor bar 2, and more preferably, components around the electrode terminal 10. An object of the present invention is to provide a main circuit structure of a power converter which is light in weight and easy to assemble by reducing the number of points.

  In order to achieve the above object, according to an embodiment of the present invention, when connecting the electrode terminal 10 and the conductor bar 2 in the case mold type capacitor 100, an electrically insulating rigid electrode is provided so as to contact the electrode terminal 10. The structure 30 is arranged. The electrically insulating structure 30 is fastened to the frame 4 together with the case 12 of the case mold type capacitor 100, and the conductor bar 2 and the electrode terminal 10 and the metal fastener are attached to the electrically insulating structure 30. Fasten at 52.

  A power converter according to the present invention includes a semiconductor element, a filter capacitor that smoothes a DC voltage, a pair of flat conductor bars connected to a pair of terminals of the filter capacitor, and a frame that supports them. A power converter, wherein a pair of terminals of the filter capacitor is formed into a flat plate shape, an electrically insulating structure is disposed in the filter capacitor, and the electrically insulating structure is mounted on a frame together with the case of the filter capacitor. The pair of conductor bars and the pair of terminals are fastened with a metal fastener to the electrically insulating structure.

  Furthermore, the power converter according to the present invention is characterized in that the electrically insulating structure has a plate-like structure disposed at one end of a case of the filter capacitor.

  Furthermore, when the power converter of the present invention fastens the pair of conductor bars and the pair of terminals to the electrically insulating structure with a metal fastener, the pair of conductor bars is high. It is characterized in that it is fastened through spacers of different sizes.

  Furthermore, the power converter according to the present invention is characterized in that the electrically insulating structure has a convex plate-like structure having a step portion disposed at one end of the case of the filter capacitor. And

  Furthermore, the power converter of the present invention is characterized in that the pair of conductor bars and the pair of terminals are fastened with a metal fastener in the step portion of the electrically insulating structure.

  According to the present invention, it is possible to achieve a power converter that does not destroy the electrode terminal 10 due to the vibration of the conductor bar 2 of the case mold type capacitor 100, more preferably the case. The number of parts around the electrode terminal 10 and the conductor bar 2 of the molded capacitor 100 can be reduced, and the weight can be reduced and the assemblability can be improved.

It is side surface sectional drawing of the case mold type capacitor | condenser in 1st embodiment of invention. It is side surface sectional drawing of the case mold type capacitor | condenser in 2nd embodiment of invention. It is a perspective view of a case mold type capacitor. It is a perspective view of one form at the time of a case mold type capacitor being mounted in a power converter. FIG. 5 is a side cross-sectional view of the case mold type capacitor of FIG. 4 viewed from the lateral direction.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, the case where the present invention is applied to a main circuit structure in which the case mold type capacitor 100 is mainly used as a filter capacitor will be described. However, the present invention is not limited to the structure of this embodiment. . In each figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. In the present invention, the vertical and horizontal directions are represented by the directions shown in FIGS.

  FIG. 1 is a diagram showing a first embodiment of a main circuit structure of a power converter according to the present invention, and is a cross-sectional view of a case mold type capacitor 100.

  As shown in FIG. 1, in a case mold type capacitor 100, a capacitor element (the range in which the capacitor element is mounted is indicated by reference numeral 11) is sandwiched between metal foil electrode terminals 10 and 10 from above and below. The resin case 12, 12 is sandwiched from above and below. The electrode terminal 10 is bent twice at the end portion, and the end portion (left end portion in FIG. 1) protrudes to the outside of the case mold type capacitor 100, and this protruding portion (left end portion of the electrode terminal 10). ) Is electrically connected to the conductor bar 2 with respect to a structure 30 to be described later. That is, the electrically insulating structure 30 is disposed so as to contact the protruding portion of the electrode terminal 10 and be sandwiched between the upper and lower cases 12 and 12. The shape of the electrically insulating structure 30 is not limited to a specific shape, but is desirably rigid so as not to resonate and vibrate even when the conductor bar 2 vibrates. In the electrically insulating structure 30, a gap for allowing the electrode terminal 10 to pass is formed in a part of the portion in contact with the case 12. Further, a step portion is provided along the electrode terminal 10 and protrudes outward to form a convex shape. A screw seat 62 is provided at the protruding step portion, and the conductor bar 2 and the electrode terminal 10 are fastened together by a metal fastener 52. A through hole 61 is provided so as to connect the upper and lower surfaces of the electrically insulating structure 30, and the frame 4 of the power converter and the upper and lower cases 12 and 12 are fastened together by a fastener 51.

  Thus, by providing the electrically insulating structure 30, the electrode terminal 10 and the conductor bar 2 are integrally supported with respect to the rigid electrically insulating structure 30 via the fastener 52. It is configured to be supported by the frame 4 via the fastener 61. As a result, the electrode terminal 10 and the conductor bar 2 are supported via the fasteners 52 as well as the combined structure of the electrically insulating structure 34 and the holding plate 8 having the structure shown in FIGS. 4 is supported by the fastener 51, and the number of parts can be reduced.

  In other words, the electrically insulating structure 30 of the present embodiment can suppress the displacement stress that is generated along with the vibration of the railway vehicle and is transmitted from the conductor bar 2 to the electrode terminal 10. Furthermore, according to this electrically insulating structure 30, since the frame 4 and the case 12 are fastened together, and the conductor bar 2 and the electrode terminal 10 are fastened together without the holding plate 8, FIG. Compared to the structure shown in FIG. 5, the number of fasteners 52 and 58 can be reduced, and the holding plate 8 can be eliminated. Therefore, the number of parts can be reduced and the weight can be reduced. Furthermore, since the electrically insulating structure 30 is built in the case mold type capacitor 100, the assemblability is facilitated and the maintainability of the power converter can be improved.

  FIG. 2 is a diagram showing a second embodiment of the main circuit structure of the power converter according to the present invention, and is a cross-sectional view of the case mold type capacitor 100. The main circuit structure of the power converter according to the present embodiment eliminates the portion protruding from the case mold type capacitor 100 to the outside by bending the end of the electrode terminal 10 once with respect to the first embodiment. The shape of the electrically insulating structure 30 is a flat plate, and the stepped portion protruding to the outside is eliminated, and the direction in which the end of the electrode terminal 10 and the conductor bar 2 are fastened is rotated by 90 degrees (the horizontal direction in the figure). Accordingly, the end of the conductor bar 2 is not bent, and the direction of the fasteners 52 and screw seats 62 is also rotated by 90 degrees (left and right direction in the figure). In addition, one conductor bar 2 and the electrode terminal 10 and the electrically insulating structure 30 are interposed via spacers 7 and 7 having different heights so as not to contact the other conductor bar 2 and the case mold type capacitor 100. The conductor bar 2 located on the outer side is provided with a hole 20 for accessing the tool to the fastener 52 of the conductor bar 2 on the side close to the case mold type capacitor 100.

  The operation and effect of the second embodiment are the same as those of the first embodiment, and furthermore, the protruding portion of the electrically insulating structure 30 and the electrode terminal 10 is eliminated. The size can be reduced, and it is difficult to interfere with surrounding parts when assembled in the power converter, and the number of bendings of the electrode terminal 10 is reduced, so that the manufacturability is facilitated.

  In the second embodiment, the case where the present invention is applied to the main circuit structure in which the case mold type capacitor 100 is a filter capacitor has been described. However, other capacitors can be similarly applied. . Even in this case, the electrically insulating structure 30 is disposed in the vicinity of the place where the thin plate-like electrode terminal 10 and the conductor bar 2 are connected in the capacitor, and the electrode terminal is disposed on the electrically insulating structure 30. 10 and the conductor bar 2 are supported by a metal fastener 52, and the electrically insulating structure 30 is supported by the frame 4 of the power converter. The effect of this can be obtained.

DESCRIPTION OF SYMBOLS 100 Case mold type capacitor | condenser 10 Electrode terminal 11 Range in which a capacitor | condenser element is mounted 12 Case 2 Conductor bar 20 Through-hole 30, 31, 34 of conductor bar 2 Insulating structure 4 Frame 51, 52, 54, 58 Fastener 61 Insulation Through-holes of the structural members 30 and 31 62 Screw seat 7 Spacer 8 Holding plate

Claims (6)

A power converter comprising a semiconductor element, a filter capacitor that smoothes a DC voltage, a pair of flat conductor bars connected to a pair of terminals of the filter capacitor, and a frame that supports them.
A pair of terminals of the filter capacitor is formed into a flat plate shape, and an electrically insulating structure is disposed in the filter capacitor.
Fastening the electrically insulating structure together with the filter capacitor case to a frame;
A power converter, wherein the pair of conductor bars and the pair of terminals are fastened to the electrically insulating structure with a metal fastener.   The power converter according to claim 1, wherein the electrically insulating structure has a plate-like structure disposed at one end of a case of the filter capacitor.   When the pair of conductor bars and the pair of terminals are fastened to the electrically insulating structure by a metal fastener, the pair of conductor bars are fastened via spacers having different heights. The power converter according to claim 3.   2. The power converter according to claim 1, wherein the electrically insulating structure has a convex plate-like body structure provided at one end portion of the case of the filter capacitor and provided with a stepped portion. .   5. The power converter according to claim 4, wherein the pair of conductor bars and the pair of terminals are fastened with a metal fastener at a step portion of the electrically insulating structure.   6. The power converter for a railway vehicle according to claim 1, wherein the power converter is mounted on a railway vehicle.

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