JP2013239624A - Capacitor module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitor module in which generation of noise due to vibration of a capacitor element can be suppressed regardless of the frequency of a signal being applied, or the frequency characteristics of a soundproof material.SOLUTION: A capacitor module 1 is constituted by arranging a plurality of capacitor elements 2, formed by winding a pair of insulating films each having a metal film into a flat roll and providing a pair of metallikon electrodes 6 connected with the metal films of respective insulating films, in a case 3. The metallikon electrodes 6 of respective capacitor elements 2 are connected so that the currents flow through adjoining capacitor elements 2 in the direction opposite from each other.

Description

  The present invention relates to a capacitor module configured by arranging a plurality of capacitor elements formed by winding an insulating film provided with a metal film in a case.

  Conventionally, such a capacitor module is used for the purpose of stabilizing the voltage in a power conversion device such as a hybrid vehicle or an electric vehicle. In such a case, as the capacitor element constituting the capacitor module, a metallized film capacitor that has a very long life and can be maintained free is used.

  In such a capacitor module, vibrations that cause noise may occur due to the Coulomb force that fluctuates according to the ripple current generated by a sudden voltage change. In order to block such noise, conventionally, the periphery of the capacitor element is covered with a sound insulating material, a sound insulating material, or the like.

  For example, in the case mold type capacitor described in Patent Document 1, a resin in which an elastomer which is an elastic body is blended is used as a material for a case for housing a capacitor element. Thereby, the vibration transmitted through the case is suppressed, and the generation of noise from the module is reduced.

JP 2008-211000 A

  However, when the periphery of the capacitor element is covered with a sound insulating material or a sound insulating material as described above, the frequency at which the desired effect cannot be obtained due to the increase in size of the capacitor module or the frequency characteristics of the sound insulating material. There are inconveniences such as the existence of bandwidth. Even in the case mold type capacitor described in Patent Document 1, noise may not be effectively reduced depending on the shape and material of the case and the frequency of the applied ripple current.

  An object of the present invention is to provide a capacitor module that can prevent generation of noise due to vibration of a capacitor element with a simple configuration regardless of the frequency of vibration, in view of the problems of the related art.

  The capacitor module of the present invention is a capacitor element formed by winding a pair of insulating films provided with a metal film in a flat roll shape and providing a pair of electrodes respectively connected to the metal films of each insulating film A capacitor module configured by arranging a plurality of capacitors in a case, wherein the electrodes of each capacitor element are connected such that directions of currents flowing in adjacent capacitor elements are opposite to each other. To do.

  Here, as described above, when a large ripple current is generated due to a rapid change in the voltage applied to the capacitor module, the Coulomb force acting on each capacitor element periodically fluctuates greatly, causing noise to the capacitor element. The vibration that causes this can occur.

  However, in the present invention, the directions of currents flowing in adjacent capacitor elements are opposite to each other, so that ripple currents in adjacent capacitor elements have opposite phases. As a result, the vibrations of the adjacent capacitor elements occur in opposite phases with each other and cancel each other.

  Therefore, according to the present invention, noise due to the vibration of the capacitor element can be prevented with a simple configuration regardless of the frequency of the vibration.

It is a perspective view of the capacitor module concerning one embodiment of the present invention. It is a figure which shows the connection of each capacitor | condenser element of the capacitor | condenser module of FIG. It is a wave form diagram which shows the noise prevention effect of the capacitor | condenser module of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the capacitor module 1 according to the embodiment is configured by arranging a plurality of capacitor elements 2 in a rectangular case 3. A mold resin is filled between the case 3 and each capacitor element 2. That is, the capacitor module 1 is a case mold type.

  The capacitor module 1 is used as, for example, a smoothing capacitor module disposed between an inverter that drives a three-phase motor and a battery in a hybrid vehicle or an electric vehicle. Therefore, as each capacitor element 2, a metallized film capacitor excellent in durability and pressure resistance is used.

  A metallized film capacitor is formed by winding a pair of insulating films provided with a metal film in a flat roll shape, and two metallicon electrodes connected to the metal films of the respective insulating films on both end surfaces by metal spraying. Constructed by forming. The metal film is formed by forming a film by vapor deposition or sputtering using a metal material such as aluminum or copper as a film forming material.

  Each capacitor element 2 has the same configuration, and is arranged in the case 3 in the same posture and adjacent to each other. In this arrangement, adjacent capacitor elements 2 are adjacent to each other via a flat surface in the flat roll shape or a semi-cylindrical side surface adjacent to the flat surface. The metallicon electrodes 6 (see FIG. 2) on one side and the other side of each capacitor element 2 in this arrangement are each positioned on one plane.

  The case 3 includes terminals 4 and 5 for connecting the capacitor module 1 to an external battery or the like. Connection from the terminals 4 and 5 to each capacitor element 2 is performed by wiring from the terminals 4 and 5 to the metallicon electrode 6 of each capacitor element 2 using a bus bar such as copper.

  FIG. 2 shows the connection between the terminals 4 and 5 and the metallicon electrode 6 of each capacitor element 2. As shown in FIG. 2, the capacitor elements 2 (2a, 2b) are connected in parallel so that the directions of currents flowing through the adjacent capacitor elements 2 are opposite to each other.

  That is, a capacitor element (hereinafter referred to as “capacitor element of the first group”) in which one side of the metallicon electrode 6 in the capacitor element array is connected to the positive side and the other side of the metallicon electrode 6 is connected to the negative side. ) In each capacitor element (hereinafter referred to as a “second group capacitor element”) 2b adjacent to 2a in the vertical and horizontal directions, the metallicon electrode 6 on one side is connected to the negative side, and the other side The metallicon electrode 6 on the negative side is connected to the positive side.

  In this configuration, when the voltage applied to the capacitor module 1 changes abruptly, a ripple current having a large amplitude flows through the capacitor module 1. At this time, in accordance with the ripple current, the Coulomb force acting between the metal films in each capacitor element 2 periodically fluctuates greatly, which may cause the insulating film to vibrate greatly. This vibration causes unpleasant noise.

  However, in this embodiment, the directions of the currents flowing in the adjacent first group of capacitor elements 2a and the second group of capacitor elements 2b are opposite to each other, so that the first group of capacitor elements 2a and the second group of capacitor elements 2b The ripple currents in the capacitor element 2b are in opposite phases. As a result, the vibrations of the adjacent capacitor elements 2 occur in opposite phases to each other and cancel each other. Therefore, the generation of noise due to the vibration of the capacitor element 2 is suppressed.

  FIG. 3 is a waveform diagram showing the vibration canceling effect. 3A and 3B exemplify ripple voltage waveforms at the positive and negative metallicon electrodes of the capacitor element. FIG. 3C illustrates the vibration waveform of each capacitor element in the conventional capacitor module when the ripple voltage waveform in each capacitor element is as shown in FIGS.

  FIG. 3D shows the relationship between the first group of capacitor elements 2a and the second group of capacitor elements 2b when the ripple voltage waveform in each capacitor element 2 is as shown in FIGS. The vibration waveform after the vibrations cancel each other is shown.

  In the conventional capacitor module, in all the capacitor elements arranged in the case, the metallicon electrode on one side in the arrangement is connected to the plus side, and the metallicon electrode on the other side is connected to the minus side. Therefore, when the ripple voltage waveforms at the positive and negative metallicon electrodes of each capacitor element are as shown in FIGS. 3A and 3B, all capacitor elements have the same phase. Oscillates as shown in FIG.

  In contrast, in the capacitor module 1 of the present embodiment, when the ripple voltage waveforms at the positive and negative metallicon electrodes 6 of each capacitor element 2 are as shown in FIGS. 3A and 3B, respectively. The direction of the ripple current is reversed between the capacitor element 2a in the first group and the capacitor element 2b in the second group, and the waveform of the positive ripple voltage in FIG. 3A and the negative ripple in FIG. A voltage waveform is generated on the opposite side between the first group of capacitor elements 2a and the second group of capacitor elements 2b.

  In this case, the vibration of the first group of capacitor elements 2a and the vibration of the second group of capacitor elements 2b occur in opposite phases. Therefore, the vibrations of the first group of capacitor elements 2a and the second group of capacitor elements 2b cancel each other, so that the vibrations after canceling each other have a small amplitude as shown in FIG. Therefore, noise due to vibration of the capacitor element 2 is suppressed.

  This vibration suppressing effect is considered to be obtained without being greatly affected by the frequency of the ripple current that causes the vibration, that is, the frequency of the vibration of the capacitor element 2.

  As described above, according to the present embodiment, since the metallicon electrode 6 of each capacitor element 2 is connected so that the current flowing in the adjacent capacitor element 2 is in the reverse direction, the vibration generated in each capacitor element 2 Can be canceled regardless of the frequency of vibration to prevent the generation of noise.

  The present invention is not limited to the above embodiment. For example, in the above description, the case 3 includes terminals 4 and 5 for connecting the capacitor module 1 to the outside. However, the terminals 4 and 5 are omitted and directly connected to an external battery or the like. Also good.

  In the above description, the case where the capacitor elements are connected in parallel has been described. However, the capacitor elements 2 may be connected in series. Even in this case, if adjacent capacitor elements 2 are connected so that currents flow in opposite directions, generation of noise can be similarly prevented.

  DESCRIPTION OF SYMBOLS 1 ... Capacitor module, 2 ... Capacitor element, 3 ... Case.

Claims (1)

A plurality of capacitor elements formed by winding a pair of insulating films provided with a metal film in a flat roll shape and providing a pair of electrodes respectively connected to the metal films of each insulating film are arranged in a case. A capacitor module composed of
The capacitor module is characterized in that the electrodes of each capacitor element are connected such that directions of currents flowing in adjacent capacitor elements are opposite to each other.

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