JP2011096786A - Capacitive element module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a capacitive element module in which the influence of deterioration of mutual inductance of current pathways routed in parallel in opposite directions to each other is suppressed. <P>SOLUTION: The capacitive element module 10 includes: a plurality of cylindrical capacitive elements 12, 13; and a pair of bus bars 20, 30. The bus bar 20 has a connecting plate portion 22 for connecting the cathode electrodes 14 of the capacitive elements 12, 13 to each other, and an externally connecting portion 24 for external connection. The bus bar 30 has a connecting plate portion 32 for connecting the anode electrodes 16 of the capacitive element 12, 13 to each other, and an externally connecting portion 34 for external connection. The bus bar 30 includes a lead-out plate portion 36 to be led out from the connecting plate portion 32 toward the externally connecting portion 34. Slits 40, 42, 44 for meandering the current pathways are provided on the lead-out plate portion 36. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a capacitive element module, and more particularly to a capacitive element module configured by connecting a plurality of capacitive elements having electrodes on opposite ends with a pair of bus bars.

  A smoothing capacitor used in a power inverter system such as a vehicle driving application or an industrial application typified by a hybrid vehicle is required to have a large capacity, a high rated voltage, and a large current resistance. A capacitor is a capacitive element that forms a capacitance by the electric charge between two electrodes. A film capacitor is known as a capacitive element having a high rated voltage and excellent current resistance performance. However, since each element has a small capacity, a capacitive element module in which a necessary number of capacitive elements are connected is used.

  By the way, when a plurality of capacitive elements are connected, current does not necessarily flow evenly, current concentration occurs locally, so that heat generation becomes non-uniform and heat resistance performance may not be satisfied.

  For example, in Patent Document 1, in a capacitor module formed by arranging a plurality of cylindrical capacitor elements having electrodes at both ends in two directions intersecting each other, a first bus bar and a first bus bar are connected to connect the electrodes of the capacitor elements. When using the second bus bar and taking out the first electrode terminal from the first bus bar and the second electrode terminal from the second bus bar on the same side of the capacitor module, it is pointed out that current concentration occurs in the capacitor element near each electrode terminal. ing. Here, a slit is provided in each bus bar so as to extend from the portion where the first electrode terminal and the second electrode terminal are connected toward the center of each bus bar so that current flows evenly to each capacitor element. The structure to perform is disclosed.

  Further, in Patent Document 2, in capacitors arranged in a row so that the end faces of a plurality of capacitor elements having two opposite end faces are located on the same plane, a positive electrode bus bar and a positive bus bar are arranged on the same side face of each capacitor element. It is disclosed that a negative electrode bus bar is disposed along the X direction, which is the arrangement direction of the capacitor elements, and a slit for diverting current is formed along the X direction in the positive electrode bus bar.

  In addition, in Patent Document 3, in the case of wiring a multi-phase power converter using a parallel plate-shaped conductor, in order to suppress the influence on switching of each phase on other phases, It is disclosed that a slit is provided between each phase connection provided, and a slit is provided between each phase connection provided on the negative conductor.

JP 2007-31634 A JP 2009-99884 A JP 2000-60126 A

  According to the prior art, it is shown that a slit is provided in a bus bar or the like in order to equalize the length of the current path or to suppress interference between adjacent current paths.

  By the way, when two current paths run parallel to each other in opposite directions, the magnetic fields induced by the two currents cancel each other, so that the mutual inductance of that portion may become a very low value. . When a place where the mutual inductance is locally low occurs, the high-frequency component current concentrates on the portion, and local heat generation and temperature rise occur.

  The objective of this invention is providing the capacitive element module which can suppress the influence of the fall of the mutual inductance by the electric current path | route which parallelly parallels mutually.

  In the capacitive element module according to the present invention, a plurality of electrodes arranged in parallel so that one end electrode is provided on one end face of the two opposite end faces and the other end electrode is provided on the other end face, and each end face is located on the same plane. Each of the capacitive elements, one side bus plate having one side connection plate part and one side external connection part for external connection that mutually connect one side electrodes of one end face of each capacitive element, and the other end face of each capacitive element The other-side bus bar having the other-side connection plate portion for connecting the other-side electrodes to each other and the other-side external connection portion for external connection, the capacitor element of the capacitor element from the other-side connection plate portion toward the other-side external connection portion The other side bus bar including a lead plate portion that is pulled out while being arranged in parallel with one side surface, and the lead plate portion has a capacity out of a current flowing between the other side connection plate portion and the other side external connection portion. One where current flows in the element It has a plate shape in which a current component running parallel to the direction is small.

  In the capacitive element module according to the present invention, it is preferable that the extraction plate portion has a plate shape in which a path of a current flowing between the other side connection plate portion and the other side external connection portion meanders.

  Moreover, in the capacitive element module according to the present invention, it is preferable that the extraction plate portion has a plate shape including a hole portion provided between the other side connection plate portion and the other side external connection portion.

  With the above configuration, the capacitive element module includes a drawer plate portion in a bus bar including a drawer plate portion that is pulled out while being arranged in parallel with one side surface of the capacitive element from the connection plate portion toward the external connection portion of the pair of bus bars. Has a plate shape in which the current component that runs parallel to the direction in which the current flows in the capacitive element among the current flowing between the other side connection plate and the other side external connection is small. As a result, the magnitudes of the current components that run parallel to each other in the opposite direction between the extraction plate portion and the capacitive element do not become the same, so that a decrease in mutual inductance is suppressed.

  Further, since the drawer plate portion has a plate shape in which the path of the current flowing between the other side connection plate portion and the other side external connection portion is meandering, the drawer plate portion and the capacitive element are arranged in opposite directions. Since the magnitudes of the running current components are not the same, the decrease in mutual inductance is suppressed.

  In addition, since the drawer plate portion has a shape including a hole portion between the other side connection plate portion and the other side external connection portion, the hole portion between the other side connection plate portion and the other side external connection portion. In the flowing current, the component that runs in parallel with the current flowing in the capacitor element is reduced. As a result, the magnitudes of the current components that run parallel to each other in the opposite directions between the extraction plate portion and the capacitive element do not become the same, so that a decrease in mutual inductance is suppressed.

It is a perspective view explaining the structure of the capacitive element module which concerns on this invention. It is a top view explaining the structure of the capacitive element module which concerns on this invention. FIG. 10 is a side view for explaining the reason why the mutual inductance is reduced by currents running in opposite directions in the conventional capacitive element module. FIG. 4 is a front view corresponding to FIG. 3. It is a front view explaining a current path in a capacitive element module according to the present invention. In the capacitive element module which concerns on this invention, it is a figure explaining the other structure of the drawer | drawing-out board part.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. In the following, a smoothing capacitor used in a drive circuit of a hybrid vehicle will be described as an object for which a capacitor element module is used. However, a capacitor configured by connecting a plurality of capacitor elements having electrodes at opposite ends with a pair of bus bars. It may be an element module and may be used for other uses such as industrial use.

  In the following description, the capacitive element constituting the capacitive element module is described as a film capacitor. However, any capacitive element having electrodes at both ends facing each other may be used, and a ceramic capacitor other than a film capacitor, an electrolytic capacitor, or the like may be used. In addition, although the description will be given assuming that the number of capacitive elements constituting the capacitive element module is 13, it is needless to say that the number may be other than this.

  In addition, materials, temperatures, and the like described below are examples for explanation, and can be appropriately changed according to the specifications of the capacitive element module.

  Below, the same code | symbol is attached | subjected to the same element in all the drawings, and the overlapping description is abbreviate | omitted. In the description in the text, the symbols described before are used as necessary.

  FIG. 1 is a perspective view illustrating the configuration of the capacitive element module 10, and FIG. 2 is a plan view thereof. The capacitive element module 10 is used as a smoothing capacitor for a drive circuit of a hybrid vehicle, and is a capacitor module that forms a necessary capacitance for a hybrid vehicle drive circuit by connecting a plurality of capacitive elements in parallel.

  FIG. 1 shows the X axis, Y axis, and Z axis directions that are three axes orthogonal to each other. Here, the Z axis is taken parallel to the axial direction of the cylindrical shape of the capacitive elements 12 and 13, and the X axis and the Y axis are taken so that the plane perpendicular to the Z axis is the XY plane. In FIG. 2 and subsequent figures, directions corresponding to these three axes are shown.

  The capacitive element module 10 includes 13 cylindrical capacitive elements 12 and 13 and a pair of bus bars 20 and 30. The 13 cylindrical capacitive elements 12 and 13 are arranged in parallel with the Y direction as five, three, and five, and these three columns are arranged along the X direction, and as a whole on the XY plane. 13 are arranged in a substantially rectangular area. Thus, the capacitive element module 10 in which the 13 capacitive elements 12 and 13 are arranged has a side surface parallel to the XZ plane and a side surface parallel to the YZ plane.

  The thirteen capacitive elements 12 and 13 have the same shape and the same characteristics and are not distinguished from each other. However, as will be described later, the capacitive element 13 closest to the drawer plate portion 36 of the bus bar 30 is used. Is important from the viewpoint of mutual inductance. Therefore, the symbol of this capacitive element is different from that of the other capacitive elements 12.

  The capacitive elements 12 and 13 are cylindrical film capacitors. Here, 13 capacitive elements constitute one capacitive element module 10. Each of the capacitive elements 12 and 13 is provided with one electrode on one end face of two opposing end faces and the other electrode on the other end face. In the example of FIG. 1, the capacitive elements 12 and 13 are arranged in the Z-axis direction so that the cylindrical axial direction is aligned. The positive electrode 16 is disposed in parallel so that the positive electrode 16 is located on the same plane on the lower side in the direction. The same plane is a plane parallel to the XY plane. That is, the upper end surface of the cylindrical shape corresponds to one end surface, the lower end surface corresponds to the other end surface, the negative electrode 14 corresponds to the one electrode, and the positive electrode 16 corresponds to the other electrode.

  Of the pair of bus bars 20, 30, the bus bar 20 is a conductor plate that connects the negative electrodes 14 of the capacitive elements 12, 13 to each other. The bus bar 20 has a shape in which a part of the end portion of one conductor plate is bent, and a flat plate portion corresponding to the original main body portion to be bent is connected to the negative electrode 14 of each of the capacitive elements 12 and 13. This is the connecting plate portion 22.

  A portion where a part of the end portion of the connection plate portion 22 is bent to provide an appropriate external connection hole is an external connection portion 24. The connecting plate portion 22 is disposed above the capacitive elements 12 and 13 so as to be parallel to the XY plane, and a part of the end portion thereof is bent in parallel to the XZ plane, and is externally connected to a bent surface parallel to the XZ plane. A portion 24 is provided. The external connection portion 24 corresponds to a negative electrode side electrode connection portion of the capacitive element module 10, that is, a negative terminal or an N terminal. Since the negative electrode side is one side, the connection plate portion 22 corresponds to one side connection plate portion, and the external connection portion 24 corresponds to one side external connection portion.

  As this bus bar 20, what processed the suitable metal plate into the desired shape by press molding etc. can be used. An appropriate connection method such as soldering can be used to connect the capacitive elements 12 and 13 to the negative electrode 14.

  Of the pair of bus bars 20, 30, the bus bar 30 is a conductor plate that connects the positive electrodes 16 of the capacitive elements 12, 13 to each other. As described in relation to the bus bar 20, a suitable metal plate can be used as the conductor plate, and soldering or the like can be used as the connection method.

  The bus bar 30 has a shape in which the end portion of one conductor plate is bent, and a flat plate portion corresponding to the original main body portion to be bent is connected to the positive electrode 16 of each of the capacitive elements 12 and 13. Part 32. A portion provided with an appropriate external connection hole for connection to the outside is provided at the distal end portion where the end portion of the connection plate portion 32 is bent. The external connection portion 34 corresponds to a positive electrode side electrode connection portion of the capacitive element module 10, that is, a plus terminal or a P terminal. Since the positive electrode side is the other side, the connection plate portion 32 corresponds to the other side connection plate portion, and the external connection portion 34 corresponds to the other side connection portion.

  The bus bar 30 has a drawing plate portion 36 that is drawn from the connection plate portion 32 toward the external connection portion 34 while being arranged in parallel with one side surface of the capacitive element 13. The bus bar 20 is not provided with the equivalent of the drawer plate portion 36 but the bus bar 30 is provided with the drawer plate portion 36 because of the height relationship between the external connection portion 24 of the bus bar 20 and the external connection portion 34 of the bus bar 30. This is because they are the same. The height is a dimension along the Z direction that is the axial direction of the cylindrical shape of the capacitive elements 12 and 13 in the capacitive element module 10. That is, the height of the drawer plate portion 36 is set to a dimension corresponding to the cylindrical axial height of the capacitive elements 12 and 13.

  Further, the lead plate portion 36 is bent from the connection plate portion 32 in one of the four side surfaces of the capacitive element module 10 so that the external connection portion 34 of the bus bar 30 is parallel to the external connection portion 24 of the bus bar 20. Done along one side.

  In the example of FIG. 1, the connection plate portion 32 is disposed below the capacitive elements 12 and 13 so as to be parallel to the XY plane. That is, the connection plate portion 32 of the bus bar 30 is arranged in parallel with the connection plate portion 22 of the bus bar 20 via the capacitive elements 12 and 13.

  The drawer plate portion 36 is formed by being bent in parallel with the XZ plane at the end portion of the connection plate portion 32. That is, the capacitive element module 10 has a side surface parallel to the XZ plane and a side surface parallel to the YZ plane, but the drawer plate portion 36 of the bus bar 30 extends along the side surface parallel to the XZ plane in the capacitive element module 10. It is bent from the connection plate part 32. Therefore, the external connection portion 34 of the bus bar 30 has a surface parallel to the XZ plane.

  As described above, since the external connection portion 24 of the bus bar 20 also has a surface parallel to the XZ plane, the two external connection portions 24 and 34 have surfaces parallel to the XZ plane, and further have a height in the Z direction. The relationship is aligned. In this way, the external connection portion 24 of the bus bar 20 and the external connection portion 34 of the bus bar 30 have surfaces parallel to each other and have the same height relationship, so that the capacitive element module is added to the drive circuit of the hybrid vehicle. 10 can be easily connected.

  The horizontal slits 40, 42, and 44 provided in the drawer plate portion 36 of the bus bar 30 are provided in the drawer plate portion 36 so that the path of the current flowing between the connection plate portion 32 and the external connection portion 34 meanders. It is what The lateral direction is a direction that is not parallel to the Z direction when the drawer plate 36 is parallel to the XZ plane and the direction from the connection plate 32 to the external connection 34 is the Z direction.

  Speaking laterally with respect to the Z direction usually refers to the X direction, but the slits 40, 42, and 44 mean that the path of the current flowing between the connection plate part 32 and the external connection part 34 meanders as described above. Since it is provided, the extending direction of the slits 40, 42, and 44 does not necessarily have to be parallel to the X direction, as long as the direction is different from the Z direction. In the above description, the number of slits is three, but other numbers may be used. For example, only one slit may be sufficient, and four or more may be sufficient if the strength of the drawer plate part 36 is sufficient.

  The operational effects of the above configuration will be described with reference to FIGS. 3 to 5 in comparison with the prior art that uses a flat drawer plate portion that is not provided with a slit. 3 and 4 are a side view and a front view of the capacitive element module 8 using the flat lead plate portion 35 without a slit. 3 and 4, only the vicinity of the drawer plate portion 35 is extracted and shown. FIG. 5 is a front view of the capacitive element module 10 using the extraction plate portion 36 provided with the slits 40, 42, 44 described in FIGS. 1 and 2.

  3 and 4, considering that the capacitive element module 8 is connected and disposed between the positive and negative buses of the drive circuit of the hybrid vehicle, the external connection portion of the bus bar 30 that is a plus terminal of the capacitive element module 8 34 is connected to the positive bus of the drive circuit, and the external connection portion 24 of the bus bar 20 as a negative terminal is connected to the negative bus of the drive circuit.

  At this time, if discharging is performed from the capacitive element module 8, a current flows from the external connection portion 34 of the bus bar 30 to the positive bus side of the drive circuit. Correspondingly, a current 50 flows from each of the capacitive elements 12 and 13 toward the positive electrode 16 connected to the bus bar 30 from the negative electrode 14 connected to the bus bar 20, and the connection plate portion 32 of the bus bar 30. A current 54 flows from the through plate portion 35 to the external connection portion 34. 3 and 4, only the current 50 flowing through the capacitive element 13 closest to the extraction plate portion 35 is shown.

  As described above, when the capacitive element module 8 functions as an electrostatic capacity, the current 54 that flows through the flat lead plate portion 35 and the current 50 that flows through the capacitive element 13 run in parallel in opposite directions. become. Therefore, the magnetic field 52 induced by the current 50 and the magnetic field 56 induced by the current 54 are opposite to each other and cancel each other. Thereby, the mutual inductance of the capacitive element 13 with respect to the drawer | drawing-out board part 35 becomes a small value.

  The effect of reducing the mutual inductance due to the cancellation of the magnetic fields 52 and 56 in the opposite directions becomes more prominent as the distance between the currents 50 and 54 running in opposite directions becomes shorter. In the examples of FIGS. 3 and 4, the mutual inductance is significantly reduced in the capacitive element 13 closest to the extraction plate portion 35, and in the extreme case where the magnetic fields 52 and 56 are almost canceled, the mutual inductance is reduced. Extremely small value.

  Thus, when the mutual conductance of the capacitive element 13 is extremely low compared to other capacitive elements 12, for example, a current component due to a high-frequency ripple signal or the like flows intensively in the capacitive element 13, and current unloading occurs. Balance occurs in the capacitive element module 8. As a result, in the capacitive element module 8, the capacitive element 13 generates more heat than the other capacitive elements 12, causing a local temperature increase.

  FIG. 5 is a front view of the capacitive element module 10 using the extraction plate portion 36 provided with the slits 40, 42, and 44 in the horizontal direction as described with reference to FIGS. Even in this case, when the capacitive element module 10 functions as a capacitance, the current 58 flows from the connection plate portion 32 toward the external connection portion 34 in the extraction plate portion 36 as in the case of FIGS. 3 and 4. It is. Here, since the drawer plate part 36 of FIG. 5 is provided with the slits 40, 42, 44 in the horizontal direction, the current 58 cannot flow straight from the connection plate part 32 toward the external connection part 34. The slits 40, 42, 44 meander while changing the flow direction and flow from the connection plate portion 32 toward the external connection portion 34.

  As described above, the current 58 meanders and flows from the connection plate portion 32 toward the external connection portion 34, so that the component that runs parallel to the current 50 flowing in the capacitive element 13 is smaller than in the case of FIGS. 3 and 4. As a result, the magnetic field induced by the meandering current 58 has less component in the opposite direction to the magnetic field induced by the current 50 flowing in the capacitive element 13. Therefore, the degree to which the mutual conductance of the capacitive element 13 is lower than that of the other capacitive elements 12 is suppressed compared to the cases of FIGS.

  As a result, both current imbalance and local heat generation in the capacitive element module 10 are suppressed as compared to the cases of FIGS. As an experiment, for the capacitive element module 8 and the capacitive element module 10, a high frequency current ripple signal of 400 Hz is applied between the positive terminal and the negative terminal, and the current annulus between the capacitive element 13 and the other capacitive element 12 is applied. The temperature difference due to balance and heat generation was investigated. As a result, in the capacitive element module 8, the current unbalance was 12.2A and the temperature difference was 15 ° C, but in the capacitive element module 10, the current unbalance was 4.8A and the temperature difference was 9.8 ° C. It was.

  As described above, in the extraction plate portion 36, among the current paths flowing between the connection plate portion 32 and the external connection portion 34, the current path component that runs parallel to the direction in which the current flows in the capacitive element 13 is reduced. The plate shape provided with the slits 40, 42, and 44 can suppress current imbalance and local temperature difference of the capacitive element module 10 due to a decrease in mutual inductance.

  FIG. 6 is a diagram illustrating an example of the drawer plate portion 37 having another configuration. Here, in the extraction plate portion 37, the extraction plate portion is assumed to reduce the current component that runs parallel to the direction in which the current flows in the capacitive element 13 among the current flowing between the connection plate portion 32 and the external connection portion 34. A hole 70 is provided in 37. Since the hole portion 70 is a portion where no current flows, the hole portion 70 may be a through hole, and the hole may be filled with an insulating material. By providing the hole portion 70, the currents 72 and 74 flowing between the connection plate portion 32 and the external connection portion 34 do not flow straight as compared to FIGS. 3 and 4 where the hole portion 70 is not provided. The area through which the current component running in parallel with the direction in which the current flows is reduced. As a result, the magnetic field induced by the currents 72 and 74 has fewer components in the opposite direction to the magnetic field induced by the current 50 flowing in the capacitive element 13. Therefore, the degree to which the mutual conductance of the capacitive element 13 is lower than that of the other capacitive elements 12 is suppressed compared to the cases of FIGS.

  The capacitive element module according to the present invention is used as a smoothing capacitor used in a power inverter system such as a vehicle driving application or an industrial application represented by a hybrid vehicle.

  8,10 Capacitance element module, 12,13 Capacitance element, 14 Negative electrode, 16 Positive electrode, 20, 30 Bus bar, 22, 32 Connection plate, 24, 34 External connection, 35, 36, 37 Drawer plate , 40, 42, 44 slit, 50, 54, 58, 72, 74 current, 52, 56 magnetic field, 70 holes.

Claims (3)

A plurality of capacitive elements arranged in parallel so that one end electrode is provided on one end face of two opposing end faces and the other end electrode is provided on the other end face, and each end face is located on the same plane;
One side bus bar having one side connection plate part and one side external connection part for external connection for mutually connecting one side electrodes of one end face of each capacitive element;
The other side bus bar having the other side connection plate part for connecting the other side electrodes of the other end surface of each capacitive element to each other and the other side external connection part for external connection, from the other side connection plate part to the other side external connection The other side bus bar including a drawing plate part that is drawn out while being arranged in parallel with one side surface of the capacitive element toward the part,
With
The drawer plate portion has a plate shape in which a current component that runs parallel to the direction in which the current flows in the capacitor element among currents flowing between the other side connection plate portion and the other side external connection portion is reduced. Capacitive element module. In the capacitive element module according to claim 1,
The lead plate portion has a plate shape in which a path of a current flowing between the other side connection plate portion and the other side external connection portion meanders. In the capacitive element module according to claim 1,
The lead plate portion has a plate shape including a hole provided between the other side connection plate portion and the other side external connection portion.

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