JP2014220362A - Capacitor module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique that allows efficiently dissipating heat in capacitor elements and prevents an increase in temperature of the capacitor elements.SOLUTION: A capacitor module 1 includes an element group 2 having a plurality of first capacitor elements 11 (first elements 11) that are juxtaposed, and a second capacitor element 12 (second element 12) disposed spaced apart from the element group 2. The module 1 further includes a pair of electrode bus bars (an N-pole bus bar 3 and a P-pole bus bar 4) extending along an arrangement direction of the plurality of first elements 11 and connected to an electrode on an end portion of each first element 11, and a control substrate 5 for discharging that faces the first element 11c located closer to an inner side than to the first elements 11a and 11d on both sides of the element group 2. The N-pole bus bar 3 includes a body part 31 covering side surfaces 111 of the plurality of first elements 11, and an extension part 32 branching from the body part and extending to the second element 12, and connected to an electrode of the second element 12. The extension part branches from a position facing the first element 11c located closer to the inner side than to the first elements 11a and 11d on both the side of the element group 2.

Description

  The present invention relates to a capacitor module used in a power converter.

  Conventionally, a capacitor module used for a power conversion device in an electric vehicle or a hybrid vehicle is known, and this capacitor module is generally provided with a plurality of capacitor elements arranged side by side in a casing and electrodes of the capacitor elements. And a connected bus bar. Such capacitor modules are disclosed in, for example, Patent Documents 1 to 3.

  By the way, since the power converter in an electric vehicle or a hybrid vehicle handles a large amount of electric power, the amount of heat generated by each component is large, and the above-described capacitor module is one of the components that increases the amount of heat generated.

JP 2012-249480 A JP 2012-191767 A JP 2009-194080 A

  In the configuration in which a plurality of capacitor elements as disclosed in Patent Documents 1 to 3 are arranged side by side, the generated heat is accumulated because the capacitor elements that generate heat are adjacent to each other, and this heat is The capacitor module may become hot. In particular, in the capacitor element inside the both ends of the element group, other capacitor elements are arranged on both the left and right sides thereof, so that it is difficult for heat to escape to the surroundings by receiving the heat of the capacitor elements on both sides. In particular, the capacitor module used in the power system of electric vehicles (a circuit that handles a large current supplied to the driving motor) has a circuit (discharge control board) that quickly discharges the stored charge as needed. In some cases, the circuit also releases large heat during discharge. When such a discharge control board faces the capacitor element, the discharge control board also receives heat, making it difficult to release heat to the surroundings. As a result, normally, heat is accumulated in the capacitor elements inside the both ends of the element group. Therefore, the technology disclosed in the present specification provides a capacitor module that can efficiently release the heat of the capacitor element and suppress the temperature rise.

  The technology disclosed in the present specification relates to a capacitor module including an element group having a plurality of first capacitor elements arranged side by side. The capacitor module includes a pair of second capacitor elements that are spaced apart from the element group and a pair of first capacitor elements that extend along the arrangement direction of the first capacitor elements and that are connected to the electrodes at the ends of the first capacitor elements. An electrode bus bar and a discharge control board disposed opposite to the first capacitor elements inside the first capacitor elements at both ends of the element group are provided. Further, one of the pair of electrode bus bars includes a main body portion that covers the side surfaces of the plurality of first capacitor elements, and an extending portion that branches from the main body portion and extends to the second capacitor element, and is connected to the electrode of the second capacitor element And the extension part branches off from a position facing the first capacitor element inside the first capacitor element at both ends of the element group.

  According to such a configuration, the heat generated in the first capacitor element inside both ends of the element group composed of the plurality of first capacitor elements can be efficiently utilized using the electrode bus bar connected to the second capacitor element. It can escape and temperature rise can be suppressed. That is, according to the technology disclosed in the present specification, the electrode bus bar covers the side surfaces of the plurality of first capacitor elements, and branches from the main body part to the second capacitor element, and the electrode bus bar extends to the electrode of the second capacitor element. And the extension portion branches off from a position facing the first capacitor element inside the both ends of the element group. Therefore, the first capacitor inside the both ends of the element group. Heat in the element can be released to the second capacitor element through the extended portion of the electrode bus bar. In other words, when the heat accumulated in the first capacitor element inside both ends of the element group is released to the electrode bus bar and escaped, the extended portion of the electrode bus bar branches from the position facing the first capacitor element inside. Therefore, the inner first capacitor element where heat is trapped can be brought close to the extending portion for releasing heat. Thereby, the heat in the inner first capacitor element can be efficiently released through the extending portion. Further, since the heat is released using the electrode bus bar connected to the first capacitor element and the second capacitor element, the electrode bus bar can be effectively used for heat dissipation. As described above, according to the technology disclosed in this specification, the heat generated in the first capacitor element can be efficiently released using the electrode bus bar connected to the second capacitor element, and the temperature rise is suppressed. can do.

  Further, in the capacitor module disclosed in the present specification, the main body portion covers the side surface with a gap from the side surface of the first capacitor element, and has a plurality of convex portions protruding toward the side surface. May be. According to such a configuration, since the main body of the electrode bus bar covering the side surface of the first capacitor element has the convex portion, the area of the electrode bus bar for releasing the generated heat can be expanded by the convex portion. The heat of the first capacitor element can be released more efficiently, and the temperature rise can be suppressed.

  The main body may include a covering portion that covers the electrode at the end of the first capacitor element, and the covering portion may be in contact with the electrode. According to such a configuration, since the heat generated in the first capacitor element can be dissipated from the cover portion by the cover portion contacting the electrode, the heat of the first capacitor element can be released more efficiently, Temperature rise can be suppressed.

It is sectional drawing of the capacitor | condenser module which concerns on embodiment. It is II-II sectional drawing of FIG. It is a disassembled perspective view of a capacitor module. It is a circuit diagram of the power converter device with which a capacitor module is applied. It is sectional drawing which expands and shows the principal part of the capacitor | condenser module which concerns on other embodiment. It is the perspective view which looked at the N pole bus bar from the back side.

  Hereinafter, embodiments will be described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of the capacitor module according to the embodiment, and FIG. 2 is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is an exploded perspective view of the capacitor module. In FIGS. 2 and 3, in order to facilitate understanding of the internal configuration of the capacitor module, a part of the configuration in the outer casing is omitted.

  This capacitor module 1 is applied to, for example, a power conversion device in an electric vehicle or a hybrid vehicle. As shown in FIGS. 1 to 3, a plurality of (four in this embodiment) arranged in a line. Of the first capacitor element 11 (11a, 11b, 11c, 11d), and a second capacitor element 12 disposed away from the element group 2. Capacitor module 1 also includes a pair of electrode bus bars (P-pole bus bar 4 and N-pole bus bar 3) arranged so as to extend along the arrangement direction of the plurality of first capacitor elements 11. The P pole and the N pole correspond to a positive electrode and a negative electrode, respectively. Furthermore, the capacitor module 1 includes a discharge control board 5, a cooler 6, a reactor 7, and a shielding plate 8 that are arranged to face some of the plurality of first capacitor elements 11. The element group 2 including the plurality of first capacitor elements 11 and the electrode bus bars 3 and 4 are accommodated in the inner casing 10. Further, the inner casing 10, the second capacitor element 12, the discharge control board 5, the cooler 6, the reactor 7 and the shielding plate 8 are accommodated in the outer casing 20.

  The first capacitor element 11 and the second capacitor element 12 have a function of smoothing the DC output voltage, and for example, a known film capacitor can be used. The film capacitor has a configuration in which a dielectric film deposited with a metal film is wound and electrodes are formed on both ends by metal spraying. The first capacitor element 11 and the second capacitor element 12 are heat-generating members and generate heat when energized.

  Each first capacitor element 11 has a flat shape, and a side surface 111 facing the N-pole bus bar 3 is formed on the outer periphery of each first capacitor element 11. The side surface 111 of the first capacitor element 11 is formed flat, and occupies the widest area on the outer periphery of the first capacitor element 11 in order to dissipate the heat generated in the first capacitor element 11 to the N-pole bus bar 3. . In addition, a pair of electrodes 112 (N pole 112a and P pole 112b) connected to each electrode bus bar (N pole bus bar 3 and P pole bus bar 4) are formed at both ends of each first capacitor element 11. Yes. Further, the plurality of first capacitor elements 11 are collectively arranged in the inner casing 10 with the side surfaces 111 and the electrodes 112 being aligned. More specifically, the side surfaces 111 of the plurality of first capacitor elements 11 are arranged on the same plane, and the electrodes 112 of the plurality of first capacitor elements 11 are arranged on the same plane.

  Moreover, the 1st capacitor | condenser element 11 arrange | positioned inside the 1st capacitor | condenser element 11 of the both ends of the element group 2 among the some 1st capacitor | condenser elements 11 is adjacent to the other 1st capacitor | condenser element 11 in the both sides. . In the present embodiment, the inner first capacitor element 11b is adjacent to the first capacitor elements 11a and 11c, and the first capacitor element 11c is adjacent to the first capacitor elements 11b and 11d. Thus, in the first capacitor elements 11b and 11c inside the both ends of the element group 2, other first capacitor elements (11a, 11d, etc.) are adjacent to each other on the left and right sides and surrounded by the other first capacitor elements. Therefore, the generated heat is difficult to release and is likely to become high temperature.

  The second capacitor element 12 is spaced above the first capacitor element 11d at the right end in FIG. Since the second capacitor element 12 is separated from the element group 2 of the first capacitor element 11, it is easier to release heat than the first capacitor element 11. Further, the second capacitor element 12 has a larger heat capacity than the first capacitor element 11 and is less likely to rise in temperature than the first capacitor element 11. Therefore, when the first capacitor element 11 and the second capacitor element 12 generate heat, the first capacitor element 11 becomes hotter than the second capacitor element 12 unless the cooling is performed (the second capacitor element 12 is the first capacitor element 12). 11).

  The “electrode busbar” is a conductive member that uses a metal plate instead of a wire so that it can withstand a large current. The “P-pole busbar” in this embodiment electrically connects the positive electrodes of the plurality of first capacitor elements 11. And “N-pole busbar” is used to electrically connect the negative electrodes of the plurality of first capacitor elements 11 and connect them to other devices. It is the name of a conductive member for connecting to the negative electrode of the device. The electrode bus bars (N-pole bus bar 3 and P-pole bus bar 4) are made of a conductive material such as copper, for example. The N pole bus bar 3 is connected to the N pole 112a of each first capacitor element 11 by soldering, and the P pole bus bar 4 is connected to the P pole 112b of each first capacitor element 11 by soldering. In addition, it is not limited to soldering, What is necessary is just to contact so that the electrode bus bar and each electrode of a capacitor | condenser element, such as brazing, may be electrically connected, and the method for making it contact is not limited.

  Further, the N-pole bus bar 3 includes a main body portion 31 arranged to face the plurality of first capacitor elements 11, an extension portion 32 extending from the main body portion 31, and an external connection connected to an external circuit. And a terminal 33. The main body 31 of the N-pole bus bar 3 is disposed in a state of being spaced from the side surface 111 of the first capacitor element 11, covers the side surface 111, and can receive heat generated by the first capacitor element 11. Are arranged as follows. The main body 31 extends along the arrangement direction of the plurality of first capacitor elements 11 (the left-right direction in FIG. 1), and extends from the first capacitor element 11a at one end (left end) of the element group 2 to the other end (right end). ) To the first capacitor element 11d and face each first capacitor element 11. A through-hole for pouring the sealing resin 9 is formed in the main body 31 of the N pole bus bar 3. Moreover, the main-body part 31 is formed from the bent metal plate, and the coating | coated part 311 is formed by the bent part. The covering portion 311 covers the electrode (N pole 112a) at the end of each first capacitor element 11. Further, the covering portion 311 is in close contact with the N pole 112a, whereby the main body portion 31 and each first capacitor element 11 are electrically connected.

  The extension part 32 of the N-pole bus bar 3 extends from the main body part 31 to the second capacitor element 12 and is electrically connected to the electrode of the second capacitor element by soldering. The extension portion 32 branches from the main body portion 31, extends in parallel to the end portion along the main body portion 31, then bends and protrudes to the outside of the inner casing 10, and extends to the second capacitor element 12. . Further, the extending portion 32 is branched from a position facing the first capacitor element 11 c inside the first capacitor elements 11 a and 11 d at both ends of the element group 2. The extending portion 32 branches off from a portion facing the first capacitor element 11 c facing the discharge control board 5. In other words, the branch portion of the extending portion 32 and the discharge control board 5 face the same first capacitor element 11c. In the example shown in FIG. 1, the extending portion 32 is branched from a position facing the second first capacitor element 11 c from the right of the element group 2, and the discharge control board 5 is also from the right of the element group 2. It faces the second first capacitor element 11c. The external connection terminal 33 of the N pole bus bar 3 branches off from the end of the main body 31 and protrudes to the outside of the inner casing 10.

  The P-pole bus bar 4 includes a main body portion 41 disposed to face the plurality of first capacitor elements 11 and an external connection terminal 43 connected to an external circuit. The main body 41 extends in the arrangement direction of the plurality of first capacitor elements 11 and extends from the first capacitor element 11a at one end (left end) of the element group 2 to the first capacitor element 11d at the other end (right end). The first capacitor element 11 is in close contact with the P pole 112b. Further, the external connection terminal 43 of the P-pole bus bar 4 branches off from the end of the main body 41 and protrudes to the outside of the inner casing 10.

  The discharge control board 5 is disposed so as to face the first capacitor elements 11 b and 11 c inside the first capacitor elements 11 a and 11 d at both ends of the element group 2. The discharge control board 5 is for discharging electric charge remaining in the first capacitor element 11 when the vehicle collides. Further, the discharge control board 5 is disposed on the inner casing 10 via an insulating plate (not shown) and connected to a power source (not shown). In the example shown in FIG. 1, the discharge control board 5 is arranged above the first capacitor elements 11b, 11c, and 11d excluding the first capacitor element 11a at the left end of FIG. The discharge control board 5 is a member that generates heat when energized, and the generated heat is transmitted to the plurality of first capacitor elements 11.

  The cooler 6 is disposed above the first capacitor elements 11a and 11b on the left side of FIG. 1 to cool the left first capacitor elements 11a and 11b. Moreover, the reactor 7 is arrange | positioned above the 1st capacitor | condenser elements 11b and 11c of the center of FIG. Further, the shielding plate 8 is disposed between the reactor 7 and the discharge control board 5 and between the reactor 7 and the second capacitor element 12.

  The sealing resin 9 is filled in the inner casing 10 and seals the plurality of first capacitor elements 11. The sealing resin 9 is also filled in the gap between the first capacitor element 11 and the main body 31 of the N-pole bus bar 3.

  Next, a power conversion device to which the above capacitor module is applied will be described. FIG. 4 is a circuit diagram of a power conversion device to which the capacitor module is applied. As shown in FIG. 4, the power conversion device 50 includes a DC power supply 51 that outputs a DC current, a booster circuit 54 that boosts the voltage of the DC power supply 51, and an inverter circuit 55 that converts DC to AC. And connected to the motor 56. The second capacitor element 12 is connected to the input side of the booster circuit 54, and the plurality of first capacitor elements 11 are connected to the output side of the booster circuit 54, that is, the input side of the inverter circuit 55. The plurality of first capacitor elements 11 are connected in parallel to each other. The first capacitor element 11 smoothes the output current of the booster circuit 54, and the second capacitor element 12 smoothes the output current of the DC power supply 51. The coil illustrated in the booster circuit 54 in FIG. 4 corresponds to the reactor 7 described above.

  Next, heat radiation by the capacitor module 1 having the above configuration will be described. First, according to the capacitor module 1, the plurality of first capacitor elements 11 generate heat by energization. The discharge control board 5 also generates heat when energized. At this time, according to the capacitor module 1 described above, the heat generated by the N-pole bus bar 3 arranged to face the plurality of first capacitor elements 11 is received, and this heat is branched from the main body portion 31 of the N-pole bus bar 3. It escapes to the second capacitor element 12 through the extension part 32. Thus, in the capacitor module 1 described above, the heat of the plurality of first capacitor elements 11 can be efficiently released using the N-pole bus bar 3 connected to the second capacitor elements.

  The advantages of the capacitor module 1 having the above configuration will be described. According to the capacitor module 1 of the present embodiment, the heat generated in the first capacitor element 11 inside the both ends of the element group 2 including the plurality of first capacitor elements 11 is N pole connected to the second capacitor element 12. The bus bar 3 can be used for efficient escape and temperature rise can be suppressed. That is, when the plurality of first capacitor elements 11 are arranged side by side, normally, the first capacitor elements 11 are adjacent to each other, so that it is difficult for heat generated in the first capacitor elements 11 to escape to the surroundings. In particular, in the first capacitor element inside the both ends of the element group 2 (in the example of FIG. 1, particularly the second capacitor element 11c from the right), the other first capacitor elements 11b and 11d are arranged on both right and left sides. Therefore, by receiving the heat of the first capacitor elements 11b and 11d adjacent to each other, it becomes difficult to release the heat to the surroundings. In addition, since the discharge control board 5 that generates heat is opposed to the first capacitor element 11c and receives the heat of the discharge control board 5, it is difficult for the heat to escape to the surroundings. As a result, heat typically accumulates in the first capacitor element (in particular, the second capacitor element 11c from the right in the example of FIG. 1) inside both ends of the element group 2. However, according to the technology disclosed in this specification, the N-pole bus bar 3 has the following structure, so that the heat of the inner first capacitor element 11c can be efficiently transferred to another. That is, the N-pole bus bar 3 extends from the main body portion 31 to the second capacitor element 12 and covers the side surfaces 111 of the plurality of first capacitor elements 11 and is connected to the electrodes of the second capacitor element 12. And the extended portion 32 is opposed to the first capacitor element (the second first capacitor element 11c from the right in the example of FIG. 1) inside the both ends of the element group 2. Branch from position. With this structure, heat in the first capacitor element 11 c inside the both ends of the element group 2 is transferred to the second capacitor element 12 through the extending portion 32 of the N-pole bus bar 3. That is, when the heat accumulated in the first capacitor element 11c inside the both ends of the element group 2 is radiated to the N-pole bus bar 3 and escaped, the extension part 32 of the N-pole bus bar 3 causes the inside first capacitor element to escape. Since it branches from the position which opposes 11c, the inside 1st capacitor | condenser element 11c from which heat accumulates and the extension part 32 for releasing a heat | fever can be adjoined. Thereby, the heat in the inner first capacitor element 11 c can be efficiently released through the extending portion 32. Further, since the heat is released using the N pole bus bar 3 connected to the first capacitor element 11 and the second capacitor element 12, the N pole bus bar 3 can be effectively used for heat dissipation. Thus, according to the technology disclosed in this specification, the heat generated in the first capacitor element 11 can be efficiently released using the N-pole bus bar 3 connected to the second capacitor element 12, Temperature rise can be suppressed. Further, since the covering portion 311 of the N-pole bus bar 3 is in contact with the N-pole 112 a of the first capacitor element 11, the heat generated in the first capacitor element 11 can be dissipated from the covering portion 311. Thereby, the heat of the 1st capacitor | condenser element 11 can be released more efficiently, and a temperature rise can be suppressed.

  As mentioned above, although one Embodiment of this invention was described, the specific aspect of this invention is not limited to the said embodiment. For example, the number of the first capacitor elements 11 is not particularly limited, and any number of the first capacitor elements 11 may be used. Also in this case, the extending portion 32 branches from a position facing the first capacitor element 11 inside the both ends of the element group 2.

  In the capacitor module 1 of the embodiment, the first capacitor element 11 c with which the branch point of the extending portion 32 faces is also a capacitor element facing the heat dissipation control board 5. Since the heat dissipation control board 5 also generates heat, the temperature of the first capacitor element 11c is most likely to rise among the plurality of first capacitor elements 11a-11d arranged in a row. In the capacitor module 1, the branch point of the extending portion 32 is provided at a position facing the heat dissipation control board 5 and facing the capacitor element where the temperature is most likely to rise. Such a configuration is effective in suppressing the temperature rise of the capacitor element. In addition, although it is preferable to provide the branch path of the extension part 32 in the position which opposes the capacitor | condenser element which opposes the thermal radiation control board 5, the technique which this specification discloses is not restricted to such a structure. . Since the capacitor elements except for both ends of the capacitor elements arranged in a row are more likely to rise in temperature than the capacitors at both ends, the branch paths of the extending portion 32 are connected to the capacitors at both ends regardless of the position of the heat dissipation control board 5. An improvement in the heat dissipation effect can be expected simply by providing it so as to face any one of the plurality of capacitor elements.

  FIG. 5 is an enlarged cross-sectional view showing a main part of a capacitor module according to another embodiment, and FIG. 6 is a perspective view of an N-pole bus bar viewed from the back side. In FIG. 5, the external configuration of the inner casing is omitted. As shown in FIGS. 5 and 6, as another embodiment, the main body portion 31 of the N pole bus bar 3 may have a plurality of convex portions 35. Each convex portion 35 is formed on the back surface of the main body portion 31 and has a curved surface. The convex portion 35 protrudes from the back surface of the main body portion 31 toward the side surface 111 of the first capacitor element 11, and the gap between the convex portion 35 and the side surface 111 is filled with the sealing resin 9. According to such a configuration, the area of the N-pole bus bar 3 for releasing heat can be increased by the convex portion 35, and the heat of the first capacitor element 11 can be released more efficiently.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

DESCRIPTION OF SYMBOLS 1; Capacitor module 2; Element group 3; N pole bus bar 4; P pole bus bar 5; Control board 6 for discharge; Cooler 7; Reactor 8; 12; second capacitor element 20; outer casing 31; body 32; extension 33; external connection terminal 41; body 43; external connection terminal 50; power converter 51; DC power supply 54; booster circuit 55; 56; Motor 111; Side surface 112; Electrode 112a; N pole 112b; P pole 311;

Claims (3)

An element group having a plurality of first capacitor elements arranged side by side;
A second capacitor element disposed away from the element group;
A pair of electrode bus bars extending along the arrangement direction of the plurality of first capacitor elements and connected to the electrodes at the ends of the first capacitor elements;
A discharge control board disposed opposite to the first capacitor elements inside the first capacitor elements at both ends of the element group,
One of the pair of electrode bus bars includes a main body that covers the side surfaces of the plurality of first capacitor elements, a branch from the main body to the second capacitor element, and is connected to an electrode of the second capacitor element. An extension part,
The extension module is branched from a position facing the first capacitor element inside the first capacitor element at both ends of the element group.   The said main-body part has the several convex part which covers the said side surface in the state which opened the clearance gap with the side surface of each said 1st capacitor | condenser element, and protrudes toward the said side surface. Capacitor module.   The capacitor module according to claim 1, wherein the main body portion includes a covering portion that covers an electrode at an end portion of the first capacitor element, and the covering portion is in contact with the electrode.

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