Abstract:
It is an object of the present invention to enhance connection reliability of terminals while enhancing assembling performance. A power conversion device according to the present invention includes: a power semiconductor module having a power terminal; a capacitor module for supplying smoothed power to the power semiconductor module; and a mold bus bar in which a conductor part for electrically connecting the power semiconductor module and the capacitor module is sealed by a resin material, wherein the capacitor module has a positive capacitor terminal and a negative capacitor terminal, the power terminal, the positive capacitor terminal, and the negative capacitor terminal are formed such that the main surfaces of the terminals face in the same direction, and the mold bus bar has a first terminal contacting with the main surface of the power terminal, a second terminal contacting with the main surface of the positive capacitor terminal, and a third terminal contacting with the main surface of the negative capacitor terminal.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a power conversion device, and particularly to a power conversion device for converting direct current into alternating current. 
       BACKGROUND ART 
       [0002]    Higher power of a vehicle drive motor used in hybrid automobiles or electric automobiles is required, and accordingly a power conversion device is required to be for high power. An improvement in connection reliability of a conductor member connected to a power semiconductor module for power conversion and a capacitor module for power smoothing, which are provided in the power conversion device, is required for high power. 
         [0003]    In PTL 1 (JP 2008-252962 A), a resin body  24  is connected to relay a terminal of a reactor  14  and a terminal of a capacitor  13 . 
       CITATION LIST 
     Patent Literature 
       [0004]    PTL 1: JP 2008-252962 A 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0005]    It is an object of the present invention to enhance connection reliability of terminals while enhancing assembling performance. 
       Solution to Problem 
       [0006]    In order to solve the object, a power conversion device according to the present invention includes: a power semiconductor module ( 100 ) having a power terminal ( 101 ); a capacitor module ( 200 ) for supplying smoothed power to the power semiconductor module; and a mold bus bar ( 500 ) in which a conductor part for electrically connecting the power semiconductor module and the capacitor module ( 200 ) is sealed by a resin material, wherein the capacitor module has a positive capacitor terminal ( 203 ) and a negative capacitor terminal ( 204 ), the power terminal, the positive capacitor terminal, and the negative capacitor terminal are formed such that the main surfaces of the terminals face in the same direction, and the mold bus bar ( 500 ) has a first terminal ( 506 ) contacting with the main surface of the power terminal ( 101 ), a second terminal ( 512 ) contacting with the main surface of the positive capacitor terminal, and a third terminal ( 514 ) contacting with the main surface of the negative capacitor terminal. 
       Advantageous Effects of invention 
       [0007]    According to the present invention, it is possible to enhance connection reliability of terminals while enhancing assembling performance. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0008]      FIG. 1  is a perspective view of a main circuit part  900  in a power conversion device. 
           [0009]      FIG. 2  is an exploded perspective view of the main circuit part  900  in the power conversion device. 
           [0010]      FIG. 3  is a partially enlarged view of a power terminal  101  and signal terminals  102  in a power semiconductor module  100   a  in range A illustrated in  FIG. 2 . 
           [0011]      FIG. 4  is a cross-section view of the power semiconductor module  100   a  viewed in the arrow direction in plane B illustrated in  FIG. 2 . 
           [0012]      FIG. 5  is a cross-section view of a capacitor module  200  viewed in the arrow direction in plane C in  FIG. 2 . 
           [0013]      FIG. 6  is a perspective view of an entire mold bus bar  500 . 
           [0014]      FIG. 7  is an exploded perspective view of the mold bus bar  500 . 
           [0015]      FIG. 8  is a cross-section view of the mold bus bar  500  viewed in the arrow direction in plane D illustrated in  FIG. 6 . 
           [0016]      FIG. 9  is a cross-section view of the mold bus bar  500  viewed in the arrow direction in plane E illustrated in  FIG. 6 . 
           [0017]      FIG. 10  is a partially enlarged view of a first terminal  506  in the mold bus bar  500  in range C illustrated in  FIG. 6 . 
           [0018]      FIG. 11  is a partially enlarged view of a second terminal  512  and a third terminal  514  in the mold bus bar  500  in range B in  FIG. 6 . 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0019]    An embodiment of the present invention will be described below with reference to the drawings. Specific examples of the contents of the present invention will be explained in the following description, but the present invention is not limited to the description, and various changes and modifications can be made by those skilled in the art within the scope of the technical spirit disclosed in the specification. The same functions are denoted with the same reference numerals and a repeated description thereof may be omitted throughout the drawings for describing the present invention. 
         [0020]      FIG. 1  is a perspective view of a main circuit part  900  in a power conversion device. Herein, the main circuit part  900  receives DC power from a vehicle-mounted battery and outputs AC power to a vehicle drive motor.  FIG. 2  is an exploded perspective view of the main circuit part  900  in the power conversion device.  FIG. 3  is a partially enlarged view of a power terminal  101  and signal terminals  102  in a power semiconductor module  100   a  in range A illustrated in  FIG. 2 .  FIG. 4  is a cross-section view of the power semiconductor module  100   a  viewed in the arrow direction in plane B illustrated in  FIG. 2 .  FIG. 5  is a cross-section view of a capacitor module  200  viewed in the arrow direction in plane C in  FIG. 2 . 
         [0021]    The power semiconductor modules  100   a  to  100   f  illustrated in  FIG. 1  and  FIG. 2  have inverter circuits for converting DC power into AC power. According to the present embodiment, the power semiconductor module  100   a  configures upper and lower arm circuits for outputting one phase in an inverter circuit for outputting 3-phase alternating current. For example, the power semiconductor module  100   a  is upper and lower aim circuits for U-phase, the power semiconductor module  100   b  is upper and lower arm circuits for V-phase, and the power semiconductor module  100   c  is upper and lower arm circuits for W-phase. The power semiconductor modules  100   a  to  100   c  then configure a first inverter circuit. 
         [0022]    Similarly, the power semiconductor module  100   d  is upper and lower arm circuits for U-phase, the power semiconductor module  100   e  is upper and lower arm circuits for V-phase, and the power semiconductor module  100   f  is upper and lower arm circuits for W-phase. The power semiconductor modules  100   d  to  100   f  then configure a second inverter circuit. That is, according to the present embodiment, one power conversion device comprises two inverter circuits. The two inverter circuits may drive different motors, or may drive one motor. 
         [0023]    The capacitor modules  200  illustrated in  FIG. 1  and  FIG. 2  smooth DC power supplied from the battery. A capacitor module  200  illustrated in  FIG. 2  and  FIG. 5  has a capacitor cell  201  like a film capacitor, for example, a positive capacitor terminal  203  and a negative capacitor terminal  204  for electrically connecting the capacitor cell  201  and a mold bus bar  500  described below, a capacitor case  202  for housing the capacitor cell  201  therein, and a sealing material  205  filled in the capacitor case  202 . 
         [0024]    The power terminal  101  illustrated in  FIG. 3  receives DC power supplied from the capacitor modules  200 . 
         [0025]    The power terminal  101  as negative terminal is branched by a first negative power terminal  101   a  and a second negative power terminal  101   c.  The power terminal  101  as positive terminal is branched by a first positive power terminal  101   b  and a second positive power terminal  101   d.  Thereby, it is possible to prevent current flowing into the terminals from focusing and to achieve lower inductance. An AC terminal  101   e  transfers alternating current output to the vehicle drive motor, and is arranged next to the first negative power terminal  101   a.    
         [0026]    As illustrated in  FIG. 3 , a main surface  103  of the power terminal  101  overlaps on a virtual plane  106  substantially parallel with an arrangement direction  105  of the first negative power terminal  101   a,  the first positive power terminal  101   b,  the second negative power terminal  101   c,  and the second positive power terminal  101   d.    
         [0027]    As illustrated in  FIG. 4 , a side surface  104  of the power terminal  101  is formed to be substantially orthogonal to the virtual plane  106 . In other words, the side surface  104  of the power terminal  101  overlaps on a plane crossing with the virtual plane  106 . 
         [0028]      FIG. 6  is a perspective view of the entire mold bus bar  500 .  FIG. 7  is an exploded perspective view of the mold bus bar  500 .  FIG. 8  is a cross-section view of the mold bus bar  500  viewed in the arrow direction in plane D illustrated in  FIG. 6 .  FIG. 9  is a cross-section view of the mold bus bar  500  viewed in the arrow diction in plane E illustrated in  FIG. 6 .  FIG. 10  is a partially enlarged view of a first terminal  506  in the mold bus bar  500  in range C illustrated in  FIG. 6 .  FIG. 11  is a partially enlarged view of a second terminal  512  and a third terminal  514  in the mold bus bar  500  in range B in  FIG. 6 . 
         [0029]    As illustrated in  FIG. 8 , the mold bus bar  500  is configured of a negative conductor plate  501 , a positive conductor plate  502 , a resin material  516 , an AC bus bar  504 , and an AC bus bar  505 . 
         [0030]    As illustrated in  FIG. 7  and  FIG. 8 , the negative conductor plate  501  is arranged to be stacked on the positive conductor plate  502  such that a main surface of the negative conductor plate  501  opposes a main surface of the positive conductor plate  502 . 
         [0031]    The AC bus bar  504  illustrated in  FIG. 7  is configured of an AC bus bar  504   a  connected to the power semiconductor module  100   a,  an AC bus bar  504   b  connected to the power semiconductor module  100   b,  and an AC bus bar  504   c  connected to the power semiconductor module  100   c.    
         [0032]    The AC bus bar  505  illustrated in  FIG. 7  is configured of an AC bus bar  505   a  connected to the power semiconductor module  100   d,  an AC bus bar  505   b  connected to the power semiconductor module  100   e,  and an AC bus bar  505   c  connected to the power semiconductor module  100   f.    
         [0033]    As illustrated in  FIG. 7  and  FIG. 8 , the resin material  516  seals part of each of the positive conductor plate  502 , the negative conductor plate  501 , the AC bus bar  504 , and the AC bus bar  505 . Further, the resin material  516  is inserted between the main surface of the negative conductor plate  501  and the main surface of the positive conductor plate  502  thereby to keep the negative conductor plate  501  and the positive conductor plate  502  insulated from each other. 
         [0034]    The mold bus bar  500  according to the present embodiment has an integrated structure in which the AC bus bar  504  and the AC bus bar  505  are shaped together in addition to the negative conductor plate  501  and the positive conductor plate  502  and are sealed by the resin material  516 . Thereby, the mold bus bar  500  is formed as one part with strong electric wiring sealed by the resin material  516 , and an enhancement in assembling can be expected. 
         [0035]    As illustrated in  FIG. 7  and  FIG. 10 , the first terminal  506  is configured of first negative conductor terminals  507   a  to  507   f,  first positive conductor terminals  508   a  to  508   f,  second negative conductor terminals  509   a  to  509   f,  second positive conductor terminals  510   a  to  510   f,  and AC conductor terminals  503   a  to  503   f.    
         [0036]    The first negative conductor terminals  507   a  to  507   f  and the second negative conductor terminals  509   a  to  509   f  are branched from the negative conductor plate  501 , and current is distributed thereto. The first positive conductor terminals  508   a  to  508   f  and the second positive conductor terminals  510   a  to  510   f  are branched from the positive conductor plate  502 , and current is distributed thereto. 
         [0037]    The first negative conductor terminal  507   a  is connected to the first negative power terminal  101   a  of the power semiconductor module  100   a,  the first positive conductor terminal  508   a  is connected to the first positive power terminal  101   b  of the power semiconductor module  100   a,  the second negative conductor terminal  509   a  is connected to the second negative power terminal  101   c  of the power semiconductor module  100   a,  the second positive conductor terminal  510   a  is connected to the second positive power terminal  101   d  of the power semiconductor module  100   a,  and the AC conductor terminal  503   a  is connected to the AC terminal  101   e  of the power semiconductor module  100   a.  Other terminals of the mold bus bar  500  are similarly connected to the terminals of the power semiconductor modules  100   b  to  100   f.    
         [0038]    Further, the first terminal  506  is such that the second negative conductor terminals  509   a  to  509   f  are arranged between the first positive conductor terminals  508   a  to  508   f  and the second positive conductor terminals  510   a  to  510   f.    
         [0039]    As illustrated in  FIG. 8  and  FIG. 10 , the first negative conductor terminal  507   a , the first positive conductor terminal  508   a,  the second negative conductor terminal  509   a , the second positive conductor terminal  510   a,  and the AC conductor terminal  503   a  are formed such that their main surfaces face in the same direction. Here, the main surfaces are connected to the terminals of the power semiconductor modules  100   b  to  100   f,  respectively. That is, a main surface  517  of the first terminal  506  is formed to face in the same direction. A side surface  518  of the first terminal  506  is formed to be transverse to the main surface  517 . 
         [0040]    As illustrated in  FIG. 7 , the second terminal  512  according to the present embodiment is configured of nine negative conductor terminals connected to the negative capacitor terminals  204 , respectively. Further, the third terminal  514  according to the present embodiment is configured of nine positive conductor terminals connected to the positive capacitor terminals  203 , respectively. 
         [0041]    As illustrated in  FIG. 9  and  FIG. 11 . the second terminals  512  and the third terminals  514  are formed such that a main surface  521  of a second terminal  512  and a main surface  525  of a third terminal  514  face in the same direction. The main surfaces  521  are connected to the negative capacitor terminals  204 , and the main surfaces  525  are connected to the positive capacitor terminals  203 . A side surface  522  of the second terminal  512  is formed to be transverse to the main surface  521 . A side surface  526  of the third terminal  514  is formed to be transverse to the main surface  521 . 
         [0042]    Further, as illustrated in  FIG. 7 , the third terminals  514  are formed such that the main surfaces  525  of the third terminals  514  and the main surface  517  of the first terminal  506  face in the same direction. Thus, the first terminal  506 , the second terminals  512 , and the third terminals  514  are formed such that the main surface  517  of the first terminal  506 , the main surfaces  521  of the second terminals  512 , and the main surfaces  525  of the third terminals  514  face in the same direction. 
         [0043]    As illustrated in  FIG. 1  and  FIG. 2 , the power semiconductor modules  100   a  to  100   f  are arranged such that the power terminals  101  face the main surface  517  of the first terminal  506 . Further, the capacitor modules  200  are arranged such that the positive capacitor terminals  203  face the main surfaces  521  of the second terminals  512  and the negative capacitor terminals  204  face the main surfaces  525  of the third terminals  514 . 
         [0044]    When the mold bus bar  500  is adjusted in position to the power semiconductor modules  100   a  to  100   f  and the capacitor modules  200 , any of the main surface  517  of the first terminal  506 , the main surfaces  521  of the second terminals  512 , and the main surfaces  525  of the third terminals  514  contacts with the power terminals  101 , the positive capacitor terminals  203 , or the negative capacitor terminals  204 , and the position of the mold bus bar  500  is corrected around the contact positions thereby to bring other terminals into contact. 
         [0045]    Due to the positional correction of the mold bus bar  500  which comprises the first terminal  506 , the second terminals  512 , and the third terminals  514  and is formed as one part by the resin material  516 , the terminals including the power terminals  101 , the positive capacitor terminals  203 , and the negative capacitor terminals  204 , which require large current, can reduce variation in junctions to the mold bus bar  500  and can achieve easy assembling. The junctions are welding, clip connection, and the like. 
         [0046]    Particularly according to the present embodiment, each of the power terminals  101  of the power semiconductor modules  100   a  to  100   f  is configured of the first negative power terminal  101   a,  the first positive power terminal  101   b,  the second negative power terminal  101   c,  and the second positive power terminal  101   d,  and the main surfaces of the terminals face in the same direction in order to achieve lower inductance. When the number of terminals increases, positional correction is difficult depending on the terminals. According to the present embodiment, however, a plurality of first terminals  506  of the mold bus bar  500  are provided depending on the power terminals  101 , and the main surfaces  517  of the first terminals  506  face in the same direction, thereby reducing variation in junctions and achieving easy assembling while achieving lower inductance. 
         [0047]    Even if one power terminal  101  of the power semiconductor modules  100   a  to  100   f  is present on the positive and negative sides, respectively, the technical spirit according to the present embodiment is applicable. Further, even if two power terminals  101  are present on the positive side and one is present on the negative side, or one is present on the positive side and two are present on the negative side, the technical spirit according to the present embodiment is applicable. 
         [0048]    Further, as illustrated in  FIG. 8  and  FIG. 10 , the main surfaces  517  of the respective terminals configuring the first terminal  506  overlap on a virtual plane  520  substantially parallel with an arrangement direction  519  of the first negative conductor terminal  507   a,  the first positive conductor terminal  508   a,  the second negative conductor terminal  509   a,  and the second positive conductor terminal  510   a.  Thereby, it is possible to further reduce variation in junctions and to achieve easy assembling while achieving lower inductance. 
         [0049]    As illustrated in  FIG. 6  and  FIG. 11 . the main surfaces  521  of the second terminals  512  overlap on a virtual plane  524  substantially parallel with an arrangement direction  523  of the second terminals  512 . Similarly, the main surfaces  525  of the third terminals  514  overlap on a virtual plane  528  substantially parallel with an arrangement direction  527  of the third terminals  514 . Thereby, it is possible to further reduce variation in junctions and to achieve easy assembling. 
         [0050]    Further, according to the present embodiment, the mold bus bar  500  holds the AC bus bar  504  and the AC bus bar  505  by the resin material  516 . The main surfaces of the AC conductor terminals  503   a  to  503   f  are formed to face in the same direction as the main surface  517  of the first terminal  506 , and are connected to the AC terminal  101   e  of the power semiconductor module  100   a.  Thereby, it is possible to further reduce variation in junctions of the main circuit systems and to achieve easy assembling. 
         [0051]      529  in  FIG. 8  indicates an orientation in which the main surface  517  of the first terminal  506  opposes the main surface  103  of the power terminal  101  of the power semiconductor module  100   a,  and also indicates a direction in which the mold bus bar  500  moves when the power semiconductor module  100   a  and the mold bus bar  500  are connected to each other.  530  in  FIG. 9  is an orientation in which the main surfaces  521  of the second terminals  512  oppose the main surfaces of the negative capacitor terminals  204 , and also indicates a direction in which the mold bus bar  500  moves when the capacitor modules  200  and the mold bus bar  500  are connected to each other. 
       REFERENCE SIGNS LIST 
       [0052]      100   a  to  100   f  . . . Power semiconductor module,  101  . . . Power terminal,  101   a  . . . First negative power terminal,  101   b  . . . First positive power terminal,  101   c  . . . Second negative power terminal,  101   d  . . . Second positive power terminal,  101   e  . . . AC terminal,  102  . . . Signal terminal,  103  . . . Main surface,  104  . . . Side surface,  105  . . . Arrangement direction,  106  . . . Virtual plane,  200  . . . Capacitor module,  201  . . . Capacitor cell,  202  . . . Capacitor case,  203  . . . Positive capacitor terminal,  204  . . . Negative capacitor terminal,  205  . . . Sealing material,  500  . . . Mold bus bar,  501  Negative conductor plate,  502  . . . Positive conductor plate,  503   a  to  503   f  . . . AC conductor terminal,  504  . . . AC bus bar,  505  . . . AC bus bar,  504   a  to  504   c  . . . AC bus bar,  505   a  to  505   c  . . . AC bus bar,  506  . . . First terminal,  507   a  to  507   f  . . . First negative conductor terminal,  508   a  to  508   f  . . . First positive conductor terminal,  509   a  to  509   f  . . . Second negative conductor terminal,  510   a  to  510   f  . . . Second positive conductor terminal,  512  . . . Second terminal,  514  . . . Third terminal,  516  . . . Resin material,  517  . . . Main surface,  518  . . . Side surface,  519  . . . Arrangement direction,  520  . . . Virtual plane,  521  . . . Main surface,  522  . . . Side surface,  523  . . . Arrangement direction,  524  . . . Virtual plane,  525  . . . Main surface,  526  . . . Side surface,  527  . . . Arrangement direction,  528  . . . Virtual plane,  529  . . . Opposite direction,  530  . . . Opposite direction,  900  . . . Main circuit part