JP2011004522A - Power conversion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent thermal adverse effect on a DC link capacitor unit, by enabling a plurality of switching element modules to be compactified for efficient cooling, in a power conversion apparatus in which a DC link capacitor unit having a smoothing capacitor is provided between a converter and an inverter.SOLUTION: The positive-side connection terminals and the negative-side connection terminals of switching element modules 27C and 27F mounted on a water-cooled heat sink 40 are connected to a positive-side connection terminal 139 and a negative-side connection terminal of a DC link capacitor unit 21, and also are connected with each other in common by positive-side or negative-side external bus bars. The positive-side and negative-side external bus bars, arranged outside the DC link capacitor unit 21, are stacked via an insulating member interposed between them, so that they are integrated as an external bus bar unit 136.

Description

  The present invention provides a converter for stepping up and down the voltage of a DC power supply while using a plurality of switching element modules as a component, and a plurality of switching element modules different from the switching element module as at least a part of the components. The present invention relates to a power converter including an inverter that drives an electric motor by converting a DC voltage obtained by a converter into an AC voltage, and a DC link capacitor unit that includes a smoothing capacitor and is provided between the converter and the inverter.

  Patent Document 1 already discloses a power conversion device in which a control circuit board, a plurality of switching element modules and a main circuit unit including a cooler, a bus bar, and a smoothing capacitor are stacked in order from above. It has been.

JP 2007-174759 A

  In the power conversion device disclosed in Patent Document 1, a plurality of switching element modules are arranged so as to be sandwiched between a plurality of cooling pipes provided in a cooler, and the number of switching element modules increases. This leads to an increase in the size of the main circuit portion, that is, an increase in the size of the power converter. The power from the converter is once stored in the smoothing capacitor of the DC link capacitor unit, and the inverter is supplied with the current from the smoothing capacitor and the current from the converter that does not pass through the smoothing capacitor. If the internal wiring carries all current, the internal wiring causes heat generation and enlargement, and the heat generation of the wiring has a thermal adverse effect on the DC link capacitor unit.

  The present invention has been made in view of such circumstances, and it is possible to efficiently cool a plurality of switching element modules in a compact manner, and to prevent a thermal adverse effect on the DC link capacitor unit. An object is to provide an apparatus.

  In order to achieve the above object, the present invention includes at least a converter for stepping up / down a voltage of a DC power supply while using a plurality of switching element modules as a component, and a plurality of switching element modules different from the switching element module. In a power converter comprising: an inverter that drives an electric motor by converting a DC voltage obtained by the converter into an AC voltage while using some components; and a DC link capacitor provided between the converter and the inverter. A plurality of the switching element modules included in the converter and the inverter are mounted on both upper and lower surfaces of a water-cooled heat sink, and the positive side connection terminals of the plurality of switching element modules mounted on the heat sink are the DC link capacitor unit. Preparation A negative side connection terminal provided in the DC link capacitor unit, the negative side connection terminals of the plurality of switching element modules connected to the positive side external bus bar and connected in common to the positive side external bus bar. And the negative side external bus bar is connected in common, and the positive side and the negative side external bus bar arranged outside the DC link capacitor unit are stacked with an insulating member interposed therebetween. The first feature is that it is integrated as an external bus bar unit.

  In addition to the configuration of the first feature, the present invention provides a switching element assembly in which a capacitor unit formed by integrating input capacitors included in each of the pair of converters includes the heat sink and the plurality of switching element modules. The second feature is that it is arranged above the unit.

  Furthermore, in addition to the configuration of the first or second feature, the third feature of the present invention is that the external bus bar unit is in direct contact with the heat sink.

  The fuel cell 15 and the storage battery 16 of the embodiment correspond to the DC power source of the present invention, and the first heat sink 40 of the embodiment corresponds to the heat sink of the present invention.

  According to the first feature of the present invention, since the plurality of switching element modules respectively constituting a part of the converter and the inverter are mounted on the upper and lower surfaces of the water-cooled heat sink, the plurality of switching elements can be made compact. It is possible to cool the element module with good cooling efficiency. A plurality of switching elements mounted on the heat sink are connected to the positive connection terminal of the DC link capacitor unit and connected to the positive side external bus bar in common. The negative side connection terminal of the module is connected to the negative side connection terminal of the DC link capacitor unit and is connected in common by the negative side external bus bar, and the positive side and negative side external bus bar are stacked with an insulating member interposed therebetween. The external bus bar unit that is integrated with the DC link capacitor unit is placed outside the DC link capacitor unit, so that the current passing through the internal wiring of the DC link capacitor unit is reduced and heat generation that adversely affects the smoothing capacitor is generated. DC link capacitor uni It is possible to prevent occurring bets internal wiring.

  According to the second aspect of the present invention, the capacitor unit formed by integrating the input capacitors included in the pair of converters is disposed above the switching element assembly unit including the heat sink and the plurality of switching element modules. Thus, the power conversion device can be configured more compactly.

  Furthermore, according to the third feature of the present invention, since the external bus bar unit is in direct contact with the heat sink, the heat generated in the external bus bar unit is directly transferred to the heat sink side, so that Temperature rise can be suppressed.

It is a schematic whole circuit diagram of a power converter. It is a side view of a switching element assembly unit. FIG. 3 is a view taken along arrow 3 of FIG. 2 in a state where a control circuit is omitted. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. It is a principal part notched perspective view of a switching element assembly unit. FIG. 6 is a sectional view taken along line 6-6 of FIG. It is a figure which shows the change of the heat transfer rate in the cooling water distribution direction in a 1st heat sink by contrasting with the longitudinal cross-section of a switching element assembly unit. It is a perspective view of a power converter. FIG. 9 is a plan view taken in the direction of arrow 9 in FIG. 8. FIG. 10 is a view taken in the direction of arrow 10 in FIG. 9. FIG. 11 is a cross-sectional view taken along line 11-11 in FIG. 9. It is sectional drawing of the 2nd heat sink in alignment with line 12-12 in FIG. It is a figure which shows the circulation circuit of a cooling water. FIG. 14 is a cross-sectional view taken along line 14-14 of FIG. 9. It is a disassembled perspective view of a capacitor unit. It is a disassembled perspective view of a switching element assembly unit, a DC link capacitor unit, and an external bus bar unit. It is a disassembled perspective view of an external bus bar unit. It is a figure which simplifies and shows the current path | route between a converter and an inverter in the state (a) without an external bus-bar unit, and the state (b) with an external bus-bar unit. It is a simplified diagram showing an example of a path of commutation current in a DC link capacitor unit in a state where there is an external bus bar unit. FIG. 6 is a simplified diagram showing another example of a commutation current path in a DC link capacitor unit in a state where there is an external bus bar unit. FIG. 12 is a simplified diagram showing still another example of a commutation current path in a DC link capacitor unit in a state where there is an external bus bar unit.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 21. First, in FIG. 1, this power conversion device includes direct-current power obtained by a fuel cell 15 that is a first direct-current power source, The DC power obtained by the storage battery 16 as the second DC power source is mounted on the vehicle so as to be converted into three-phase AC power supplied to the electric motor 17 that exhibits the power for driving the drive wheels. Yes, the first converter 18 for stepping up and down the DC voltage obtained from the fuel cell 15, the second converter 19 for stepping up and down the DC voltage obtained from the storage battery 16, and the DC voltage from the first and second converters 18 and 19 are exchanged. An inverter 20 that converts the voltage to drive the electric motor 17 and a DC link capacitor unit 21 provided between the converters 18 and 19 and the inverter 20 are provided. That.

  The first converter 18 includes a first input capacitor 22, a first inductor 24, a three-phase transformer 26 having a primary winding 26A, a secondary winding 26B, and a tertiary winding 26C, and first, second, and third. Switching element modules 27A, 27B, and 27C are provided.

  A ground line 28 that is common to the first converter 18, the second converter 19, and the inverter 20 is connected to the negative terminal of the fuel cell 15, and the first input capacitor 22 is connected to the positive terminal of the fuel cell 15. Provided between the first input side plus line 29 and the ground line 28 to be connected, one end of the first inductor 24 is connected to the first input side plus line 29. One end of the primary winding 26A, the secondary winding 26B, and the tertiary winding 26C in the three-phase transformer 26 is connected in parallel to the other end of the first inductor 24.

  The first switching element module 27A includes a first plus side switching element disposed between the common plus line 30 common to the first converter 18, the second converter 19 and the inverter 20 and the primary winding 26A of the three-phase transformer 26. 31A and a first negative side switching element 32A disposed between the primary winding 26A and the ground line 28. The second switching element module 27B includes two common positive lines 30 and a three-phase transformer 26. A second switching element 31B disposed between the secondary windings 26B and a second switching element 32B disposed between the secondary windings 26B and the ground line 28; The element module 27C includes the common plus line 30 and the three-phase transistor. And a third positive side switching element 31C is disposed between 26 tertiary winding 26C, and a third negative side switching element 32C is disposed between the tertiary winding 26C and the ground line 28.

  The second converter 19 includes a second input capacitor 23, a second inductor 25, a two-phase transformer 33 having a primary winding 33A and a secondary winding 33B, and fourth and fifth switching element modules 27D and 27E. Prepare.

  The second input capacitor 23 is provided between a second input side plus line 34 connected to the plus side terminal of the storage battery 16 and a ground line 28 connected to the minus side terminal of the storage battery 16, and the second inductor 25. Is connected to the second input side plus line 34. One end of the primary winding 33 </ b> A and the secondary winding 33 </ b> B in the two-phase transformer 33 is connected in parallel to the other end of the second inductor 25.

  The fourth switching element module 27D includes a fourth plus-side switching element 31D disposed between the common plus line 30 and the primary winding 33A of the two-phase transformer 33, and the common plus line 30 and the ground line 28. And a fifth switching element module 27E is provided between the common plus line 30 and the secondary winding 33B of the two-phase transformer 33. An element 31E and a fifth minus side switching element 32E disposed between the common plus line 30 and the ground line 28 are provided.

  The inverter 20 includes sixth, seventh, and eighth switching element modules 27F, 27G, and 27H.

  The sixth switching element module 27F includes a sixth plus-side switching element 31F disposed between the common plus line 30 and the U-phase power supply line 35U connected to the electric motor 17 which is a three-phase AC motor, And a sixth negative switching element 32F disposed between the power line 35U and the ground line 28. The seventh switching element module 27G includes a V-phase power line 35V connected to the common positive line 30 and the electric motor 17. A seventh plus-side switching element 31G disposed between the V-phase power supply line 35V and the ground line 28, and an eighth switching element module 27H includes: The common plus line 30 and the electric motor 17. Comprising an eighth positive side switching element 31H disposed between becomes W phase power supply line 35W, and an eighth negative side switching element 32H disposed between the W phase power supply line 35W and the ground line 28.

  By the way, in this embodiment, the first to eighth plus side switching elements 31A to 31H and the first to eighth minus side switching elements 32A to 32H in the first to eighth switching element modules 27A to 27H are IGBTs (Insulatead Gate). Bipolar Transistor) and a diode connected in parallel to each IGBT with the side from the emitter toward the collector as the forward direction.

  The DC link capacitor unit 21 has smoothing capacitors 36... Provided between the common plus line 30 and the ground line 28. Although only one smoothing capacitor 36 is shown in FIG. 1 for the sake of simplification, the DC link capacitor unit 21 includes a U-phase, a V-phase, and a W-phase of the electric motor 17 that is a three-phase AC motor. Smoothing capacitors 36... Provided between the common plus line 30 and the ground line 28 corresponding to the phases are provided.

  A series circuit including a pair of discharge resistors 37 and 37 is connected between the common plus line 30 and the ground line 28.

  2 and 3 together, the first, second, and third switching element modules 27A, 27B, and 27C included in the first converter 18 and the fourth and fifth switching element modules included in the second converter 19 are referred to. 27D and 27E and the sixth, seventh and eighth switching element modules 27F, 27G and 27H included in the inverter 20 are disposed on both upper and lower surfaces of the water-cooled first heat sink 40.

  4 to 6 together, the first heat sink 40 has a heat sink body 41 that is formed long in one direction and a first cooling water passage 43 formed between the heat sink body 41. Thus, the cover body 42 is coupled to the heat sink body 41 from above. Thus, the first cooling water passage 43 includes an outward path 43a extending in the longitudinal direction of the heat sink 40 from one end of the first heat sink 40 toward the other end, and one end side from the other end of the first heat sink 40. A return path 43b extending in parallel with the forward path 43a is formed to communicate with each other on the other end side of the first heat sink 40, and at one end of the first heat sink 40, A cooling water inlet pipe 44 leading to the forward path portion 43 a in the first cooling water passage 43 and a cooling water outlet pipe 45 leading to the return path portion 43 b in the first cooling water passage 43 are provided. The cooling water introduced into one cooling water passage 43 flows in the forward path portion 43a to the other end side of the first heat sink 40 along the flow direction indicated by the arrow 46 in FIG. Other Will be derived from the cooling water outlet pipe 45 at one end of the first heat sink 40 is inverted to return part 43b side on the side.

  By the way, the first converter 18 includes three first, second, and third switching element modules 27A, 27B, and 27C, and the second converter 19 includes two fourth and fifth switching element modules 27D and 27E. The inverter 20 includes three sixth, seventh, and eighth switching element modules 27F, 27G, and 27H. Therefore, an even number is provided on both surfaces of the first heat sink 40, in this embodiment. Eight switching element modules 27 </ b> A to 27 </ b> H are mounted on the upper and lower surfaces of the first heat sink 40 in a substantially symmetrical arrangement.

  Moreover, when the heat generation amount of the first to third switching element modules 27A to 27C is 700 W, for example, the heat generation amount of the fourth and fifth switching element modules 27D and 27E is 500 W, for example, and the sixth to eighth switching element modules 27F. Since the heating value of .about.27H is 1100 W, for example, the switching element modules having a higher heating value are arranged on the lower surface side of the first heat sink 40 that is easier to cool, while the first to eighth switching element modules. 27A to 27H are mounted on the upper and lower surfaces of the first heat sink 40 in a substantially symmetrical arrangement. In this embodiment, the second and third switching element modules 27B and 27C are arranged on the upper surface of the first heat sink 40. , Fourth and fifth switching element modules 27D, 27E, Is disposed, and a first switching element module 27A, sixth, seventh and eighth switching element modules 27F, 27G, and the 27H is disposed on the lower surface of the first heat sink 40.

  Focusing on FIG. 4, the first to eighth switching element modules 27 </ b> A to 27 </ b> H include the first to eighth plus side switching elements 31 </ b> A to 31 </ b> H on one side in the width direction of the first heat sink 40, in this embodiment. The first cooling water passage 43 is disposed on the forward path 43a side, and the first to eighth negative side switching elements 32A to 32H are arranged on the other side in the width direction of the first heat sink 40, in this embodiment, the first cooling water. The first heat sink 40 is disposed on both upper and lower surfaces so as to be disposed on the return path 43 b side of the passage 43.

  A plurality of chips constituting the first to eighth plus side switching elements 31A to 31H and the first to eighth minus side switching elements 32A to 32H, respectively, in this embodiment, six chips 47, 48, 49, 50, As shown in FIG. 3, 51 and 52 are arranged so as to be arranged two by two in the direction along the flow direction 46 of the cooling water in the first cooling water passage 43, as shown in FIG. 4, A copper electrode 56 disposed on the copper electrode 53 via the solder layer 54 and sandwiching the insulating substrate 55 between the copper electrode 53 is fixed on the copper base plate 58 via the solder layer 57.

  On the copper base plate 58, the first to eighth plus-side switching elements 31A to 31H and the first to eighth minus-side switching elements 32A to 32H are arranged for the first to eighth switching element modules 27A to 27H. Are made of a synthetic resin and each has a portion 59... And is formed in a rectangular frame shape. The copper base plate 58 and the case 60 are fixed to the first heat sink 40. The

  In the first heat sink 40, as clearly shown in FIG. 5, a plurality of stud bolts 63 having screw shaft portions 63a and 63a at both ends respectively correspond to the four corner portions of each case 60. The screw shafts 63a... Are planted so as to protrude from both the upper and lower surfaces of the first heat sink 40 at the position. Thus, the cases 60 of the first to eighth switching element modules 27A to 27H and the copper base plate 58 are screwed into the screw shafts 63a of the stud bolts 63 selected from the stud bolts 63. The first to eighth switching element modules 27 </ b> A to 27 </ b> H are mounted on the upper and lower surfaces of the first heat sink 40 by tightening and fastening the nuts 64.

  In addition, in the case 60, the chips 47 to 52, the copper electrode 53, the solder layer 54, the insulating substrate 55, the copper electrode 56, and the solder layer 57 are buried, and the covering layer 65 made of a synthetic resin is buried. The first to eighth plus side switching elements 31A to 31H and the first to eighth minus side switching elements 32A to 32H of the first to eighth switching element modules 27A to 27H are formed of the covering layer. 65... In the case 60, the first to eighth plus side switching elements 31A to 31H and the first to eighth minus side switching elements 32A to 32H in the first to eighth switching element modules 27A to 27H are electrically connected and cut off, respectively. Control circuits 66 for switching control are attached so as to cover the first to eighth switching element modules 27A to 27H.

  The first heat sink 40 and the first to eighth switching element modules 27A to 27H mounted on the upper and lower surfaces of the first heat sink 40 constitute a switching element assembly unit 67 including their control circuits 66.

  By the way, in the first to eighth switching element modules 27A to 27H, the terminals to be connected to the three-phase transformer 26, the two-phase transformer 33, and the electric motor 17 are arranged on one side in the width direction of the first heat sink 40. Terminal members 68A, 68B, and 68C that are attached to the first heat sink 40 and are connected to the terminals to be connected to the three-phase transformer 26 of the first to third switching element modules 27A to 27C; Terminal members 68D and 68E connected to the terminals to be connected to the two-phase transformer 33 of the five switching element modules 27D and 27E, and terminals to be connected to the electric motor 17 of the sixth to eighth switching element modules 27F to 27H. The terminal members 68F, 68G, 68H are arranged on one side in the width direction of the first heat sink 40. And to so that, attached to the case 60 ....

  In each of the switching element modules 27A to 27H, the plus side connection terminals 69, 69... To be connected to the common plus line 30 and the minus side connection terminals 70, 70. One heat sink 40 is attached to the case 60 in such a manner that it is arranged in parallel for each of the switching element modules 27A to 27H on the other side in the width direction.

  In the first cooling water passage 43 of the first heat sink 40, a plurality of plate members made of light metal such as aluminum alloy having a V-shaped cross section perpendicular to the flow direction 46 are juxtaposed. The cooling fins 71 are arranged so as to extend in the flow direction 46 while dividing the inside of the first cooling water passage 43 into a plurality in the width direction.

  On the other hand, the plurality of chips 47 to 52 constituting the first to eighth plus side switching elements 31A to 31H and the first to eighth minus side switching elements 32A to 32H in the first to eighth switching element modules 27A to 27H, respectively. The chips 47 and 48, the chips 49 and 50, and the chips 51 and 52 are arranged in the flow direction 46 so as to be arranged two by two in the direction along the flow direction 46 of the cooling water in the first cooling water passage 43. Arranged side by side. On the other hand, as shown in FIG. 7A, the cooling fins 71, 71... Are arranged separately for each chip 47, 49, 51; 48, 50, 52 arranged along the flow direction 46. In addition, as clearly shown in FIG. 6, the chips 47, 49, 51; 48, 50, 52 arranged along the flow direction 46 are arranged offset in the direction orthogonal to the flow direction 46.

  By the way, when the cooling water flows along the cooling fins 71, 71 ..., there is a temperature run-up section in the vicinity of the inlet of each cooling fin 71, 71 ..., and the downstream side in the section. It is known that the heat transfer rate decreases toward the temperature and gradually approaches the constant heat transfer coefficient in the developed region where the flow velocity distribution becomes constant after passing through the temperature run-up section, which is relatively high in the run-up section Although the heat transfer coefficient can be obtained, in the developed region, the boundary layer between the surfaces of the cooling fins 71 becomes thick and the heat transfer efficiency is lowered. For this reason, in the case where fins that extend long along the flow direction 46 are arranged in the first cooling water passage 43, it is difficult to obtain high cooling efficiency in the entire first cooling water passage 43. However, as described above, the cooling fins 71, 71... Are separated into the respective chips 47, 49, 51; 48, 50, 52 arranged along the flow direction 46, and the chips 47, 49, 51; 50 and 52 are offset from each other in a direction orthogonal to the flow direction 46, so that the cooling fins 71 and 71 separated for each chip 47, 49, 51; 48, 50, 52 aligned along the flow direction 46. A temperature run-up section as shown in FIG. 7B can be formed for each entrance of..., Whereby high cooling efficiency can be obtained in the entire first cooling water passage 43.

  8 to 11 together, a terminal member attached to the case 60 so as to be disposed on one side in the width direction of the first heat sink 40 on one side of the switching element assembly unit 67. A substrate 72 for disposing a current sensor or the like is disposed so as to penetrate through 68 </ b> A to 68 </ b> H, and the substrate 72 is fixed to the first heat sink 40. A second heat sink 73 is disposed above the switching element assembly unit 67, and the first inductor 24 and the three-phase transformer 26 in the first converter 18, and the second inductor 25 and the two-phase transformer in the second converter 19. 33 and a capacitor unit 38 in which the first input capacitor 22 of the first converter 18 and the second input capacitor 23 of the second converter 19 are integrated, and a second heat sink 73 is connected to the switching element assembly unit 67. It is disposed above the second heat sink 73 so as to be interposed therebetween.

  The second heat sink 73 includes a heat sink body 74 that is formed long in the same direction as the longitudinal direction of the first heat sink 40, and a second cooling water passage 76 formed between the heat sink body 74 and the heat sink body 74. The lid body 75 is coupled to the main body 74 from below, and is formed thinner than the first heat sink 40.

  In FIG. 12, the second cooling water passage 76 has an outward path portion 76 a extending in the longitudinal direction of the heat sink 73 from one end of the second heat sink 73 toward the other end, and one end from the other end of the second heat sink 73. A return path portion 76b extending in parallel with the forward path portion 76a toward the side is formed between the heat sink body 74 and the lid body 75 so as to communicate with each other on the other end side of the second heat sink 73. One end of the second heat sink 73 is provided with a cooling water inlet pipe 78 leading to the forward path portion 76a and a cooling water outlet pipe 79 leading to the backward path portion 76b. The cooling water introduced into the water passage 76 flows in the forward path portion 76a of the second cooling water passage 76 along the flow direction indicated by the arrow 77 to the other end side of the second heat sink 73, and further to the second. Will be derived from one end of the cooling water outlet pipe 79 of the second heat sink 73 is inverted to return part 76bb side at the other end of the heat sink 73. The heat sink main body 74 of the second heat sink 73 is integrally provided with a rectifying wall portion 74 a disposed in the forward path portion 76 a of the second cooling water passage 76 so as to extend along the flow direction 77.

  In FIG. 13, a discharge port of a cooling water pump 80 that is a cooling water supply source is provided in the first cooling water passage 43 in the first heat sink 40 and the second cooling water passage 76 in the second heat sink 73. The cooling water that is connected in parallel and led out from the first and second cooling water passages 43 and 76 cools the electric motor 17, is then cooled by the radiator 81, and returns to the inlet of the cooling water pump 80.

  The three-phase transformer 26 of the first converter 18 is one side in the width direction of the first and second heat sinks 40, 73, that is, the side on which the substrate 72 is disposed, and one end side of the first and second heat sinks 40, 73. That is, the first cover 84 is fixed on the second heat sink 73 so as to be arranged on the side where the cooling water inlet pipes 44 and 78 and the cooling water outlet pipes 45 and 79 are provided, and covers the three-phase transformer 26. Is fixed to the second heat sink 73.

  The two-phase transformer 33 of the second converter 19 is arranged at a position aligned with the three-phase transformer 26 on one side in the width direction of the first and second heat sinks 40 and 73, and the second inductor 25 of the second converter 19 is The two-phase transformer 33 is disposed on one side in the width direction of the first and second heat sinks 40 and 73 so as to sandwich the two-phase transformer 33 between the three-phase transformer 26 and fixed on the second heat sink 73. The transformer 33 and the second inductor 25 are commonly covered with a second cover 85 fixed to the second heat sink 73. In addition, a first terminal block 86 positioned above the substrate 72 is fixed to the first cover 84, and a second terminal block 87 positioned above the substrate 72 is fixed to the second cover 85.

  The first terminal block 86 includes a common terminal 88 for connecting the windings 26A, 26B, and 26C of the three-phase transformer 26 to the first inductor 24, and the windings 26A, 26B, and 26C to the first to third switching elements. Individual terminals 89, 90 and 91 for individually connecting to the modules 27A to 27C are provided, and the individual terminals 89 to 91 are provided with the three-phase transformer 26 of the first to third switching element modules 27A to 27C. Terminal members 68A, 68B, and 68C penetrating through the board 72 connected to terminals to be connected to the board are connected via bus bars 92, 93, and 94 located outside the board 72.

  The second terminal block 87 has a common terminal 95 for connecting the windings 33A and 33B of the two-phase transformer 26 to the second inductor 25, and the windings 33A and 33B as fourth and fifth switching element modules 27D and 27E. The individual terminals 96 and 97 for connection to the second inductor are provided such that the individual terminal 96 is disposed below the common terminal 95 and the individual terminal 97 is disposed above the common terminal 95, and the second inductor. Terminals 98 and 99 connected to both ends of 25 are provided. The individual terminals 96 and 97 include terminal members 68D and 68E penetrating through the substrate 72 connected to terminals to be connected to the two-phase transformer 33 of the fourth and fifth switching element modules 27D and 27E. They are connected via bus bars 100 and 101 located outside. The common terminal 95 and the terminal 98 are connected via a bus bar 102.

  The first inductor 24 of the first converter 18 is the other side in the width direction of the first and second heat sinks 40 and 73, that is, the side opposite to the side where the substrate 72 is disposed, and the first and second heat sinks 40 and 73. Is arranged on the second heat sink 73 so as to be aligned with the three-phase transformer 26 on one end side thereof, that is, on the side where the cooling water inlet pipes 44 and 78 and the cooling water outlet pipes 45 and 79 are provided. A third cover 105 covering the first inductor 24 is fixed to the second heat sink 73. Moreover, the third terminal block 106 is fixed to the third cover 105 so as to be disposed on one end side of the first and second heat sinks 40 and 73.

  The third terminal block 106 is provided with terminals 107 and 108 connected to both ends of the first inductor 24. One terminal 107 has a second gap between the switching element assembly unit 67 and the second heat sink 73. The bus bar 109 extending to the other end in the longitudinal direction of the heat sink 73 is connected, and the common terminal 88 provided on the first terminal block 86 is connected to the other terminal 108 via the bus bar 110.

  The capacitor unit 38 is arranged on the other side in the width direction of the first and second heat sinks 40, 73, that is, on the opposite side to the side on which the substrate 72 is arranged so as to be aligned with the first inductor 24. The capacitor unit 38 is covered with a fourth cover 111 fixed to the second heat sink 73.

  14 and 15, the first input capacitor 22 constituting a part of the capacitor unit 38 is formed by connecting a plurality of first capacitor elements 112, 112... Arranged in parallel. The second input capacitor 23 is formed by connecting a plurality of second capacitor elements 113, 113... Arranged in parallel with the arrangement direction of the first capacitor elements 112, 112. The first and second capacitor elements 112, 112... 113, 113... That are set to the same number are arranged so that the minus sides thereof face each other, and the first and second capacitor elements 112, 112 are arranged. The common bus bar 114 having a plurality of negative side connection pieces 114a, 114a ... connected to the negative side of 113, 113 ... by soldering leads the first and second capacitor elements 112, 112 ...; 113, 113 ... from above. A first individual bus bar 115 having a plurality of positive side connection pieces 115a, 115a,..., Which are arranged so as to be covered and soldered to the positive side of the first capacitor elements 112, 112. 2nd individual bus bar having a plurality of plus side connection pieces 116a, 116a,. 16 and is disposed on the common bus bar 114 so as to sandwich the insulating sheet 117 between the common bus bar 114. Thus, the capacitor unit 38 in which the first and second capacitor elements 112, 112,..., 113, 113... Are connected by the common bus bar 114 and the first and second bus bars 115, 116 is a covering layer made of a synthetic resin. The case 119 is accommodated in the case 119 so as to be embedded in the case 118, and the case 119 is covered with the fourth cover 111.

  In addition, the common bus bar 114 is integrally provided with a ground terminal 120 common to the first and second input capacitors 22 and 23 so as to protrude from the covering layer 118, and the first and second individual bus bars 115, 116, positive terminals 121 and 122 individually corresponding to the first and second input capacitors 22 and 23 are integrally projected so as to sandwich the ground terminal 120 from both sides, and both the positive terminals 121 and 122 are also provided with the covering layer. Protrudes from 118.

  A fourth terminal block 123 is fixed on the other end of the second heat sink 73 at a position where the capacitor unit 38 is sandwiched between the first inductor 24 and a fuel cell. 15 are provided, plus and minus terminals 124 and 125 for the fuel cell for connecting 15, and plus and minus terminals 126 and 127 for the storage battery for connecting the storage battery 16.

  Thus, the positive terminal 121 of the capacitor unit 38 and the bus bar 109 connected to the terminal 107 provided on the third terminal base 106 connected to the first inductor 24 are connected to the positive terminal 124 for the fuel cell. The positive terminal 122 of the capacitor unit 38 and the bus bar 128 connected to the terminal 99 provided on the second terminal block 87 so as to be connected to the second inductor 25 are connected to the fourth terminal block 123. It is connected to the fourth terminal block 123 so as to be connected to the side terminal 126.

  A fifth terminal block 130 for connecting U-phase, V-phase and W-phase power supply lines 35U, 36V, 35W connected to the electric motor 17 is fixed to the other end of the first heat sink 40. Bus bars 131, 132, and 133 are connected to terminals to be connected to the electric motor 17 of the sixth to eighth switching element modules 27 </ b> F to 27 </ b> H and are connected to terminal members 68 </ b> F to 68 </ b> H penetrating the substrate 72. It extends to the terminal block 130.

  By the way, the DC link capacitor unit 21 is disposed on the opposite side of the substrate 72. The DC link capacitor unit 21 is supported by the first heat sink 40 by the stays 135 and 135, and the first heat sink 40 and the DC An external bus bar unit 136 is disposed between the link capacitor units 21.

  In FIG. 16, in the DC link capacitor unit 21, the first heat sink 40 side is provided with the first to eighth switching element modules 27A to 27H mounted on the upper and lower surfaces of the first heat sink 40, respectively. The plus side connection terminals 139 and minus side connection terminals 140 to be connected to the connection terminals 69 and minus side connection terminals 70 are projected.

  In FIG. 17, the external bus bar unit 136 includes a plurality of positive side terminals connected to the positive side connection terminals 69 of the first to eighth switching element modules 27A to 27H and the positive side connection terminals 139 of the DC link capacitor unit 21. Are connected to the positive external bus bar 141 projecting the connection pieces 141a, 141a from both sides, the negative connection terminal 70 of the first to eighth switching element modules 27A to 27H, and the negative connection terminal 140 of the DC link capacitor unit 21. A plurality of minus side connection pieces 142a, 142a... That project from both sides, and a plus side and minus side external bus bar 141, 142, and between the plus side and minus side external bus bar 141, 142. Flat sandwiched between And the flat insulating members 144 and 145 sandwiching the positive and negative external bus bars 141 and 142 between the insulating member 143 and the insulating member 143 are stacked. An external bus bar unit 136 is formed.

  In addition, a mounting plate portion 142b that protrudes from one end of the positive-side external bus bar 141 is integrally provided at one end of the negative-side external bus bar 142 in the external bus bar unit 136. The external bus bar unit 136 is directly in contact with the first heat sink 40.

  Thus, the plus side connection terminals 139 of the DC link capacitor unit 21, the plus side connection pieces 141a of the external bus bar unit 136, and the plus side connection terminals 69 of the first to eighth switching element modules 27A to 27H. As shown in FIG. 11, the positive side connection terminals 141a are sandwiched between the positive side connection terminals 139,. The minus side connection terminals 140 of the DC link capacitor unit 21, the minus side connection pieces 142a of the external bus bar unit 136, and the minus side connection terminals 70 of the first to eighth switching element modules 27A to 27H are minus. The negative connection pieces 142a are sandwiched between the side connection terminals 140, 70, and so on by bolts 148.

  By the way, the DC power obtained by the first converter 18 or the second converter 19 is converted into AC power by the inverter 20 and supplied to the electric motor 17. The power from the first converter 18 or the second converter 19 is supplied. Are temporarily stored in the smoothing capacitors 36 of the DC link capacitor unit 21 and the inverter 20 takes out the stored electric power. Such a power flow can be replaced with a current flow. When the external bus bar unit 136 is not provided, the current i1 supplied from the smoothing capacitor 36 and the current i1 supplied from the smoothing capacitor 36 are shown in FIG. The current i 2 supplied from the first converter 18 or the second converter 19 without passing through the smoothing capacitor 36 flows to the inverter 20 through the internal wiring of the DC link capacitor unit 21. When the internal wiring of the DC link capacitor unit 21 bears all the current in this way, the internal wiring generates heat and enlarges, and the heat generation of the wiring adversely affects the smoothing capacitor 36 thermally. .

  On the other hand, when the external bus bar unit 136 is interposed between the first converter 18 and the second converter 19 and the DC link capacitor unit 21, as shown by the thin line arrows in FIG. Since a part i2 ′ of the current i2 supplied from the second converter 19 flows directly to the inverter 20 side through the plus side external bus bar 141 in the external bus bar unit 136, the current flowing through the internal wiring of the DC link capacitor unit 21 is The heat effect on the smoothing capacitor 36 can be suppressed to a low level.

  Further, the direct current is switched by switching conduction / cutoff of the sixth to eighth plus side switching elements 31F to 31H and the sixth to eighth minus side switching elements 32F to 32H in the sixth to eighth switching element modules 27F to 27H of the inverter 20. A commutation current flows in the link capacitor unit 21, and for simplification, the portion corresponding to the W phase of the inverter 20 is omitted, and the sixth and seventh plus side switching elements 31F and 31G and the first The path of the commutation current flowing in the DC link capacitor unit 21 and the external bus bar unit 136 when the sixth and seventh negative side switching elements 32F and 32G are switched on and off will be described with reference to FIGS. .

  First, when the sixth plus-side switching element 31F and the seventh minus-side switching element 32G are turned on and the sixth minus-side switching element 32F and the seventh plus-side switching element 31G are cut off, as shown by the thin line arrows in FIG. The currents i3 'and i4' corresponding to the currents i3 and i4 flowing through the internal wiring of the DC link capacitor unit 21 flow through the positive and negative bus bars 141 and 142 of the external bus bar unit 136. The current flowing through the internal wiring can be kept small.

  Further, when the sixth and seventh minus side switching elements 32F and 32G are made conductive and the sixth and seventh plus side switching elements 31F and 31G are cut off, as shown by the thin line arrows in FIG. The current i5 ′ corresponding to the current i5 flowing through the internal wiring flows through the minus side bus bar 142 of the external bus bar unit 136, and the current flowing through the internal wiring of the DC link capacitor unit 21 can be kept small.

  Further, when the sixth and seventh plus side switching elements 31F and 31G are turned on and the sixth and seventh minus side switching elements 32F and 32G are cut off, as shown by the thin line arrows in FIG. The current i6 ′ corresponding to the current i6 flowing through the internal wiring flows through the plus side bus bar 141 of the external bus bar unit 136, and the current flowing through the internal wiring of the DC link capacitor unit 21 can be suppressed to a small value.

  That is, the positive side connection terminals 69 of the first to eighth switching element modules 27A to 27H are commonly connected outside the DC link capacitor unit 21 by the external bus bar unit 136, and the first to eighth switching element modules 27A to 27H are connected. Are connected to the outside of the DC link capacitor unit 21 by the external bus bar unit 136, so that a part of the current supplied from the first converter 18 or the second converter 19 to the inverter 20 is reduced. The commutation current that passes through the outside of the DC link capacitor unit 21 and is generated by switching on / off of the sixth to eighth plus-side switching elements 31F to 31H and the sixth to eighth minus-side switching elements 32F to 32H in the inverter 20 Part of the DC link It can be made to pass through the outside of the capacitor unit 21.

  Next, the operation of the present embodiment will be described. First to eighth switching while forming a part of the first converter 18, the second converter 19 and the inverter 20 on the upper and lower surfaces of the water-cooled first heat sink 40, respectively. The switching element assembly unit 67 is configured by mounting the element modules 27 </ b> A to 27 </ b> H, and a water-cooled second heat sink 73 is interposed between the switching element assembly unit 67 and the switching element assembly unit 67. Thus, since the first inductor 24 and the three-phase transformer 26 in the first converter 18 and the second inductor 25 and the two-phase transformer 33 in the second converter 19 are arranged, the first converter 18 can be made compact while being made compact. To eighth switching element modules 27A to 27H and the first switch The ductor 24, the three-phase transformer 26, the second inductor 25, and the two-phase transformer 33 can be efficiently cooled, and the first inductor 24, the three-phase transformer 26, the second inductor 25, and the two-phase transformer 33 are used. The second heat sink 73 can suppress the influence of noise on the first to eighth switching element modules 27 </ b> A to 27 </ b> H.

  The capacitor unit 38 formed by integrating the first input capacitor 22 included in the first converter 18 and the second input capacitor 23 included in the second converter 19 is connected to the switching element assembly unit 67 with the second heat sink 73. Since it is disposed above the switching element assembly unit 67 so as to be interposed therebetween, the compact arrangement of the first and second input capacitors 22 and 23 enables the power converter to be made compact, and the first In addition, heat transfer from the first to eighth switching element modules 27 </ b> A to 27 </ b> H to the second input capacitors 22 and 23 can be suppressed by the second heat sink 73.

  Moreover, since the capacitor unit 38 has a single ground terminal 120 that is common to the first and second input capacitors 22 and 23, not only can the capacitor unit 38 be made more compact. The wiring inductance can be reduced.

  Further, since the even number of first to eighth switching element modules 27A to 27H are mounted on the upper and lower surfaces of the first heat sink 40 in a substantially symmetrical arrangement, the cooling performance of the first to eighth switching element modules 27A to 27H. Can be optimized.

  Moreover, the first to eighth switching element modules 27A to 27H are mounted on the first heat sink 40 with the same orientation of the connection terminals, and constitute a part of the first and second converters 18 and 19 to form the first The first to fifth switching element modules 27A to 27E mounted on the heat sink 40 and a part of the first and second converters 18 and 19 are arranged on the second heat sink 73 and the first to first switching elements modules 27A to 27E are arranged. Since the three-phase transformer 26 and the two-phase transformer 33 directly connected to the fifth switching element modules 27A to 27E are connected by the bus bars 92, 93, 94, 100, and 101, the bus bars 92 to 94, 100, and 101 are shortened. As well as being easy to assemble.

  Incidentally, a plurality of stud bolts 63 having screw shaft portions 63a, 63a at both ends are implanted in the first heat sink 40 so as to protrude from both the upper and lower surfaces of the first heat sink 40. The cases 60... And the copper base plates 58 of the eighth switching element modules 27A to 27H are tightened with nuts 64 that are screwed into the screw shaft portions 63a of the stud bolts 63 selected from the stud bolts 63. Since the first to eighth switching element modules 27A to 27H are mounted on the upper and lower surfaces of the first heat sink 40, the first to eighth switching element modules are mounted on the upper and lower surfaces of the first heat sink 40. 27A to 27H can be easily mounted with few parts.

  The cooling water pump 80 for supplying cooling water to the first cooling water passage 43 in the first heat sink 40 and the second cooling water passage 76 in the second heat sink 73 includes the first and second cooling water passages 43, 76, since the cooling water from the cooling water pump 80 is distributed and supplied to the first and second heat sinks 40 and 73, the first to eighth switching element modules 27A to 27H and the first Optimum cooling performance can be obtained for cooling the inductor 24, the three-phase transformer 26, the second inductor 25, and the two-phase transformer 33.

  The first to eighth plus side switching elements 31A to 31H and the first to eighth minus side switching elements 32A to 32H constituting the first to eighth switching element modules 27A to 27H include a plurality of chips 47, 48, 49. , 50, 51, 52, and two of these chips 47, 48, 49, 50, 51, 52 are arranged in a direction along the flow direction 46 of the cooling water in the first cooling water passage 43. In the first cooling water passage 43 of the first heat sink 40, the chips 47, 49, 51; 48, 50 arranged along the flow direction 46 are arranged in the first heat sink 40. , 52 are arranged separately for each chip 47, 49, 51; 48, 50, 52 for each chip 47, 49, 51; A plurality of cooling fins 71, 71 are arranged offset in a direction orthogonal ... it is disposed.

  Thus, for each inlet of the cooling fins 71, 71... Separated for each of the chips 47, 49, 51; 48, 50, 52 aligned along the flow direction 46, a temperature running section as shown in FIG. By forming, it becomes possible to obtain high cooling efficiency in the first cooling water passage 43 as a whole.

  The first to eighth plus-side switching elements 31A to 31H and the first to eighth minus-side switching elements 32A to 32H constituting the first to eighth switching element modules 27A to 27H are the first cooling water passages. 43, the first to eighth plus-side switching elements 31A to 31H are arranged in the forward path portion 43a of the first cooling water passage 43 in this embodiment. The first to eighth minus side switching elements 32A to 32H are arranged at positions corresponding to the return path portion 433b of the first cooling water passage 43 while being arranged at corresponding positions. Cooling effect is improved by generating a temperature run-up section for each of the 8 plus side switching elements 31A to 31H and the 1st to 8th minus side switching elements 32A to 32H. It can be increased.

  Further, the first to eighth switching element modules 27A to 27H are formed of a synthetic resin for the first to eighth plus side switching elements 31A to 31H and the first to eighth minus side switching elements 32A to 32H constituting the first to eighth switching element modules 27A to 27H. 65... Are attached to the first heat sink 40 in a state of being enclosed in the first heat sink 40. The first to eighth switching element modules 27 </ b> A to 27 </ b> H are radiated from the covering layer 65 and cooled by the first heat sink 40. Can be cooled more effectively.

  Meanwhile, a DC link capacitor unit 21 having smoothing capacitors 36 is provided between the first and second converters 18 and 19 and the inverter 20, and the first converter 18, the second converter 19 and the inverter 20 are connected to each other. The plus side connection terminals 69... And the minus side connection terminals 70... Of the first to eighth switching element modules 27 </ b> A to 27 </ b> H provided are connected to the plus side connection terminals 139 and the minus side connection terminals 140. The positive side connection terminals 69..., 139... Are connected in common to the plus side external bus bar 141, and the minus side connection terminals 70..., 140. To the outside of the DC link capacitor unit 21 Since the plus side and minus side external bus bars 141 and 142 are stacked with the insulating member 143 interposed therebetween to be integrated as the external bus bar unit 136, the internal bus of the DC link capacitor unit 21 is passed through. It is possible to prevent the generation of heat in the internal wiring of the DC link capacitor unit 21 by reducing the current and causing a thermal adverse effect on the smoothing capacitors 36.

  Further, since the external bus bar unit 136 is directly brought into contact with the first heat sink 40, the heat generated in the external bus bar unit 136 is directly transmitted to the first heat sink 40 side so that the vicinity of the DC link capacitor unit 21 is reached. Temperature rise can be suppressed.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

15 ... DC fuel cell 16 ... DC storage battery 18,19 ... converter 20 ... inverter 21 ... DC link capacitor units 22,23 ... input capacitors 27A, 27B 27C, 27D, 27E, 27F, 27G, 27H ... switching element module 36 ... smoothing capacitor 38 ... capacitor unit 40 ... heat sink 67 ... switching element assembly unit 69, 139 ... plus Side connection terminals 70, 140 ... Minus side connection terminal 136 ... External bus bar unit 141 ... Plus side external bus bar 142 ... Minus side external bus bar 143 ... Insulating member

Claims (3)

  A converter (18, 19) for stepping up and down the voltage of the DC power supply (15, 16) while using a plurality of switching element modules (27A, 27B, 27C, 27D, 27E) as a part of the components, and the switching element module (27A To 27E), a DC voltage obtained by the converter (18, 19) is converted into an AC voltage by using a plurality of switching element modules (27F, 27G, 27H) different from at least a part of the electric motors. Power conversion comprising an inverter (20) for driving (17) and a DC link capacitor unit (21) having a smoothing capacitor (36) and provided between the converter (18, 19) and the inverter (20) In the apparatus, a water-cooled heat sink (40) is connected to the converter (18, 19) and the A plurality of the switching element modules (27A to 27H) included in the inverter (20) are mounted, and positive side connection terminals (a plurality of the switching element modules (27A to 27H) mounted on the upper and lower surfaces of the heat sink (40) ( 69) is connected to the plus side connection terminal (139) included in the DC link capacitor unit (21) and is commonly connected to the plus side external bus bar (141), and is connected to the heat sink (40). The negative connection terminal (70) of the switching element module (27A to 27H) is connected to the negative connection terminal (140) included in the DC link capacitor unit (21) and is common to the negative external bus bar (142). Connected to the DC link capacitor unit ( The external bus bars (141, 142) arranged on the outer side of 1) are laminated with an insulating member (143) interposed therebetween to be integrated as an external bus bar unit (136). The power converter characterized by the above-mentioned.   A capacitor unit (38) formed by integrating input capacitors (22, 23) included in each of the pair of converters (18, 19) includes the heat sink (40) and the plurality of switching element modules (27A to 27H). A power conversion device, which is arranged above a configured switching element assembly unit (67).   The power converter according to claim 1 or 2, wherein the external bus bar unit (136) is in direct contact with the heat sink (40).

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