JP2012217322A - Power conversion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power conversion apparatus capable of easily restraining temperature rise of a capacitor.SOLUTION: A power conversion apparatus 1 comprises: a plurality of semiconductor modules 2; a positive electrode bus bar 3; a negative electrode bus bar 4; a capacitor; and a discharge resistor 6. The semiconductor module 2 comprises: a body part 20 sealing a semiconductor element; and a positive electrode terminal 21a and a negative electrode terminal 21b projecting from the body part 20. The positive electrode bus bar 3 is connected to the positive electrode terminal 21a, and the negative electrode bus bar 4 is connected to the negative electrode terminal 21b. The capacitor 5 is connected to the positive electrode bus bar 3 and the negative electrode bus bar 4, in order to smooth voltage applied to the semiconductor modules 2. Discharge current flows into the discharge resistor 6. The discharge resistor 6 is connected to the positive bus bar 3 and the negative bus bar 4.

Description

  The present invention relates to a power conversion device provided with a discharge resistor.

  2. Description of the Related Art Conventionally, a power conversion device (see Patent Document 1 below) for performing power conversion between DC power and AC power is known. The power conversion device includes a semiconductor module incorporating a switching element and a capacitor for smoothing a voltage applied to the semiconductor module.

  As shown in FIG. 15, the capacitor 95 includes a case 92, a capacitor element (not shown) accommodated in the case 92, and a sealing member 93 that seals the capacitor element in the case 92. A pair of connection terminals 94 are connected to the capacitor element. A part of the connection terminal 94 protrudes from the sealing member 93. The connection terminal 94 is electrically connected to a DC power source and a semiconductor module (not shown).

  A discharge resistor 96 is connected to the connection terminal 94. By flowing the discharge current I of the capacitor 95 through the discharge resistor 96, the electric charge stored in the capacitor element is discharged. As shown in FIG. 15, no relay or the like is interposed between the capacitor 95 and the discharge resistor 96. That is, the capacitor 95 keeps flowing the discharge current I through the discharge resistor 96 even while using the power converter, and always discharges the charge stored in the capacitor element little by little.

  It is possible to provide a relay between the capacitor 95 and the discharge resistor 96 and turn on the relay only after stopping the use of the power converter, but in this case, if the relay breaks down, it becomes impossible to discharge. There is. Therefore, as described above, if the discharge current I is always supplied without providing a relay, the capacitor 95 can be reliably discharged after using the power converter. Therefore, an electric shock accident or the like can be prevented more reliably.

  Thus, while the power conversion device is used, the discharge current I always flows through the discharge resistor 96, and the discharge resistor 96 always generates heat.

JP 2006-42498 A

  However, in the conventional power converter, since the connection terminal 94 of the capacitor 95 and the discharge resistor 96 are directly connected by the wire 91, the heat that is always generated from the discharge resistor 96 as described above is applied to the wire 91. There is a problem that it is easy to be transmitted to the capacitor 95 through. For this reason, the temperature of the capacitor 95 is likely to rise. When the temperature rises, problems such as shortening the life of the capacitor 95 occur. Therefore, a power conversion device that can suppress the temperature rise of the capacitor has been desired.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a power conversion device that can easily suppress a rise in the temperature of a capacitor.

The present invention is a power conversion device having a plurality of semiconductor modules in which power terminals protrude from a main body portion in which a semiconductor element is sealed,
The power terminal includes a positive terminal connected to the positive electrode of the DC power source and a negative terminal connected to the negative electrode of the DC power source,
A positive electrode bus bar and a negative electrode bus bar made of a metal plate and connected to the positive electrode terminal and the negative electrode terminal, respectively;
A capacitor connected to the positive bus bar and the negative bus bar and smoothing a voltage applied to the semiconductor module;
A discharge resistor through which the discharge current of the capacitor flows,
The discharge resistor is connected to the positive electrode bus bar and the negative electrode bus bar in the power conversion device (claim 1).

  In the power converter, a discharge resistor is connected to the positive electrode bus bar and the negative electrode bus bar to which a smoothing capacitor is connected. Therefore, the discharge current of the capacitor can flow to the discharge resistor through the positive electrode bus bar and the negative electrode bus bar. Even when the discharge current flows and the discharge resistor generates heat, the temperature of the capacitor does not easily rise. That is, the heat generated from the discharge resistance is transferred to the positive electrode bus bar and the negative electrode bus bar, and most of the heat is radiated from the positive electrode bus bar and the negative electrode bus bar. Moreover, since the positive electrode bus bar and the negative electrode bus bar are made of a metal plate and have a large heat capacity, the temperature of the bus bar does not increase so much even if the heat generated from the discharge resistance is transmitted to these bus bars. Therefore, the temperature of the capacitor connected to the bus bar is also difficult to rise.

  As described above, according to this example, it is possible to provide a power conversion device that can easily suppress the temperature rise of the capacitor.

The top view of the power converter device in Example 1. FIG. AA sectional drawing of FIG. The principal part enlarged view of FIG. CC sectional drawing of FIG. BB sectional drawing of FIG. The top view of the power converter device which removed the positive electrode bus bar and the insulating resin body in Example 1. FIG. The top view of the power converter device which removed the positive electrode bus bar, the negative electrode bus bar, and the discharge resistance in Example 1. The example which integrated the semiconductor module and the refrigerant | coolant flow path in Example 1. FIG. The top view of the power converter device in Example 2. FIG. The top view of the power converter device in Example 3. FIG. The principal part enlarged view of FIG. The top view of the flame | frame in Example 3. FIG. The perspective view of the discharge resistance in Example 3. FIG. The principal part enlarged view of the power converter device in Example 4. FIG. The perspective view showing the connection structure of the discharge resistance and a capacitor | condenser in a prior art example.

  For example, the power conversion device is mounted on an electric vehicle or a hybrid vehicle, and can be a vehicle-mounted power conversion device for converting DC power supplied from a vehicle-mounted battery into AC power.

In the power converter, the semiconductor module is preferably cooled by a cooler.
In this case, the positive electrode bus bar and the negative electrode bus bar are connected to the semiconductor module cooled using the cooler. Therefore, these bus bars can be cooled by the cooler via the semiconductor module. As a result, the heat generated from the discharge resistor is easily cooled when being transmitted through the bus bar, and the temperature rise of the capacitor is easily suppressed.

A plurality of refrigerant flow paths through which a refrigerant for cooling the semiconductor module flows; the plurality of refrigerant flow paths and the plurality of semiconductor modules being stacked to form a laminated body; and the plurality of refrigerant flow paths Among these, in the refrigerant flow path located at one end in the stacking direction of the laminated body, an introduction pipe for introducing the refrigerant into the refrigerant flow path, and for deriving the refrigerant from the refrigerant flow path It is preferable that the cooler is constituted by the plurality of refrigerant flow paths, the introduction pipe, and the lead pipe (Claim 3).
In this case, since the semiconductor module and the coolant channel are stacked, the semiconductor module can be cooled from both sides in the stacking direction, and the cooling efficiency of the semiconductor module can be increased. Therefore, the positive electrode bus bar and the negative electrode bus bar connected to the semiconductor module can be easily cooled. As a result, the heat generated from the discharge resistor is easily cooled when being transmitted through the bus bar, and the temperature rise of the capacitor is more easily suppressed.

The positive electrode bus bar and the negative electrode bus bar are connected to the discharge resistor provided at a position adjacent to the plurality of power connection terminals in the stacking direction with respect to the plurality of power connection terminals. Preferably, the plurality of power connection terminals and the plurality of power connection terminals are arranged at a constant pitch in the stacking direction.
In this case, since the plurality of power connection terminals and the resistance connection terminals are arranged at a constant pitch, a step of connecting the power connection terminals to the power terminals at the time of manufacturing the power converter, The step of connecting the resistance connection terminal to the discharge resistor can be continuously performed. Therefore, these connection processes can be performed in a short time. Moreover, it is not necessary to perform these connection processes with separate facilities, and it is possible to perform with one facility. Therefore, the number of facilities can be reduced, and the manufacturing cost of the power conversion device can be reduced.

The positive electrode bus bar and the negative electrode bus bar include a plurality of power connection terminals for connection to the power terminals, and the power connection terminals located at one end in the stacking direction among the plurality of power connection terminals. The terminal of the discharge resistor is preferably connected together with the power terminal (claim 5).
In this case, at the time of manufacturing the power conversion device, the power terminal located at one end in the stacking direction and the terminal of the discharge resistor can be simultaneously connected to the bus bar. Therefore, the time required for the connection process can be shortened. In addition, since it is not necessary to provide a dedicated portion for connecting to the discharge resistor in the bus bar, the bus bar can be reduced in size and the manufacturing cost of the bus bar can be reduced.

Preferably, a metal frame for fixing the plurality of semiconductor modules and the cooler is provided, the frame is cooled by the cooler, and the discharge resistor is attached to the frame. ).
In this case, it becomes possible to cool the discharge resistance through the frame using a cooler. Therefore, the temperature of the discharge resistor is unlikely to rise, and heat transferred from the discharge resistor to the capacitor can be reduced. Therefore, it becomes easy to suppress the temperature rise of the capacitor.

Further, it is preferable that the frame has a resistance accommodation hole opened in a protruding direction of the power terminal, and the discharge resistance is accommodated in the resistance accommodation hole.
In this case, since the discharge resistance is surrounded by the inner surface of the resistance accommodation hole, the heat generated from the discharge resistance easily escapes to the surroundings. For this reason, the temperature of the discharge resistor is unlikely to rise, and the heat transferred from the discharge resistor to the capacitor can be reduced. This makes it possible to more effectively suppress the temperature rise of the capacitor.

Moreover, it is preferable that at least a part of the discharge resistance overlaps with the cooler when viewed from the protruding direction of the power terminal.
In this case, since the discharge resistor can be disposed near the cooler, the discharge resistor can be cooled using the cooler. For this reason, the temperature of the discharge resistor is unlikely to rise, and the heat transferred from the discharge resistor to the capacitor can be reduced. Therefore, it becomes easy to suppress the temperature rise of the capacitor.

Further, a metal frame for fixing the plurality of semiconductor modules and the cooler is provided, the frame is cooled by the cooler, and is interposed between the positive electrode bus bar and the negative electrode bus bar to insulate both of them. Preferably, the discharge resistor is mounted on an insulating resin body fixed to the frame.
In this case, the discharge resistance can be cooled through the frame and the insulating resin body using a cooler. Therefore, the temperature of the discharge resistor is unlikely to rise, and heat transferred from the discharge resistor to the capacitor can be reduced. Therefore, it becomes easy to suppress the temperature rise of the capacitor. In addition, the insulating resin body on which the discharge resistor is mounted is also a member for insulation between the positive electrode bus bar and the negative electrode bus bar, and has two functions. Therefore, the number of parts of the power conversion device can be reduced, and the manufacturing cost can be reduced.

In addition, the plurality of positive terminals and the plurality of negative terminals protrude in the same direction from the main body, respectively, a positive connection part connecting the positive terminal and the positive bus bar, and the negative terminal and the negative bus bar. And the resistance connecting part connecting the bus bar and the discharge resistor are located on the same direction side in the protruding direction of the positive terminal and the negative terminal with respect to the cooler. (Claim 10).
In this case, since the positive electrode connecting portion, the negative electrode connecting portion, and the resistance connecting portion are located on the same direction side in the protruding direction with respect to the cooler, at the time of manufacturing the power conversion device When connecting these connection portions by welding or the like, it is possible to perform connection work of all the connection portions from the same direction. Therefore, it is not necessary to change the direction of the power converter for each connection portion, and the power converter can be easily manufactured.

Example 1
A power converter according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2, the power conversion device 1 of this example includes a plurality of semiconductor modules 2, a positive bus bar 3, a negative bus bar 4, a capacitor 5, and a discharge resistor 6.
The semiconductor module 2 has a main body 20 in which a semiconductor element is sealed. A plurality of power terminals 21 protrude from the main body 20. The power terminal 21 includes a positive terminal 21a connected to a positive electrode of a DC power source (not shown), a negative terminal 21b connected to a negative electrode of the DC power source, and an AC terminal 21c connected to an AC load. .

The positive electrode bus bar 3 and the negative electrode bus bar 4 are made of metal plates. The positive electrode bus bar 3 is connected to the positive electrode terminal 21a, and the negative electrode bus bar 4 is connected to the negative electrode terminal 21b.
The capacitor 5 is connected to the positive bus bar 3 and the negative bus bar 4 to smooth the voltage applied to the semiconductor module 2.
A discharge current of the capacitor 5 flows through the discharge resistor 6. The discharge resistor 6 is connected to the positive electrode bus bar 3 and the negative electrode bus bar 4.

  As shown in FIG. 1, the power conversion device 1 includes a plurality of refrigerant flow paths 70 through which the refrigerant 16 that cools the semiconductor module 2 flows. The refrigerant flow path 70 is formed in the cooling pipe 71. A plurality of cooling pipes 71 (refrigerant flow paths 70) and a plurality of semiconductor modules 2 are stacked to constitute the stacked body 10. Among the plurality of cooling pipes 71, a cooling pipe 71 a located at one end in the stacking direction (X direction) of the stacked body 10 includes an introduction pipe 72 for introducing the refrigerant 16 into the refrigerant flow path 70, and a refrigerant A lead-out pipe 73 for leading the refrigerant 16 from the flow path 70 is provided. The cooler 7 is configured by the plurality of refrigerant flow paths 70, the introduction pipe 72, and the outlet pipe 73. When the refrigerant 16 is introduced from the introduction pipe 72, the refrigerant 16 is distributed and flows into the plurality of refrigerant flow paths 70, and is led out from the outlet pipe 73. Thereby, the plurality of semiconductor modules 2 are cooled.

  As shown in FIG. 2, the semiconductor module 2 includes a plurality of control terminals 22 in addition to the power terminals 21 a to 21 c. The control terminal is connected to the control circuit board 15. By using this control circuit board 15 to control the switching operation of the semiconductor elements in the semiconductor module 2, the DC voltage applied between the positive terminal 21a and the negative terminal 21b is converted into an AC voltage, and the AC terminal 21c is output.

  As shown in FIG. 1, the positive electrode bus bar 3 is connected to a plurality of positive electrode terminals 21a. The positive electrode bus bar 3 includes a plate-like main body portion 38 and a plurality of power connection terminals 39 protruding from the plate-like main body portion 38. Each power connection terminal 39 is connected to the positive electrode terminal 21 a of each semiconductor module 2.

  Moreover, as shown in FIG. 6, the negative electrode bus bar 4 has the same structure. That is, the negative electrode bus bar 4 includes a plate-like main body portion 48 and power connection terminals 49 protruding from the plate-like main body portion 48. Each power connection terminal 49 extends in a direction (Y direction) orthogonal to both the protruding direction of the power terminal 21 (Z direction: see FIG. 2) and the stacking direction (X direction) of the laminate 10. Yes. The power connection terminal 49 passes between the positive terminal 21a and the negative terminal 21b and is connected to the negative terminal 21b.

  The positions of the positive terminal 21a and the negative terminal 21b in the semiconductor module 2 may be reversed.

  The power conversion device 1 of this example includes a metal frame 8 for fixing the laminated body 10. As shown in FIG. 7, the frame 8 has a substantially rectangular shape when viewed from the Z direction, a laminated body fixing portion 81 for fixing the laminated body 10, an accommodation recess 50 for housing the capacitor 5, and Is provided. Among the inner surfaces 82 and 83 orthogonal to the X direction in the frame 8, the spring member 14 is disposed between the inner surface 82 (one inner surface 82) on the side where the introduction pipe 72 and the outlet pipe 73 are provided and the laminate 10. Is provided. The laminated body 10 is fixed in the frame 8 by pressing the laminated body 10 in the X direction using the spring member 14 and pressing the laminated body 10 against the other inner surface 83. A reinforcing plate 17 is provided between the spring member 14 and the laminated body 10 to prevent the cooling pipe 71a from being dented by the elastic force of the spring member 14.

  Of the plurality of cooling pipes 71 constituting the laminated body 10, the cooling pipe 71 b located on the opposite side in the X direction from the cooling pipe 71 a to which the pipes 72 and 73 are attached contacts the other inner surface 83 of the frame 8. is doing. Therefore, the frame 8 is cooled by the cooling pipe 71b.

  In this example, the spring member 14 is provided between one inner surface 82 and the laminate 10 in the frame 8, but the spring member 14 may be provided between the other inner surface 83 and the laminate 10. In this case, the frame 8 is pressed toward one inner surface 82. In this example, only the reinforcing plate 17 is provided between the spring member 14 and the laminated body 10, but other electronic components such as a reactor may be interposed between them.

  As shown in FIG. 2, a capacitor case 55 is fitted in the housing recess 50 of the frame 8. A capacitor element 53 is accommodated in the capacitor case 55 and is sealed by a sealing member 54. The capacitor case 55 opens on the protruding side of the power terminal 21 in the Z direction. The opening edge 550 of the capacitor case 55 exists in a position farther from the bottom 510 of the housing recess 50 than the tip 210 of the power terminal 21 in the Z direction.

  In this example, a film capacitor is used as the capacitor element 53. Both end surfaces of the capacitor element 53 are electrode surfaces 530 and 531 for electrical connection. Connection terminals 51 and 52 are connected to the electrode surfaces 530 and 531. The connection terminals 51 and 52 are fastened to the bus bars 3 and 4 by bolts 57 and 58 (see FIG. 1), respectively. As a result, the bus bars 3 and 4 and the capacitor element 53 are electrically connected.

Of the electrode surfaces 530 and 531 of the capacitor element 53, the electrode surface 531 on the side closer to the bottom 510 of the housing recess 50 is the positive electrode surface, and the electrode surface 530 far from the bottom 510 is the negative electrode. Surface.
The positive connection terminal 51 is connected to the electrode surface 531. The positive side connection terminal 51 includes a first portion 51a, a second portion 51b, a third portion 51c, a fourth portion 51d, and a fifth portion 51e. The first portion 51 a is connected to the positive electrode surface 531. The second portion 51 b is erected in the Z direction from the end of the first portion 51 a on the semiconductor module 2 side in the Y direction, and extends to a position beyond the opening edge 550 of the capacitor case 55. The third portion 51c extends in the Y direction from the second portion 51b and straddles the opening edge 550. The fourth portion 51d extends from the third portion 51c to the bottom 510 side in the Z direction. The fifth portion 51e extends from the fourth portion 51d to the semiconductor module 2 side in the Y direction. The fifth portion 51 e is fastened to the positive bus bar 3 by a bolt 57.

  A negative connection terminal 52 is connected to the negative electrode surface 530 of the capacitor element 53. The structure of the negative connection terminal 52 is substantially the same as the structure of the positive connection terminal 51. As shown in FIG. 1, the plate-like main body 38 of the positive electrode bus bar 3 is formed with a through portion 580 penetrating in the Z direction. In the through portion 580, the negative side connection terminal 52 is fastened to the negative electrode bus bar 4 using a bolt 58.

  As shown in FIGS. 2 and 5, the plate-like main body 48 of the negative electrode bus bar 4 is covered with an insulating resin body 30. The plate-like main body 38 of the positive electrode bus bar 3 is placed on the insulating resin body 30. The positive electrode bus bar 3 and the negative electrode bus bar 4 are electrically insulated by the insulating resin body 30.

  As shown in FIG. 5, a part of the insulating resin body 30 does not cover the negative electrode bus bar 4 but serves as a resistance mounting plate 300 for mounting the discharge resistance 6. As shown in FIGS. 1 and 5, the resistance mounting plate 300 includes a first portion 300 a extending from the portion covering the negative electrode bus bar 4 (covering portion 301) toward the introduction pipe 72 in the X direction, and the first portion 300 a. The second portion 300b extends from the portion 300a to the outlet pipe 16 side in the Y direction. The resistance mounting plate 300 is fastened to the frame 8 by a fastening member 32.

  As shown in FIG. 3, the discharge resistor 6 includes a frame body 63 made of ceramic, an electric resistor (not shown) housed in the frame body 63, and the electric resistor is sealed in the frame body 63. Cement 64. From the frame 63, the terminals 61 and 62 of the electrical resistor extend in the same direction in the X direction. The frame 63 is formed in a substantially rectangular shape and includes a pair of fixed portions 310. The fixed portion 310 has a semicircular shape when viewed from the Z direction, and protrudes from the short sides L1 and L2 of the frame 63 toward the opposite sides in the Y direction. In this fixed portion 310, the discharge resistor 6 is fixed to the insulating resin body 30 (resistance mounting plate 300).

  As shown in FIG. 4, the insulating resin body 30 has a pair of bosses 33 projecting toward the discharge resistor 6 in the Z direction. A pair of fixing pins 34 protrude from the center of the boss 33 in the Z direction. Further, a fixing through hole 35 penetrating in the Z direction is formed in the fixed portion 310 of the discharge resistor 6. The fixing pin 34 is inserted into the fixing through hole 35. Further, the tip 340 of the fixing pin 34 protrudes from the surface 65 of the discharge resistor 6 opposite to the insulating resin body 30. The tip 340 is a heat caulking portion 31 that is melted and deformed by applying heat. The outer diameter of the heat caulking portion 31 is larger than the inner diameter of the fixing through hole 35. The discharge resistor 6 is fixed by sandwiching the discharge resistor 6 in the Z direction between the heat caulking portion 31 and the boss 33.

  When a discharge current is passed through the discharge resistor 6, the portion where the electrical resistor is sealed (the heat generating portion 69) generates heat. In this example, by providing the boss 33, a gap d is formed between the heat generating portion 69 and the insulating resin body 30. Thereby, the influence on the insulating resin body 30 by the heat generation of the discharge resistor 6 is reduced.

  Further, as shown in FIG. 3, the positive terminal 61 of the discharge resistor 6 is connected to the positive bus bar 3, and the negative terminal 62 is connected to the negative bus bar 4. The bus bars 3 and 4 have connection bodies 37 and 47 for connecting to the terminals 61 and 62, respectively. The connection body 37 of the positive electrode bus bar 3 includes a first portion 371 extending in the X direction from the plate-like main body portion 38 toward the discharge resistor 6, and the capacitor 5 in the Y direction from the tip of the first portion 371 (see FIG. 1). ) And a second portion 372 extending to the opposite side. The second portion 372 is connected to the terminal 61. The connecting body 47 of the negative electrode bus bar 4 has the same structure, and extends from the power connection terminal 49 in the X direction and extends from the tip of the first portion 471 in the Y direction. A second portion 472. The second portion 472 is connected to the terminal 62.

  As shown in FIG. 3, in this example, the bus bars 3 and 4 and the discharge resistor 6 are directly connected, and no relay or the like is interposed therebetween. In other words, in this example, the discharge current is kept flowing through the discharge resistor 6 while the power conversion device 1 is used, and the charge stored in the capacitor element 53 is always discharged little by little.

It is possible to provide a relay between the capacitor 5 and the discharge resistor 6 and turn on the relay only after stopping the use of the power converter, but in this case, if the relay breaks down, it becomes impossible to discharge. There is. Therefore, as in this example, if a discharge current is always supplied without providing a relay, the capacitor 5 can be reliably discharged after using the power conversion device 1. Therefore, an electric shock accident or the like can be prevented more reliably.
Accordingly, while the power conversion device 1 is used, a discharge current always flows through the discharge resistor 6 and the discharge resistor 6 always generates heat.

  As shown in FIG. 5, the portion where the bus bars 3, 4 and the discharge resistor 6 are connected (resistance connection portion 13) is located on the opposite side of the control circuit board 15 with respect to the cooler 7 in the Z direction. Further, the portion (positive electrode connecting portion 11) connecting the positive electrode bus bar 3 and the positive electrode terminal 21a is also located on the opposite side of the control circuit board 15 with respect to the cooler 7 in the Z direction. Furthermore, the part (negative electrode connection part 12) which connected the negative electrode bus bar 4 and the negative electrode terminal 21b is also located in the other side of the control circuit board 15 with respect to the cooler 7 in a Z direction. That is, the resistance connection part 13, the positive electrode connection part 11, and the negative electrode connection part 12 are respectively located on the same direction side in the Z direction.

The effect of this example will be described.
As shown in FIG. 1, in this example, a discharge resistor 6 is connected to a positive bus bar 3 and a negative bus bar 4 to which a smoothing capacitor 5 is connected. Therefore, the discharge current of the capacitor 5 can flow to the discharge resistor 6 through the positive electrode bus bar 3 and the negative electrode bus bar 4. And even if the discharge current flows and the discharge resistor 6 generates heat, the temperature of the capacitor 5 is hardly increased. That is, the heat generated from the discharge resistor 6 is transmitted to the positive electrode bus bar 3 and the negative electrode bus bar 4, and most of the heat is radiated from the positive electrode bus bar 3 and the negative electrode bus bar 4. Moreover, since the positive electrode bus bar 3 and the negative electrode bus bar 4 are made of a metal plate and have a large heat capacity, even if heat generated from the discharge resistor 6 is transmitted to the bus bars 3 and 4, the temperature of the bus bars 3 and 4 does not increase so much. Therefore, the temperature of the capacitor 5 connected to the bus bars 3 and 4 is also difficult to rise.

In this example, the semiconductor module 2 is cooled by the cooler 7.
If it does in this way, the positive electrode bus bar 3 and the negative electrode bus bar 4 will be connected to the semiconductor module 2 cooled using the cooler 7. Therefore, these bus bars 3 and 4 can be cooled by the cooler 7 via the semiconductor module 2. Thereby, the heat generated from the discharge resistor 6 is easily cooled when being transmitted through the bus bars 3 and 4, and the temperature rise of the capacitor 5 is more easily suppressed.

As shown in FIG. 1, in this example, a part of the discharge resistor 6 overlaps with the cooler 7 when viewed from the Z direction.
In this way, since the discharge resistor 6 can be disposed near the cooler 7, the discharge resistor 6 can be cooled using the cooler 7. For this reason, the temperature of the discharge resistor 6 is unlikely to rise, and the heat transmitted from the discharge resistor 6 to the capacitor 5 can be reduced. Therefore, it becomes easy to suppress the temperature rise of the capacitor 5.

In addition, as shown in FIG. 1, this example includes a metal frame 8 that fixes the plurality of semiconductor modules 2 and the cooler 7. The frame 8 is cooled by the cooling pipe 71 b of the cooler 7. In addition, the discharge resistor 6 is mounted on an insulating resin body 30 (see FIGS. 2 and 5) that is interposed between the positive electrode bus bar 3 and the negative electrode bus bar 4 to insulate them and is fixed to the frame 8.
In this way, the discharge resistor 6 can be cooled through the frame 8 and the insulating resin body 30 using the cooler 7. Therefore, the temperature of the discharge resistor 6 is unlikely to rise, and the heat transferred from the discharge resistor 6 to the capacitor 5 can be reduced. Therefore, it becomes easy to suppress the temperature rise of the capacitor 5. The insulating resin body 30 on which the discharge resistor 6 is mounted is also a member for insulation between the positive electrode bus bar 3 and the negative electrode bus bar 4, and has two functions. Therefore, the number of parts of the power conversion device 1 can be reduced, and the manufacturing cost can be reduced.

Further, as shown in FIG. 5, in this example, the positive electrode connection portion 11, the negative electrode connection portion 12 (see FIG. 1), and the resistance connection portion 13 are on the same direction side in the Z direction with respect to the cooler 7. positioned.
If it does in this way, when connecting these connection parts 11, 12, and 13 by welding etc. at the time of manufacture of the power converter device 1, the connection operation of all the connection parts 11, 12, and 13 will be performed from the same direction. Is possible. Therefore, it is not necessary to change the direction of the power conversion device 1 for each of the connection parts 11, 12, and 13, and the power conversion device 1 can be easily manufactured.

Further, in this example, as shown in FIG. 1, a laminated body 10 is configured by laminating a plurality of refrigerant flow paths 70 and a plurality of semiconductor modules 2.
In this way, the semiconductor module 2 can be cooled from both sides in the stacking direction (X direction), and the cooling efficiency of the semiconductor module 2 can be increased. Therefore, the positive electrode bus bar 3 and the negative electrode bus bar 4 connected to the semiconductor module 2 are also easily cooled. Thereby, the heat generated from the discharge resistor 6 is easily cooled when being transmitted through the bus bars 3 and 4, and the temperature rise of the capacitor 5 is more easily suppressed.

  As described above, according to this example, it is possible to provide a power conversion device that can easily suppress the temperature rise of the capacitor.

  In addition, in this example, although the laminated body 10 was comprised by laminating | stacking the several cooling pipe 71 which has the refrigerant flow path 70 inside, and the several semiconductor module 2, as shown in FIG. 8, the semiconductor element was incorporated. The main body 20 of the semiconductor module 2 is surrounded while providing a space from a direction orthogonal to the stacking direction (X direction), and a frame 28 having a larger width in the stacking direction (X direction) than the main body 20 is provided. The semiconductor module 2 and the coolant channel 70 may be stacked by stacking the cooler-integrated semiconductor module 78 provided integrally with the semiconductor module 20.

(Example 2)
In this example, the mounting structure of the discharge resistor 6 is changed. As shown in FIG. 9, the power conversion device 1 of this example includes a metal frame 8 for fixing the multilayer body 10 and the capacitor 5, as in the first embodiment. In this example, the discharge resistor 6 is not mounted on the insulating resin body 30 but directly mounted on the frame 8.
In addition, the same configuration as that of the first embodiment is provided.

  The effect of this example will be described. In this example, the discharge resistor 6 can be cooled via the frame 8 using the cooler 7 as in the first embodiment. For this reason, the temperature of the discharge resistor 6 is unlikely to rise, and the heat transmitted from the discharge resistor 6 to the capacitor 5 can be reduced. Therefore, it becomes easy to suppress the temperature rise of the capacitor 5.

In this example, the discharge resistor 6 is directly mounted on the frame 8 without the insulating resin body 30 interposed. Therefore, the heat generated from the discharge resistor 6 can be easily cooled by the frame 8. Thereby, it becomes easier to suppress the temperature rise of the capacitor 5.
In addition, the same functions and effects as those of the first embodiment are provided.

(Example 3)
In this example, the fixing method of the discharge resistance is changed. In this example, as shown in FIG. 12, a resistance accommodation hole 85 that opens in the Z direction is formed in the frame 8. Then, as shown in FIGS. 10 and 11, the discharge resistor 6 was accommodated in the resistance accommodation hole 85. The discharge resistor 6 is in contact with the inner surface 850 of the resistor housing hole 85.

  As in the first embodiment, the bus bars 3 and 4 of this example include a plurality of power connection terminals 39 and 49 connected to the power terminal 21. The bus bars 3 and 4 have resistance connection terminals 36 and 46 connected to the discharge resistor 6. The resistance connection terminals 36 and 46 are provided at positions adjacent to the plurality of power connection terminals in the X direction. The plurality of power connection terminals 39 and 49 and the resistance connection terminals 36 and 46 are arranged at a constant pitch in the X direction. The power connection terminals 39 and 49 and the resistance connection terminals 36 and 46 have the same shape.

  As shown in FIG. 12, the frame 8 is formed with a rectangular protrusion 86 protruding inward from the side wall 87 of the frame 8. The resistance housing hole 85 is formed in the protrusion 86. As shown in FIG. 10, the resistance accommodation hole 85 is located between the introduction pipe 72 and the extraction pipe 73 when viewed from the Z direction. Further, the cooling pipe 71 a located at one end in the X direction among the plurality of cooling pipes 71 constituting the stacked body 10 is in contact with the protrusion 86.

  The discharge resistor 6 includes a pair of terminals 61 and 62. The terminals 61 and 62 are connected to the resistance connection terminals 36 and 46 of the bus bars 3 and 4. Further, the discharge resistor 6 is fixed to the protrusion 86 by a bolt 68.

  As shown in FIG. 13, the discharge resistor 6 includes a ceramic sealing member 60, an electric resistor (not shown) sealed by the sealing member 60, terminals 61 and 62, and a heat dissipation plate 67. Prepare. The heat sink 67 is in contact with the main surface of the sealing member 60. Further, two crimping portions 671 and 672 protrude from the heat radiating plate 67 in the X direction. The heat sink 67 is fixed to the sealing member 60 by crimping the sealing member 60 in the Y direction by the crimping portions 671 and 672.

  Further, the resistance connection plate 673 is formed so as to protrude in the X direction from one end of the heat dissipation plate 67 in the Y direction. A bolt insertion hole 674 is formed at the tip of the resistance connection plate 673 so as to penetrate in the Z direction. The discharge resistor 6 is fixed to the frame 8 by inserting a bolt 68 (see FIG. 10) into the bolt insertion hole 674 and screwing it into a screw hole 861 formed in the protrusion 86 (see FIG. 12).

  Further, as shown in FIG. 13, a locking portion 675 is formed on the heat radiating plate 67. The locking portion 675 protrudes from the side surface 600 of the sealing member 60 toward the capacitor 5 (see FIG. 10) side in the Y direction. When the discharge resistor 6 is stored in the resistance storage hole 85 (see FIG. 11), the locking portion 675 is locked to the protrusion 86. As described above, in this example, the discharge resistor 6 is fixed to the frame 8 using the bolt 68 in a state where the locking portion 675 is locked to the protrusion 86.

  In this example, when the discharge resistor 6 is housed in the resistor housing hole 85, the heat radiating plate 67 of the discharge resistor 6 comes into contact with the inner surface 850 of the resistor housing hole 85.

Further, as shown in FIG. 13, the two terminals 61 and 62 of the discharge resistor 6 are bent at a plurality of locations, respectively. Of the two terminals 61 and 62, the terminal 61 connected to the positive electrode bus bar 3 is composed of four parts: a first part 611 to a fourth part 614. The first portion 611 protrudes from the sealing member 60 in the Z direction. The second portion 612 extends from the first portion 611 in the X direction. Further, the third portion 613 extends from the second portion 612 to the capacitor 5 (see FIG. 10) side in the Y direction. The fourth portion 614 protrudes from the third portion 613 in the Z direction. As shown in FIG. 11, the fourth portion 614 is connected to the resistance connection terminal 36.
In this example, the terminal 61 is prevented from coming into contact with the resistance connection terminal 46 of the negative electrode bus bar by forming the terminal 61 in the above shape.

  As shown in FIG. 13, of the two terminals 61 and 62 of the discharge resistor 6, the terminal 62 connected to the negative electrode bus bar 3 is composed of three parts: a first part 621 to a third part 623. The first portion 621 protrudes from the sealing member 60 in the Z direction. The second portion 622 extends from the first portion 621 in the X direction. The third portion 623 extends from the second portion 622 in the Z direction. As shown in FIG. 11, the third portion 623 is connected to the resistance connection terminal 46.

  The fourth portion 614 of the positive-side terminal 61 and the third portion 623 of the negative-side terminal 62 are parallel to each other, and the heights of the respective tips are substantially the same in the Z direction.

On the other hand, as shown in FIG. 10, a spring member 14 is provided in the frame 8. The spring member 14 is interposed between the laminated body 10 and the side wall 88 opposite to the side wall 87 on the side where the discharge resistance 6 is provided, of the two side walls 87 and 88 orthogonal to the X direction of the frame 8. is doing. By using the spring member 14 to press the laminated body 10 toward the protrusion 86, the laminated body 10 is fixed in the frame 8 while ensuring the contact pressure between the semiconductor module 2 and the cooling pipe 71. Yes.
In addition, the same configuration as that of the first embodiment is provided.

The effect of this example will be described. As shown in FIG. 10, in this example, a resistance accommodation hole 85 is formed in the frame 8, and the discharge resistor 6 is accommodated in the resistance accommodation hole 85.
In this way, since the discharge resistor 6 is surrounded by the inner surface 850 of the resistor housing hole 85, the heat generated from the discharge resistor 6 can easily escape to the surroundings. For this reason, the temperature of the discharge resistor 6 is unlikely to rise, and the heat transmitted from the discharge resistor 6 to the capacitor 5 can be reduced. Thereby, the temperature rise of the capacitor 5 can be more effectively suppressed.

Further, as shown in FIG. 10, the bus bars 3 and 4 of the present example have a plurality of power connection terminals 39 and 49 and resistance connection terminals 36 and 46. A plurality of power connection terminals 39 and 49 and resistance connection terminals 36 and 46 are arranged at a constant pitch in the X direction.
If it does in this way, at the time of manufacture of power converter 1, the process of connecting power connection terminals 39 and 49 to power terminal 21, and the process of connecting connection terminals 36 and 46 for resistance to discharge resistor 6 are continued. Can be done. Therefore, these connection processes can be performed in a short time. Moreover, since these connection processes can be performed by one installation, the number of installations can be reduced and the manufacturing cost of the power converter device 1 can be reduced.
In addition, the same effects as those of the first embodiment are obtained.

Example 4
In this example, the shape of the bus bars 3 and 4 is changed. As shown in FIG. 14, the bus bars 3 and 4 of this example include a plurality of power connection terminals 39 and 49 for connection to the power terminal 21. The terminals 61 and 62 of the discharge resistor 6 are connected together with the power terminal 21 to the power connection terminals 39 a and 49 a located at one end in the X direction among the plurality of power connection terminals 39 and 49.
In this way, the positive electrode terminal 21a located at one end in the X direction and the positive terminal 61 of the discharge resistor 6 can be simultaneously connected to the positive electrode bus bar 3 when the power conversion device 1 is manufactured. Similarly, the negative electrode terminal 21 b located at one end in the X direction and the negative terminal 62 of the discharge resistor 6 can be simultaneously connected to the negative electrode bus bar 4. Therefore, the time required for the connection process can be shortened. In addition, since it is not necessary to provide a dedicated portion for connecting to the discharge resistor 6 on the bus bars 3 and 4, the bus bars 3 and 4 can be reduced in size and the manufacturing cost of the bus bars 3 and 4 can be reduced.

DESCRIPTION OF SYMBOLS 1 Power converter 2 Semiconductor module 21 Power terminal 21a Positive electrode terminal 21b Negative electrode terminal 3 Positive electrode bus bar 4 Negative electrode bus bar 5 Capacitor 6 Discharge resistance 7 Cooler 8 Frame

Claims (10)

A power conversion device having a plurality of semiconductor modules in which power terminals protrude from a body portion in which a semiconductor element is sealed,
The power terminal includes a positive terminal connected to the positive electrode of the DC power source and a negative terminal connected to the negative electrode of the DC power source,
A positive electrode bus bar and a negative electrode bus bar made of a metal plate and connected to the positive electrode terminal and the negative electrode terminal, respectively;
A capacitor connected to the positive bus bar and the negative bus bar and smoothing a voltage applied to the semiconductor module;
A discharge resistor through which the discharge current of the capacitor flows,
The power converter according to claim 1, wherein the discharge resistor is connected to the positive bus bar and the negative bus bar.   The power conversion device according to claim 1, wherein the semiconductor module is cooled by a cooler.   3. The power conversion device according to claim 2, further comprising a plurality of refrigerant flow paths through which a refrigerant for cooling the semiconductor module flows, wherein the plurality of refrigerant flow paths and the plurality of semiconductor modules are stacked to form a stacked body. Among the plurality of refrigerant flow paths, a refrigerant flow path located at one end in the stacking direction of the stacked body includes an introduction pipe for introducing the refrigerant into the refrigerant flow path, and the refrigerant A power conversion system comprising: a lead pipe for leading the refrigerant from the flow path; and the plurality of refrigerant flow paths, the introduction pipe, and the lead pipe constitute the cooler. apparatus.   4. The power converter according to claim 3, wherein the positive electrode bus bar and the negative electrode bus bar are adjacent to the plurality of power connection terminals connected to the power terminal in the stacking direction with respect to the plurality of power connection terminals. Each of the plurality of power connection terminals and the resistance connection terminals are arranged at a constant pitch in the stacking direction. The power converter characterized by this.   4. The power conversion device according to claim 3, wherein the positive electrode bus bar and the negative electrode bus bar include a plurality of power connection terminals for connection to the power terminals, and among the plurality of power connection terminals in the stacking direction. A power conversion device, wherein a terminal of the discharge resistor is connected to a power connection terminal located at one end together with the power terminal.   The power conversion device according to any one of claims 2 to 5, further comprising a metal frame that fixes the plurality of semiconductor modules and the cooler, and the frame is cooled by the cooler, The power conversion device, wherein the discharge resistor is attached to the frame.   7. The power converter according to claim 6, wherein the frame has a resistance accommodation hole opened in a protruding direction of the power terminal, and the discharge resistance is accommodated in the resistance accommodation hole. Conversion device.   7. The power conversion device according to claim 3, wherein at least a part of the discharge resistance overlaps with the cooler when viewed from a protruding direction of the power terminal. A power conversion device.   The power conversion device according to any one of claims 3 to 5, further comprising a metal frame that fixes the plurality of semiconductor modules and the cooler, and the frame is cooled by the cooler, A power conversion device, wherein the discharge resistor is mounted on an insulating resin body that is interposed between the positive electrode bus bar and the negative electrode bus bar to insulate both of them and is fixed to the frame.   The power conversion device according to any one of claims 3 to 9, wherein the plurality of positive terminals and the plurality of negative terminals protrude in the same direction from the main body, respectively, The positive electrode connecting portion connecting the positive electrode bus bar, the negative electrode connecting portion connecting the negative electrode terminal and the negative electrode bus bar, and the resistance connecting portion connecting the bus bar and the discharge resistor are as follows: The power conversion device is located on the same direction side in the protruding direction of the positive electrode terminal and the negative electrode terminal.

Images