Power conversion device

Abstract

To provide a power conversion device that can stabilize a retention state of a plurality of bus bars and an insulation sheet without increasing the number of components.SOLUTION: A power conversion device 100 comprises: a first bus bar 1 provided with a hole part 1g; a semiconductor module 4 for power conversion in which a semiconductor switching element is housed and which is connected to the first bus bar 1; a second bus bar 2 connected to the semiconductor module 4; and an insulation sheet 3 that insulates between the first bus bar 1 and the second bus bar 2. The insulation sheet 3 includes a projection part 3a and is fixed to the first bus bar 1 by engagement of the projection part 3a with the hole part 1g of the first bus bar 1.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a power converter, and more particularly to a power converter in which an insulating sheet and a bus bar are fixed together. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been known a power conversion device having a configuration in which a plurality of bus bars and an insulating sheet (insulating material) are laminated on a semiconductor module (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 describes a laminate structure in which an insulating sheet larger than both conductors is interposed between a positive conductor and a negative conductor arranged on a power semiconductor module, in which insertion holes are provided in the positive conductor, negative conductor, and insulating sheet, and a resin clamping member is inserted into the insertion holes to hold the positive conductor, negative conductor, and insulating sheet in an aligned state. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4474902 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the power converter described in the above Patent Document 1 has a structure in which the conductor and the insulating sheet are fixed by a clamping member, which increases the number of parts and the assembly man-hours. In addition, there is a risk that the clamping member may come off due to vibration or the reaction force of the insulating sheet, and there is a problem that the holding state may not be stable.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a power conversion device that can stabilize the holding state between multiple bus bars and an insulating sheet without increasing the number of parts. [Means for solving the problem]

[0007] A power conversion device according to one aspect of the present invention comprises a first bus bar having a first engagement portion, a semiconductor module for power conversion in which semiconductor switching elements are housed and connected to the first bus bar, a second bus bar connected to the semiconductor module, and an insulating sheet that insulates the first bus bar from the second bus bar, the insulating sheet including a second engagement portion that is fixed to the first bus bar by engaging with the first engagement portion of the first bus bar.

[0008] In the power conversion device according to one aspect of the present invention, as described above, the insulating sheet includes the second engagement portion, and is fixed to the first bus bar by engaging the second engagement portion with the first engagement portion of the first bus bar. This makes it possible to fix the position of the insulating sheet relative to the first bus bar. As a result, it is possible to stabilize the holding state between the multiple bus bars and the insulating sheet without increasing the number of parts.

[0009] In the power conversion device according to the above aspect, preferably, one of the first engagement portion and the second engagement portion is a hole having a hole shape, and the other is a protrusion protruding from the first bus bar or the insulating sheet, and the first bus bar and the insulating sheet are fixed by inserting the protrusion into the hole. With this configuration, the first bus bar and the insulating sheet can be fixed by a simple assembly operation of inserting the protrusion into the hole. Furthermore, since the first bus bar and the insulating sheet can be fixed without separately providing a fastening member for fixing, the first bus bar and the insulating sheet can be fixed with a simple configuration with a reduced number of parts.

[0010] In this case, preferably, the first busbar includes a sidewall portion that protrudes in a first direction in which the first busbar and the second busbar are stacked and extends in a second direction along a predetermined side of the first busbar, the first engagement portion being a hole provided in the sidewall portion of the first busbar, and the second engagement portion being a protrusion provided in the insulating sheet. With this configuration, even if there is an obstacle in the first direction in which the first busbar and the insulating sheet are stacked, the first busbar and the insulating sheet can be fixed together by using the sidewall portion that extends in the second direction along the predetermined side of the first busbar.

[0011] In the power converter in which the first busbar includes sidewalls, preferably, the sidewalls of the first busbar are provided at opposing positions in a third direction perpendicular to the second direction as viewed from the first direction, the protrusions of the insulating sheet are provided on both sides in the third direction as viewed from the first direction, and the insulating sheet is provided on the inside of the opposing sidewalls of the first busbar as viewed from the first direction so as to extend in the third direction, and the protrusions provided on both sides of the insulating sheet are engaged with holes provided in the opposing sidewalls to be fixed to the first busbar. With this configuration, the both sides of the insulating sheet provided on the inside of the sidewalls opposing the third direction are fixed to the sidewalls, making the insulating sheet less likely to move in the third direction. As a result, the first busbar and the insulating sheet can be fixed more firmly.

[0012] In this case, preferably, the second bus bar is provided inside the opposing side wall portions of the first bus bar, extending in the third direction and spaced apart from each of the opposing side wall portions, and the length of the second bus bar extending in the third direction is shorter than the length of the insulating sheet extending in the third direction. With this configuration, the first bus bar and the second bus bar are provided spaced apart in the third direction, and therefore do not come into contact with each other in the third direction. Furthermore, the length of the second bus bar in the third direction is shorter than the length of the insulating sheet in the third direction, and therefore the first bus bar and the second bus bar do not come into contact with each other in the first direction either. As a result, even if the side wall portions are provided on the first bus bar, insulation between the first bus bar and the second bus bar is maintained.

[0013] In the power converter in which the first busbar includes a sidewall portion, the protrusion of the insulating sheet preferably protrudes outward from the first busbar from the sidewall portion through the hole. With this configuration, the protrusion is less likely to come out of the hole. As a result, the first busbar and the insulating sheet can be more firmly fixed together.

[0014] In the power converter in which the first busbar includes the sidewall portion, the first busbar preferably further includes a flat plate portion extending in a plane perpendicular to the sidewall portion, and the hole portion is provided near a boundary portion between the sidewall portion and the flat plate portion. With this configuration, the hole portion is arranged so that the position (height) of the hole portion in the first direction is equal to the height of the flat plate portion. Here, when the hole portion is provided in the sidewall portion at a height position that is a predetermined height higher than the flat plate portion, the insulating sheet is deflected by the difference in height between the flat plate portion and the hole portion. On the other hand, when the position (height) of the hole portion in the first direction is equal to the height of the flat plate portion, the deflection of the insulating sheet can be reduced or eliminated. As a result, the protrusion of the insulating sheet can be inserted into the hole portion of the first busbar while suppressing the deflection of the insulating sheet.

[0015] In this case, preferably, the second busbar extends in the first direction, and the height of the portion of the second busbar extending in the first direction relative to the flat plate portion is greater than the height of the sidewall portion in the first direction. With this configuration, when another member is arranged to be stacked on the end of the portion of the second busbar extending in the first direction, it is possible to prevent the other member from interfering with the end of the portion of the sidewall portion extending in the first direction. As a result, designing when stacking multiple members becomes easier.

[0016] In the power converter according to the above aspect, preferably, a plurality of second bus bars are provided, a plurality of insulating sheets are provided corresponding to the plurality of second bus bars, and one first bus bar is provided in common to the plurality of second bus bars and the plurality of insulating sheets. With this configuration, it is not necessary to provide a first bus bar corresponding to each of the second bus bars and the insulating sheets. As a result, the number of parts constituting the power converter can be reduced, and the structure of the power converter can be simplified.

[0017] In the power converter according to the above aspect, the second busbar preferably includes a flat first portion connected to the semiconductor module, a flat second portion connected to the first portion and extending in a first direction in which the first busbar and the second busbar are stacked, and a flat third portion connected to an end of the second portion opposite to the side on which the semiconductor module is arranged and perpendicular to the second portion. With this configuration, the flat third portion is provided at a position of the second busbar that is higher than the first portion connected to the semiconductor module by the length of the second portion. As a result, even when another member is attached to the second busbar at a position different from the semiconductor module, the attachment can be easily performed using the third portion of the second busbar. Effect of the Invention

[0018] According to the present invention, as described above, it is possible to provide a power conversion device capable of stably holding a plurality of bus bars and insulating sheets without increasing the number of parts or the number of assembly steps. [Brief description of the drawings]

[0019] [Figure 1] 1 is a diagram showing a configuration of a power conversion device according to an embodiment of the present invention; [Diagram 2] 1 is a diagram showing a structure of a power conversion circuit disposed inside a power conversion device according to an embodiment of the present invention. [Diagram 3] 1A and 1B are diagrams illustrating a structure of stacked semiconductor modules, insulating sheets, a first bus bar, and a second bus bar according to an embodiment of the present invention. [Figure 4] 1 is a circuit diagram of a power conversion circuit according to an embodiment of the present invention; [Diagram 5] 4A to 4C are diagrams illustrating a structure of a first bus bar according to an embodiment of the present invention. [Figure 6] 6A to 6C are diagrams illustrating a structure of a second bus bar according to an embodiment of the present invention. [Figure 7] 1 is a diagram showing a structure of an insulating sheet according to an embodiment of the present invention. [Figure 8] 1 is a diagram showing a structure of a semiconductor module according to an embodiment of the present invention; [Figure 9] 3A and 3B are diagrams illustrating a structure of stacked semiconductor modules and a first bus bar according to an embodiment of the present invention. [Figure 10] 13 is a diagram illustrating a state in which one side of a protrusion of an insulating sheet is inserted into a hole provided in a side wall of a first bus bar according to an embodiment of the present invention. FIG. [Figure 11] FIG. 13 is a diagram illustrating the bending of an insulating sheet with one side of a protrusion of the insulating sheet inserted into a hole provided in a side wall of a first bus bar according to one embodiment of the present invention. [Figure 12] 13 is a diagram illustrating a state in which protrusions on both sides of an insulating sheet have been inserted into holes formed in a sidewall of a first bus bar according to an embodiment of the present invention. FIG. [Figure 13] 3A and 3B are diagrams illustrating a structure of stacked semiconductor modules, insulating sheets, and a first bus bar according to an embodiment of the present invention. [Figure 14] 5A to 5C are diagrams for explaining the width and thickness of a hole and a protrusion according to an embodiment of the present invention. [Figure 15] FIG. 4 is a diagram illustrating the positional relationship between stacked insulating sheets, a first bus bar, and a second bus bar according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0021] The configuration of a power conversion device 100 according to an embodiment will be described with reference to FIGS.

[0022] (Device configuration of power conversion device 100) In this embodiment, the power conversion device 100 includes a housing 10, a power connection unit 20, and a cooling mechanism 30, as shown in FIG. 1. Here, in this embodiment, the height direction (vertical direction) of the power conversion device 100 installed on the floor is the Z direction, the direction of increasing height (direction moving away from the floor on which it is installed) is the Z1 direction, and the direction of decreasing height (direction moving closer to the floor on which it is installed) is the Z2 direction. In this embodiment, the housing 10 has a short side and a long side, and the direction along the short side is the X direction, and the direction along the long side is the Y direction. Also, the directions from the front side to the back side of FIG. 1 are the X1 direction and the Y1 direction, and the directions from the back side to the front side of FIG. 1 are the X2 direction and the Y2 direction. The X direction is an example of the "first direction" in the claims. Also, the Z direction is an example of the "second direction" in the claims. Also, the Y direction is an example of the "third direction" in the claims.

[0023] The power conversion device 100 converts DC power supplied to the power connection unit 20 into AC power and outputs the power, or converts supplied AC power into DC power and outputs the power from the power connection unit 20. The cooling mechanism 30 is, for example, a fan, and cools the inside of the housing 10 by discharging high-temperature air inside the housing of the power conversion device 100 to the outside. As shown in FIG. 2, the power conversion device 100 includes a power conversion circuit 40 inside the housing 10.

[0024] As shown in Fig. 2, in this embodiment, the power conversion circuit 40 includes at least one first bus bar 1, three second bus bars 2, three insulating sheets 3, and a plurality of semiconductor modules 4. Furthermore, the power conversion circuit 40 in this embodiment is provided with a snubber capacitor CS and an output bus bar B for noise reduction. As shown in Fig. 3, in which the snubber capacitor CS and the output bus bar B are omitted, the one first bus bar 1, the three second bus bars 2, the three insulating sheets 3, and the plurality of semiconductor modules 4 (4a to 4l) are arranged in a stacked manner.

[0025] Here, the configuration of the power conversion circuit 40 will be described with reference to the electric circuit diagram shown in FIG. 4. As shown in FIG. 4, DC input terminals P and N are provided, and a smoothing capacitor C is connected between a positive line and a negative line. A first bus bar 1 is connected to the positive line side, and DC power is supplied to a plurality of semiconductor modules 4a to 4l to which snubber capacitors CS are connected in parallel. A negative bus bar (not shown) is connected to the negative line side. Two semiconductor switching elements Q are connected in series to each other inside the plurality of semiconductor modules 4a to 4l. In this embodiment, the semiconductor switching elements Q are IGBTs (Insulated Gate Bipolar Transistors) made of silicon (Si) semiconductor, for example. The semiconductor switching elements Q included in the plurality of semiconductor modules 4 and connected in series to each other are connected between the positive line and the negative line. Here, the semiconductor switching elements Q included in each of the four semiconductor modules 4a to 4d are switched and controlled by a control unit (not shown), thereby generating one-phase AC power. In the power conversion circuit 40, three-phase AC power with different phases is generated by a set of four semiconductor modules 4a-4d, 4e-4h, and 4i-4l. The AC power generated by the semiconductor modules 4a-4l is configured to be supplied to a load L via a second bus bar 2 connected to the semiconductor modules 4a-4l and an output bus bar B.

[0026] 5, the first busbar 1 includes sidewall 1a, sidewall 1b, connection portion 1c, flat portion 1d, connection hole 1e, opening 1f, hole 1g, and boundary portion 1h, and is made of a single sheet metal having a thickness t1. In this embodiment, sidewall 1a and sidewall 1b are formed to face each other by bending the Y-direction end of first busbar 1 extending in the YZ plane in the X2 direction to a height h1. Connection portion 1c is formed by bending the Z1-direction end of first busbar 1 extending in the YZ plane in the X2 direction and then in the Z1 direction. The flat plate portion 1d is a flat plate on which three insulating sheets 3 can be placed, and is provided with a connection hole 1e connected to the semiconductor module 4 and an opening portion 1f for connection to the semiconductor module 4, and the holes 1g are through holes provided near a boundary portion 1h which is a boundary between the side wall portions 1a and 1b and the flat plate portion 1d. In this embodiment, the holes 1g are rectangular, and three holes are provided in each of the first busbar 1 in the Z direction. The holes 1g are an example of a "first engagement portion" in the claims.

[0027] 6, the second busbar 2 is a sheet metal member having a thickness of t2, and includes a flat first portion 2a connected to the semiconductor module 4 and having a width w1, a flat second portion 2b perpendicular to the first portion 2a and extending in the X2 direction and having a height h2, and a flat third portion 2c perpendicular to the second portion 2b, provided on the X2-direction side of the second portion 2b, and extending in the Z1 direction. The second busbar 2 is fixed at a position spaced apart from the sidewall portions 1a and 1b of the first busbar 1 by being connected to the semiconductor module 4. The fixing of the second busbar 2 will be described in detail later.

[0028] As shown in FIG. 7, in this embodiment, the insulating sheet 3 includes a protrusion 3a and a cutout 3b. The insulating sheet 3 is an insulating material for insulating the first bus bar 1 and the second bus bar 2, and is made of, for example, PET (Polyethylene terephthalate) resin or PC (Polycarbonate) resin. In this embodiment, the thickness t3 of the insulating sheet 3 is thinner than the thickness t1 of the first bus bar 1 shown in FIG. 5 and the thickness t2 of the second bus bar 2 shown in FIG. 6, and is flexible. The protrusions 3a are provided on both sides of the insulating sheet 3 in the Y direction, and are parts of the insulating sheet 3 that protrude from the insulating sheet 3 in the Y direction and have a rectangular shape. The protrusions 3a are an example of a "second engagement portion" in the claims. The cutouts 3b are provided in four places so as to avoid the first portion 2a of the second bus bar 2 in order to connect the first portion 2a of the second bus bar 2 to the terminal 5c of the semiconductor module 4.

[0029] 8, in this embodiment, the semiconductor module 4 includes terminals 5a, 5b, and 5c. The terminal 5a is a collector terminal of the switching element, to which the first bus bar 1 is connected and from which DC power is supplied or output. The terminal 5b is an emitter terminal of the switching element, to which a bus bar (not shown) is connected. The terminal 5c is an AC terminal (emitter-collector terminal) of the switching element, to which the second bus bar 2 is connected and from which AC power is output or supplied.

[0030] Next, the structure in which semiconductor modules 4a to 4l, first bus bar 1, insulating sheet 3, and second bus bar 2 are laminated will be described with reference to FIGS.

[0031] In this embodiment, the semiconductor modules 4a to 4l are arranged in a row of four in the Y direction as shown in FIG. 9. Since the semiconductor modules 4a to 4l are configured to include a semiconductor switching element Q therein as in the circuit shown in FIG. 3, a bridge circuit is formed by the four semiconductor modules 4a to 4l. As a result, the semiconductor modules 4a to 4l convert DC power inputted through the first bus bar 1 into AC power. In this embodiment, the four sets of semiconductor modules 4 arranged in the Y direction are provided in three sets in the Z direction as shown in FIG. 8. As a result, each set of semiconductor modules 4 converts DC power inputted through the first bus bar 1 into three-phase AC power.

[0032] 9, in this embodiment, the first bus bar 1 is fixed to each of the terminals 5a of the multiple semiconductor modules 4 by using fastening members such as screws (not shown) through the connection holes 1e so as to be stacked in the X direction. Next, with the semiconductor modules 4 and the first bus bar 1 fixed in place, the first bus bar 1 and the insulating sheet 3 are fixed together.

[0033] Here, as shown in FIG. 9, the distance from the inner surface (Y1 side) of the side wall 1a of the first bus bar 1 to the inner surface (Y2 side) of the side wall 1b is defined as the side wall distance d1. In this embodiment, the protrusion length l1 connecting the protrusions 3a provided on both sides of the insulating sheet 3 shown in FIG. 7 is greater than the side wall distance d1. Moreover, the sheet length l2 connecting the parts of the side on which the protrusions 3a of the insulating sheet 3 are provided that do not have the protrusions 3a is equal to or less than the side wall distance d1. In this embodiment, the sheet length l2 is slightly smaller than the side wall distance d1 to such an extent that the insulating sheet 3 cannot move in the Y direction when the insulating sheet 3 is attached to the inner sides of the side walls 1a and 1b of the first bus bar 1.

[0034] Next, a procedure for attaching the insulating sheet 3 in the state shown in Fig. 9 in which the semiconductor module 4 and the first busbar 1 are fixed will be described with reference to Figs. 10 to 12. When fixing the first busbar 1 and the insulating sheet 3 together, first, the protrusion 3a on one side of the insulating sheet 3 is inserted into the hole 1g on the side wall 1a side of the first busbar 1. At this time, as shown in Fig. 10, the length l1 between the protrusions 3a provided on both sides of the insulating sheet 3 is longer than the sidewall distance d1 from the inner surface (Y1 side) of the side wall 1a of the first busbar 1 to the inner surface (Y2 side) of the side wall 1b. Therefore, the insulating sheet 3 is not fixed parallel to the flat plate portion 1d of the first busbar 1.

[0035] Here, in this embodiment, since the insulating sheet 3 has flexibility, it is possible to bend the insulating sheet 3 in the X2 direction as shown in FIG. 11 with the protrusion 3a inserted into the hole 1g on the side wall 1a side of the first busbar 1. Therefore, the other protrusion 3a of the insulating sheet 3 can be inserted into the hole 1g on the side wall 1b side of the first busbar 1 by bending the insulating sheet 3. This fixes the insulating sheet 3 so that it cannot move in the Y direction relative to the first busbar 1. Note that in this embodiment, the hole 1g of the first busbar 1 is provided near the boundary 1h, which is the boundary between the side walls 1a and 1b and the flat plate portion 1d. Therefore, as shown in FIG. 12, when the first busbar 1 and the insulating sheet 3 are fixed, the surface of the insulating sheet 3 is provided parallel to the flat plate portion 1d of the first busbar 1 without being bent.

[0036] 13, the protrusion 3a on one side of the insulating sheet 3 protrudes outward (Y2 side) from the side wall 1a of the first busbar 1. The protrusion 3a on the other side of the insulating sheet 3 protrudes outward (Y1 side) from the side wall 1b of the first busbar 1. In this embodiment, the distance d2 from the protrusion 3a to the outside (Y2 side) of the side wall 1a of the first busbar 1 and the distance d3 from the protrusion 3a to the outside (Y1 side) of the side wall 1b of the first busbar 1 are at least twice the thickness t1 of the first busbar 1.

[0037] 14, the Z-direction width wg of the hole 1g of the first busbar 1 is slightly larger than the Z-direction width w3 of the protrusion 3a of the insulating sheet 3. This fixes the insulating sheet 3 to the first busbar 1 so that it is unable to move in the Z direction. Meanwhile, in this embodiment, the X-direction height hg of the hole 1g of the first busbar 1 is sufficiently larger than the X-direction height (thickness t3) of the protrusion 3a of the insulating sheet 3. This makes it easy to insert the protrusion 3a into the hole 1g with the insulating sheet 3 tilted as shown in FIG. 10, while allowing the insulating sheet 3 to move or bend slightly in the X direction relative to the first busbar 1.

[0038] After the three insulating sheets 3 are attached to the first busbar 1 as described above, the second busbar 2 is connected to the semiconductor module 4. Here, the busbar length l3, which is the length in the Y direction of the second busbar 2 shown in FIG. 6, is shorter than the sheet length l2 of the insulating sheet 3. Moreover, the busbar width w1 in the Z direction of the second busbar 2 is shorter than the sheet width w2 in the Z direction of the insulating sheet 3. Moreover, the height h2 in the X direction of the second busbar 2 is greater than the height h1 of the side wall portions 1a and 1b of the first busbar 1 shown in FIG. 5.

[0039] Here, as shown in FIG. 2, the second busbar 2 is fixed to the terminal 5c of the semiconductor module 4 via the first portion 2a by a fastening member (not shown). At this time, in this embodiment, since the insulating sheet 3 is provided with the cutout portion 3b, the first portion 2a of the second busbar 2 is fixed to the terminal 5c of the semiconductor module 4 without contacting the insulating sheet 3. Also, at this time, the second busbar 2 and the semiconductor modules 4a to 4l are fixed so that the end portion of the second busbar 2 extending in the Y2 direction is located at a position separated from the side wall portion 1a of the first busbar 1. Similarly, the second busbar 2 and the semiconductor module 4 are fixed so that the end portion of the second busbar 2 extending in the Y1 direction is located at a position separated from the side wall portion 1b of the first busbar 1. Note that the height of the second busbar 2 in the X2 direction with respect to the flat plate portion 1d of the first busbar 1 is higher than the height h1 of the side wall portions 1a and 1b of the first busbar 1 shown in FIG. 5.

[0040] 15, the insulating sheet 3 is sandwiched between the first bus bar 1 and the second bus bar 2. In this embodiment, the gap between the first bus bar 1 and the second bus bar 2 is larger than the thickness t3 of the insulating sheet 3, but is not large enough to cause the insulating sheet 3 to bend to an amount necessary for the protrusion 3a to come out of the hole 1g. Therefore, the engagement between the protrusion 3a and the hole 1g is not released, and the fixation between the insulating sheet 3 and the first bus bar 1 is not released.

[0041] (Effects of this embodiment) Next, the effects of this embodiment will be described.

[0042] The power conversion device 100 of this embodiment includes a first busbar 1 having a hole 1g, a semiconductor module 4 for power conversion in which a semiconductor switching element Q is housed and which is connected to the first busbar 1, a second busbar 2 connected to the semiconductor module 4, and an insulating sheet 3 that insulates the first busbar 1 from the second busbar 2, the insulating sheet 3 including a protrusion 3a which is fixed to the first busbar 1 by engaging with the hole 1g of the first busbar 1. This makes it possible to fix the position of the insulating sheet 3 relative to the first busbar 1. As a result, the multiple busbars and the insulating sheet 3 can be stably held without increasing the number of parts or the number of assembly steps.

[0043] In this embodiment, one of the first engaging portion and the second engaging portion is a hole 1g having a hole shape, and the other is a protruding portion 3a protruding from the first busbar 1 or the insulating sheet 3, and the first busbar 1 and the insulating sheet 3 are fixed together by inserting the protruding portion 3a into the hole 1g. This makes it possible to fix the first busbar 1 and the insulating sheet 3 together by a simple assembly operation of inserting the protruding portion 3a into the hole 1g. Furthermore, since the first busbar 1 and the insulating sheet 3 can be fixed together without separately providing a fastening member or the like for fixing, the first busbar 1 and the insulating sheet 3 can be fixed together with a simple configuration with a reduced number of parts.

[0044] Furthermore, in this embodiment, first busbar 1 includes sidewall portions 1a and 1b that protrude in the X direction in which first busbar 1 and second busbar 2 are stacked and extend in the Z direction along a predetermined side of first busbar 1, the first engagement portion is hole portion 1g provided in sidewall portions 1a and 1b of first busbar 1, and the second engagement portion is protrusion portion 3a provided on insulating sheet 3. As a result, even if there is an obstacle in the X direction in which first busbar 1 and insulating sheet 3 are stacked, first busbar 1 and insulating sheet 3 can be fixed to each other using sidewall portions 1a and 1b that extend in the Z direction along the predetermined side of first busbar 1.

[0045] In this embodiment, the side walls 1a and 1b of the first busbar 1 are provided at opposing positions in the Y direction perpendicular to the Z direction when viewed from the X direction, and the protrusions 3a of the insulating sheet 3 are provided on both sides in the Y direction. The insulating sheet 3 is provided inside the opposing side walls 1a and 1b of the first busbar 1 so as to extend in the Y direction, and the protrusions 3a provided on both sides of the insulating sheet 3 are engaged with the holes 1g provided in the opposing side walls 1a and 1b, thereby fixing the insulating sheet 3 to the first busbar 1. As a result, both sides of the insulating sheet 3 provided inside the side walls 1a and 1b facing each other in the Y direction are fixed to the side walls 1a and 1b, making the insulating sheet 3 less likely to move in the Y direction. As a result, the first busbar 1 and the insulating sheet 3 can be fixed more firmly.

[0046] In this embodiment, the second busbar 2 extends in the Y direction inside the opposing sidewalls 1a and 1b of the first busbar 1 and is spaced apart from each of the opposing sidewalls 1a and 1b, and the length of the second busbar 2 extending in the Y direction is shorter than the length of the insulating sheet 3 extending in the Y direction. As a result, the first busbar 1 and the second busbar 2 are spaced apart in the Y direction and do not come into contact with each other in the Y direction. Furthermore, the length of the second busbar 2 in the Y direction is shorter than the length of the insulating sheet 3 in the Y direction, so the first busbar 1 and the second busbar 2 do not come into contact with each other in the X direction either. As a result, even if the first busbar 1 is provided with the sidewalls 1a and 1b, insulation between the first busbar 1 and the second busbar 2 is maintained.

[0047] In this embodiment, the protruding portion 3a of the insulating sheet 3 protrudes from the side walls 1a and 1b through the hole 1g to the outside of the first busbar 1. This makes it difficult for the protruding portion 3a to come out of the hole 1g. As a result, the first busbar 1 and the insulating sheet 3 can be fixed more firmly.

[0048] In this embodiment, the first busbar 1 further includes a flat plate portion 1d extending in a plane perpendicular to the sidewall portions 1a and 1b, and the hole portion 1g is provided in the vicinity of a boundary portion 1h between the sidewall portions 1a and 1b and the flat plate portion 1d. As a result, the hole portion 1g is arranged so that the position (height) of the hole portion 1g in the X direction is equal to the height of the flat plate portion 1d. Here, if the hole portion 1g is provided at a height position of the sidewall portions 1a and 1b that is a predetermined height higher than the flat plate portion 1d, the insulating sheet 3 is deflected by the difference in height between the flat plate portion 1d and the hole portion 1g. On the other hand, if the position (height) of the hole portion 1g in the X direction is equal to the height of the flat plate portion 1d, the deflection of the insulating sheet 3 can be reduced or eliminated. As a result, the protrusion portion 3a of the insulating sheet 3 can be inserted into the hole portion 1g of the first busbar 1 while suppressing the deflection of the insulating sheet 3.

[0049] Furthermore, in this embodiment, the second busbar 2 extends in the X direction, and the height of the portion of the second busbar 2 extending in the X direction relative to the flat plate portion 1d is greater than the height h1 of the side wall portions 1a and 1b relative to the flat plate portion 1d in the X direction. This makes it possible to prevent interference between the ends of the portions of the side wall portions 1a and 1b extending in the X direction and another member that is to be stacked on the ends of the portions of the second busbar 2 extending in the X direction. As a result, design is facilitated when multiple members are stacked.

[0050] Furthermore, in this embodiment, a plurality of second bus bars 2 are provided, a plurality of insulating sheets 3 are provided corresponding to the plurality of second bus bars 2, and one first bus bar 1 is provided in common to the plurality of second bus bars 2 and the plurality of insulating sheets 3. This eliminates the need to provide a first bus bar 1 corresponding to each of the second bus bars 2 and the insulating sheets 3. As a result, the number of parts constituting the power conversion device 100 can be reduced, and the structure of the power conversion device 100 can be simplified.

[0051] In this embodiment, the second busbar 2 includes a flat first portion 2a connected to the semiconductor module 4, a flat second portion 2b connected to the first portion 2a and extending in the X direction in which the first busbar 1 and the second busbar 2 are stacked, and a flat third portion 2c connected to an end of the second portion 2b opposite to the side on which the semiconductor module 4 is arranged and perpendicular to the second portion 2b. This allows the flat third portion 2c to be provided at a position higher than the first portion 2a connected to the semiconductor module 4 by the length of the second portion 2b. As a result, even when another member is attached to the second busbar 2 at a position other than the semiconductor module 4, the attachment can be easily performed using the third portion 2c of the second busbar 2.

[0052] [Variations] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the description of the embodiments above, and further includes all modifications (variations) within the meaning and scope of the claims.

[0053] For example, in the present embodiment, an example has been shown in which the first engagement portion is hole 1g and the second engagement portion is protrusion 3a, but the present invention is not limited to this. In the present invention, for example, both the first engagement portion and the second engagement portion may be claw-shaped protrusions, and first bus bar 1 and second bus bar 2 may be fixed together by engagement of both protrusions.

[0054] In the present embodiment, the first bus bar 1 has the hole 1g and the protrusion 3a of the insulating sheet 3 is inserted therein, but the present invention is not limited to this. In the present invention, the insulating sheet 31 may have a hole, and the first bus bar 1 may have a protrusion.

[0055] In addition, in the present embodiment, an example has been described in which the holes 1g are provided in the side walls 1a and 1b of the first busbar 1, but the present invention is not limited to this. In the present invention, the first busbar 1 may not have the side walls 1a and 1b, and may instead have the holes 1g provided in, for example, the flat plate portion 1d.

[0056] In the present embodiment, the first busbar 1 is provided with side wall portions 1a and 1b facing each other, and protrusions 3a on both sides of the insulating sheet 3 are inserted therein. However, the present invention is not limited to this. In the present invention, the first busbar 1 may be configured to have only side wall portion 1a, or may be provided in a position where side wall portions 1a and 1b do not face each other. The first busbar 1 may also have another wall portion in addition to side wall portions 1a and 1b. In the above case, it is sufficient that the insulating sheet 3 has protrusions 3a provided so as to correspond to the positions of the holes 1g of the first busbar 1.

[0057] In addition, in the present embodiment, the second busbar 2 is provided inside the sidewall portions 1a and 1b so as to be spaced apart from the sidewall portions 1a and 1b, and is insulated from the first busbar 1, but the present invention is not limited to this. In the present invention, for example, the second busbar 2 may be provided so as to protrude in the X2 direction and be spaced apart from the first busbar 1, and be insulated from the first busbar 1.

[0058] In the present embodiment, the protrusion 3a protrudes outward from the side walls 1a and 1b through the hole 1g, but the present invention is not limited to this. In the present invention, the protrusion 3a may be configured to be flush with the outer surfaces of the side walls 1a and 1b through the hole 1g, or to be slightly inward from the outer surfaces of the side walls 1a and 1b.

[0059] In the present embodiment, the hole 1g is provided near the boundary 1h between the sidewalls 1a and 1b and the flat plate 1d, but the present invention is not limited to this. In the present invention, the hole 1g may be provided above the sidewalls 1a and 1b (on the X2 direction side).

[0060] In the present embodiment, the second busbar 2 extends in the X2 direction, and the height h2 of the portion of the second busbar 2 extending in the X2 direction relative to the flat plate portion 1d is greater than the height h1 of the side wall portions 1a and 1b relative to the flat plate portion 1d in the X2 direction. However, the present invention is not limited to this. In the present invention, the height h2 of the portion of the second busbar 2 extending in the X2 direction relative to the flat plate portion 1d may be smaller than the height h1 of the side wall portions 1a and 1b relative to the flat plate portion 1d in the X2 direction. In this case, the output busbar B connected to the second busbar 2 may be provided to match the height h2 of the second busbar 2.

[0061] In addition, in the present embodiment, an example has been shown in which three second bus bars 2 are provided, three insulating sheets 3 are provided corresponding to the three second bus bars 2, and one first bus bar 1 is provided in common to the three second bus bars 2 and the three insulating sheets 3, but the present invention is not limited to this. In the present invention, one insulating sheet 3 may be provided in common to the three second bus bars 2, or a first bus bar 1 may be provided in correspondence with each of the three second bus bars 2 and the three insulating sheets 3.

[0062] In the present embodiment, the second busbar 2 includes a flat first portion 2a connected to the semiconductor module 4, a flat second portion 2b connected to the first portion 2a and extending in the X2 direction in which the first busbar 1 and the second busbar 2 are stacked, and a flat third portion 2c connected to the end of the second portion 2b opposite to the side on which the semiconductor module 4 is arranged and perpendicular to the second portion 2b, but the present invention is not limited to this. In the present invention, the second busbar 2 may simply be flat, for example.

[0063] In addition, in the present embodiment, the insulating sheet 3 is made of PET resin or PC resin, but the present invention is not limited to this. In the present invention, the insulating sheet 3 may be made of any material that can insulate the first bus bar 1 and the second bus bar 2, and may be made of a resin material other than PET resin or PC resin, or a rubber material such as silicone rubber.

[0064] In addition, in the present embodiment, an example has been described in which the insulating sheet 3 and the second bus bar 2 are provided with a gap therebetween, but the present invention is not limited to this. In the present invention, the insulating sheet 3 and the second bus bar 2 may be provided so as to be in contact with each other.

[0065] In addition, in the present embodiment, an example of a three-phase circuit in which four semiconductor modules 4 are connected in parallel per phase has been shown, but the present invention is not limited to this. In the present invention, one semiconductor module 4 may be connected in parallel per phase, or the number of modules connected in parallel may be other than four (for example, two, three, or five or more modules connected in parallel). In addition, a three-phase circuit is not essential, and a single-phase circuit may be used, for example. [Explanation of symbols]

[0066] 1 First bus bar 1a, 1b side wall part 1d flat plate part 1g Hole (first engagement part) 1h border 2 Second bus bar 2a Part 1 2b 2nd part 2c 3rd part 3. Insulation sheet 3a Projection part (second engagement part) 4, 4a~4l Semiconductor Modules 10. Chassis 20 Power Connection 30 Cooling section 40 Power Conversion Circuit 100 Power conversion device

Claims

1. a first bus bar provided with a first engagement portion; a semiconductor module for power conversion that houses a semiconductor switching element and is connected to the first bus bar; A second bus bar connected to the semiconductor module; an insulating sheet that insulates the first bus bar from the second bus bar, The insulating sheet includes a second engagement portion, and is fixed to the first bus bar by engaging the second engagement portion with the first engagement portion of the first bus bar.

2. one of the first engagement portion and the second engagement portion is a hole having a hole shape, and the other is a protrusion protruding from the first bus bar or the insulating sheet, The power conversion device according to claim 1 , wherein the first bus bar and the insulating sheet are fixed together by inserting the protrusion into the hole.

3. the first bus bar includes a sidewall portion that protrudes in a first direction in which the first bus bar and the second bus bar are stacked and extends in a second direction along a predetermined side of the first bus bar, the first engagement portion is the hole provided in the side wall portion of the first bus bar, The power conversion device according to claim 2 , wherein the second engagement portion is the protrusion provided on the insulating sheet.

4. the side wall portions of the first bus bar are provided at opposing positions in a third direction perpendicular to the second direction when viewed from the first direction, The protruding portions of the insulating sheet are provided on both sides in the third direction when viewed from the first direction, 4. The power conversion device according to claim 3, wherein the insulating sheet is provided inside the opposing side wall portions of the first bus bar so as to extend in the third direction when viewed from the first direction, and each of the protrusions provided on both sides of the insulating sheet is engaged with each of the holes provided in each of the opposing side wall portions, thereby fixing the insulating sheet to the first bus bar.

5. the second bus bar is provided inside the opposing side wall portions of the first bus bar, extends in the third direction, and is spaced apart from each of the opposing side wall portions; The power conversion device according to claim 4 , wherein a length of the second bus bar extending in the third direction is shorter than a length of the insulating sheet extending in the third direction.

6. The power conversion device according to claim 3 , wherein the protrusion of the insulating sheet protrudes from the side wall to an outside of the first bus bar through the hole.

7. the first bus bar further includes a flat plate portion extending in a plane perpendicular to the side wall portion, The power conversion device according to claim 3 , wherein the hole is provided near a boundary between the side wall portion and the flat plate portion.

8. The second bus bar extends in the first direction, The power conversion device according to claim 7 , wherein a height of the portion of the second bus bar extending in the first direction relative to the flat plate portion is greater than a height of the side wall portion in the first direction relative to the flat plate portion.

9. The second bus bar is provided in plurality, the insulating sheets are provided in a plurality to correspond to the plurality of second bus bars, The power conversion device according to claim 1 , wherein the first bus bar is provided in common to the second bus bars and the insulating sheets.

10. 2. The power conversion device according to claim 1, wherein the second bus bar includes a flat first portion connected to the semiconductor module, a flat second portion connected to the first portion and extending in a first direction in which the first bus bar and the second bus bar are stacked, and a flat third portion connected to an end of the second portion opposite to the side on which the semiconductor module is arranged and perpendicular to the second portion.

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