Power converter

Abstract

To improve the efficiency of production and maintenance while limiting the size of the equipment. [Solution] The power converter (1) includes a rectifier unit (10) which includes a first converter section (21) and a second converter section (22) each composed of multiple switching elements (24) arranged along a vertical plane, and a capacitor unit (30) composed of multiple capacitors (33) arranged in a row. The rectifier unit and the capacitor unit are provided in mutually independent unit structures. In the rectifier unit, a space is formed between the first converter section and the second converter section for the capacitor unit to be disposed of. An inlet / outlet opening (16) is formed in the rectifier unit that allows relative movement between the rectifier unit and the capacitor unit in the direction for moving the capacitor unit in and out of the space.

Description

Technical Field

[0004] , , ,

[0001] The present invention relates to a power conversion device.

Background Art

[0002] Patent Document 1 discloses a power conversion device including a converter or an inverter including a plurality of switching elements and a capacitor. Patent Document 1 constitutes a unit structure in which the converter or the inverter is disposed above the capacitor. In this unit structure, the converter or the inverter is integrated with the capacitor via a conductor.

Prior Art Documents

[0007] According to the present invention, since the capacitor unit is positioned in the space formed between the two semiconductor devices, the entire device can be miniaturized. Furthermore, in this invention, the rectifier unit and the capacitor unit are in separate unit structures, and an access port is formed in the rectifier unit. This makes it easier to assemble and disassemble the rectifier unit and the capacitor unit, thereby improving productivity and maintenance efficiency. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic perspective view of the power conversion device in the embodiment. [Figure 2] This is a schematic perspective view of the rectifier unit in the embodiment. [Figure 3] This is a schematic perspective view of the capacitor unit in the embodiment. [Figure 4] Figure 1 is an exploded view. [Figure 5] This is an enlarged cross-sectional view of the connection area in the embodiment. [Figure 6] Figure 5 is an exploded view. [Figure 7] This is a diagram illustrating the insertion and removal of capacitor units into and out of space. [Figure 8] This is a plan view showing some of the components of the power conversion device in the embodiment omitted. [Modes for carrying out the invention]

[0009] A power conversion device according to one embodiment of the present invention will be described in detail below with reference to the attached drawings.

[0010] Herein, the present invention is not limited to the embodiments described below, and can be implemented by modifying it as appropriate without changing its essence. In the following figures, some components may be omitted for the sake of explanation. Also, in the following description, the X, Y, and Z directions indicated by arrows in each figure will be used as the basis for explanation. In the following embodiments, the X and Y directions are horizontal directions (left-right direction, front-back direction), and the Z direction is the height direction (vertical direction, up-down direction), so the X, Y, and Z directions form three orthogonal axes. However, these directions may be changed as long as they can perform the same functions as in the embodiments. In the following, "X", "Y", and "Z" will be used both when describing the above three orthogonal axes and when describing each phase of the multiphase AC described later, but there will be no particular relationship between them.

[0011] Figure 1 is a schematic perspective view of a power converter 1 in an embodiment. The power converter 1 shown in Figure 1 is not particularly limited, but for example, it is a power converter 1 for a hydrogen production apparatus. The power converter 1 is configured to convert alternating current input from a three-phase AC power source into direct current using a plurality of switching elements 24 (see Figure 2). The power converter 1 includes a rectifier unit 10, a capacitor unit 30, an insertion / removal mechanism 40, and a laminated busbar 50.

[0012] Figure 2 is a schematic perspective view of the rectifier unit 10 in the embodiment. The rectifier unit 10 shown in Figure 2 comprises a rectifier support 11, a first converter unit 21 (first semiconductor device) supported on the +X side of the rectifier support 11, and a second converter unit 22 (second semiconductor device) supported on the -X side of the rectifier support 11.

[0013] The rectifier support 11 comprises a first support portion 13 and a second support portion 14 arranged at a predetermined distance apart in the X direction with a space 12 in between, and a plurality of connecting frames 15 that connect the first support portion 13 and the second support portion 14.

[0014] The rectifier support 11 is configured such that the capacitor unit 30 (see Figure 1) fits within the space 12, with the spacing width in the X direction and the dimensions in the Y and Z directions set for the first support portion 13 and the second support portion 14.

[0015] The first support section 13 and the second support section 14 each comprise a frame-shaped outer frame 17 that follows the YZ plane, and a single intermediate frame 18 and a plurality of cooling plates 19 provided inside the outer frame 17. The first support section 13 and the second support section 14 are arranged in a symmetrical structure with respect to the YZ plane.

[0016] The outer frame 17 and the intermediate frame 18 are formed by assembling long members such as angle materials and structural steel in a rectangular shape when viewed from the X direction. The outer frame 17 is provided with a width (height) in the Z direction that is more than twice as large as the width in the Y direction, and the intermediate frame 18 is provided so as to connect the long members on both sides in the Y direction at the center position in the Z direction.

[0017] The cooling plate 19 is formed in a plate shape along the YZ plane (vertical plane). A plurality of cooling plates 19 are provided side by side in the Z direction while being accommodated inside the outer frame 17. In the present embodiment, four cooling plates 19 are provided on each of the +Z side and the -Z side of the intermediate frame 18. Each cooling plate 19 is provided in a rectangular shape whose width in the Y direction is larger than its width in the Z direction. Each cooling plate 19 exhibits a function of cooling the switching element 24, for example, by allowing cooling water or the like supplied from a cooling structure (not shown) to flow therethrough. Further, the cooling plate 19 also functions as a support for supporting the switching element 24. Note that the number of cooling plates 19 arranged side by side in the Z direction is not limited to four, and may be increased or decreased as appropriate.

[0018] The connecting frames 15 are provided in two at positions where the first support portion 13 and the second support portion 14 are divided into three in the Z direction on the +Y side, and one on the -Z side, for a total of three connecting frames 15. The first support portion 13 and the second support portion 14 are integrated via the three connecting frames 15, and the rectifier support 11 is configured like a rack, and the rectifier unit 10 is provided in an independent unit structure. Note that the number of connecting frames 15 installed is not limited to three, and may be increased or decreased as appropriate.

[0019] The rectifier support 11 is formed in a substantially U shape that opens to the -Y side when viewed from the Z direction by the first support portion 13, the second support portion 14, and the connecting frames 15. In other words, in the rectifier support 11 (rectifier unit 10), an access port 16 that is open in the Y direction and communicates with the space 12 is formed on the -Y side of the first support portion 13 and the second support portion 14. Since the rectifier support 11 is formed in a substantially U shape when viewed from the Z direction, the rectifier unit 10 has an independent and self-supporting structure.

[0020] The first converter section 21 is constituted by a plurality of switching elements 24 arranged along a predetermined vertical plane direction (YZ plane direction). It can be exemplified that high-speed semiconductor switching elements such as insulated gate bipolar transistors (IGBTs) are used for each of the plurality of switching elements 24.

[0021] The multiple switching elements 24 are composed of multiple positive-side switching elements 25 and multiple negative-side switching elements 26. The multiple positive-side switching elements 25 are arranged in the region enclosed by the upper half (the +Z-side half) of the outer frame 17 of the first support portion 13 and the intermediate frame 18. The multiple negative-side switching elements 26 are arranged in the region enclosed by the lower half (the -Z-side half) of the outer frame 17 of the first support portion 13 and the intermediate frame 18.

[0022] In this embodiment, twelve positive-side switching elements 25 are provided, arranged in three rows in the Z direction (vertical direction) and four rows in the Y direction. The number of elements and rows can be changed as appropriate. Three positive-side switching elements 25 arranged in rows in the Y direction are supported by a single common cooling plate 19. All positive-side switching elements 25 are supported on the +X side vertical plane of the cooling plate 19, thus oriented along the vertical direction.

[0023] Multiple positive-side switching elements 25 are connected in four parallel configurations to a stacked busbar 50 (see Figure 4) according to the first to third phases of the input three-phase AC. Here, the first phase is the U phase, the second phase is the V phase, and the third phase is the W phase. In this embodiment, the multiple positive-side switching elements 25 consist of four U-phase positive-side switching elements 25u arranged in a row in the Z direction on the +Y side, four W-phase positive-side switching elements 25w arranged in a row in the Z direction on the -Y side, and four V-phase positive-side switching elements 25v arranged in a row in the Z direction between them. In this embodiment, the case of four parallel configurations is described as described above, but the number of parallel configurations is not particularly limited.

[0024] The negative electrode switching elements 26 are arranged in a row of 12, similar to the positive electrode switching elements 25, and are supported by a cooling plate 19. Furthermore, depending on the three-phase AC, multiple negative electrode switching elements 26 are configured in the same way as multiple positive electrode switching elements 25. Specifically, the multiple negative electrode switching elements 26 consist of four X-phase negative electrode switching elements 26x arranged in a row in the Z direction on the +Y side, four Z-phase negative electrode switching elements 26z arranged in a row in the Z direction on the -Y side, and four Y-phase negative electrode switching elements 26y arranged in a row in the Z direction between them.

[0025] As shown by the dashed line in Figure 2, the second converter section 22 is provided in a structure symmetrical to the first converter section 21 with respect to the YZ plane, and a detailed explanation is omitted. In the rectifier unit 10, the first converter section 21 and the second converter section 22 are supported apart in the X direction by the rectifier support 11, and the space 12 described above is formed between the first converter section 21 and the second converter section 22. Furthermore, since the first converter section 21 and the second converter section 22 are arranged along planes parallel to the YZ plane, the first converter section 21 and the second converter section 22 are oriented in the vertical direction and are arranged parallel to each other.

[0026] Although not shown in the diagram, each of the multiple switching elements 24 constituting the first converter section 21 has an emitter terminal, a collector terminal, and an output terminal on the +X side. In the second converter section 22, which has a structure symmetric to that of the first converter section 21, the emitter terminal, collector terminal, and output terminal of each of the multiple switching elements 24 are provided on the -X side.

[0027] Figure 3 is a schematic perspective view of the capacitor unit 30 in the embodiment. As shown in Figure 3, the capacitor unit 30 comprises three shelf sections 31 spaced apart in the Z direction, a pair of shelf support frames 32 that support the three shelf sections 31 from both sides in the X direction, and a plurality of capacitors 33 supported by each shelf section 31. In this embodiment, there are three capacitors 33, but the number of capacitors 33 may be increased or decreased as appropriate along with the shelf sections 31.

[0028] Of the three shelf sections 31, the shelf section 31 closest to the -Z direction is positioned to align with the -Z end of the shelf support frame 32. The positions of the other two shelf sections 31 in the Z direction are set according to the Z-direction dimensions of the capacitor 33, so that the capacitor 33 can be placed in each of the three shelf sections 31. The position of the connecting frame 15 (see Figure 2) in the rectifier support 11 in the Z direction is set to align with the Z-direction position of the shelf section 31.

[0029] Each shelf support frame 32 is provided in a frame shape along the YZ plane (vertical plane) and supports each shelf section 31 while being interconnected via each shelf section 31. This connection integrates a pair of shelf support frames 32 and three shelf sections 31 to form a rack-like structure. As a result, the capacitor unit 30 has a self-supporting structure that allows it to stand independently, and the capacitor unit 30 is provided in an independent unit structure.

[0030] Furthermore, multiple reinforcing frames 34 are provided between the +Z-side ends of each shelf support frame 32.

[0031] The three capacitors 33 consist of AC film capacitors having a roughly rectangular parallelepiped shape. The capacitor unit 30 is constructed by arranging the three capacitors 33 in the Z direction (vertical direction) via each shelf section 31 and each shelf support frame 32.

[0032] A stopper 35 is provided on the -Y side of the capacitor unit 30. The stopper 35 is mounted so as to span across the -Y end of the first support portion 13 and the second support portion 14, and restricts the movement of the capacitor unit 30 toward the -Y side within the space 12.

[0033] Although not shown in the diagram, each capacitor 33 has a positive terminal and a negative terminal on the +Y side. In addition, although one capacitor 33 is provided in each of the three shelf sections 31, multiple capacitors 33 may be provided in a single shelf section 31 by reducing the size of the capacitor 33 in the X direction.

[0034] The loading / unloading mechanism 40 includes casters 41 for the rectifier unit 10 (see Figures 1 and 2) provided at the four corners on the -Z side of the rectifier unit 10, and casters 42 for the capacitor unit 30 provided at the four corners on the -Z side of the capacitor unit 30. The loading / unloading mechanism 40 is provided so that the rectifier unit 10 and the capacitor unit 30 can move relative to each other in the Y direction, which is the direction in which the capacitor unit 30 is loaded or unloaded from the space 12.

[0035] Each caster 41 and 42 is provided so as to be able to roll on a mounting surface such as the floor. The caster 41 for the rectifier unit allows the rectifier unit 10 to move at least in the Y direction (horizontal direction), and the caster 42 for the capacitor unit allows the capacitor unit 30 to move at least in the Y direction (horizontal direction).

[0036] Figure 4 is an exploded view of Figure 1. As shown in Figure 4, the laminated busbar 50 comprises a capacitor-side laminated busbar 51 electrically connected to the capacitor 33, a first laminated busbar 53 electrically connected to the first converter section 21, and a second laminated busbar 54 electrically connected to the second converter section 22.

[0037] The capacitor-side multilayer busbar 51 is electrically connected to the first multilayer busbar 53 on the +X side and to the second multilayer busbar 54 on the -X side. The capacitor-side multilayer busbar 51 is oriented parallel to the ZX plane, while the first and second multilayer busbars 53 and 54 are oriented primarily parallel to the YZ plane. Therefore, the capacitor-side multilayer busbar 51 and the first and second multilayer busbars 53 and 54 are positioned in mutually orthogonal (intersecting) directions.

[0038] The capacitor-side stacked busbar 51 has its thickness in the Y direction and is composed of a W-phase capacitor-side busbar 51w, a V-phase capacitor-side busbar 51v, and a U-phase capacitor-side busbar 51u, which are stacked sequentially from the +Y side to the -Y side.

[0039] Each capacitor-side busbar 51w, 51v, and 51u is divided into upper and lower sections and electrically connected via an intermediate busbar. Specifically, the W-phase capacitor-side busbar 51w comprises an upper W-phase capacitor-side busbar 51w1 located on the upper side (+Z side), a lower W-phase capacitor-side busbar 51w2 located on the lower side (-Z side), and an intermediate W-phase capacitor-side busbar 51w3 positioned between them and electrically connected.

[0040] The V-phase capacitor-side busbar 51v comprises an upper V-phase capacitor-side upper busbar 51v1 located on the upper side, a lower V-phase capacitor-side lower busbar 51v2 located on the lower side, and an intermediate V-phase capacitor-side intermediate busbar 51v3 positioned between these and electrically connected.

[0041] The U-phase capacitor-side busbar 51u comprises an upper U-phase capacitor-side upper busbar 51u1 located on the upper side, a lower U-phase capacitor-side lower busbar 51u2 located on the lower side, and an intermediate U-phase capacitor-side intermediate busbar 51u3 positioned between these and electrically connected.

[0042] An insulating layer 52 (see Figure 5) is provided on both sides of each upper busbar 51w1, 51v1, and 51u1, and they are laminated and integrated with the insulating layer 52 in between. An insulating layer (not shown) is provided on both sides of each lower busbar 51w2, 51v2, and 51u2, and they are laminated and integrated with the insulating layer in between. An insulating layer (not shown) is provided on both sides of each intermediate busbar 51w3, 51v3, and 51u3, and they are laminated and integrated with the insulating layer in between.

[0043] A notch is formed at the lower end of the upper busbar 51v1 on the V-phase capacitor side to form a region that does not cover the lower end of the upper busbar 51u1 on the U-phase capacitor side. A notch is formed at the upper end of the lower busbar 51v2 on the V-phase capacitor side to form a region that does not cover the upper end of the lower busbar 51u2 on the U-phase capacitor side. An intermediate busbar 51u3 on the U-phase capacitor side is provided so as to contact and electrically connect with the upper busbar 51u1 and the lower busbar 51u2 on the U-phase capacitor side inside these notches.

[0044] A notch is formed at the lower end of the upper busbar 51w1 on the W-phase capacitor side to form an area that does not cover the lower ends of the upper busbar 51v1 on the V-phase capacitor side and the upper busbar 51u1 on the U-phase capacitor side. A notch is formed at the upper end of the lower busbar 51w2 on the W-phase capacitor side to form an area that does not cover the upper ends of the lower busbar 51v2 on the V-phase capacitor side and the lower busbar 51u2 on the U-phase capacitor side. An intermediate busbar 51v3 on the V-phase capacitor side is provided so as to contact and electrically connect with the upper busbar 51v1 and the lower busbar 51v2 on the V-phase capacitor side within the notches of the upper busbar 51w1 and the lower busbar 51w2 on the W-phase capacitor side.

[0045] The intermediate busbar 51w3 on the W-phase capacitor side is provided to be electrically connected by contacting the upper region of the notch at the lower end of the upper busbar 51w1 on the W-phase capacitor side and the lower region of the notch formed at the upper end of the lower busbar 51w2 on the W-phase capacitor side.

[0046] The electrically connected areas described above are maintained by inserting a male threaded member, such as a bolt, through a hole that penetrates each busbar, and fastening it with a female threaded member, such as a nut, attached to the male threaded member.

[0047] On the +Z side of the upper busbars 51w1 for the W-phase capacitor, 51v1 for the V-phase capacitor, and 51u1 for the U-phase capacitor, rectangular connecting protrusions 51w4, 51v4, and 51u4 are formed. The connecting protrusions 51w4, 51v4, and 51u4 are arranged so that their positions do not overlap in the X direction and are connected to the AC power supply that is the input side.

[0048] The capacitor-side laminated busbar 51 is connected to each terminal (not shown) of the opposing capacitor 33 on the -Y side via a connecting conductor (not shown) made of a screw shaft or the like.

[0049] The first stacked busbar 53 comprises a first positive electrode stacked busbar 55 and a first negative electrode stacked busbar 56. The second stacked busbar 54 comprises a second positive electrode stacked busbar 57 and a second negative electrode stacked busbar 58.

[0050] The first positive electrode side stacked busbar 55 is composed of a positive electrode busbar 55p, a W-phase busbar 55w, a V-phase busbar 55v, and a U-phase busbar 55u. The first positive electrode side stacked busbar 55 has a bent shape when viewed from the Z direction and includes a main surface 55A provided parallel to the YZ plane so as to face the positive electrode side switching element 25, and a bent portion 55B provided parallel to the ZX plane. Therefore, the first positive electrode side stacked busbar 55 has a shape that is bent on the +Y side of the main surface 55A and on the +X side of the bent portion 55B.

[0051] On the main surface 55A of the first positive electrode stacked busbar 55, the positive electrode busbar 55p, W-phase busbar 55w, V-phase busbar 55v, and U-phase busbar 55u are stacked in order from the +X side to the -X side, and their dimensions in the Y direction are different. More specifically, the U-phase busbar 55u has a Y-direction width that faces each U-phase positive electrode switching element 25u. The V-phase busbar 55v is larger on the -Y side than the U-phase busbar 55u and has a Y-direction width that faces the V-phase positive electrode switching element 25v. The W-phase busbar 55w is larger on the -Y side than the V-phase busbar 55v and has a Y-direction width that faces the W-phase positive electrode switching element 25w. The positive electrode busbar 55p has a Y-direction width that is larger on the -Y side than the W-phase busbar 55w.

[0052] The U-phase busbar 55u, V-phase busbar 55v, and W-phase busbar 55w are connected to their respective opposing positive-side switching elements 25u, 25v, and 25w via connecting conductors (not shown) made of screw shafts or the like. The positive-side busbar 55p is connected to the respective positive-side switching elements 25u, 25v, and 25w via insulated connecting conductors (not shown) that pass through holes (not shown) formed in the U-phase busbar 55u, V-phase busbar 55v, and W-phase busbar 55w. As a result, the DC voltage converted from the AC voltage by each positive-side switching element 25u, 25v, and 25w is applied to the positive-side busbar 55p. A rectangular connecting projection 55pp4 is formed on the +Y side of the positive-side busbar 55p. The connecting projection 55p4 is connected to the positive electrode on the load side of the DC output side.

[0053] The busbars 55w for the W phase, 55v for the V phase, 55u for the U phase, and 55p for the positive electrode are each provided with an insulating layer 59 (see Figure 5) on both sides, and are laminated together with the insulating layer 59 in between.

[0054] The first negative electrode side stacked busbar 56, which constitutes the first stacked busbar 53, has the same form and configuration as the first positive electrode side stacked busbar 55. More specifically, the first negative electrode side stacked busbar 56 is positioned on the -Z side of the first positive electrode side stacked busbar 55 and is provided to be connected to the negative electrode side switching element 26. The first negative electrode side stacked busbar 56 has a negative electrode busbar 56n stacked on the outside (+X side and +Y side), and a connecting projection 56n4 is formed protruding from the +Y side of the negative electrode busbar 56n. The other configurations are generally the same as those of the first positive electrode side stacked busbar 55, so a detailed explanation is omitted.

[0055] Furthermore, the second stacked busbar 54 is arranged in a symmetrical structure with respect to the YZ plane relative to the first stacked busbar 53, with the second positive electrode stacked busbar 57 positioned on the upper side (+Z side) and the second negative electrode stacked busbar 58 positioned on the lower side (-Z side). The second stacked busbar 54 is generally the same as the first stacked busbar 53, except that it has a symmetrical structure, so a detailed explanation will be omitted.

[0056] Here, the laminated busbar 50 is provided with connection portions 60 near the intersection of the capacitor-side laminated busbar 51 and the first laminated busbar 53, and near the intersection of the capacitor-side laminated busbar 51 and the second laminated busbar 54. The capacitor-side laminated busbar 51 and the first laminated busbar 53 are electrically connected via the connection portion 60 near the intersection. The capacitor-side laminated busbar 51 and the second laminated busbar 54 are electrically connected via the connection portion 60 near the intersection.

[0057] To electrically connect to the capacitor-side laminated busbar 51, a portion of the connection portion 60 is formed on each of the first positive-side laminated busbar 55, the first negative-side laminated busbar 56, the second positive-side laminated busbar 57, and the second negative-side laminated busbar 58. Since the portion of this connection portion 60 is generally common or symmetrical in structure across each of the laminated busbars 55 to 58, the following description will focus on the connection portion 60 formed on the first positive-side laminated busbar 55 and the capacitor-side laminated busbar 51, and the description of the other connection portions 60 will be omitted.

[0058] Figure 5 is an enlarged cross-sectional view of the connection portion in the embodiment. Figure 6 is an exploded view of Figure 5. As shown in Figures 5 and 6, the connection portion 60 includes a first contact region 61 formed on the capacitor-side laminated busbar 51 and a second contact region 62 formed on the bent portion 55B of the first positive electrode-side laminated busbar 55. The connection portion 60 allows the capacitor-side laminated busbar 51 and the first positive electrode-side laminated busbar 55 to conduct electricity when the first contact region 61 and the second contact region 62 are in contact with each other.

[0059] The first contact region 61 is formed by shifting the +X end positions of the W-phase capacitor-side upper busbar 51w1, the V-phase capacitor-side upper busbar 51v1, and the U-phase capacitor-side upper busbar 51u1 that constitute the capacitor-side laminated busbar 51. More specifically, in the first contact region 61, the V-phase capacitor-side upper busbar 51v1, which is laminated in the middle in the Y direction, has its +X end position shifted to the -X side relative to the W-phase capacitor-side upper busbar 51w1, which is on the +Y side. Also, the U-phase capacitor-side upper busbar 51u1, which is on the -Y side, has its +X end position shifted to the -X side relative to the V-phase capacitor-side upper busbar 51v1. As a result, the end positions of each upper busbar 51w1, 51v1, and 51u1 are formed in a stepped manner.

[0060] Therefore, in the first contact region 61, three regions are formed side by side from the -X side to the +X side: a region where all three upper busbars 51w1, 51v1, and 51u1 are stacked, a region where two of the upper busbars, the W-phase capacitor-side upper busbar 51w1 and the V-phase capacitor-side upper busbar 51v1, are stacked, and a region where only the W-phase capacitor-side upper busbar 51w1 is stacked. These regions are formed to align to the same range in the Z direction, or in other words, they are formed to include the same range in the Z direction (see Figure 4).

[0061] A first hole 63 is formed near the +X end of the upper busbar 51u1 on the U-phase capacitor side, penetrating all three upper busbars 51w1, 51v1, and 51u1. A second hole 64 is formed near the +X end of the upper busbar 51v1 on the V-phase capacitor side, penetrating both the upper busbar 51v1 on the V-phase capacitor side and the upper busbar 51w1 on the W-phase capacitor side. A third hole 65 is formed near the +X end of the upper busbar 51w1 on the W-phase capacitor side, penetrating the upper busbar 51w1 on the W-phase capacitor side.

[0062] As described above, insulating layers 52 are provided on both sides of each upper busbar 51w1, 51v1, and 51u1, but the insulating layer 52 is not laminated on the -Y side surface near each hole 63 to 65. Therefore, all of the upper busbars 51w1, 51v1, and 51u1, which form a step-like structure in the first contact region 61, are formed to be electrically connectable.

[0063] The second contact region 62 is formed by shifting the -X-side end positions of the W-phase busbar 55w, V-phase busbar 55v, and U-phase busbar 55u that form the bent portion 55B in the first positive electrode stacked busbar 55. More specifically, in the second contact region 62, the V-phase busbar 55v, which is stacked in the middle in the Y direction, has its -X-side end position shifted to the -X side relative to the W-phase busbar 55w, which is on the +Y side. Also, the U-phase busbar 55u, which is on the -Y side relative to the V-phase busbar 55v, has its -X-side end position shifted to the -X side. As a result, the end positions of the W-phase busbar 55w, V-phase busbar 55v, and U-phase busbar 55u are formed in a stepped manner.

[0064] Therefore, in the second contact region 62, three regions are formed side by side from the +X side to the -X side: a region where all three busbars 55w, 55v, and 55u are stacked, a region where two busbars, the V-phase busbar 55v and the U-phase busbar 55u, are stacked, and a region where only the U-phase busbar 55u is present. These regions are formed to align to the same extent in the Z direction, or in other words, they are formed to include the same extent in the Z direction (see Figure 4).

[0065] In the second contact region 62, the first screw shaft 67, which is inserted through the first hole 63, is fixed to the +Y side surface of the U-phase busbar 55u so as to protrude towards the +Y side. Also in the second contact region 62, the second screw shaft 68, which is inserted through the second hole 64, is fixed to the +Y side surface of the V-phase busbar 55v so as to protrude towards the +Y side. Furthermore, in the second contact region 62, the third screw shaft 69, which is inserted through the third hole 65, is fixed to the +Y side surface of the W-phase busbar 55w so as to protrude towards the +Y side.

[0066] As described above, insulating layers 59 are provided on both sides of each busbar 55w, 55v, and 55u, but the insulating layer 59 is not laminated on the +Y side surface near each screw shaft 67-69. Therefore, all of the busbars 55w, 55v, and 55u, which form a step-like structure in the second contact region 62, are formed to be electrically connectable.

[0067] When connecting the capacitor-side laminated busbar 51 and the first positive electrode-side laminated busbar 55 at the connection section 60, the screw shafts 67 to 69 are inserted through the holes 63 to 65 from the state shown in Figure 6, bringing the first contact area 61 and the second contact area 62 into contact with each other. As a result, as shown in Figure 5, the upper busbar 51u1 for the U-phase capacitor and the U-phase busbar 55u make surface contact and conduct electricity. Also, the upper busbar 51v1 for the V-phase capacitor and the V-phase busbar 55v make surface contact and conduct electricity, and the upper busbar 51w1 for the W-phase capacitor and the W-phase busbar 55w make surface contact and conduct electricity.

[0068] In the state shown in Figure 5, the capacitor-side laminated busbar 51 and the first positive electrode-side laminated busbar 55 are fixed to each other by screwing nuts 71 to 73 onto the tip of each screw shaft 67 to 69 and tightening them. In the connection portion 60, the first contact area 61 and the second contact area 62 are formed in a stepped shape, so that a portion of them in the Y direction overlaps with each other, thereby suppressing an increase in the width of the connection portion 60 in the Y direction.

[0069] Furthermore, as shown in Figure 4, the Z-direction ranges of the three upper busbars 51w1, 51v1, and 51u1 are the same in the first contact region 61, and the Z-direction ranges of the three busbars 55w, 55v, and 55u are the same in the second contact region 62. This allows the first contact region 61 and the second contact region 62 to be in contact over a wide area, reducing the current density between them and avoiding losses due to heat generation, etc.

[0070] Figure 7 is an explanatory diagram for inserting and removing the capacitor unit 30 into and out of space 12. Figure 8 is a plan view of the power converter 1 in the embodiment. Here, in Figure 7, the capacitor unit 30 is simplified and shown with a dashed line.

[0071] As shown in Figure 7, in the power conversion device 1 of the above embodiment, the capacitor unit 30 can be inserted into and removed from the space 12 of the rectifier unit 10 through the inlet / outlet 16.

[0072] As shown in Figure 8, when moving the capacitor unit 30, which is located inside the space 12 of the rectifier unit 10, to the outside of space 12, the stopper 35 is removed. Then, the capacitor unit 30 is moved to the -Y side via the caster 42 for the capacitor unit (see Figure 4) and moved to the outside of space 12 through the access port 16 of the rectifier unit 10.

[0073] Furthermore, when moving the capacitor unit 30 from outside to inside space 12, the capacitor unit 30 positioned on the -Y side of space 12 is moved to the +Y side via the capacitor unit caster 42. This allows the capacitor unit 30 to be moved from outside to inside space 12 through the access opening 16 and placed inside space 12. After that, stoppers 35 are attached to each support part 13, 14 to restrict the movement of the capacitor unit 30 on the -Y side.

[0074] According to the above embodiment, the rectifier unit 10 and the capacitor unit 30 are provided in a mutually independent unit structure, and an inlet / outlet 16 is formed in the rectifier unit 10, so that the capacitor unit 30 can be moved in and out of the space 12 through the inlet / outlet 16. In other words, the inlet / outlet 16 allows relative movement between the rectifier unit 10 and the capacitor unit 30 in the horizontal direction (Y direction), which is the direction in which the capacitor unit 30 is moved in and out of the space 12.

[0075] As a result, in this embodiment, the assembly of the rectifier unit 10 and the capacitor unit 30, and the separation and maintenance of them can be made easier and quicker. Therefore, the power conversion device 1 of this embodiment can be made more productive and easier to maintain. Moreover, the capacitor unit 30 is arranged in the space 12 formed between the two converter sections 21 and 22 in the horizontal direction (X direction). As a result, compared to the conventional configuration in which the capacitor and converter are arranged vertically, the vertical width can be significantly reduced while keeping the installation area to a slight increase, making the power conversion device 1 more compact and space-saving.

[0076] Furthermore, the rectifier unit 10 and the capacitor unit 30 are provided with a retraction mechanism 40 consisting of casters 41 and 42, allowing them to move relative to each other in the Y direction (horizontal direction). This makes it easy for an operator to move the capacitor unit 30 into and out of the space 12 simply by pushing or pulling the capacitor unit 30.

[0077] Furthermore, since the rectifier unit 10 and the capacitor unit 30 have independent, self-supporting structures, stands and positioning mechanisms for supporting and positioning them can be omitted, further improving work efficiency.

[0078] Furthermore, since the converter sections 21 and 22 are arranged symmetrically in the X direction along the vertical direction, with multiple capacitors 33 arranged vertically in between, the distance between the capacitors 33 and the switching element 24 can be shortened. This reduces the inductance between the capacitors 33 and the switching element 24, thereby suppressing the voltage spike during switching of the switching element 24. Moreover, since the converter sections 21 and 22 are symmetrical with respect to the capacitors 33, the inductances between the capacitors 33 and the first converter section 21, and between the capacitors 33 and the second converter section 22 can be made equal, thereby suppressing variations in the output of the switching element 24.

[0079] Furthermore, the present invention is not limited to the embodiments described above, and can be implemented with various modifications. In the embodiments described above, the size, shape, orientation, etc., shown in the accompanying drawings are not limited thereto, and can be appropriately modified within the scope that allows the present invention to exert its effects. In addition, the present invention can be implemented with appropriate modifications as long as it does not deviate from the scope of its objectives.

[0080] In the above embodiment, the case in which the capacitor unit 30 is moved via the caster 42 for the capacitor unit when moving the capacitor unit 30 in and out of space 12 was described, but the invention is not limited to this. When moving the capacitor unit in and out, only the rectifier unit 10 may be moved via the caster 41 for the rectifier unit, or both the rectifier unit 10 and the capacitor unit 30 may be moved via the respective casters 41 and 42.

[0081] Furthermore, the loading / unloading mechanism 40 may be changed to a configuration other than the casters 41 and 42, as long as the capacitor unit 30 can be loaded and unloaded through the loading / unloading opening 16 in the space 12 of the rectifier unit 10. For example, the loading / unloading mechanism 40 may be a slider structure arranged on the installation surface, or the loading / unloading mechanism 40 itself may be omitted, making it movable by a transport mechanism other than the power converter 1.

[0082] Furthermore, the first converter section 21 and the second converter section 22 may be oriented in directions that intersect or orthogonal to each other, as long as a space 12 is formed between them in which a capacitor unit 30 can be placed.

[0083] Furthermore, although the capacitor-side laminated busbar 51 is structured to be divided into upper and lower busbars and an intermediate busbar, these may also be made into a single integrated busbar.

[0084] Furthermore, although the rectifier unit 10 was described in which the first semiconductor device is the first converter unit 21 and the second semiconductor device is the second converter unit 22, other semiconductor devices may be used, such as making at least one of them an inverter unit. Therefore, the power conversion device 1 can be modified in various ways, such as making it a device that converts DC to AC, or AC to AC with different voltages, etc.

[0085] Furthermore, the insulating layers 52 and 59 shown in Figures 5 and 6 may be replaced with insulating plates having the same thickness as each busbar.

[0086] Furthermore, in the connection portion 60, the bent portion 55B of the first positive electrode side laminated busbar 55 may be omitted, and bent portions may be formed at the +X side and -X side ends of the capacitor side laminated busbar 51. In this configuration, a first contact region is formed at the bent portion of the capacitor side laminated busbar 51, and a second contact region is formed at the +Y side end of the first positive electrode side laminated busbar 55. [Explanation of Symbols]

[0087] 1: Power converter 10: Rectifier Unit 12: Space 16: Opening 21: First converter section (first semiconductor device) 22: Second converter section (second semiconductor device) 24: Switching element 30: Capacitor Unit 33: Capacitor 40: Removal and retraction mechanism 50: Laminated busbar 51: Capacitor-side multilayer busbar 51u1: Upper busbar on the capacitor side for U-phase (busbar) 51V1: Upper busbar on the V-phase capacitor side (busbar) 51w1: Upper busbar on the capacitor side for W phase (busbar) 53: First layer busbar 54: Second layer busbar 55u: U-type busbar (busbar) 55V: V-phase busbar (busbar) 55W: W-phase busbar (busbar) 60: Connection part 61: 1st contact area 62:Second contact area

Claims

1. A rectifier unit including a first semiconductor device and a second semiconductor device, each configured by arranging a plurality of switching elements along a predetermined planar direction, A power conversion device comprising a capacitor unit formed by arranging multiple capacitors in a row, The rectifier unit and the capacitor unit are provided in mutually independent unit structures. In the rectifier unit, a space is formed between the first semiconductor device and the second semiconductor device for the capacitor unit to be disposed of. A power conversion device characterized in that an opening is formed in the rectifier unit that allows relative movement between the rectifier unit and the capacitor unit in the direction of inserting and removing the capacitor unit from the space.

2. The power conversion device according to claim 1, further comprising an insertion / removal mechanism for moving the rectifier unit and the capacitor unit relative to each other in the horizontal direction for inserting and removing the capacitor unit from the aforementioned space.

3. The power conversion device according to claim 1 or 2, characterized in that the rectifier unit and the capacitor unit each have an independent, self-supporting structure.

4. The aforementioned plurality of capacitors are arranged in a vertical direction, The power conversion device according to claim 1 or 2, characterized in that the first semiconductor device and the second semiconductor device are arranged in a direction parallel to each other and along the vertical direction.

5. A capacitor-side stacked busbar electrically connected to the aforementioned capacitor, The first semiconductor device and the first laminated busbar electrically connected to the capacitor-side laminated busbar and The device comprises the second semiconductor device and a second stacked busbar electrically connected to the capacitor-side stacked busbar, The capacitor-side laminated busbar, the first laminated busbar, and the second laminated busbar are oriented in a direction of intersection and are electrically connected via a connection portion near the point of intersection. The aforementioned connection portion is formed by staggering the end positions of the multiple busbars constituting the capacitor-side laminated busbar in a stepped manner, and creating a first contact region that allows all of the multiple busbars to be electrically connected. The first stacked busbar and the second stacked busbar are formed by staggering the end positions of a plurality of busbars in a stepped manner, and a second contact region is formed so that all of the plurality of busbars can be electrically connected. The power conversion device according to claim 1 or 2, characterized in that conductivity is achieved by the first contact area and the second contact area being in contact with each other.

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