Capacitor and capacitor assembly

Abstract

This capacitor and capacitor assembly according to an embodiment have a capacitor body and a plate-like terminal. The capacitor body has a planar board surface. The plate-like terminal can connect a mating component to a connection surface parallel to the board surface. The connection surface of the plate-like terminal on the positive electrode side and the connection surface of the plate-like terminal on the negative electrode side are arranged so as to be skewed from each other in the normal direction of the board surface.

Description

Capacitor and capacitor assembly

[0001] SUMMARY OF THE INVENTION Embodiments of the present invention relate to capacitors and capacitor assemblies.

[0002] Conventionally, in capacitors having plate terminals, when connecting the plate terminals between capacitors or to a semiconductor module or the like, various measures have been taken to reduce size, improve cooling performance, and reduce inductance.

[0003] In the case of capacitors used in power conversion equipment, as the capacity of the power conversion equipment increases, the capacity (volume) of the capacitor also increases. Therefore, it becomes necessary to save space by improving the terminal connection structure, reduce inductance, and improve cooling performance.

[0004] JP 2007-299781 A Japanese Patent No. 7113937 A

[0005] The problem to be solved by the present invention is to provide a capacitor and a capacitor assembly that can be made smaller, have lower inductance, and have improved cooling properties by improving the terminal connection structure.

[0006] The capacitor and capacitor assembly of the embodiment include a capacitor body and plate terminals. The capacitor body has a planar surface. The plate terminals have connection surfaces parallel to the surface that can be connected to mating components. The connection surfaces of the positive and negative plate terminals are offset from each other in the normal direction of the surface.

[0007] 6 is a circuit diagram showing an example of a DAB circuit of an embodiment. A perspective view of a power conversion device of an embodiment. A perspective view of a capacitor of a power conversion device of an embodiment. A perspective view of a capacitor pack of a capacitor of an embodiment. A VV cross-sectional view of FIG. 4. A perspective view of a state in which a first conductor plate is attached to the capacitor pack. A perspective view of a state in which a second conductor plate is further attached from FIG. 6. An explanatory diagram of a terminal butting portion of a capacitor assembly of an embodiment.

[0008] A piping connection structure according to an embodiment will now be described with reference to the drawings. Fig. 1 is a circuit diagram showing an example of a DAB (Dual Active Bridge) circuit 1 according to an embodiment. Fig. 2 is a perspective view of a power conversion device 2 according to an embodiment. In the following description, arrow Y in the drawings indicates the front-to-rear direction, arrow X the left-to-right direction, and arrow Z the up-to-down direction. In the drawings, arrow FR indicates the forward direction in the Y direction, arrow LH indicates the leftward direction in the X direction, and arrow UP indicates the upward direction in the Z direction. The front-to-rear and left-to-right directions in the embodiment do not limit the arrangement of the power conversion device 2.

[0009] The power converter 2 constitutes a DAB circuit 1, which is a type of circuit system that performs DC / DC conversion while maintaining insulation. The DAB circuit 1 includes two bridge circuits (active bridges) and a high-frequency transformer 6. The power converter 2 is a power distribution board, a distribution board, a control panel, etc. that constitute a power supply device, a motor drive device, etc. Each power converter 2 includes various circuit components such as semiconductor elements, conductors, fuses, capacitors, transformers, switches, circuit breakers, and measuring instruments.

[0010] In the power conversion device 2 of the embodiment, the input and output capacitors 3A, 3B and the semiconductor circuit units 4A, 4B are arranged on the front side (forward side), and the high-frequency transformer 6 is arranged on the back side (rear side). The power conversion device 2 has an overall configuration in which the components are arranged in a U-shaped fold in a plan view.

[0011] 1, the DAB circuit 1 of the power conversion device 2 includes a full bridge circuit (first full bridge circuit) consisting of two switching legs, in which semiconductor switching elements Q11 to Q14 are connected as positive and negative semiconductor elements between the positive terminal (high potential side DC terminal) Np1 and the negative terminal (low potential side DC terminal) Nn1 of the input-side capacitor 3A. The DAB circuit 1 of the power conversion device 2 also includes a full bridge circuit (second full bridge circuit) consisting of two switching legs, in which semiconductor switching elements Q21 to Q24 are connected as positive and negative semiconductor elements between the positive terminal Np2 and the negative terminal Nn2 of the output-side capacitor 3B.

[0012] 2, the power conversion device 2 includes input-side and output-side semiconductor circuit units 4A, 4B, input-side and output-side capacitors 3A, 3B connected to the respective semiconductor circuit units 4A, 4B, and a transformer 6 to which the respective semiconductor circuit units 4A, 4B are connected. In a top view of the power conversion device 2, the components are connected in the order of the input-side capacitor 3A, the input-side semiconductor circuit unit 4A, the transformer 6, the output-side semiconductor circuit unit 4B, and the output-side capacitor 3B.

[0013] FIG. 3 is a perspective view of a capacitor 3A or 3B of a power conversion device 2 according to an embodiment. FIG. 4 is a perspective view of a capacitor pack 15A of the capacitor 3A or 3B according to an embodiment. FIG. 5 is a V-V cross-sectional view of FIG. 4. Referring to FIGS. 2 and 3, an input-side semiconductor circuit unit 4A and a capacitor 3A are disposed on one of the left and right sides (right side in the figure) of the front side of the transformer 6. An output-side semiconductor circuit unit 4B and a capacitor 3B are disposed on the other left and right side (left side in the figure) of the front side of the transformer 6. Each capacitor 3A, 3B includes a pair of left and right capacitor packs 15A, 15B formed into a rectangular parallelepiped shape by arranging a plurality of unit cells, for example. Each capacitor pack 15A, 15B has a rectangular parallelepiped shape with its thickness oriented in the left-right direction and a flat shape with a reduced dimension in the thickness direction.

[0014] A flat positive conductor plate 16a and a flat negative conductor plate 16b are sandwiched between the pair of capacitor packs 15A, 15B. These conductor plates 16a, 16b form front terminals 17a, 17b and rear terminals 18a, 18b for connecting external components. Each capacitor 3A, 3B is configured as a capacitor assembly 14, which is an integral assembly of the pair of left and right capacitor packs 15A, 15B and the conductor plates 16a, 16b.

[0015] Fig. 4 shows, for example, the capacitor pack (first capacitor pack) 15A on the right side in Fig. 3. For example, the capacitor pack (second capacitor pack) 15B on the left side in Fig. 3 has the same configuration except for the displacement heights of the positive electrode terminal 15d and the negative electrode terminal 15e, which will be described later, and therefore detailed description thereof will be omitted.

[0016] 3 to 5, a plurality of connection terminals 15d, 15e are protruding from the upper and lower edges of one side in the left-right direction of the rectangular parallelepiped main body (capacitor body) 15c of the capacitor pack 15A. The connection terminals 15d, 15e are a positive terminal 15d and a negative terminal 15e. The positive terminals 15d and the negative terminals 15e are alternately arranged in the front-rear direction on the top and bottom of the capacitor pack 15A.

[0017] The positive electrode terminal 15d and the negative electrode terminal 15e are each strip-shaped with their widths aligned in the front-to-rear direction. Each of the positive electrode terminal 15d and the negative electrode terminal 15e includes an upright portion 15d1, 15e1 extending from a side surface (disk surface) 15c1 on one left-to-right side of the capacitor body 15c of the capacitor pack 15A in a normal direction (left-to-right direction) to the side surface, and a connecting portion 15d2, 15e2 bending from the tip of the upright portion 15d1, 15e1 and extending toward the outside (upward or downward) of the capacitor pack 15A in a side view.

[0018] The connection portions 15d2, 15e2 of the positive and negative terminals 15d, 15e are formed in a flat plate shape parallel to the side surface 15c1 of the capacitor pack 15A. The connection portions 15d2, 15e2 of the positive and negative terminals 15d, 15e are formed with openings (notches that open upward or downward in this embodiment) that penetrate in the left-right direction, allowing connection to external components using fasteners (not shown). The connection portions 15d2, 15e2 of the positive and negative terminals 15d, 15e are formed so as not to protrude outward (upward or downward) beyond the upper and lower edges of the capacitor pack 15A in a side view.

[0019] The positive terminal 15d and the negative terminal 15e have different displacements D1 and D2 from a side surface 15c1 on one side in the left-right direction of the capacitor body 15c. The displacements D1 and D2 are the amounts of displacement from the side surface 15c1 on one side in the left-right direction of the capacitor pack 15A to the side surfaces (connection surfaces 15d3 and 15e3) on one side in the left-right direction of the connection portions 15d2 and 15e2. For example, the displacement D1 of the positive terminal 15d is larger than the displacement D2 of the negative terminal 15e by a certain amount. The connection portion 15d2 of the positive terminal 15d and the connection portion 15e2 of the negative terminal 15e are arranged in a staggered manner.

[0020] The difference between the displacement amounts D1 and D2 of the positive electrode terminal 15d and the negative electrode terminal 15e is set to be larger than the plate thickness of the conductor plates 16a and 16b. Note that, as in the positive electrode terminal 15d and the negative electrode terminal 15e shown in Fig. 5, the upright portions 15d1 and 15e1 may have different vertical heights, or the upright portions 15d1 and 15e1 may have the same vertical height.

[0021] Fig. 6 is a perspective view of the capacitor pack 15A with a positive conductor plate 16a attached. Fig. 7 is a perspective view of the capacitor pack 15A with a negative conductor plate 16b attached. Fig. 8 is an explanatory view of the terminal butting portion of the capacitor assembly 14 according to the embodiment. Referring to Figs. 3 and 8, flat conductor plates 16a and 16b, each with its thickness oriented in the left-right direction, are sandwiched between the pair of capacitor packs 15A and 15B.

[0022] The pair of left and right conductor plates 16a, 16b is the positive conductor plate 16a connected to the positive terminal 15d of the capacitor pack 15A, and the negative conductor plate 16b connected to the negative terminal 15e of the capacitor pack 15A. The positive conductor plate 16a and the negative conductor plate 16b are arranged so as to entirely overlap each other when viewed from the left and right. The positive conductor plate 16a and the negative conductor plate 16b are arranged with a specified clearance S1 between them in the left and right direction.

[0023] Each conductor plate 16a, 16b has a rectangular main body 16c which, when viewed from the side, has a narrower vertical width than the capacitor pack 15A but roughly the same front-to-back width, conductor terminals 19a, 19b protruding upward or downward from the upper and lower edges of the main body 16c, front terminals 17a, 17b protruding forward from the front edge of the main body 16c, and rear terminals 18a, 18b protruding rearward from the rear edge of the main body 16c.

[0024] For example, the front terminals 17a, 17b include a front positive terminal 17a extending forward from the upper half of the front edge of the positive conductor plate 16a, and a front negative terminal 17b extending forward from the lower half of the front edge of the negative conductor plate 16b. The front positive terminal 17a and the front negative terminal 17b are divided into two sections, upper and lower.

[0025] The front terminals 17a, 17b each have a connecting portion 17c with an opening (e.g., an endless through-hole) at their front portions. Each opening (through-hole) is a fastening hole for connecting to an external component with a bolt or the like extending in the left-right direction. The front positive terminal 17a and the front negative terminal 17b are each formed in a plate shape with a width along the surface (front-rear and up-down directions), which contributes to low inductance.

[0026] For example, the rear terminals 18a, 18b include a rear positive terminal 18a and a rear negative terminal 18b that extend rearward from the entire rear edge of each conductor plate 16a, 16b (including, for example, the upper and lower conductor terminals 19a, 19b) by different lengths. The rear positive terminal 18a extends rearward from the rear edge of the positive conductor plate 16a, and the rear negative terminal 18b extends rearward from the rear edge of the negative conductor plate 16b. For example, the rear positive terminal 18a formed on the positive conductor plate 16a on the other left-right side extends rearward further than the rear negative terminal 18b formed on the negative conductor plate 16b on one left-right side.

[0027] The rear portions (extending tip portions) of the rear positive terminal 18 a and the rear negative terminal 18 b are provided with a plurality of connection portions 18 c having openings (e.g., endless through holes) in the left-right direction. Each opening (through hole) is a fastening hole for connecting to an external component (each of the semiconductor circuit units 4A and 4B in this embodiment) with a bolt or the like extending in the left-right direction.

[0028] The rear positive terminal 18a, which extends rearward, has a circular access hole 18d, for example, in a side view, between the rear edge of the main body 16c and each connection portion 18c in the front-to-rear direction. Each access hole 18d is formed in a position overlapping with each connection portion 18c of the rear negative terminal 18b in a side view. This allows external components to be fastened to each connection portion 18c of the rear negative terminal 18b. The rear positive terminal 18a and the rear negative terminal 18b are each formed in a plate shape with a width in the direction along the surface (front-to-rear and up-down directions), which contributes to low inductance.

[0029] 6 and 7 , conductor terminals 19a (hereinafter referred to as positive conductor terminals 19a) that overlap the positive terminal 15d of the capacitor pack 15A are protruding from the top and bottom of the positive conductor plate 16a. Portions of the positive conductor plate 16a that avoid the positive conductor terminal 19a are cut out. Conductor terminals 19b (hereinafter referred to as negative conductor terminals 19b) that overlap the negative terminal 15e of the capacitor pack 15A are protruding from the top and bottom of the negative conductor plate 16b. Portions of the negative conductor plate 16b that avoid the negative conductor terminal 19b are cut out. The tip of each conductor terminal 19a, 19b serves as a connecting portion 19c that can be used to fasten an external component.

[0030] 8, in the capacitor pack 15A, the positive terminal 15d, which is displaced relatively greatly in the left-right direction, is connected to the positive conductor terminal 19a of the positive conductor plate 16a, and the negative terminal 15e, which is displaced relatively little in the left-right direction, is connected to the negative conductor terminal 19b of the negative conductor plate 16b.

[0031] Since the difference between the displacement amounts D1, D2 of the positive terminal 15d and the negative terminal 15e is greater than the plate thickness of each conductor plate 16a, 16b, when the positive conductor terminal 19a and the negative conductor terminal 19b are connected to the positive terminal 15d and the negative terminal 15e of the capacitor pack 15A, a specified clearance S1 is formed between the positive conductor plate 16a and the negative conductor plate 16b.

[0032] For example, the pair of capacitor packs 15A, 15B can be divided into capacitor pack 15A, in which the positive terminal 15d has a large displacement amount D1 and the negative terminal 15e has a small displacement amount D2, and capacitor pack 15B, in which the positive terminal 15d has a small displacement amount D2 and the negative terminal 15e has a large displacement amount D1. When the two capacitor packs 15A, 15B are placed face to face with each other, the positive terminal 15d with the large displacement amount D1 butts up against the positive terminal 15d with the small displacement amount D2. Also, the negative terminal 15e with the small displacement amount D2 butts up against the negative terminal 15e with the large displacement amount D1.

[0033] The positive terminal 15d of the positive conductor plate 16a is sandwiched between the abutted positive terminals 15d. The negative terminal 15e of the negative conductor plate 16b is sandwiched between the abutted negative terminals 15e. The positive conductor plate 16a and the negative conductor plate 16b are held in positions offset from each other in the left-right direction between the capacitor packs 15A and 15B. At this time, a left-right clearance S1 is formed between the conductor plates 16a and 16b.

[0034] As described above, the capacitor packs 15A and 15B of the embodiment comprise a capacitor body 15c having a planar plate surface 15c1, and plate terminals 15d and 15e having connection surfaces 15d3 and 15e3 parallel to the plate surface 15c1 to which mating components can be connected, and the connection surface 15d3 of the positive plate terminal 15d and the connection surface 15e3 of the negative plate terminal 15e are positioned offset from each other in the normal direction of the plate surface 15c1.

[0035] The capacitor assembly 14 of the embodiment includes capacitor packs 15A and 15B each including a capacitor body 15c having a flat board surface 15c1 and plate-like terminals 15d and 15e having connection surfaces 15d3 and 15e3 parallel to the board surface 15c1 to which mating components can be connected; a first conductor plate 16a having a plate shape parallel to the board surface 15c1 and connected to the connection surface 15d3 of the positive-electrode plate-like terminal 15d of the capacitor packs 15A and 15B; and a second conductor plate 16b that is plate-shaped and parallel to the first conductor plate 16a and is connected to the connection surface 15e3 of the negative-side plate terminal 15e of the capacitor packs 15A and 15B, and the connection surface 15d3 of the positive-side plate terminal 15d and the connection surface 15e3 of the negative-side plate terminal 15e are positioned so as to be offset from each other in the normal direction of the plate surface 15c1, and a gap S1 is formed between the first conductor plate 16a and the second conductor plate 16b in the normal direction of the plate surface 15c1.

[0036] According to this configuration, in capacitor packs 15A and 15B having plate-shaped terminals 15d and 15e, the connection surface 15d3 of the positive terminal 15d and the connection surface 15e3 of the negative terminal 15e are staggered. This allows flat conductor plates 16a and 16b parallel to the board surface 15c1 to be attached to the connection surfaces 15d3 and 15e3 of the positive and negative terminals 15d and 15e, respectively. This prevents the conductor plates 16a and 16b from protruding in the normal direction of the board surface 15c1, thereby enabling a more compact terminal connection structure. Furthermore, the positive and negative conductor plates 16a and 16b are fixed at different heights in the normal direction of the board surface 15c1, allowing a gap S1 to be defined between the conductor plates 16a and 16b. This allows the conductor plates 16a and 16b to be used as effective heat dissipation members, improving cooling performance. Furthermore, by providing wide conductive plates 16a and 16b along the board surfaces 15c1 of the capacitor packs 15A and 15B, it is possible to achieve low inductance.

[0037] In the capacitor assembly 14 of the embodiment, the capacitor packs 15A and 15B include a first capacitor pack 15A in which the connection surface 15d3 of the positive plate terminal 15d is positioned higher from the plate surface 15c1 by a specified amount (gap S1) than the connection surface 15e3 of the negative plate terminal 15e, and a second capacitor pack 15B in which the connection surface 15e3 of the negative plate terminal 15e is positioned higher from the plate surface 15c1 by a specified amount (gap S1) than the connection surface 15d3 of the positive plate terminal 15d. The first capacitor pack 15A and the second capacitor pack 15B are joined by facing their plate surfaces 15c1 and butting their positive and negative connection surfaces 15d3 together.

[0038] According to this configuration, a first capacitor pack 15A, in which the connection surface 15d3 of the positive terminal 15d is located higher than the connection surface 15e3 of the negative terminal 15e, and a second capacitor pack 15B, in which the connection surface 15e3 of the negative terminal 15e is located higher than the connection surface 15d3 of the positive terminal 15d, are arranged with their plate surfaces 15c1 facing each other. The higher-positioned positive terminal 15d butts against the lower-positioned positive terminal 15d, and the lower-positioned negative terminal 15e butts against the higher-positioned negative terminal 15e. This allows the conductor plate 16a, which is aligned with the butting position of the positive terminal 15d, and the conductor plate 16b, which is aligned with the butting position of the negative terminal 15e, to be held between the capacitor packs 15A and 15B. By placing the planar conductor plates 16a and 16b between the capacitor packs 15A and 15B, the terminal connection structure can be made more compact. In this case, a gap S1 can be provided between the conductive plates 16a and 16b, allowing the conductive plates 16a and 16b to be used as effective heat dissipation members, thereby improving cooling performance. Also, by providing wide conductive plates 16a and 16b along the board surfaces 15c1 of the capacitor packs 15A and 15B, low inductance can be achieved.

[0039] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims.

[0040] 1...DAB circuit, 2...power conversion device, 3A...input side capacitor, 3B...output side capacitor, 14...capacitor assembly, 15A...first capacitor pack (capacitor), 15B...second capacitor pack (capacitor), 15c...capacitor body, 15c1...side surface (disk surface), 15d...positive terminal (plate-shaped terminal), 15d3...connection surface, 15e...negative terminal (plate-shaped terminal), 15e3...connection surface, 16a...first conductor plate, 16b...second conductor plate, S1...gap

Claims

1. The capacitor comprises a capacitor body having a flat surface and a plate-shaped terminal on a connection surface parallel to the surface, to which a mating component can be connected. The connection surface of the plate-shaped terminal on the positive side and the connection surface of the plate-shaped terminal on the negative side are positioned offset from each other in the direction normal to the panel surface. The plate-shaped terminal comprises an upright portion extending from the surface in the direction normal to the surface, and a connecting portion extending from the tip of the upright portion, bending outward in a side view from the direction normal to the surface, and forming the connecting surface. The entire connection portion, in the side view, does not protrude beyond the outer edge of the capacitor body and is positioned to overlap with the capacitor body. A capacitor in which a notch is formed in the connection portion, which opens outwards toward the outside of the capacitor body when viewed from the side.

2. A capacitor pack comprising a capacitor body having a flat surface, and a plate-shaped terminal on a connection surface parallel to the surface that can connect to a mating component, A first conductor plate, which is plate-shaped and parallel to the aforementioned surface, is connected to the connection surface of the plate-shaped terminal on the positive side of the capacitor pack. It comprises a second conductor plate that is plate-shaped and parallel to the aforementioned surface, and is connected to the connection surface of the plate-shaped terminal on the negative side of the capacitor pack, The connection surface of the positive electrode plate-shaped terminal and the connection surface of the negative electrode plate-shaped terminal are positioned offset from each other in the direction normal to the panel surface. A gap is formed between the first conductor plate and the second conductor plate in the direction normal to the surface of the board. The plate-shaped terminal comprises an upright portion extending from the surface in the direction normal to the surface, and a connecting portion extending from the tip of the upright portion, bending outward in a side view from the direction normal to the surface, and forming the connecting surface. The entire connection portion, in the side view, does not protrude beyond the outer edge of the capacitor body and is positioned to overlap with the capacitor body. A capacitor assembly having a notch formed in the connection portion that opens outwards toward the outside of the capacitor body when viewed from the side.

3. The capacitor pack comprises a first capacitor pack in which the connection surface of the positive electrode plate terminal is located a specified amount higher from the panel surface than the connection surface of the negative electrode plate terminal, and a second capacitor pack in which the connection surface of the negative electrode plate terminal is located a specified amount higher from the panel surface than the connection surface of the positive electrode plate terminal. The capacitor assembly according to claim 2, wherein the first capacitor pack and the second capacitor pack are joined by facing each other with their disc surfaces facing each other, abutting the positive electrode connection surfaces together, and abutting the negative electrode connection surfaces together.

4. When the first capacitor pack and the second capacitor pack are arranged with their surfaces facing each other, the conductor terminals of the first conductor plate are sandwiched between the positive terminal connection surfaces, and the conductor terminals of the second conductor plate are sandwiched between the negative terminal connection surfaces. The capacitor assembly according to claim 3, wherein the conductor terminal has a notch formed therein that opens outwards toward the outside of the capacitor body when viewed from the side.