JP2013131589A - Winding for transformer, transformer, and power converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a winding for a transformer having a high degree of coupling with a simple coil configuration, and to provide a transformer including the winding, and a power converter including the transformer.SOLUTION: A transformer 1 includes a winding 3 laminating a plurality of unit laminates 2 formed by laminating a primary coil 5 that is formed by winding a thin planar rectangular wire spirally two turns, and a secondary coil 6 of one layer and one turn consisting of a flat metal plate material, and a core 4 of magnetic material to which the winding 3 is attached. The primary coil 5 and the secondary coil 6 of the unit laminate 2 are laminated while being arranged along the rectangular wire of the primary coil 5 so that half turn of the secondary coil 6 is sandwiched between the first turn and the second turn of the primary coil 5.

Description

  The present invention relates to a transformer winding portion used when realizing an insulating function, a transformer including the winding portion, and a power conversion device including the transformer to convert DC power into desired DC power. .

  In the conventional transformer, a plurality of unit coil plates consisting of a flat plate coil portion of one turn and connection portions formed at both ends of the plate coil portion are stacked, and the connection portions of the unit coil plates are sequentially linked to each other. The coils Ca and Cb are connected to each other, and the transformer is formed by stacking the coils Ca and Cb, whereby the transformer is reduced in size and thickness. Then, another coil Cb is interposed in the gap between the unit coil plates in the coil Ca to increase the degree of coupling between the primary side and the secondary side of the transformer T (see, for example, Patent Document 1).

JP-A-5-335158

In the conventional transformer, the coil Cb is sandwiched between the unit coil plates of the coil Ca, so that the winding structure is a so-called sandwich structure, and the degree of coupling between the primary side and the secondary side is increased. However, in order to maintain the interval between the unit coil plates of the coil Ca, a separator is interposed between the unit coil plates and the unit Ca is coupled by a fixing screw and a nut. There is also a problem that the connection of the coils is complicated, such as electrical connection between the unit coil plates of the coil Ca.
The present invention has been made to solve the above-described problems, and an object thereof is to obtain a transformer having a high degree of coupling with a simple coil configuration.

  The transformer winding portion according to the present invention is formed by laminating a first coil having one or more turns and a second coil having one turn, and at least a part of the second coil is the first coil. A unit laminate body disposed along the winding of the first coil so as to be sandwiched between the lamination direction of the first end and the last end of the first coil.

  The transformer according to the present invention is formed by laminating a first coil having one or more turns and a second coil having one turn, and at least a part of the second coil has a start end and a terminal end of the first coil. A winding portion having a unit laminated body disposed along the winding of the first coil so as to be sandwiched between the winding directions of the first coil, and a magnetic core portion to which the winding portion is attached. ing.

  The power conversion device according to the present invention smoothes the output of the transformer, the switching element connected in series to the primary coil of the transformer, the rectifier circuit connected to the secondary coil of the transformer, and the rectifier circuit. And a smoothing circuit for converting a DC power input by on / off control of the switching element into a DC power of a desired voltage and outputting the DC power, the primary coil or the secondary side of the transformer One of the coils is a first coil, the other is a second coil, and the transformer is formed by laminating the first coil having one or more turns and the second coil having one turn. A unit laminated body arranged along the winding of the first coil so that at least a part of the second coil is sandwiched between the starting and terminating directions of the first coil; A winding section, the winding section and a core portion of the magnetic body to be attached.

  The transformer winding portion according to the present invention is formed by laminating a first coil having one or more turns and a second coil having one turn, and at least a part of the second coil is the first coil. A unit laminate body disposed along the winding of the first coil so as to be sandwiched between the lamination direction of the first end and the last end of the first coil. For this reason, the winding part for transformers with a high coupling degree between the first coil and the second coil can be obtained with a simple configuration with a small number of parts.

  The transformer according to the present invention is formed by laminating a first coil having one or more turns and a second coil having one turn, and at least a part of the second coil has a start end and a terminal end of the first coil. A winding portion having a unit laminated body disposed along the winding of the first coil so as to be sandwiched between the winding directions of the first coil, and a magnetic core portion to which the winding portion is attached. ing. Therefore, a transformer having a high degree of coupling between the first coil and the second coil can be obtained with a simple configuration having a small number of parts.

  The power conversion device according to the present invention smoothes the output of the transformer, the switching element connected in series to the primary coil of the transformer, the rectifier circuit connected to the secondary coil of the transformer, and the rectifier circuit. And a smoothing circuit for converting a DC power input by on / off control of the switching element into a DC power of a desired voltage and outputting the DC power, the primary coil or the secondary side of the transformer One of the coils is a first coil, the other is a second coil, and the transformer is formed by laminating the first coil having one or more turns and the second coil having one turn. A unit laminated body arranged along the winding of the first coil so that at least a part of the second coil is sandwiched between the starting and terminating directions of the first coil; A winding section, the winding section and a core portion of the magnetic body to be attached. For this reason, a transformer with a high coupling degree between the first coil and the second coil can be obtained with a simple configuration with a small number of parts, and the efficiency of the power converter can be increased.

It is a disassembled perspective view for demonstrating the structure of the trans | transformer in Embodiment 1 of this invention. It is a figure for demonstrating the structure of the unit laminated body in Embodiment 1 of this invention. It is a figure for demonstrating the connection method between the unit laminated bodies of the coil | winding part in Embodiment 1 of this invention. It is a disassembled perspective view for demonstrating the structure of the trans | transformer in Embodiment 2 of this invention. It is a disassembled perspective view for demonstrating the structure of the trans | transformer in Embodiment 3 of this invention. It is a figure for demonstrating the structure of the unit laminated body in Embodiment 3 of this invention. It is a disassembled perspective view for demonstrating the structure of the trans | transformer in Embodiment 4 of this invention. It is a figure which shows the circuit structure of the vehicle-mounted power supply device in Embodiment 5 of this invention.

Embodiment 1 FIG.
Hereinafter, the transformer according to the first embodiment of the present invention will be described. 1 is an exploded perspective view for explaining the structure of a transformer according to Embodiment 1 of the present invention, FIG. 2 is a view for explaining the structure of a unit laminated body forming a winding portion of the transformer, and FIG. It is a figure for demonstrating the connection method between the unit laminated bodies of a line part.
As shown in FIG. 1, the transformer 1 includes a winding part 3 formed by laminating a plurality of unit laminates 2 and a magnetic core part 4 to which the winding part 3 is attached.

First, the configuration of the unit laminate body 2 will be described in detail. As shown in FIG. 2, the unit laminate 2 includes a primary coil 5 as a first coil and a secondary coil 6 as a second coil.
The primary side coil 5 is formed by winding a thin plate-like winding spirally into a substantially circular shape for two turns. Here, as the thin plate-like winding, a rectangular wire in which a wire made of a conductor such as copper or aluminum and having a substantially rectangular cross section is coated with insulation is used. The starting end portion and the terminating end portion of the primary side coil 5 extend outward from the circular portion of the primary side coil 5 to form connection portions 51 and 52.
The secondary coil 6 is composed of a flat plate winding formed by, for example, punching a flat plate-like metal plate material such as a copper plate into a desired shape, and the flat plate winding has an insulation coating. The secondary side coil 6 is composed of one turn and one turn, and its planar shape is formed to be substantially the same as the planar shape of the primary side coil 5. As with the primary side coil 5, both end portions of the secondary side coil 6 extend outward from the circular portion of the secondary side coil 6 to form connection portions 61 and 62.
The unit laminated body 2 is formed by concentrically laminating the primary side coil 5 and the secondary side coil 6 as described above. As shown in FIG. The side coil 5 is laminated by being disposed along the rectangular wire of the primary side coil 5 so as to be sandwiched between the first turn and the second turn of the side coil 5.

The winding part 3 is configured by laminating a plurality of unit laminated bodies 2, here two. The unit laminates 2 are laminated in the same direction, and the connection parts 61 and 62 of the secondary coil 6 are in the same direction so that the connection parts 51 and 52 of the primary coil 5 of each unit laminate 2 are in the same direction. It is piled up to become. The primary side coils 5 of each unit laminate body 2 are connected in series, the secondary side coils 6 are connected in parallel, and the winding ratio of the total primary side coil and the total secondary side coil as the whole winding part 3 is 4: 1. It becomes. Moreover, since the secondary side coils 6 are connected in parallel, the sectional area of the total secondary side coil is substantially twice the sectional area of the secondary side coil 6.
In the first embodiment, the winding part 3 is composed of two unit laminated bodies 2, but the number of unit laminated bodies 2 constituting the winding part 3 is not limited to this. Of course, three or more unit laminate bodies 2 may be stacked to form a winding portion, or one unit laminate body 2 may be used as a winding portion.

  The core part 4 is composed of a pair of core pieces 41. The core piece 41 is a magnetic body, and its cross-sectional shape is a substantially E shape. Specifically, the flat plate portion 42, the substantially cylindrical main leg portion 43 protruding from the center of the flat plate portion 42, and the side leg portions 44 disposed on both sides of the main leg portion 43 and protruding from the end portions of the flat plate portion 42, Consists of. The main leg portion 43 of each core piece 41 is inserted into the central portion of the winding portion 3 from the upper and lower sides in the stacking direction, and the end surfaces of the main leg portion 43 and the side leg portion 44 are brought into contact with each other so 3 is mounted. In addition, the structure of the core part 4 is not restricted to this, What is necessary is just to set it as a suitable structure according to a use etc. For example, the core portion may be configured by combining one of the core pieces with a substantially I-shaped cross section and the other with a substantially E-shaped cross section. In the first embodiment, since the winding of the winding part 3 is wound in a substantially circular shape, the main leg part of the core piece is cylindrical, but for example, the primary side coil and the secondary side coil of the winding part May be wound in a substantially quadrangular or elliptical shape, and in this case, the main leg portion of the core piece may be formed into a substantially prismatic or elliptical cylindrical shape in accordance with the winding shape of the winding portion.

Here, when there are two or more unit laminated bodies 2 constituting the winding part 3, it is necessary to electrically connect the primary side coils 5 and the secondary side coils 6 of each unit laminated body 2 to each other. An example of this specific connection method will be described in detail with reference to FIG.
FIG. 3 shows a case where the number of unit laminated bodies 2 constituting the winding part 3 is three. For convenience of explanation, an X is added to the end of each component of the unit laminate 2 arranged on the upper side in the stacking direction, and each component of the unit laminate 2 arranged at the center in the stacking direction is placed behind the reference. Each unit laminate body 2 is distinguished from each other by attaching a Y after the symbol and adding Z after the reference numeral for each component of the unit laminate body 2 arranged on the lower side in the stacking direction.

The primary side coils 5X, 5Y, and 5Z are connected in series. That is, the connection part 51X of the upper primary coil 5X and the connection part 52Y of the central primary coil 5Y are connected, and the connection part 51Y of the central primary coil 5Y and the connection part 52Z of the lower primary coil 5Z. And connect. Specifically, if the connection portion 51X and the connection portion 52Y are connected, the shape of each connection portion 51X and 52Y is previously set, the end portion of the connection portion 51X is set to the connection portion 52Y side, and the end portion of the connection portion 52Y is set. It is formed in a wide shape widened to the connection part 51X side. And the connection part 51X and the connection part 52Y can be connected by ultrasonically connecting or soldering the location where the part formed in the wide shape of each connection part 51X and 52Y mutually overlaps. The specific method of electrical connection is not limited to this, and any method may be used as long as the primary side coils 5X, 5Y, and 5Z can be connected in series.
In this way, by connecting the three primary coils 5X, 5Y, and 5Z wound in two turns each in series, the winding unit 3 as a whole forms a total primary coil of 6 turns.

Secondary coils 6X, 6Y, 6Z are connected in parallel. That is, the connection part 61X of the upper secondary coil 6X, the connection part 61Y of the central secondary coil 6Y, and the connection part 61Z of the lower secondary coil 6Z are connected, and the upper secondary coil 6X. The connecting portion 62X, the connecting portion 62Y of the central secondary coil 6Y, and the connecting portion 62Z of the lower secondary coil 6Z are connected. Specifically, if the connection portion 61X, the connection portion 61Y, and the connection portion 61Z are connected, the connection portions 61X, 61Y, and 61Z are overlapped and the end portions thereof are fixed with a spacer or the like. The specific method of electrical connection is not limited to this, and any method may be used as long as the secondary coils 6X, 6Y, and 6Z can be connected in parallel.
Thus, by connecting the secondary side coils 6X, 6Y, 6Z of 1 turn in parallel, the winding part 3 as a whole forms a total secondary side coil of 1 turn, and its sectional area is substantially The secondary coils 6X, 6Y, and 6Z are combined in cross-sectional area.

  As described above, in the first embodiment, the primary side coil 5 is sandwiched between the first turn and the second turn of the primary side coil 5 for the half turn of the secondary side coil 6 of the unit laminate body 2. The unit laminated body 2 is configured by being arranged along the rectangular wire of the above structure, so that a so-called winding sandwich structure is realized without dividing one primary coil 5, that is, the primary coil 5 into two parts. Can do. Therefore, the transformer 1 having a high degree of coupling between the primary side coil 5 and the secondary side coil 6 can be obtained, and the conversion efficiency can be improved by preventing the loss of the transformer. In order to realize the sandwich structure, the primary coil 5 is not divided into two parts. Therefore, in the unit laminate 2, a fixing member for electrical fixation of the primary coils 5 and electrical connection are provided. Therefore, the number of components is small because one member for the primary side coil 5 itself is sufficient. Further, the unit laminated body 2 has a very simple configuration in which the secondary coil 6 is simply sandwiched between the primary coil 5.

  In the first embodiment, the primary coil 5 is formed of a thin flat wire, the secondary coil 6 is formed of a thin flat coil, and the planar shapes of the coils 5 and 6 are the same. The primary side coil 5 and the secondary side coil 6 can be easily stacked, and a gap or the like does not occur between the primary side coil 5 and the secondary side coil 6, so that the degree of coupling can be further improved. In addition, since the primary side coil 5 and the secondary side coil 6 are formed by thin plate-like windings, for example, the space factor is higher than that in the case of using a copper wire or the like as the wire for the primary side coil and the secondary side coil. As a result, the transformer performance can be improved and the entire transformer can be made thinner.

In the first embodiment, the winding part 3 is formed by laminating a plurality of unit laminated bodies 2, the primary side coils 5 in the winding part 3 are connected in series, and the secondary side coils 6 are connected to each other. Are connected in parallel, the turns ratio of the total primary coil and the total secondary coil as the entire winding section 3 can be easily increased, and the cross sectional area of the total secondary coil can be substantially increased. can do.
Here, in the field of electric vehicles such as hybrid vehicles and electric vehicles, a transformer is used as a part of a power conversion device inserted between a high voltage battery and a low voltage battery having a large voltage difference. The input / output step-down ratio is large, and it is necessary to be able to cope with a large secondary current. A large input / output step-down ratio of the transformer requires that the turns ratio, which is the ratio of the turns of the primary coil and the secondary coil of the transformer, be increased. Moreover, in order to cope with the secondary side large current, it is necessary to increase the cross-sectional area of the winding of the secondary side coil.
As described above, the transformer 1 according to the first embodiment can easily increase the turns ratio of the total primary side coil and the total secondary side coil as the entire winding portion 3 and can substantially increase the cross-sectional area of the secondary side coil. Therefore, the input / output step-down ratio is large and the secondary side large current can be accommodated, which is preferable in the field of electric vehicles.
If the turn ratio between the primary side coil and the secondary side coil is fixed, a large current flows in the primary side coil when a large current flows in the secondary side coil. It is necessary to secure. In the transformer 1 according to the first embodiment, the primary coil is a rectangular wire, and has a higher space factor than a case where, for example, a round copper wire or the like is used.
As a matter of course, the field of use of the transformer 1 of the first embodiment is not limited to the field of electric vehicles, and can be applied in various fields.

In the first embodiment, the half turn of the secondary coil 6 of the unit laminate 2 is sandwiched between the first turn and the second turn of the primary coil 5, but this is not necessarily limited thereto. What is necessary is just to arrange | position so that at least one part of the secondary side coil 6 may be pinched | interposed between the primary side coils 5.
For example, from the state of the unit laminate body 2 in FIG. 1, the secondary side coil 6 is rotated clockwise 180 degrees in the drawing along the winding of the primary side coil 5, that is, the connection portion of the primary side coil 5. 51, 52 and the connecting portions 61, 62 of the secondary side coil 6 are substantially overlapped with each other so that all turns of the secondary side coil 6 are between the first turn and the second turn of the primary side coil 5. You may laminate | stack so that a part may be pinched | interposed. Such a configuration is preferable because the entire secondary coil 6 is sandwiched between the primary coils 5 and the degree of coupling is increased. In this case, since the positions of the connection parts 51 and 52 of the primary coil 5 in the unit laminate and the connection parts 61 and 62 of the secondary coil 6 overlap, The connection between the side coils 6 may be appropriately devised so that they do not contact each other.

In the first embodiment, the number of turns of the primary coil 5 is set to two. However, the number of turns may be one or more, and may be set as appropriate according to the specifications of the transformer.
If the number of turns of the primary coil is one turn, if the secondary coil is arranged so that a part of the secondary coil is sandwiched between the start and end of the primary coil, the secondary coil is simply connected to the secondary coil. The effect of improving the degree of coupling can be obtained compared to the case where the secondary coil is laminated. Here, for example, in the case of the primary side coil 5 in FIG. 1, the starting end and the end point of the primary side coil indicate the root portions of the connecting portions 51 and 52 (both ends of the circular portion of the primary side coil 5). When a part of the secondary coil is sandwiched between the stacking direction of the start end and the end, the secondary coil is between the stacking direction of the surface including the start end and the surface including the end of the primary coil 5. It means that at least a part of is sandwiched. Preferably, the primary side coil and the secondary side coil are arranged so that the half turn of the primary side coil is on the upper side of the secondary side coil and the remaining half turn of the primary side coil is on the lower side of the secondary side coil. It is good to laminate.
If the number of turns of the primary side coil is 3 turns, a half turn of the secondary side coil is sandwiched between the first turn and the second turn of the primary side coil, and the second turn and 3 of the primary side coil are sandwiched. It is good to laminate | stack so that the remaining half turn of a secondary side coil may be pinched | interposed between the turns. Since the entire secondary side coil is sandwiched between the primary side coils, the degree of coupling is high, and the position of the primary side coil connecting portion and the secondary side coil connecting portion is shifted by 180 degrees, so the primary side coil in the winding portion It is easy to connect the secondary coils to each other. Of course, the arrangement position of the secondary side coil is not limited to this, and at least a part of the secondary side coil is arranged so as to be sandwiched between the lamination direction of the start end and the termination end of the primary side coil. The degree of coupling can be improved.

  In the first embodiment, the primary side coil is formed of a rectangular wire and the secondary side coil is formed of a flat plate winding. However, the type of winding forming each coil is not necessarily limited to this. For example, when the primary side coil is formed by a flat wire and the secondary side coil is formed by a rectangular wire, when both the primary side coil and the secondary side coil are formed by a rectangular wire, or both the primary side coil and the secondary side coil are flat plates. The case where it forms with a coil | winding etc. can also be considered. Further, for example, a round wire having a substantially circular cross section may be used as the winding forming each coil, and the stacking direction of the starting end and the terminating end of the primary coil is whatever the shape of the winding. If it arrange | positions so that a part of secondary side coil may be pinched | interposed in between, a coupling degree can be improved rather than the case where a primary side coil and a secondary side coil are simply piled up.

  In the first embodiment, the secondary coil 6 constituting the unit laminate 2 is a single plate winding of one turn per layer, but a plurality of secondary coils 6 having such a shape are provided. Those which are stacked and connected in parallel may be used as the secondary coil, and the substantial conductor cross-sectional area of the secondary coil constituting the unit laminate 2 can be increased.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described. FIG. 4 is an exploded perspective view for illustrating the configuration of the transformer according to Embodiment 2 of the present invention. The transformer 1A of the second embodiment is partially different from the transformer 1 of the first embodiment in the configuration of the winding part. In the first embodiment, the winding part 3 is formed by laminating two unit laminated bodies 2, but the winding part 3A of the second embodiment is composed of the unit laminated body 2 and the third coil. A single secondary coil 6 is alternately stacked. Other configurations are the same as those in the first embodiment, and the same reference numerals are given and the description thereof is omitted.

  As shown in FIG. 4, the winding portion 3 </ b> A of the transformer 1 </ b> A is formed by sequentially laminating the unit laminated body 2, the single secondary coil 6, and the unit laminated body 2. The upper unit laminate 2 in the figure and the primary coil 5 of the lower unit laminate 2 in the figure are connected in series, and the upper unit laminate 2 in the figure and the lower unit laminate 2 in the figure 2 Three secondary coils 6 are connected in parallel, including two secondary coils 6 and one secondary coil 6 sandwiched between the upper and lower unit laminates 2. Therefore, the turns ratio of the total primary coil and the total secondary coil as the entire winding portion 3A is 4: 1, and the cross sectional area of the total secondary coil is three times the cross sectional area of the secondary coil 6. Become.

  As described above, in the second embodiment, the winding portion 3A is formed by alternately laminating the unit laminate 2 and the single secondary coil 6, so that the winding portion 3A as a whole is formed. The conductor cross-sectional area of the total secondary coil can be increased. Therefore, in addition to the effect of the first embodiment, the transformer 1A of the second embodiment can cope with a further large secondary current by reducing the resistance of the total secondary coil of the winding portion 3A. Have

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described. FIG. 5 is an exploded perspective view for explaining the structure of the transformer according to Embodiment 3 of the present invention, and FIG. 6 is a view for explaining the structure of the unit laminate body forming the winding portion of the transformer. The transformer 1B of the third embodiment is different from the transformer 1 of the first embodiment in the configuration of the primary side coil. Other configurations are the same as those in the first embodiment, and the same reference numerals are given and the description thereof is omitted.

As shown in FIGS. 5 and 6, the primary coil 5 </ b> B constituting the unit laminated body 2 </ b> B of the third embodiment is composed of a plurality of rectangular wires having the same shape, here two rectangular wires 50 </ b> A and 50 </ b> B, The two rectangular wires 50A and 50B are arranged side by side in parallel and are formed by winding a thin plate-like winding body into a substantially circular shape for two turns. Therefore, the winding outer diameter R1 of the rectangular wire 50A arranged on the inner side and the winding outer diameter R2 of the rectangular wire 50B arranged on the outer side are different by two widths of the flat wire 50B. Both ends of the flat wires 50A and 50B extend outward from the circular portion, the flat wire 50A forms the connecting portions 51A and 52A, and the flat wire 50B forms the connecting portions 51B and 52B. The rectangular wires 50A and 50B are electrically connected in parallel to each other.
The planar shape of the primary side coil 5B composed of the rectangular wires 50A and 50B is the same as that of the primary side coil 5 of the first embodiment, and a part of the secondary side coil 6 is the first turn and 2 of the primary side coil 5B. The unit laminated body 2B is configured by being sandwiched and stacked between the turns. Winding portion 3B is formed by laminating two unit laminated bodies 2B, and the electrical connection between primary side coils 5B of each unit laminated body 2B is a series connection as in the first embodiment, and a secondary side coil. The electrical connection between the six is also in parallel connection as in the first embodiment. Therefore, the turn ratio of the total primary coil and the total secondary coil as the entire winding portion 3B is 4: 1, and the cross-sectional area of the total secondary coil is substantially equal to the cross-sectional area of the secondary coil 6. Doubled.

Here, a preferable shape of the flat wire will be described.
When a high-frequency current flows through a conductor forming a flat wire or the like, it is generally known that a phenomenon called a skin effect occurs in which a high-frequency current does not flow evenly in the cross section of the conductor but flows closer to the surface. Therefore, when a high-frequency current flows through a flat wire, a flat wire having the same cross-sectional area can flow a current more efficiently when the aspect ratio (the width / thickness of the flat wire) is large. That is, when the skin effect is taken into consideration, the shape of the flat wire is preferably as thin as possible.
On the other hand, a flat wire has a manufacturing limit that can be spirally wound into a substantially circular shape. The production limit can be expressed by the aspect ratio, and the cross-sectional shape of the rectangular wire must be set so as to be less than the aspect ratio of the production limit. Therefore, if the shape of the flat wire is made too thin in consideration of the skin effect, the aspect ratio of the production limit will be exceeded. The production limit aspect ratio differs depending on the rectangular wire, but the production limit aspect ratio of the rectangular wire used in the third embodiment is, for example, 10.
In the third embodiment, when the cross-sectional shape of the rectangular wires 50A and 50B is set to an aspect ratio of 10, which is an aspect ratio of the production limit, the primary coil 5B has the rectangular wires 50A and 50B having an aspect ratio of 10 arranged in parallel. Therefore, the winding body in which the rectangular wires 50A and 50B are combined is apparently a thin winding body having an aspect ratio of 20.

  As described above, in the third embodiment, the primary side coil 5B constituting the unit laminate body 2B is formed by a thin plate-like winding body formed by arranging two rectangular wires 50A and 50B side by side in parallel. It is composed. Therefore, a thin primary coil 5B having a large aspect ratio can be obtained as a whole of the winding body without exceeding the production limit aspect ratio of each of the rectangular wires 50A and 50B. Therefore, in the third embodiment, in addition to the effect of the first embodiment, the influence of the skin effect of the primary side coil 5B can be suppressed and the high frequency current can be efficiently flowed. be able to.

Embodiment 4 FIG.
Next, a fourth embodiment of the present invention will be described. In the fourth embodiment, the unit laminate body 2B of the third embodiment is applied to the configuration of the second embodiment. The description of the fourth embodiment will be described below in comparison with the third embodiment.
FIG. 7 is an exploded perspective view for explaining the structure of the transformer according to the fourth embodiment of the present invention. The structure of the winding part is different from that of the transformer 1B of the third embodiment. In the third embodiment, the winding portion 3B is formed by laminating two unit laminated bodies 2B. However, the winding portion 3C of the fourth embodiment includes the unit laminated body 2B and the third coil. A single secondary coil 6 is alternately stacked. Other configurations are the same as those in the third embodiment, and the same reference numerals are given and the description thereof is omitted.

  As shown in FIG. 7, the winding portion 3C of the transformer 1C is formed by laminating a unit laminate 2B, a single secondary coil 6, and a unit laminate 2B in this order. In the figure, the upper unit laminate 2B and the lower unit laminate 2B primary coils 5B are connected in series, the two secondary coils 6 of the upper and lower unit laminates 2B, and the unit laminate 2B. A total of three secondary coils 6 are connected in parallel with one secondary coil 6 sandwiched between them. Therefore, the turn ratio of the total primary coil and the total secondary coil as the entire winding portion 3C is 4: 1, and the cross-sectional area of the total secondary coil is three times the cross-sectional area of the secondary coil 6. Become.

  As described above, in Embodiment 4, the winding portion 3C is formed by alternately laminating the unit laminated body 2B and the single secondary coil 6, so that the winding portion 3C as a whole is formed. The conductor cross-sectional area of the total secondary coil can be increased. Therefore, in addition to the effect of the third embodiment, the transformer 1C of the fourth embodiment can cope with a further large secondary current by reducing the resistance of the total secondary coil of the winding portion 3C. Have

Embodiment 5 FIG.
Next, a fifth embodiment of the present invention will be described. FIG. 8 is a diagram showing a circuit configuration of an in-vehicle power supply device according to Embodiment 5 of the present invention. The in-vehicle power supply device 7 includes a high voltage battery 8 for driving a traveling motor of the electric vehicle, and a power conversion device 10 that steps down an input voltage from the high voltage battery 8 to generate an output voltage and supplies power to the load 9. Yes.
The power conversion device 10 includes a voltage conversion transformer 1 described in the first embodiment and a MOSFET 12 (Metal-Oxide-Semiconductor-Field-Effect Transistor) as a switching element connected in series to the primary coil 50 of the transformer 1. ), A rectifier circuit 13 connected to the secondary coil 60 of the transformer 1, a smoothing circuit 14 that smoothes the voltage rectified by the rectifier circuit 13, and a control circuit 15 that controls on / off of the MOSFET 12. ing. The high-voltage battery 8 is connected to the DC input terminals 11A and 11B of the power converter 10, and the load 9 is connected to the DC output terminals 16A and 16B. The power conversion device 10 adjusts the output DC voltage output from the smoothing circuit 14 by changing the input DC voltage from the high-voltage battery 8 to a high-frequency rectangular wave voltage by ON / OFF control of the MOSFET 12 by the control circuit 15.

  As described in the first embodiment, the transformer 1 has a total primary coil of 4 turns (hereinafter referred to as a primary coil 50) and a total secondary coil of 1 turn (hereinafter referred to as a coil) as a whole of the winding section 3. , A secondary coil 60), and a core portion 4 to which such a winding portion 3 is attached. The rectifier circuit 13 is composed of two diodes, a first rectifier diode 13A and a second rectifier diode 13B. The smoothing circuit 14 includes a smoothing inductor 14A and a smoothing capacitor 14B.

One end of the primary coil 50 of the transformer 1 is connected to the positive DC input terminal 11A, the other end of the primary coil 50 is connected to the drain terminal of the MOSFET 12, and the source terminal of the MOSFET 12 is connected to the negative DC input terminal 11B. Has been.
One end of the secondary coil 60 of the transformer 1 is connected to the anode terminal of the first rectifier diode 13A, and the cathode terminal of the first rectifier diode 13A is the cathode terminal of the second rectifier diode 13B and one end of the smoothing inductor 14A. Connected to. The other end of the smoothing inductor 14A is connected to one end of the smoothing capacitor 14B and the positive side DC output terminal 16A. The other end of the secondary side coil 60 of the transformer 1 is connected to the anode terminal of the second rectifier diode 13B, the other end of the smoothing capacitor 14B, and the negative side DC output terminal 16B.
The terminal 15A of the control circuit 15 is connected to the gate terminal of the MOSFET 12, the terminal 15B of the control circuit 15 is connected to the positive side DC output terminal 16A, and the terminal 15C of the control circuit 15 is connected to the negative side DC output terminal 16B. Then, the control circuit 15 generates an on / off signal for the MOSFET 12 based on the output voltage, which is the voltage of the smoothing capacitor 14B, and outputs it from the terminal 15A to the gate terminal of the MOSFET 12.

Next, the operation of the in-vehicle power supply device 7 will be described.
When the high voltage battery 8 is connected to the DC input terminals 11 </ b> A and 11 </ b> B, the MOSFET 12 is turned on / off under the control of the control circuit 15, and a rectangular wave voltage is applied to both ends of the primary coil 50 of the transformer 1. As a result, a voltage determined by the transformer turns ratio (4: 1 in the case of the transformer 1) is induced in the secondary coil 60 of the transformer 1. The induced voltage is rectified by the rectifier circuit 13, smoothed by the smoothing circuit 14, and power is supplied to the load 9.

  As described above, in the fifth embodiment, the power conversion device 10 includes the transformer 1 of the first embodiment. Therefore, the power conversion device 10 has the effects of the first embodiment and increases the efficiency of the power conversion device 10. Can be planned.

In the fifth embodiment, MOSFET 12 is used as the switching element, but the switching element is not limited to this. For example, a bipolar transistor, an insulated bipolar transistor (IGBT), a silicon carbide transistor, a silicon carbide MOSFET, or the like may be used as the switching element, and the same effect can be obtained.
In the fifth embodiment, the transformer 1 of the first embodiment is applied to the power conversion device 10 using a forward converter circuit, but the present invention is not limited to this. The transformer 1 can be applied to various converter circuits such as a flyback converter circuit, and the same effect can be obtained.
In the fifth embodiment, the full-wave rectifier circuit configuration is adopted as the secondary-side circuit configuration of the transformer 1, but the present invention is not limited to this. For example, a circuit configuration such as diode bridge rectification may be employed, and the same effect can be obtained. Further, although diode rectification using a diode element is employed as the rectifier circuit on the secondary side, the present invention is not limited to this. For example, synchronous rectification using a switching element may be employed, and the same effect can be obtained.
In the fifth embodiment, the case where the transformer 1 according to the first embodiment is applied to the power conversion device 10 has been described. However, the transformer according to the second to fourth embodiments may be applied. .

  It should be noted that within the scope of the present invention, the embodiments can be freely combined, or the embodiments can be appropriately modified or omitted.

1, 1A-1C transformer, 2, 2B unit laminate, 3, 3A-3C winding part,
4 Core part, 5, 5B Primary coil as the first coil,
6 Secondary coil as second coil, 10 power converter,
12 MOSFET as switching element, 13 rectifier circuit, 14 smoothing circuit,
15 Control circuit.

Claims (11)

A first coil having a turn number of 1 turn or more and a second coil having a turn number of 1 turn are stacked, and at least a part of the second coil is between the start and end of the first coil. A transformer winding portion including a unit laminate disposed along the winding of the first coil so as to be sandwiched. 2. The transformer winding portion according to claim 1, wherein the surfaces of the first coil and the second coil overlap with each other in substantially the same shape. 3. The transformer winding portion according to claim 1, wherein the first coil and the second coil are formed of a thin plate-like winding. 4. 4. The transformer winding part according to claim 3, wherein one or both of the first coil and the second coil is formed by a rectangular wire having a substantially rectangular cross section. 4. The transformer winding portion according to claim 3, wherein one or both of the first coil and the second coil are formed by a flat plate winding made of a flat plate material. 5. 4. The transformer winding portion according to claim 3, wherein the first coil is formed by a rectangular wire having a substantially rectangular cross section, and the second coil is formed by a flat plate winding made of a flat plate material. . 7. The transformer winding according to claim 4, wherein the first coil is formed by a thin plate-like winding body formed by arranging a plurality of the rectangular wires in parallel and connecting them in parallel. Line part. The plurality of unit laminates are laminated, the first coils of each unit laminate are connected in series, and the second coils of each unit laminate are connected in parallel. The transformer winding part according to claim 7. The unit laminated body includes a third coil having the same configuration as the second coil, the unit laminated body and the third coil are laminated, and the second coil and the third coil of the unit laminated body are laminated. The winding part for transformers according to any one of claims 1 to 8, wherein are connected in parallel. A first coil having a turn number of 1 turn or more and a second coil having a turn number of 1 turn are stacked, and at least a part of the second coil is between the start and end of the first coil. A winding part comprising a unit laminate disposed along the winding of the first coil so as to be sandwiched;
A transformer having a magnetic core portion on which the winding portion is mounted. A switching element connected in series to the primary coil of the transformer; a rectifier circuit connected to the secondary coil of the transformer; and a smoothing circuit that smoothes the output of the rectifier circuit; A power conversion device that converts DC power input by on / off control of the power into DC power of a desired voltage and outputs the power,
Either one of the primary coil or secondary coil of the transformer is a first coil and the other is a second coil.
The transformer is formed by laminating the first coil having one or more turns and the second coil having one turn, and at least a part of the second coil includes a starting end and a terminal end of the first coil. A winding portion provided with a unit laminated body arranged along the winding of the first coil so as to be sandwiched between the lamination directions of the magnetic core, and a magnetic core portion to which the winding portion is attached. The power converter characterized by the above-mentioned.

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