JP6160388B2 - Power converter - Google Patents

Description

  The present invention relates to a power conversion device including a transformer.

  A power conversion device such as a DC-DC converter has various electronic components such as a transformer, a semiconductor component, a capacitor, and a coil. The power converter is provided with a circuit board that constitutes a part of the control circuit and the main circuit. For example, Patent Document 1 discloses a power conversion device in which various electronic components including a transformer and a circuit board are provided in a case.

JP 2000-014149 A

  However, in the configuration of Patent Document 1, the axial direction of the coil provided in the transformer matches the normal direction of the circuit board. For this reason, the leakage magnetic flux from the transformer may affect the control circuit, the main circuit, and the like configured on the circuit board. Further, in order to reduce the influence of the leakage magnetic flux from the transformer, if a shielding object that shields the leakage magnetic flux is provided in the case, it is necessary to secure an installation space for the shielding object in the case. There is a problem that the apparatus becomes larger.

  The present invention has been made in view of such a background, and intends to provide a power converter capable of reducing the influence of leakage magnetic flux from a transformer on a circuit formed on a circuit board while being small. Is.

One aspect of the present invention includes a core formed by dividing a first core and a second core, a transformer having a primary coil and a secondary coil,
A primary circuit section connected to the primary coil side of the transformer;
A secondary circuit section connected to the secondary coil side of the transformer;
And at least one circuit board for connecting the primary side electronic component forming the primary side circuit part or the secondary side electronic component forming the secondary side circuit part, and
The axial direction of the primary coil and the secondary coil of the transformer is orthogonal to the normal direction of the at least one circuit board,
A laminate is formed by laminating the transformer and an electronic component including at least one of the primary side electronic component and the secondary side electronic component, and the lamination direction of the laminate is the axis of the transformer. It is arranged to be the same as the direction ,
In the power conversion device, the boundary between the first core and the second core is located at a position overlapping the at least one circuit board in the normal direction of the at least one circuit board. is there.

  In the power converter, the axial directions of the primary and secondary coils provided in the transformer are orthogonal to the normal direction of the circuit board. Therefore, it is possible to reduce the influence of the leakage magnetic flux from the transformer on the circuit formed on the circuit board. In addition, since it is not necessary to provide a shield that shields leakage magnetic flux from the transformer, a small power conversion device can be provided.

  As described above, according to the present invention, it is possible to provide a power converter that can reduce the influence of leakage magnetic flux from a transformer on a circuit formed on a circuit board while being small.

The top view of the power converter device in Example 1. FIG. II-II sectional view taken on the line in FIG. The cross-sectional enlarged view of the circuit board in a modification. The top view of the power converter device in Example 2. FIG.

  In the power conversion apparatus, at least one of a primary electronic component constituting the primary circuit unit and a secondary electronic component constituting the secondary circuit unit is connected to the circuit board. The primary side circuit unit includes an input filter circuit unit and a control circuit unit connected to the primary side electronic component. The secondary side circuit unit includes an output filter circuit unit and a control circuit unit connected to the secondary side electronic component. Examples of the electronic components constituting the input filter circuit section and the electronic components constituting the output filter circuit section include a capacitor and a coil.

Example 1
Examples of the power conversion device will be described with reference to FIGS.
As shown in FIG. 1, the power conversion device 1 of this example includes a transformer 2, a primary side circuit unit 3, a secondary side circuit unit 4, and circuit boards 71, 72, 73, and 74.
As shown in FIG. 2, the transformer 2 includes a primary coil 21 and a secondary coil 22.
The primary side circuit unit 3 is connected to the primary coil 21 side of the transformer 2.
The secondary circuit section 4 shown in FIG. 1 is connected to the secondary coil 22 side of the transformer 2 shown in FIG.
At least one of the circuit boards 71, 72, 73, and 74 shown in FIG. 1 is connected to the primary side electronic component 30 that forms the primary side circuit unit 3 or the secondary side electronic component 40 that forms the secondary side circuit unit 4. Has been. In this example, the circuit boards 71 and 72 are connected to the primary-side electronic component 30.
As shown in FIG. 2, the axial direction Z of the primary coil 21 and the secondary coil 22 of the transformer 2 is orthogonal to the normal direction of at least one circuit board. In this example, the normal direction Y of the circuit boards 71 and 72 and the axial direction Z of the transformer 2 are orthogonal to each other. Although not shown, the normal direction X of the circuit boards 73 and 74 is also orthogonal to the axial direction Z of the transformer 2.

  In this example, the power conversion device 1 is a DC-DC converter, which is mounted on, for example, an electric vehicle or a hybrid vehicle, and steps down high-voltage DC power from a DC power source to a low-voltage DC voltage and supplies it to an auxiliary battery. Used for.

  As shown in FIG. 2, the transformer 2 includes a coil 20 and a core 25. The core 25 is an EE type core formed by being divided into a first core 23 and a second core 24. By interposing the coil 20 between the first core 23 and the second core 24, the coil 25 20 is sandwiched between the cores 25 to form the transformer 2. As the coil 20, a primary coil 21 and a secondary coil 22 are provided. In the transformer 2, the primary coil 21 and the secondary coil 22 are disposed so as to be wound around the shaft portion 25 a of the core 25. As shown in FIG. 1, at both ends of the transformer 2 in the X direction, the primary coil 21 and a part of the secondary coil 22 are exposed to form coil exposed portions 20 a and 20 b.

  The primary side circuit unit 3 is formed by a primary side electronic component 30 formed of a semiconductor module incorporating a plurality of switching elements, and constitutes a switching circuit. As the switching element, for example, IGBT (insulated gate bipolar transistor) or MOSFET (MOS type field effect transistor) can be used. Note that the primary electronic component 30 is not necessarily a semiconductor module, and may be a discrete semiconductor component, for example.

  As shown in FIG. 2, the primary-side electronic component 30 constituting the primary-side circuit unit 3 is arranged in parallel to the inner bottom surface 80 a of the case 8. The transformer 2 is disposed on one main surface 30a (surface opposite to the inner bottom surface 80a) of the primary-side electronic component 30. Thereby, the primary side circuit unit 3 (primary side electronic component 30) and the transformer 2 are laminated to form the laminated body 11. In the multilayer body 11, the transformer 2 is provided such that the Z direction that is the axial direction thereof (that is, the standing direction of the shaft portion 25 a) is parallel to the normal direction of the main surface 30 a of the primary electronic component 30. Yes.

  The secondary side circuit unit 4 constitutes a rectifier circuit, and includes a secondary side electronic component 40 formed of a diode module incorporating a plurality of diodes. Note that the secondary electronic component 40 may be a semiconductor module including a plurality of MOSFETs. Further, the secondary electronic component 40 may be a discrete semiconductor component.

  As shown in FIG. 2, the control circuit unit 7 includes a control circuit (drive circuit) formed on a pair of circuit boards 71 and 72. The circuit boards 71 and 72 are erected with respect to the inner bottom surface 80 a of the case 8, and the normal directions Y of the circuit boards 71 and 72 are orthogonal to the axial direction Z of the transformer 2. The circuit boards 71 and 72 are disposed such that the main surfaces 71a and 72a face each other. The pair of circuit boards 71 and 72 are disposed so as to sandwich the stacked body 11, whereby the main surfaces of the circuit board 71 (first circuit board) and the circuit board 72 (second circuit board) are arranged. The laminate 11 having the transformer 2 is disposed between 71a and 72a. As shown in FIG. 1, the circuit boards 71 and 72 are disposed so as to be adjacent to the laminate 11.

  As shown in FIG. 1, the primary electronic component 30 is provided with a plurality of control terminals 31 and 32. Of the plurality of control terminals 31 and 32, the control terminal 31 positioned closest to the circuit board 71 and the circuit board 71 are connected via the bus bar 711. Similarly, among the plurality of control terminals 31 and 32, the control terminal 32 positioned closest to the circuit board 72 and the circuit board 72 are connected via the bus bar 721. Each switching element of the primary-side electronic component 30 is controlled by a signal current from the control circuit unit 7 so that the primary-side circuit unit 3 performs a switching operation.

  The input filter circuit unit 5 forms a smoothing circuit and includes a choke coil 51 as shown in FIG. The choke coil 51 is mounted on the second main surface 73 b of the circuit board 73. The circuit board 73 is provided with an input terminal 81 to which power is input.

  Further, a ground conductor layer 73 c is laminated on the circuit board 73 in parallel with the first main surface 73 a of the circuit board 73. That is, the circuit board 73 is constituted by, for example, a multilayer printed wiring board, and one of the plurality of conductor layers 73 is a ground conductor layer 73c. The ground conductor layer 73c is particularly preferably provided at a portion of the circuit board 73 that faces the transformer 2.

  The output filter circuit section 6 constitutes a smoothing circuit and includes a choke coil 61 as shown in FIG. The choke coil 61 is mounted on the second main surface 74 b of the circuit board 74. The circuit board 74 is provided with an output terminal 82 from which power is output.

  As shown in FIG. 1, the circuit boards 73 and 74 are arranged such that their main surfaces 73 a and 74 a face each other. The circuit board 73 (third circuit board) is disposed orthogonal to the circuit boards 71 and 72 (first circuit board, second circuit board). Similarly, the circuit board 74 (fourth circuit board) is also arranged orthogonal to the circuit boards 71 and 72 (first circuit board, second circuit board).

  As shown in FIG. 1, the stacked body 11 having the transformer 2 includes an arrangement region 10 surrounded by circuit boards 71 and 72 (first circuit board and second circuit board) and a circuit board 73 (third circuit board). It is arranged. In this example, the arrangement | positioning area | region 10 is enclosed from three sides, and is prescribed | regulated as a planar view rectangular area. The main surface 73 a of the circuit board 73 faces one coil exposed portion 20 a of the transformer 2.

  In the power conversion device 1 of this example, the DC power input to the power conversion device 1 via the input terminal 81 is smoothed in the input filter circuit unit 5 (smoothing circuit), and then the primary side circuit unit 3 (switching). Circuit) is converted into AC power and input to the transformer 2. The AC power input to the transformer 2 is stepped down and then rectified in the secondary side circuit unit 4 (rectifier circuit) to become DC power. Then, the DC power after the step-down is smoothed in the output filter circuit unit 6 (smoothing circuit) and then output through the output terminal 82.

  The circuit boards 71, 72, 73, 74 may be connected to each other or may be independent from each other. Further, even when they are connected to each other, their circuits may be electrically connected or may not be electrically connected.

Next, the function and effect of this example will be described.
According to the power conversion device 1 of this example, the axial direction Z of the primary coil 21 and the secondary coil 22 provided in the transformer 2, and the normal direction Y of the circuit boards 71 and 72 connected to the primary-side electronic component 30. Are orthogonal. Therefore, the influence of the leakage magnetic flux from the transformer 2 on the circuit (control circuit unit 7) formed on the circuit boards 71 and 72 can be reduced. Further, the axial direction Z of the primary coil 21 and the secondary coil 22 provided in the transformer 2 and the normal direction X of the circuit boards 73 and 74 are orthogonal to each other. Therefore, the influence of leakage magnetic flux from the transformer 2 on the circuit (input filter circuit unit 5) formed on the circuit board 73 and the circuit (output filter circuit unit 6) formed on the circuit board 74 can be reduced. it can. Thereby, since it is not necessary to provide the shielding object which shields the leakage magnetic flux from the transformer 2 in the case 8, it can be set as the small-sized power converter device 1. FIG.

  Moreover, in the power converter device 1 of this example, a pair of circuit boards 71 and 72 are arrange | positioned with the mutual main surfaces 71a and 72a facing each other. Therefore, the main surfaces 71a and 72a of the pair of circuit boards 71 and 72 are not located on the same plane, and when the circuit boards 71 and 72 are arranged side by side in the spreading direction, or on one circuit board. Compared with a case where necessary circuits are placed and arranged, it is possible to suppress an increase in the projected area in a specific direction for the entire apparatus. As a result, it is possible to suppress the physique of the power conversion device 1 from increasing in a specific direction, and it is possible to obtain the power conversion device 1 that is easily reduced in size. Further, in the present example, the pair of circuit boards 73 and 74 are also disposed so as to be orthogonal to the pair of circuit boards 71 and 72 while the main surfaces 73a and 74a are opposed to each other. Thereby, it can suppress further that the projection area to a specific direction becomes large, and can obtain the power converter device 1 which is easier to reduce in size.

  In the power conversion device 1 of this example, the transformer 2 and an electronic component (in this example, the primary electronic component 30) including at least one of the primary electronic component 30 and the secondary electronic component 40 are provided. A stacked body 11 is provided, and the stacking direction Z of the stacked body 11 is the same as the axial direction Z of the transformer 2. Thereby, since the normal direction Y of the circuit boards 71 and 72 is orthogonal to the stacking direction Z of the multilayer body 11, the main surfaces 71a and 72a of the circuit boards 71 and 72 and the main surface 30a of the primary electronic component 30 are It will not be located on the same plane. As a result, it is possible to suppress an increase in the projected area in a direction parallel to both the main surfaces 71a and 72a, which contributes to downsizing of the power converter 1.

  Moreover, in the laminated body 11, it has a switching element as the primary side electronic component 30, and the circuit boards 71 and 72 form the control circuit part 7 which controls the primary side circuit part 3 which has a switching element. The laminated body 11 is disposed adjacent to the laminated body 11. Thereby, the distance of the primary side electronic component 30 with which the laminated body 11 is equipped, and the circuit boards 71 and 72 can be shortened. As a result, since the bus bars 711 and 721 for connecting the two need only be short, the handling of the bus bars 711 and 721 is facilitated, the assembling workability is improved, and the manufacturing cost is advantageous.

  Moreover, in the power converter device 1 of this example, the first circuit board 71 and the second circuit board 72 are provided as circuit boards, and the first circuit board 71 and the second circuit board 72 face each other's main surfaces 71a and 72a. The transformer 2 is disposed between the main surfaces 71a and 72a. Thereby, in the control circuit part 7 formed in both the circuit boards 71 and 72, the influence of the leakage magnetic flux from the transformer 2 can be reduced. Furthermore, since the transformer 2 forms the multilayer body 11 together with the primary electronic component 30 that is a switching element, the distance between the circuit board 71 and 72 and the primary electronic component 30 included in the multilayer body 11 is increased. Can be shortened. As a result, the assembly workability can be improved and the manufacturing cost is excellent. Moreover, the whole apparatus can be reduced in size compared with the case where the laminated body 11 is arrange | positioned on the outer side of both main surface 71a, 72a.

  Further, the power conversion device 1 of this example includes a switching element as the primary-side electronic component 30, and includes a third circuit board 73 disposed orthogonal to the first circuit board 71 as a circuit board. The first circuit board 71 forms a control circuit section 7 that controls the primary circuit section 3, and the third circuit board 73 forms a filter circuit section (input filter circuit section 5). Thereby, it is possible to reduce the influence of noise generated from the first circuit board 71 forming the control circuit unit 7 on the input filter circuit unit 5. Furthermore, since the first circuit board 71 and the third circuit board 73 are disposed orthogonally, the projected area in the direction parallel to the main surfaces 71a and 73a of both is reduced, and the power converter 1 is small in that direction. Is achieved.

  Further, in the power conversion device 1 of this example, the transformer 2 is arranged in the arrangement region 10 surrounded by the first circuit board 71, the second circuit board 72, and the third circuit board 73. Thereby, the influence of the leakage magnetic flux from the transformer 2 on each circuit formed on the first circuit board 71, the second circuit board 72, and the third circuit board 73 can be reduced. In addition, the projected area of the entire device in the direction parallel to the main surfaces 71a, 72a, 73a of the first circuit board 71, the second circuit board 72, and the third circuit board 73, that is, the axial direction Z of the transformer 2 can be reduced. This contributes to downsizing of the power conversion device 1. An area surrounded by the first circuit board 71, the second circuit board 72, the third circuit board 73, and the fourth circuit board 74 from four directions may be used as the arrangement area 10.

  Further, at least one circuit board (the third circuit board 73 in this example) of the first circuit board 71, the second circuit board 72, and the third circuit board 73 is parallel to the first main surface 73a of the circuit board 73. A ground conductor layer 73c is formed by being laminated. Thereby, the leakage magnetic flux from the transformer 2 can be shielded by the ground conductor layer 73c, and the leakage magnetic flux can be prevented from being released to the outside of the power conversion device 1. Note that a ground conductor layer may be formed on the fourth circuit board 74.

  In this example, the circuit boards 71, 72, 73, and 74 are separated from each other. However, the present invention is not limited to this, and some of the circuit boards 7 are configured by continuously formed flexible boards. It is good. For example, as shown in FIG. 3, circuit boards 71 and 73 are continuously formed by a flexible board, and the two arranged substantially at right angles are connected via a curved portion 730 between the circuit boards 71 and 73. State. Even in this case, the same effects as those of the first embodiment are obtained. Similarly, in the circuit boards 72 and 73, both can be continuously formed by a flexible board, and the two arranged so as to be substantially perpendicular can be connected.

  In addition, in the laminated body 11, it is good also as laminating | stacking the secondary side electronic component 40 and another electronic component instead of the primary side electronic component 30, or this. Moreover, while making the laminated body 11 into a 1st laminated body, it is good also as laminating | stacking the secondary side electronic component 40 and another electronic component, and forming a 2nd laminated body. And the said 1st laminated body and 2nd laminated body can be arrange | positioned in the arrangement | positioning area | region 10. FIG.

  As described above, according to the present example, it is possible to provide the power conversion device 1 that can reduce the influence of the leakage magnetic flux from the transformer 2 on the circuits formed on the circuit boards 71, 72, 73, and 74 while being small. Can do.

(Example 2)
The power converter device 1 of this example is shown in FIG. In addition, the same code | symbol is attached | subjected to the component same as the case of Example 1, and the description is abbreviate | omitted.
In the power conversion device 1 of this example, as illustrated in FIG. 4, the stacked body 11 is 90 ° different from the stacked body 11 (see FIG. 1) in Example 1 in the arrangement direction. Accordingly, the circuit boards 71, 73, and 74 are arranged 90 ° different from the first embodiment in the plan view. And the control circuit part 7 is formed in the circuit board 71, and the circuit board 72 (refer FIG. 1) is not provided. The circuit board 73 forming the input filter circuit unit 5 and the circuit board 74 forming the output filter circuit unit 6 are arranged so that the main surfaces 73a and 74a face each other. A laminated body 11 is disposed therebetween.

  Except for the operational effect of the circuit board 72 being provided, the present embodiment also exhibits the operational effect equivalent to that of the first embodiment.

DESCRIPTION OF SYMBOLS 1 Power converter 2 Transformer 3 Primary side circuit part 30 Primary side electronic component 4 Secondary side circuit part 40 Secondary side electronic component 7 Control circuit part 71 1st circuit board 72 2nd circuit board 73 3rd circuit board 74 4th Circuit board 81 Input terminal 82 Output terminal

Claims (7)

A transformer (2) having a core (25) formed by being divided into a first core (23) and a second core (24), a primary coil (21), and a secondary coil (22);
A primary circuit section (3) connected to the primary coil (21) side of the transformer (2);
A secondary circuit section (4) connected to the secondary coil (22) side of the transformer (2);
At least one circuit board (71, 71) connecting the primary side electronic component (30) forming the primary side circuit portion (3) or the secondary side electronic component (40) forming the secondary side circuit portion (4). 72, 73, 74)
The axial direction of the primary coil (21) and the secondary coil (22) of the transformer (2) is orthogonal to the normal direction of the at least one circuit board (71, 72, 73, 74). ,
A laminate (11) formed by laminating the transformer (2) and an electronic component including at least one of the primary electronic component (30) and the secondary electronic component (40) is provided. , The laminated body (11) is arranged so that the lamination direction is the same as the axial direction of the transformer (2) ,
The boundary between the first core (23) and the second core (24) is at least one circuit board (71) in the normal direction of the at least one circuit board (71, 72, 73, 74). , 72, 73, 74), the power conversion device (1) characterized by being located at a position overlapping with the power conversion device (1).   At least three circuit boards (71, 72, 73, 74) are provided, and the transformer (2) is surrounded from three sides by the at least three circuit boards (71, 72, 73, 74). The power conversion device (1) according to claim 1, wherein the axial direction of (2) and the normal direction of the at least three circuit boards (71, 72, 73, 74) are orthogonal to each other. .   In the laminate (11), the primary side electronic component (30) and the secondary side electronic component (40) have switching elements, and the circuit board (71) has the switching element. The control circuit part (7) for controlling the side circuit part (3) is formed, and is disposed so as to be adjacent to the laminate (11). Power converter (1).   The circuit board (71, 72) includes a first circuit board (71) and a second circuit board (72), and the first circuit board (71) and the second circuit board (72) are main surfaces of each other. The said transformer (2) is arrange | positioned between this mutual main surface (71a, 72a) while arrange | positioning so that (71a, 72a) may oppose. The power converter device (1) as described in any one.   The primary side electronic component (30) or the secondary side electronic component (40) has a switching element, and is disposed as the circuit board (71, 73) orthogonal to the first circuit board (71). And the first circuit board (71) forms a control circuit part (7) for controlling the primary circuit part (3) provided with the switching element, The power converter (1) according to claim 4, wherein the third circuit board (73) forms a filter circuit section (5, 6).   The transformer (2) is disposed in a region (10) surrounded by the first circuit board (71), the second circuit board (72), and the third circuit board (73). The power converter device (1) according to claim 5.   At least one circuit board of the first circuit board (71), the second circuit board (72), and the third circuit board (73) is formed by being laminated in parallel with the main surface of the circuit board. It has a conductor layer, The power converter device (1) as described in any one of Claims 1-6 characterized by the above-mentioned.

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