JP2016058495A - Common mode choke coil, common mode filter, and power converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a common mode choke coil corresponding to high efficiency with high output density, and to provide a common mode filter, and a power converter.SOLUTION: A common mode choke coil 1 includes two coils 10, 15 formed by winding conductors 11a, 11b, coated with an insulating layer on the periphery and having a flat profile, while superposing the side faces of the conductors in the longitudinal direction of the flat shape, and a magnetic core 20 inserted into the air cores 13, respectively. The magnetic core is molded so that a magnetic field generated by a current flowing through two coils pass the same closed magnetic path. A magnetic field generated by a common mode current flowing through two coils and passing through the closed magnetic path increases the common mode impedance of the other coil.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a common mode choke coil, a common mode filter, and a power converter.

  Power converters typified by inverters are becoming more and more compact year by year, aiming at higher output density by achieving higher efficiency. In power converters, there is a strong demand for higher frequency of built-in switching elements in order to achieve higher output density. In recent years, development of a new inverter circuit system such as a multi-level system has progressed, and power devices using SiC and GaN have been put into practical use, and the frequency of switching elements has been increased. As the frequency of switching elements increases, the need to suppress common mode noise is increasing, and the use of common mode choke coils and common mode filters is expanding.

JP-A-9-84357

  An object of the embodiment is to provide a common mode choke coil, a common mode filter, and a power conversion device that correspond to high power density and high efficiency.

  In the common mode choke coil according to the embodiment, the first conductor having a flat cross-section and covered with an insulating layer is wound with the side surface of the first conductor along the flat longitudinal direction. A first coil and a second coil in which a second conductor having a flat cross section and covered with an insulating layer is wound around the side surface of the second conductor along the lengthwise direction of the flat shape. And a magnetic core inserted through each air core portion of the first coil and the second coil. The magnetic core has a closed magnetic path through which a magnetic field generated by a current flowing in the first coil and a magnetic field generated by a current flowing in the second coil pass, and is generated by a common mode current flowing in the first coil The magnetic field passing through the closed magnetic path increases the common mode impedance of the second coil, and the magnetic field generated by the common mode current flowing through the second coil and passing through the closed magnetic path is the common mode of the first coil. Increase impedance.

FIG. 1A is a schematic plan view illustrating a common mode choke coil according to the first embodiment (FIG. 1A), a schematic front view (FIG. 1B), and a schematic side view (FIG. 1C). FIG. 1D is a schematic cross-sectional view taken along line AA ′ of FIG. It is typical sectional drawing of the conducting wire used for a common mode choke coil. 2A shows a rectangular cross section, FIG. 2B shows a flat cross section, and FIG. 2C shows a rounded rectangular cross section. FIG. 3A to FIG. 3C are schematic plan views showing the procedure when the common mode choke coil is an alpha coil. It is an equivalent circuit diagram illustrating the common mode choke coil according to the first embodiment. 1 is a schematic exploded view illustrating a common mode choke coil according to a first embodiment. It is a typical block diagram which illustrates the common mode filter and power converter concerning a 2nd embodiment. It is a typical block diagram which illustrates the common mode filter and power converter concerning the modification 1 of a 2nd embodiment. It is a typical block diagram which illustrates the common mode filter and power converter concerning the modification 2 of a 2nd embodiment. It is a typical block diagram which illustrates the common mode filter and power converter concerning the modification 3 of a 2nd embodiment. It is a typical block diagram which illustrates the 2nd capacitor circuit used for the common mode filter and power converter concerning the modification 4 of a 2nd embodiment. It is a typical block diagram which illustrates the common mode filter and power converter concerning a 3rd embodiment. It is a typical block diagram which illustrates the common mode filter and power converter concerning a 4th embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between the parts, and the like are not necessarily the same as actual ones. Further, even when the same part is represented, the dimensions and ratios may be represented differently depending on the drawings.

  Further, in the present specification and each drawing, the same reference numerals are given to the same elements as those described above with reference to the previous drawings, and detailed description thereof will be omitted as appropriate.

(First embodiment)
FIG. 1A to FIG. 1C are a schematic plan view (FIG. 1A), a schematic front view (FIG. 1B) illustrating a common mode choke coil according to this embodiment, and FIG. It is a typical side view (Drawing 1 (c)). FIG.1 (d) is typical sectional drawing in the AA 'line of Fig.1 (a).

  FIG. 2A to FIG. 2C are schematic cross-sectional views of conductive wires used for the respective coils of the common mode choke coil according to the present embodiment.

  As shown in FIGS. 1A to 1D, the common mode choke coil 1 includes a first coil 10, a second coil 15, a first magnetic core 20, and a second magnetic core. 25.

  As shown in FIG. 2 (a), the first coil 10 has a single conductor 11a in which the periphery of a metal conductor 5 such as copper or an alloy containing copper is covered with an insulating layer 6 such as an insulating film or an insulating coating. , 11b. Hereinafter, the case where an insulating film is used as an example of the insulating layer 6 will be described.

  The conducting wires 11a and 11b are wound in an annular shape with the air core portion 13 as the center. The cross section of conducting wire 11a, 11b is flat shape, for example, is substantially rectangular. The conducting wires 11a and 11b are wound with overlapping side surfaces along the longitudinal direction of the flat cross section. Specifically, the conducting wires 11a and 11b are wound with overlapping side surfaces along the long sides of the rectangular cross section. Since the conducting wires 11a and 11b are wound with an alpha winding, which will be described later, a conducting wire 11a on one side having one end and a conducting wire 11b on the other side having the other end. Including.

  Similarly to the first coil 10, the second coil 15 has one conductor 16 a and 16 b in which the periphery of a metal conductor 5 having a rectangular cross section is covered with an insulating film 6. The conducting wires 16a and 16b are wound in an annular shape around the air core 18. The cross sections of the conductive wires 16a and 16b are also flat, for example, substantially rectangular. The conducting wires 16a and 16b are also wound with overlapping side surfaces along the longitudinal direction of the flat cross section. Specifically, the conducting wires 16a and 16b are wound so as to overlap the side surfaces along the long side of the rectangular cross section. In addition, since the conducting wires 16a and 16b are also wound by an alpha winding described later, the conducting wire 16a on one side having one end portion and the conducting wire 16b on the other side having the other end portion are provided. ,including.

  The wound first coil 10 and second coil 15 are inserted into the respective leg portions 23 and 28 of the first magnetic core 20 and the second magnetic core 25. The first coil 10 has terminals 12a and 12b at both ends. The second coil 15 has terminals 17a and 17b at both ends. The first magnetic core 20 and the second magnetic core 25 are connected to each other at a predetermined position.

  In the following description, the first coil 10 and the second coil 15 are made of a conductive wire having the same thickness and width and a conductive wire having the same material and thickness as the same number of turns. And are configured as the same coil. However, the first coil 10 and the second coil 15 may be different from each other by changing the number of turns.

  The shapes of the first coil 10 and the second coil 15 can be selected according to the shapes of the magnetic cores 20 and 25. When the magnetic cores 20 and 25 are PQ cores, the first coil 10 and the second coil 15 are wound in an annular shape having circular air core portions 13 and 18. When the magnetic core is an EE core, an EI core, or the like, the first coil 10 and the second coil 15 are formed into an annular square shape having square air core portions 13 and 18. By matching the shape of the coil to the leg shape of the magnetic core, the space factor of the conducting wire can be increased. Since the magnetic core can have any shape, the first coil 10 and the second coil 15 can also have any shape according to the shape of the magnetic core.

  The conducting wire used for each coil constituting the common mode choke coil 1 of the present embodiment will be described. The conductor used for the coil has a rectangular space with a rectangular cross section as shown in FIG. 2A, rather than a round wire with a round cross section. Can be increased. For example, the space factor when using round conductors having the same cross-sectional area is limited to about 20% although it depends on the thickness of the insulating film. On the other hand, when a rectangular wire having a rectangular cross section is used, the space factor can be about 50%. That is, the space factor when a flat wire is used as the coil conductor can be increased by a factor of two or more compared to the case of the round wire. Therefore, by forming the coil using a conducting wire using a rectangular wire, the space for the winding can be reduced, and the coil is greatly reduced in size.

  The cross-sectional shape of the conducting wire is not limited to a rectangular shape, and may be a flat circular shape or an elliptical shape as shown in FIG. 2 (b). A rectangular shape having round corners as shown in FIG. 2 (c). It may be in the shape. In the present specification, a conductive wire having a flat cross-sectional shape including these is referred to as a flat conductive wire. As described above, the conductive wire is wound by overlapping the side surfaces (hereinafter also referred to as flat surfaces) along the flat longitudinal direction (left and right direction in FIG. 2) of the cross section of the conductive wire, among the side surfaces of the conductive wire. Thus, the space factor of the coil can be increased. Thus, when a coil is formed by winding a flat wire, the space factor can be increased as compared with the case where a coil is formed by winding a round wire.

  The thickness dc of the conductor 5 does not necessarily have to be constant along the longitudinal direction of the cross-sectional shape. In the present specification, the thickness dc of the conductor 5 is an average value of the thickness dc 'at a position along the longitudinal direction of the cross-sectional shape. For example, the cross-sectional area S of the conductor 5 is determined as a required value based on current capacity, copper loss, and the like. The length (width of the conductor 5) w of the cross-sectional shape of the conductor 5 is determined as a required value based on the winding space of the magnetic core around which the conducting wire is wound. Therefore, if the cross-sectional area S and the width w of the conductor 5 are set, the average thickness dc can be calculated by a simple calculation.

  The insulating film 6 covering the periphery of the conductor 5 ensures electrical insulation from other portions of the conducting wire wound around the coil. Further, the insulating film 6 ensures electrical insulation from the windings of other phases. The insulating film 6 ensures electrical insulation from the magnetic core. Therefore, an insulating material that can ensure electrical insulation is used for the insulating film 6. For example, a polyimide film or paper is used for the insulating film 6. Since paper has a low dielectric constant, paper is suitably used in this embodiment and other embodiments described later. When the thickness dc of the conductor 5 is the same, the thinner the thickness di of the insulating film 6 is, the thinner the entire thickness of the conducting wire is. If the overall thickness of the conducting wire is thin, the conducting wire can be wound in the same space with a greater number of turns. Alternatively, the conductor can be wound into a smaller space. However, the capacitance formed by winding the conductor 5 covered with the insulating film 6 increases in proportion to the reciprocal of the thickness of the insulating film 6. When the thickness di of the insulating film 6 is reduced, the stray capacitance generated between the windings of the coil increases, so that the high frequency characteristics of the common mode choke coil are deteriorated. On the other hand, when the thickness di of the insulating film 6 is increased, the space factor of the conducting wire decreases. Therefore, the thickness di of the insulating film 6 is desirably 50 μm to 500 μm.

  The larger the cross-sectional area of the conductor 5, the lower the resistance value, so that the copper loss of the coil decreases. Therefore, it is preferable that the thickness dc of the conductor 5 be, for example, four times or more the thickness di of the insulating film 6. On the other hand, when the width of the flat conductive wire and the thickness of the insulating film 6 are constant, increasing the thickness dc of the conductor 5 increases the coil diameter for the same number of turns. Therefore, the ratio between the thickness dc of the conductor 5 and the insulating film 6 is desirably 100 times or less.

  In the first coil 10 and the second coil 15 of the present embodiment, since the conducting wire is wound using alpha winding, the number of turns can be increased in a limited space. FIG. 3A to FIG. 3C are schematic plan views for explaining a procedure of winding a conducting wire by alpha winding to form a coil.

  The alpha winding of the coil is a winding method in which one coil is divided into two coil parts, and the two coil parts are coaxially adjacent to each other on a plane perpendicular to the axial direction of the wound coil part. The coil wound with alpha is composed of a coil portion formed by winding one side from the center of one flat wire 11 constituting the coil, and a coil formed by winding the other side of the flat wire. And part of. In the alpha winding, the central portion of the flat conducting wire is bent, and the respective coil portions are arranged coaxially adjacent to each other in a plane perpendicular to the winding direction of the conducting wire.

  Specifically, the coil by alpha winding is configured as follows. As shown in FIG. 3A, the flat wire 11 has a direction (hereinafter referred to as the y-axis direction) perpendicular to the x-axis direction at a position approximately half the length direction (hereinafter referred to as the x-axis direction). And a center line 11c set along the line. The flat conducting wire 11 has a conducting wire 11a on one end side from the center line 11c and a conducting wire 11b on the other end side from the center line 11c. The flat conducting wire 11 has an edge part 11d that is an edge along the x-axis direction, and an edge part 11f that is an edge at a position facing the edge part 11d on the y-axis. The conducting wire 11a has a bent portion 11e toward the edge portion 11f at an angle of approximately 45 ° from the intersection of the center line 11c and the edge portion 11d. The conducting wire 11b has a bent portion 11g toward the edge 11d at an angle of approximately 45 ° from the intersection of the center line 11c and the edge 11f.

  The conducting wire 11a has one terminal 12a of the coil 10 at the tip. The conducting wire 11b has the other terminal 12b of the coil 10 at the tip. The terminals 12a and 12b are formed by removing the insulating film 6 covering the periphery of the conductor 5. The terminals 12a and 12b may be pre-soldered on the surface.

  As shown in FIG. 3B, the lead wire 11b is bent at the bent portion 11g so that the edge portion 11f of the lead wire 11b is along the center line 11c.

  As shown in FIG.3 (c), the conducting wire 11a is bend | folded by the bending part 11e so that the edge part 11d of the conducting wire 11a may follow the centerline 11c. In this way, the conducting wires 11a and 11b are arranged so that the respective edge portions 11d and 11f are bent along the center line 11c. The conducting wire 11a is wound with a flat surface overlapped, and the conducting wire 11b is wound with a flat surface overlapped. By winding in this way, an annular surface constituted by the edge portion 11d by winding the conducting wire 11a and an annular surface constituted by the edge portion 11f by winding the conducting wire 11b are formed. Adjacent to each other. These two adjacent coils constitute one coil connected at the central portion of the conducting wire 11.

  Since the coil 15 can be configured in exactly the same way as the coil 10, a detailed description thereof will be omitted.

  Since the coil wound with the alpha winding has both ends of the conductive wire on the outermost periphery, a terminal for connection to an external circuit is easily configured. Moreover, in the coil wound by alpha winding, since the conducting wire is wound in two coil parts, the number of turns is ensured even when the winding space is limited in the radial direction of the coil.

  When winding a coil, flat-wise winding may be used instead of alpha winding. The flatwise winding forms one coil without being bent at the center of the conducting wire. When a coil is formed by flatwise winding, the end on the inner diameter side of the coil is used as a terminal. The terminal on the inner diameter side of the coil is pulled out to the outside of the coil by bending it approximately 90 ° with respect to the longitudinal direction of the conducting wire. For example, as shown in FIG. 3B, the terminal is configured by pulling out the bent end from the inner diameter side of the coil.

  Returning to FIG. 1, the magnetic core which comprises the common mode choke coil 1 of this embodiment is demonstrated. As shown in FIGS. 1A to 1D, the first magnetic core 20 includes an upper side wall part 21, a lower side wall part 22, a leg part 23, and a side wall part 24. The first magnetic core 20 is a so-called PQ core.

  The side wall portion 24 is a plate-like member in which an upper end portion and a lower end portion are substantially square and are each formed in a wedge shape toward the center portion. The upper end and the lower end are ends to which the upper side wall 21 and the lower side wall 22 are connected, respectively. The side wall portion 24 is disposed substantially parallel to a plane perpendicular to the axial direction of the first coil 10 around which the flat conducting wire 11 is wound. The side wall portion 24 supports a surface perpendicular to the axial direction of the first coil 10 inserted through the leg portion 23.

  The upper side wall portion 21 is a substantially square plate-like member. One end of the upper wall portion 21 is connected to the upper end portion of the side wall portion 24 substantially perpendicularly to the side wall portion 24. The surface facing the lower wall portion 22 of the upper wall portion 21 has an arc-shaped recess according to the shape of the outer periphery of the first coil 10. The upper side wall portion 21 is disposed on the upper portion of the first coil 10 inserted through the leg portion 23 and captures a magnetic field generated mainly on the upper portion of the first coil 10.

  The lower wall portion 22 is a substantially square plate-like member. One end of the lower side wall portion 22 is disposed at a lower end portion of the side wall portion 24 substantially perpendicular to the side wall portion 24. The lower wall portion 22 is disposed substantially parallel to the upper wall portion 21 so as to face it. The surface facing the upper wall portion 21 of the lower wall portion 22 has an arc-shaped recess according to the shape of the outer periphery of the first coil 10. The lower side wall portion 22 is disposed below the first coil 10 inserted through the leg portion 23, and captures a magnetic field generated mainly at the lower portion of the first coil 10.

  One end of the leg portion 23 is connected to the substantially central portion of the side wall portion 24 substantially perpendicularly to the side wall portion 24. The leg part 23 is a columnar column. The leg portion 23 passes through the air core portion 13 of the first coil 10 and captures the magnetic field generated by the current flowing through the first coil 10.

  The upper side wall part 21, the lower side wall part 22, and the leg part 23 have substantially the same length from the position connected to the side wall part 24 to the end part. The first magnetic core 20 having such a shape is configured by an upper side wall part 21, a lower side wall part 22, and a side wall part 24 by inserting a leg part 23 through the air core part 13 of the first coil 10. The first coil 10 is accommodated in the space.

  The second magnetic core 25 is also configured in the same way as the first magnetic core 20. The second magnetic core 25 is a so-called PQ core having an upper side wall part 26, a lower side wall part 27, a leg part 28 and a side wall part 29. The second magnetic core 20 having the same shape as the first magnetic core is inserted into the air core 18 of the second coil 15 through the leg 28, and is formed by the upper side wall 26, the lower side wall 27, and the side wall 29. The second coil 15 is accommodated in the configured space.

  The upper side wall portions 21 and 26, the lower side wall portions 22 and 27, and the leg portions 23 and 28 constituting the first magnetic core 20 and the second magnetic core 25 are each made of an adhesive, an adhesive tape, or the like. The connection is made using a well-known connection technique. As described above, the first magnetic core 20 and the second magnetic core 25 form a closed magnetic circuit by connecting the respective end portions.

  The first magnetic core 20 and the second magnetic core 25 are made of the same magnetic material and include the same soft magnetic material. The magnetic material of the first magnetic core 20 and the second magnetic core 25 is a soft ferrite material such as Mn—Zn ferrite, Ni—Zn ferrite, or Cu—Zn ferrite, for example. The magnetic material is not limited to the soft ferrite material, and may be a soft magnetic material such as amorphous alloy, iron, silicon steel, sendust, and permalloy.

  When soft ferrite is used, the first magnetic core 20 and the second magnetic core 25 are formed into the above-described shape by using a known technique such as sintering an appropriate ferrite material. When an amorphous alloy is used, the first magnetic core 20 and the second magnetic core 25 are configured by using a well-known technique such as forming a thin ribbon of an amorphous alloy and laminating the formed thin ribbons. Is done. Other materials can also be formed into the above-described shape using known techniques.

FIG. 4 is an example of an equivalent circuit of the common mode choke coil according to the present embodiment.
As shown in FIG. 4, the common mode choke coil 1 includes a first coil 10 and a second coil 15. In the common mode choke coil 1, one terminal 12a of the first coil 10 is used as an input terminal for common mode current, and the other terminal 12b is used as an output terminal for common mode current. Similarly, the common mode choke coil 1 has one terminal 17a of the second coil as an input terminal for common mode current and the other terminal 17b as an output terminal for common mode current. In the first coil 10 and the second coil 15, the conducting wire is wound around the same magnetic core in the same winding direction. It shows by the position of a dot that the conducting wire is wound around the same magnetic core in the same direction.

  For example, by connecting the terminals 12a and 17a to two power supply lines generating a common mode current, a current from which the common mode current is removed is output from the terminals 12b and 17b.

  The first coil 10 and the second coil 15 cause an in-phase current to flow through a magnetic core having the same closed magnetic path. Magnetic fields in the same direction are generated in the magnetic core, and the magnetic fields generated by the currents of the two coils are added, so that the impedances of the first coil 10 and the second coil 15 increase. Therefore, the common mode current that is the current of the same phase is removed.

  In the above-described example, the common mode choke coil is configured by housing the coil formed by winding the flat conducting wire by alpha winding or flatwise winding in the PQ core. The shape of the magnetic core is not limited to the PQ core, but may be any core that is configured so that the magnetic fields generated by the currents flowing in the first coil and the second coil flow in the same closed magnetic path.

  For example, in the case of the EE core, the leg portion is a quadrangular prism, and the upper side wall portion and the lower side wall portion are both plate-shaped or quadrangular prism-shaped. In the case of the EI core, a common mode choke coil can be configured in the same manner as the EE core by inserting the air core portions of the first and second coils through a magnetic core having legs. By using the UU core, a common mode choke coil can be formed in a ring shape.

  Next, a method for manufacturing the common mode choke coil 1 of the present embodiment will be described. FIG. 5 is an exploded view schematically showing an example of the common mode choke coil 1 of the present embodiment. As described above, the first coil 10 and the second coil 15 are configured in the same manner by winding a rectangular conductor wire in an annular shape by alpha winding. The first coil 10 and the second coil 15 around which the conductive wire is wound have terminals 12a, 12b, 17a, and 17b from which the insulating films 6 at both ends of the flat conductive wires 11 and 16 are removed.

  In the first coil 10, the air core portion 13 of the first coil 10 is inserted into the leg portion 23 through the first magnetic core 20 surrounded by the upper side wall portion 21, the side wall portion 24, and the lower side wall portion 22. Stored.

  When the first magnetic core 20 is a PQ core, the leg portion 23 has a cylindrical shape. A concave portion is formed in an arc shape on the side of the upper wall portion 21 where the coil is accommodated. Similarly, a concave portion is formed in an arc shape on the side of the lower wall portion 22 where the coil is stored. In the first coil 10, the inner wall of the air core part 13 is substantially in close contact with the columnar shape of the leg part 23, and the upper part and the lower part of the coil 10 correspond to the upper wall part 21 and the lower wall part. Each of the 22 is housed in close contact with the arcuate recess.

  Similarly to the first coil 10, the second coil 15 has an air core portion 18 of the second coil 15 in a magnetic core surrounded by the upper side wall portion 26, the side wall portion 29, and the lower side wall portion 27. Is inserted through the leg portion 28 and stored.

  When the second magnetic core 25 is a PQ core, the leg portion 28 has a cylindrical shape. On the coil housing side of the upper side wall portion 26, a concave portion is formed in an arc shape. Similarly, a concave portion is formed in an arc shape on the coil housing side of the lower side wall portion 27. In the second coil 15, the air core portion 18 is in close contact with the columnar shape of the leg portion 28, and the upper and lower portions of the second coil 15 are arc-shaped recesses in the upper side wall portion 26 and the lower side wall portion 27, respectively. Stored in close contact with the

  The first magnetic core 20 in which the first coil 10 is accommodated and the second magnetic core 25 in which the second coil 15 is accommodated include leg portions 23 and 28, upper side wall portions 21 and 26, and End portions of the lower side wall portions 22 and 27 are connected to each other. The first magnetic core 20 and the second magnetic core 25 can be connected to each other by using a known technique such as an epoxy-based adhesive. In addition to the adhesive, a well-known connection / adhesion technique such as a double-sided tape may be additionally used, or bonding may be performed by applying pressure to the connection surface from the outside with a band or a tape.

  Since the common mode choke coil 1 is configured in this way, the closed magnetic circuit is formed by the leg portion 23 → the side wall portion 24 → the upper side wall portion 21 → the upper side wall portion 26 → the side wall portion 29 → the leg portion 28 → the leg portion 23. Configured as follows. Further, the other closed magnetic path is configured so that the leg portion 23 → the side wall portion 24 → the lower side wall portion 22 → the lower side wall portion 27 → the side wall portion 29 → the leg portion 28 → the leg portion 23 at the same time.

  In the common mode choke coil 1 of the present embodiment, unlike a toroidal coil, it is not necessary to go through a complicated manufacturing process in which the coil is wound up while passing the lead wire through the inner diameter portion. That is, the first coil 10 and the second coil 15 are manufactured by being easily wound in an annular shape by using, for example, a conductive wire winding jig. The wound coils 10 and 15 are easily accommodated in the magnetic cores 20 and 25 by being inserted into the leg portions 23 and 28 of the magnetic cores 20 and 25. Since the magnetic cores 20 and 25 house the wound coils 10 and 15 respectively and are joined to each other, the common mode choke coil 1 of the present embodiment is easily manufactured.

  In the common mode choke coil of this embodiment, the inner diameter portion of the coil is in close contact with the columnar leg portions 23 and 28, and the outer peripheral portion of the coil is the concave portion of the arcuate upper side wall portions 21 and 26, and It arrange | positions so that it may contact | adhere to the recessed part of the lower side wall parts 22 and 27 on a circular arc. Therefore, each of the coils 10 and 15 can increase the space factor and secure the number of turns, and can further minimize the leakage of magnetic flux.

  The common mode choke coil 1 has a strong demand for downsizing. Generally, as shown in the following formula (1), when the number of turns N and the magnetic flux density B are constant, the excitation current I is proportional to the core cross-sectional area Ae. In order to reduce the size of the common mode choke coil, the core cross-sectional area needs to be reduced. The number of turns N needs to be increased as much as the core cross-sectional area Ae is reduced.

L ・ I = N ・ B ・ Ae (1)
Here, L is the inductance of the coil, I is the exciting current of the coil, N is the number of turns of the coil, B is the magnetic flux density of the magnetic core, and Ae is the cross-sectional area of the magnetic core.

  In the common mode choke coil 1 according to the present embodiment, since a rectangular conducting wire is used, the space factor of the conducting wire is improved. Therefore, the number N of turns of the coil increases. Further, in the common mode choke coil 1 of the present embodiment, the space factor is further improved by using the alpha winding together, so that a necessary excitation current is ensured. Further, the common mode choke coil 1 can be reduced in size by using a magnetic material having a high saturation magnetic flux density from the equation (1). When soft ferrite is used as the soft magnetic material, the saturation magnetic flux density is desirably 0.5 T or more, for example.

  In the common mode choke coil 1 according to the present embodiment, a flat conducting wire having a flat cross section is used, and the insulating film 6 covers the periphery of the conductor 5 constituting the conducting wire, so that a high withstand voltage is realized. In the common mode choke coil 1 of the present embodiment, the insulating film 6 is made of, for example, an insulating resin material such as polyimide, insulating paper, or the like, so that the withstand voltage of the conducting wire is higher than that of the enamel-coated wire. be able to. Further, since the insulating film 6 is made of polyimide, insulating paper, or the like, the withstand voltage can be ensured between the windings of adjacent phases or between the winding and the magnetic core. In the common mode choke coil 1 according to the present embodiment, since the conducting wire itself has such a high withstand voltage, it is necessary to store the magnetic core in a resin bobbin or case to ensure the withstand voltage between the windings. The conductor can be wound directly around the magnetic core. Therefore, the common mode choke coil 1 of the present embodiment can be reduced in size.

  Furthermore, the common mode choke coil 1 of this embodiment can increase the space factor as compared to the toroidal type common mode choke coil, and even if the number of turns of the coil is increased to a large number of times, the stray capacitance between the lines can be increased. Does not grow. Therefore, the common mode choke coil 1 of the present embodiment can efficiently remove high frequency common mode noise. In the common mode choke coil 1 of the present embodiment, the thickness di of the insulating film can be set to 50 μm to 500 μm, for example, and can be set to an optimum thickness from the high frequency characteristics and the space factor.

  If the width w of the conductor 5 constituting the conducting wire is constant, the resistance value of the conducting wire decreases as the thickness of the conductor 5 increases, and the copper loss decreases. In the common mode choke coil 1 of the present embodiment, the ratio (dc / di) between the conductor thickness dc and the insulation film thickness di is, for example, 4 to 100 times, thereby reducing the copper loss and the space factor. And the optimum value can be set.

  In the above description, the common mode choke coil for removing the common mode currents of the two power lines by inserting the two coils in the two power lines has been described. The common mode choke coil of this embodiment may include three or more coils. By inserting three or more coils into three or more power lines, respectively, the common mode current can be removed.

  As will be described in the following embodiments, the common mode choke coil 1 according to the present embodiment can be used as a common mode noise filter that forms a closed loop of a common mode current, and prevents leakage current from flowing to the ground potential. be able to. In this case, since the common mode current is very large, it is necessary to increase the number of turns of the coil or increase the cross-sectional area of the magnetic core. However, an increase in the number of turns and an increase in the core cross-sectional area increase the volume of the choke coil, which is against the demand for miniaturization. In the common mode choke coil 1 of the present embodiment, since the space factor of the conducting wire can be increased, the entire coil can be downsized even if the core cross-sectional area is increased. The number of turns can be increased without increasing the volume of the coil by making the wire winding alpha.

(Second Embodiment)
The above-described common mode choke coil 1 is suitable for configuring a common mode filter and a power conversion device described below, and can efficiently remove common mode current while having a small external shape.

FIG. 6 is a schematic block diagram illustrating an example of the common mode filter and the power conversion device according to the second embodiment.
The power conversion device 60 includes a common mode filter 40 and a power conversion circuit 62. The power conversion device 60 is connected between the DC input power supply 66 and the load 68. The power converter 60 has an input connected to the output of the DC input power supply 66 and is supplied with DC power from the DC input power supply 66. The power converter 60 is connected to a load 68 at its output, and supplies AC power to the load 68.

  The power conversion circuit 62 is connected in series between the DC input power supply 66 and the load 68. For example, the power conversion circuit 62 is an inverter that converts DC power into AC power. The DC input power supply 66 is, for example, a solar power generation device including a solar power generation panel or a DC-DC converter. The load 68 is an AC load such as an induction motor, for example.

  The power conversion device 60 may be an AC-DC converter that converts AC power into DC power. In that case, the power source input to the power converter 60 is an AC input power source 66a, and the load 68 is a DC load. Further, the power conversion device 60 may be a DC-DC converter that converts DC power to DC power, or may be a power conversion device that converts AC power to AC power.

  The power conversion circuit 62 includes a switching element inside. In the power conversion circuit 62, the switching element performs a high-speed, high-power (high voltage, large current) switching operation. For this reason, the power conversion circuit 62 generates a common mode voltage. The common mode voltage is converted into a common mode current via a stray capacitance such as a circuit board or wiring, a parasitic capacitance, and the like, and is discharged to a power supply line or a load line.

  The common mode filter 40 includes the common mode choke coil 1, a first capacitor circuit 41, and a second capacitor circuit 45.

  The common mode choke coil 1 is connected in series between the DC input power supply 66 and the power conversion circuit 62. The common mode choke coil 1 is connected to the input side of the power conversion circuit 62, that is, the side to which the DC input power supply 66 is connected, and configures the series circuit 50 with the power conversion circuit 62. Series circuit 50 is connected to DC input power supply 66 via power supply lines 1a and 1b. The series circuit 50 is connected to a load 68 via load lines 62a and 62b.

  In the first capacitor circuit 41, the terminals 41a and 41b are connected to the power supply lines 1a and 1b, respectively. The remaining terminal 41c is connected to the terminal 45c of the second capacitor circuit.

  In the second capacitor circuit 45, the terminals 45a and 45b are connected to the load lines 62a and 62b, respectively.

  The common mode choke coil 1 is the common mode choke coil 1 of the first embodiment described above. That is, the common mode choke coil 1 includes a first coil 10, a second coil 15, a first magnetic core 20, and a second magnetic core 25. The first coil 10 has an input terminal 2 a connected to one output of the DC input power supply 66 through the power supply line 1 a and an output terminal 2 b connected to one input of the power conversion circuit 62. The second coil 15 has an input terminal 2 c connected to the other output of the DC input power supply 66 through the power supply line 1 b, and an output terminal 2 d connected to the other input of the power conversion circuit 62. The magnetic cores 20 and 25 constitute one closed magnetic circuit. In the first coil 10 and the second coil 15, conductive wires are wound around the first magnetic core 20 and the second magnetic core 25, respectively. The magnetic cores 20 and 25 are configured such that the magnetic field generated by the current flowing through the first coil 10 and the magnetic field generated by the current flowing through the second coil 15 flow through the same closed magnetic circuit. In the first coil 10, a conducting wire is wound so as to increase the impedance with respect to the common mode current flowing in the second coil 15 by a magnetic field generated by the common mode current flowing in the first coil 10. In the case of the second coil 15, the conducting wire is wound so as to increase the impedance with respect to the common mode current flowing through the first coil 10 by the magnetic field generated by the common mode current flowing through the second coil 15.

  The first capacitor circuit 41 includes two capacitors 42a and 42b connected in series. The second capacitor circuit 45 includes two capacitors 46a and 46b connected in series. One terminal 41a, 41b of capacitor 42a, 42b connected in series is connected to power supply line 1a, 1b, and one terminal 45a, 45b of capacitor 46a, 46b connected in series is connected to load line 62a, 62b, respectively. Connecting. The terminal 41c including the neutral point of the two capacitors 42a and 42b is connected to the terminal 45c including the neutral point of the capacitors 46a and 46b.

  In the common mode filter 40 of the present embodiment, a path including the first capacitor circuit 41, the common mode choke coil 1, the power conversion circuit 62, and the second capacitor circuit forms a closed loop of the common mode current. To do. Since the common mode choke coil 1 is arranged in this closed loop, the common mode current flowing in the same phase through the power supply lines 1a and 1b and the load lines 62a and 62b is removed.

  In recent years, private power generation facilities have been widely promoted by the introduction of solar power generation devices and the like, and the sale of private power generation has become popular due to the introduction of the feed-in tariff system. In such an in-house power generation facility or the like, it is strongly desired to reduce the size and increase the output density of a power converter, that is, a power conditioner. In order to realize miniaturization of power converters, circuit technologies such as multilevel inverters have been developed. Also, SiC and GaN devices are becoming widespread as high-speed and high breakdown voltage switching elements. Therefore, in the power conditioner, a switching frequency several times as high as that in the prior art is realized.

  In the conventional common mode filter system, the common mode current is reduced by the common mode choke coil, and the remaining common mode current flows to the ground. However, as the switching element becomes higher in frequency, the common mode current flowing to the ground has become apparent as a leakage current exceeding the safety standard.

  In the common mode filter 40 of the present embodiment, the common mode current flows in a closed loop that does not include the ground 61, and thus is removed without flowing to the ground 61.

  Conventionally, a part of the common mode current has flowed to the ground 61. However, in applications such as a power conditioner, it is necessary to significantly reduce the common mode current. On the other hand, the generated common mode current itself is increased due to the higher frequency of the switching element. In the common mode filter 40 of the present embodiment, the common mode current is from several tens of times the current handled by the conventional common mode filter. It becomes several hundred times. However, the excitation current I is proportional to the number of turns N, the cross-sectional area Ae, and the magnetic flux density B as shown in the above-described equation (1). Therefore, in order to increase the excitation current I, it is necessary to increase all of these. However, increasing the number of turns N and the cross-sectional area Ae means increasing the size of the common mode choke coil.

L ・ I = N ・ B ・ Ae (1)
Here, L is the inductance of the coil, I is the exciting current of the coil, N is the number of turns of the coil, B is the magnetic flux density of the magnetic core, and Ae is the cross-sectional area of the magnetic core.

  As described above, a common mode choke coil capable of flowing a large common mode current is required due to the higher frequency of the switching element, but an increase in size of the common mode choke coil becomes a problem.

  Conventionally, a toroidal coil in which a winding is wound around a ring-shaped magnetic core is often used as a common mode choke coil in a power conditioner or the like. In a toroidal type common mode choke coil, it is common to wind a round wire as a conducting wire around a magnetic core, so it is difficult to improve the space factor. Therefore, the increase in the number of turns and the core cross-sectional area leads to an increase in the size of the common mode choke coil. Further, when the windings are wound in order to increase the number of turns N of the toroidal coil, the coil conductors are capacitively coupled between the windings, and the high frequency characteristics of the common mode choke coil are deteriorated. Therefore, the toroidal coil has a problem that it is difficult to ensure performance as a common mode choke coil. Furthermore, in the case of a toroidal type coil, a widely used enamel-coated wire is used as a conducting wire, so that the withstand voltage is not sufficient. Therefore, an insulating member needs to be added to the toroidal coil in order to ensure insulation from the magnetic core and insulation between phases. For example, in the case of a toroidal coil, the magnetic core is housed in a case or bobbin formed of resin or the like, and it is necessary to wind a conducting wire from the top of the case or provide an insulating partition plate between the phases. is there. Such a member for insulation further enlarges the common mode choke coil.

  In the common mode filter 40 of the present embodiment, the coil wound with the flat wire is used together with a magnetic core such as soft ferrite, so that the space factor is improved. Therefore, in the common mode filter 40 of the present embodiment, the number N of turns of the coil winding is improved. Therefore, since the exciting current of the coil can be increased, the coil is reduced in size. When alpha winding is used together as a method of winding the coil, the space factor is further improved, and the common mode choke coil can be further reduced in size.

  In addition, since the common mode choke coil 1 of the common mode filter 40 uses a flat conductor wire coated with an insulating film on the conductor, the insulation withstand voltage is high, and a case for insulation from the magnetic core is unnecessary. An insulating partition between the phases is also unnecessary. Therefore, since the conducting wire can be wound directly around the magnetic core, the size can be reduced. Therefore, the common mode choke coil 1 can achieve miniaturization while realizing a large excitation current.

  As the insulating film, for example, a polyimide film or paper can be used. Paper can be preferably used because of its low dielectric constant and high withstand voltage. The thickness of the insulating film can be set to, for example, 50 μm to 500 μm, and can be set to an optimum thickness from the high frequency characteristics and the space factor.

  The cross-sectional area of the conductor of the flat wire is related to copper loss. That is, when the width of the conductor is constant, the resistance value of the conducting wire becomes lower and the copper loss decreases as the conductor thickness increases. By setting the ratio (dc / di) between the thickness dc of the conductor and the thickness di of the insulating film to 4 to 100, for example, the optimum value of the copper loss and the space factor can be set.

  As described above, the common mode filter 40 of the present embodiment can be used for the power conversion device 60 in which a large common mode current flows, and can be downsized. Moreover, the power converter 60 including such a common mode filter 40 can be reduced in size as a whole.

(Modification 1)
FIG. 7 is a block diagram schematically showing Modification 1 of the second embodiment.
As shown in FIG. 7, the power conversion device 60 may include a filter circuit 63 connected in series between the power conversion circuit 62 and the load 68. The filter circuit 63 is connected so as to be parallel to the load 68 at the other end of each of the filter coils 63a and 63b, one end of which is connected to each output of the power conversion circuit 62, and each of the filter coils 63a and 63b. And a smoothing capacitor 63c.

  The filter circuit 63 has a high impedance with respect to the normal mode current, but has a low impedance with respect to the common mode current, and hardly participates in the removal of the common mode current. One terminals 45a and 45b of the second capacitors 46a and 46b may be connected to the lines 63d and 63e on the input side of the filter circuit 63, respectively, or are connected to the load lines 62a and 62b of the power conversion circuit 62, respectively. May be. Since there is a finite physical distance between the power conversion circuit 62 and the load 68, in the present modification, the above-described connection position can be set according to the generation state of the common mode current, and design freedom is achieved. Degree and tolerance are improved.

(Modification 2)
FIG. 8 is a block diagram schematically showing Modification 2 of the second embodiment.
As illustrated in FIG. 8, the second modification of the second embodiment is obtained by changing the first capacitor circuit 41 and the second capacitor circuit 45 from the first modification.

  The first capacitor circuit 41 is a series circuit of two capacitors 42a and 42b, and terminals 41a and 41b at both ends of the capacitor 42a are connected to power supply lines 1a and 1b on the input side of the common mode choke coil, respectively.

  The second capacitor circuit 45 is a series circuit of two capacitors 46 a and 46 b, and terminals 45 a and 45 b at both ends of the capacitor 46 a are connected to the two load lines 62 a and 62 b of the power conversion circuit 62. The terminal 41c of the capacitor 42b is connected to the terminal 45c of the capacitor 46b.

  The capacitor 46a of the second capacitor circuit 45 is also used as the smoothing capacitor 63c of the first modification. It can be considered that the capacitor 42 a of the first capacitor circuit 41 is also used as the smoothing capacitor of the DC input power supply 66.

  As described above, in this modification, the number of parts is reduced by combining the capacitor of the other filter circuit such as the smoothing capacitor and the capacitor of the first and second capacitor circuits.

(Modification 3)
In the above-described second embodiment and its modifications, the power conversion device 60 is shown as an example including a single power conversion circuit 62. The power conversion circuit included in the power conversion device 60 of the present embodiment is not limited to a single power conversion circuit. In the present modification, the power conversion circuit is a circuit in which a first power conversion circuit 64 and a second power conversion circuit 62 are connected in cascade. For example, the first power conversion circuit 64 is an AC-DC converter that converts AC power into DC power. The second power conversion circuit 62 is an inverter that converts DC power into AC power. By connecting the AC-DC converter and the inverter in cascade, the power conversion device 60 is configured as a power conversion device that converts AC power into AC power.

  Moreover, regarding the input / output of AC power, in the above-described embodiments and modification examples, an example of single-phase AC is shown, but three-phase AC or more phases may be included.

FIG. 9 is a block diagram schematically showing Modification 3 of the second embodiment.
As shown in FIG. 9, the power conversion device 60 includes a common mode filter 40, a first power conversion circuit 64, and a second power conversion circuit 62 between an AC input power supply 66 a and a load 68. . The first power conversion circuit 64 is cascade-connected to the second power conversion circuit 62.

  The common mode filter 40 includes a common mode choke coil 1, a first capacitor circuit 41, and a second capacitor circuit 45. The common mode choke coil 1 is the same as the common mode choke coil 1 described in the first embodiment, and a detailed description thereof is omitted.

  The common mode choke coil 1 constitutes a cascade circuit and a series circuit 50 between the cascade circuit including the first power conversion circuit 64 and the second power conversion circuit 62 and the AC input power supply 66a. The series circuit 50 is connected to the AC input power supply 66a via the power supply lines 1a, 1b, and 1c. The series circuit 50 is connected to a load 68 via load lines 62a, 62b, and 62c.

  The first capacitor circuit 41 includes three capacitors 42a, 42b, and 42c. One terminal 41a, 41b, 41c of the three capacitors 42a, 42b, 42c is connected to the power supply lines 1a, 1b, 1c, respectively.

  The second capacitor circuit 45 includes three capacitors 46a, 46b, and 46c. One terminal 45a, 45b, 45c of the three capacitors 46a, 46b, 46c is connected to the load lines 62a, 62b, 62c, respectively.

  The other terminals of the three capacitors 42 a, 42 b, 42 c constituting the first capacitor circuit 41 are connected to each other at a terminal 41 d, and the other of the three capacitors 46 a, 46 b, 46 c constituting the second capacitor circuit 45. Are connected to a terminal 45d connected to each other.

  In the power conversion device 60, a closed loop including the common mode choke coil 1, the first power conversion circuit 64, the second power conversion circuit 62, the second capacitor circuit 45, and the first capacitor circuit 41 is configured. A common mode current flows through the closed loop, and the common mode choke coil 1 removes the common mode current. Since the power conversion device 60 of this modification includes a plurality of different power conversion circuits, a common mode current is generated in each power conversion circuit. Therefore, the power conversion device 60 may generate a larger common mode current as a whole. Since the common mode choke coil 1 is used in the common mode filter 40 of the present modification, a large common mode current can be removed while reducing the size.

  In the description of this modification, the case where the power conversion circuit is a cascade connection of two power conversion circuits has been described, but the power conversion device is not limited to such a configuration. For example, the power conversion circuit may be a cascade connection of three or more power conversion circuits, or may be a parallel connection of two or more power conversion circuits. Further, it may be a combination of cascade connection and parallel connection of a plurality of power conversion circuits. In the power conversion device 60 of the present embodiment, the common mode current is removed in the closed loop including the common mode choke coil 1, the power conversion circuit, the first capacitor circuit 41, and the second capacitor circuit 46. It is possible to prevent leakage current from flowing through 61.

(Modification 4)
As described above, in the power conversion device 60, the common mode current is removed in the closed loop including the common mode choke coil 1, the power conversion circuit 62, the second capacitor circuit 45, and the first capacitor circuit 41. In order to further reduce the common mode current, the common mode filter may include a modified second capacitor circuit. The modified second capacitor circuit extracts the remaining common mode current, and flows the extracted common mode current through the common mode choke coil to remove it. Therefore, the common mode filter of this modification can further efficiently remove the common mode current.

  FIG. 10 is a block diagram schematically illustrating an example of a second capacitor circuit used in the common mode filter according to the fourth modification of the second embodiment. The second capacitor circuit 70 shown in FIG. 10 can be replaced with the second capacitor circuit 45 of the power conversion device 60 shown in FIG.

  As shown in FIG. 10, the second capacitor circuit 70 includes three extraction capacitors 71a, 71b, 71c and three single-phase reactors 72a, 72b, 72c. One end of each of the three extraction capacitors 71a, 71b, 71c is connected to the three load lines 62a, 62b, 62c via terminals 70a, 70b, 70c, and the other end is a single-phase reactor 72a, 72b, 72c. Are connected to one input 72a1, 72b1, 72c1, respectively. The other inputs 72 a 2, 72 b 2, 72 c 2 of the single-phase reactors 72 a, 72 b, 72 c are connected to each other and connected to the first capacitor circuit 41 as the other terminal 70 d of the second capacitor circuit 70. One output 72a3, 72b3, 72c3 of single-phase reactor 72a, 72b, 72c is connected to the other output 72c4, 72a4, 72b4 of adjacent single-phase reactor 72a, 72b, 72c, respectively. By connecting in this way, the three single-phase reactors 72a, 72b, and 72c exhibit a high impedance for the normal mode current and a low impedance for the common mode current in each phase. Show. Therefore, the common mode current is extracted from the three load lines 62 a, 62 b, and 62 c and is input to the common mode choke coil 1 through the first capacitor circuit 41. Therefore, the extracted common mode current is removed. In this modification, the common mode current that appears in the load lines 62a, 62b, and 62c is extracted and input to the common mode choke coil 1 connected to the power supply lines 1a, 1b, and 1c. Can be removed.

(Third embodiment)
In the second embodiment, the case where the common mode choke coil 1 is connected in series with the power conversion circuit 62 and arranged on the input side of the power conversion circuit 62 has been described. In the power conversion device of this embodiment, the common mode choke coil 1 is disposed on the output side of the power conversion circuit 62.

FIG. 11 is a block diagram schematically illustrating an example of the power conversion apparatus according to the third embodiment.
As shown in FIG. 11, in the power conversion device of this embodiment, the common mode choke coil 1 is connected in series between a power conversion circuit 62 and a load 68. That is, the common mode choke coil 1 is connected to the output side of the power conversion circuit 62. The power conversion circuit 62 constitutes the common mode choke coil 1 and the series circuit 50. Series circuit 50 is connected to DC input power supply 66 through power supply lines 1a and 1b. The series circuit 50 is connected to a load 68 via load lines 62a and 62b.

  As in the present embodiment, the connection position of the common mode choke coil 1 is changed in accordance with the common mode current generated by the arrangement, wiring structure, etc. of the power conversion circuit 62, the DC input power supply, the load or other circuit elements. Can do. Therefore, it is possible to increase the degree of freedom of circuit arrangement and the design margin.

  Needless to say, the third embodiment can be combined with the modifications of the second embodiment described above.

(Fourth embodiment)
In the power conversion device of this embodiment, the common mode choke coils 1 and 100 are connected to both the input side and the output side of the power conversion circuit.

FIG. 12 is a block diagram schematically illustrating an example of the power conversion apparatus according to the fourth embodiment.
As shown in FIG. 12, in the power conversion device 60 of the present embodiment, the first common mode choke coil 1 is connected in series between a DC input power supply 66 and a power conversion circuit 62. In the power conversion device 60, the second common mode choke coil 100 is connected in series between the power conversion circuit 62 and the load 68. The first common mode choke coil 1, the power conversion circuit 62, and the second common mode choke coil 100 constitute a series circuit 50. The series circuit 50 is connected to the DC input power supply 66 through the power supply lines 1a and 1b. The series circuit 50 is connected to a load 68 via load lines 62a and 62b.

  It goes without saying that the modification examples of the second embodiment described above can be combined with the fourth embodiment.

  Since the common mode choke coils 1 and 100 can be reduced in size even when handling a large current as described above, they can be connected to both the input side and the output side of the power conversion circuit 62. . The power conversion device 60 can remove the common mode current more efficiently by connecting the two common mode choke coils 1 and 100 to the input side and the output side of the power conversion circuit 62.

  According to the embodiments described above, it is possible to realize a common mode choke coil, a common mode filter, and a power conversion device that are compatible with high power density and high efficiency.

The embodiments of the present invention have been described above with reference to specific examples. However, embodiments of the present invention are not limited to these specific examples. For example, regarding the specific configuration of each element such as a common mode choke coil, a common mode filter, and a power converter, the present invention is similarly implemented by appropriately selecting from a well-known range by those skilled in the art, and similar effects Is included in the scope of the present invention.
Moreover, what combined any two or more elements of each specific example in the technically possible range is also included in the scope of the present invention as long as the gist of the present invention is included.

  In addition, all common mode choke coils and common mode filters that can be appropriately designed and implemented by those skilled in the art based on the common mode choke coil, common mode filter, and power converter described above as the embodiments of the present invention. As long as the power converter includes the gist of the present invention, it also belongs to the scope of the present invention.

  In addition, in the category of the idea of the present invention, those skilled in the art can conceive of various changes and modifications, and it is understood that these changes and modifications also belong to the scope of the present invention. .

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  1,100 Common mode choke coil, 1a, 1b, 1c Power line, 2a, 2b terminal, 5 conductors, 6 Insulating layer (insulating film), 10, 15 coil, 11, 16 Flat conductor, 11a, 11b, 16a, 16b Conductor, 11c center part, 11d, 11f edge part, 11e, 11g bent part, 12a, 12b, 17a, 17b terminal, 13, 18 air core part, 20, 25 magnetic core part, 21, 26 upper side wall part, 22, 27 Lower side wall part, 23, 28 Leg part, 24, 29 Side wall part, 40 Common mode filter, 41 First capacitor circuit, 41a, 41b, 41c, 41d terminal, 42a, 42b, 42c capacitor, 45 Second capacitor circuit , 45a, 5b, 45c terminal, 46a, 46b, 46c capacitor, 50 series circuit, 60 power change Device, 61 Ground, 62, 64 Power conversion circuit, 62a, 62b Load line, 63 Output filter, 63a, 63b Filter coil, 63c Smoothing capacitor, 66 DC input power supply, 66a AC input power supply, 68 load, 70 Second capacitor Circuit, 70a, 70b, 70c, 70c terminal, 71a, 71b, 71c extraction capacitor, 72a, 72b, 72c single phase reactor, 72a1, 72a2, 72a3, 72a4, 72b1, 72b2, 72b3, 72b4, 72c1, 72c2, 72c3 72c4, 72d1, 72d2, 72d3, 72d4 terminals

Claims (11)

A first coil in which a first conductor having a flat cross section and covered with an insulating layer is wound around the side surface of the first conductor along the flat longitudinal direction;
A second coil in which the periphery is covered with an insulating layer and a second conductor having a flat cross section is wound around the side surface of the second conductor along the flat longitudinal direction;
A magnetic core inserted through each air core portion of the first coil and the second coil;
With
The magnetic core has a closed magnetic path through which a magnetic field generated by a current flowing in the first coil and a magnetic field generated by a current flowing in the second coil pass;
A magnetic field generated by a common mode current flowing through the first coil and passing through the closed magnetic path increases the common mode impedance of the second coil;
A common mode choke coil in which a magnetic field generated by a common mode current flowing through the second coil and passing through the closed magnetic path increases the common mode impedance of the first coil.   The common mode choke coil according to claim 1, wherein the first coil and the second coil are wound by alpha winding.   The common mode choke coil according to claim 1, wherein the first coil and the second coil are wound by flatwise winding.   The common mode choke coil according to claim 1, wherein the insulating layer has a thickness of 50 μm to 500 μm. The first conductor and the second conductor are substantially rectangular in cross section;
5. The common mode choke coil according to claim 1, wherein a ratio between the thicknesses of the first and second conducting wires and the thickness of the insulating layer is 4 to 100 times. A common mode choke connected in series between the power supply circuit and the load to a power conversion circuit that converts DC power or AC power supplied from the power supply circuit to supply AC power or DC power to the load. Coils,
A plurality of first capacitors each having one terminal connected to a plurality of power supply lines connecting the power supply circuit and a series circuit including the power conversion circuit and the common mode choke coil;
A plurality of second capacitors each having one terminal connected to a plurality of load lines connecting the series circuit and the load;
With
The other terminals of the plurality of first capacitors are connected to the other terminals of the plurality of second capacitors,
The common mode choke coil is
A first coil in which a first conductor having a flat cross section and covered with an insulating layer is wound around the side surface of the first conductor along the flat longitudinal direction;
A second coil in which the periphery is covered with an insulating layer and a second conductor having a flat cross section is wound around the side surface of the second conductor along the flat longitudinal direction;
A magnetic core inserted through each air core portion of the first coil and the second coil;
Have
The magnetic core has a closed magnetic path through which a magnetic field generated by a current flowing in the first coil and a magnetic field generated by a current flowing in the second coil pass;
A magnetic field generated by a common mode current flowing through the first coil and passing through the closed magnetic path increases the common mode impedance of the second coil;
A common mode filter in which a magnetic field generated by a common mode current flowing in the second coil and passing through the closed magnetic path increases a common mode impedance of the first coil.   The common mode filter according to claim 6, wherein the common mode choke coil is connected to an input side of the power conversion circuit.   The common mode filter according to claim 6 or 7, wherein the common mode choke coil is connected to an output side of the power conversion circuit. A power conversion circuit that converts DC power or AC power supplied from a power supply circuit to supply AC power or DC power to a load; and
A common mode choke coil connected in series with the power conversion circuit between the power supply circuit and the load;
A plurality of first capacitors each having one terminal connected to a plurality of power supply lines connecting the power supply circuit and a series circuit including the power conversion circuit and the common mode choke coil;
A plurality of second capacitors each having one terminal connected to a plurality of load lines connecting the series circuit and the load;
With
The other terminals of the plurality of first capacitors are connected to the other terminals of the plurality of second capacitors,
The common mode choke coil is
A first coil in which a first conductor having a flat cross section and covered with an insulating layer is wound around the side surface of the first conductor along the flat longitudinal direction;
A second coil in which the periphery is covered with an insulating layer and a second conductor having a flat cross section is wound around the side surface of the second conductor along the flat longitudinal direction;
A magnetic core inserted through each air core portion of the first coil and the second coil;
Have
The magnetic core has a closed magnetic path through which a magnetic field generated by a current flowing in the first coil and a magnetic field generated by a current flowing in the second coil pass;
A magnetic field generated by a common mode current flowing through the first coil and passing through the closed magnetic path increases the common mode impedance of the second coil;
A power conversion device in which a magnetic field generated by a common mode current flowing in the second coil and passing through the closed magnetic circuit increases the common mode impedance of the first coil.   The power converter according to claim 9, wherein the common mode choke coil is connected to an input side of the power converter circuit.   The power converter according to claim 9 or 10, wherein the common mode choke coil is connected to an output side of the power converter circuit.

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