Magnetic component and power conversion equipment

Abstract

To reduce an occupied volume of a plurality of inductors and an occupied volume of a plurality of transformers.SOLUTION: In a magnetic component 40, a first core 10a includes: a first middle leg portion 12a; and a pair of first outer leg portions 14a and 16a provided on both sides of the first middle leg portion. A second core 10b includes: a second middle leg portion 12b; and a pair of second outer leg portions 14b and 16b provided on both sides of the second middle leg portion. A first inductor winding 20u is wound around the first middle leg portion 12a. A second inductor winding 20v is wound around the second middle leg portion 12b. A first transformer winding 22u is wound around one first outer leg portion 14a and one second outer leg portion 14b, and is wound around the other first outer leg portion 16a and the other second outer leg portion 16b. The second transformer winding 22v is wound around one first outer leg portion 14a and one second outer leg portion 14b, and is wound around the other first outer leg portion 16a and the other second outer leg portion 16b.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a magnetic component and a power conversion device. [Background technology]

[0002] In recent years, the emergence of next-generation semiconductor power devices such as SiC and GaN has made it possible to achieve high-speed and high-frequency switching in high-voltage ranges of, for example, 600 V or more, which was difficult with conventional silicon devices. As a result, the application of SiC and GaN devices to power conversion equipment used in electric vehicles and other applications is on the rise.

[0003] In such power conversion equipment, the high speed of SiC and GaN devices tends to worsen the level of common-mode noise generated during switching, which means that the size of the required common-mode filter circuit tends to increase in order to meet the noise level standards required by the system.

[0004] Patent Document 1 discloses a filter component in which windings wound around a magnetic core constitute a differential mode inductor and a common mode inductor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-164194 Summary of the Invention [Problem to be solved by the invention]

[0006] A passive common mode noise canceller is known as one type of common mode filter circuit. For example, a passive common mode canceller installed in a single-phase power converter has two common mode transformers with different cores. Some single-phase power converters also have two inductors with different cores. When these common mode transformers and inductors are installed, the occupied volume tends to be large due to the space between the components.

[0007] An object of the present invention is to provide a technique that can reduce the volume occupied by a plurality of inductors and a plurality of transformers. [Means for solving the problem]

[0008] In order to solve the above problems, a magnetic component according to one embodiment of the present invention comprises: a first core having a first center leg and a pair of first outer legs provided on both sides of the first center leg; a second core having a second center leg and a pair of second outer legs provided on both sides of the second center leg; a first inductor winding wound around the first center leg; a second inductor winding wound around the second center leg; a first transformer winding wound around one of the first outer legs and one of the second outer legs and also wound around the other of the first outer legs and the other of the second outer legs; and a second transformer winding wound around one of the first outer legs and one of the second outer legs and also wound around the other of the first outer legs and the other of the second outer legs.

[0009] Another aspect of the present invention is a power conversion device. The device includes a magnetic component, a switching circuit having a first AC node, a second AC node, a first DC node, and a second DC node, and converting power between DC power and AC power by switching operations of switching elements, a first capacitor and a second capacitor connected in series between the first DC node and the second DC node, and a third capacitor and a fourth capacitor connected in series between the first DC node and the second DC node. The magnetic component includes a first core having a first center leg and a pair of first outer legs provided on both sides of the first center leg, a second core having a second center leg and a pair of second outer legs provided on both sides of the second center leg, a first inductor winding wound around the first center leg, a second inductor winding wound around the second center leg, and a third inductor winding wound around one of the first outer legs and one of the second outer legs and a fourth capacitor connected in series between the first outer legs and the other of the first outer legs. the first inductor winding is connected to the first AC node, and the second inductor winding is connected to the second AC node. The first inductor winding is connected to the first AC node, and the second inductor winding is connected to the second AC node. The second inductor winding is connected to the second AC node and the first AC node. The second inductor winding is connected to the second AC node and the second AC node. The first inductor winding is connected to the first AC node. The second inductor winding is connected to the second AC node and the second .... The first inductor winding is connected to the first AC node. The second inductor winding is connected to the second AC node. The first inductor winding is connected to the first AC node. The second inductor winding is connected to the second AC node. The second inductor winding is connected to the second AC node. The first inductor winding is connected to the first AC node. The second inductor winding is connected to the second AC node. The first inductor winding is connected to the second AC node. The second inductor winding is connected to the second AC node. The first inductor winding is connected to the first AC node. The second inductor winding is connected to the second AC node. The second inductor winding is connected to the second AC node. The first inductor winding is connected to the first AC node. The second inductor winding is connected to the second AC node. [Effects of the Invention]

[0010] According to the present invention, a technique can be provided that can reduce the volume occupied by a plurality of inductors and a plurality of transformers. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1(a) is a diagram schematically showing a circuit configuration of a power conversion device according to a first embodiment, and FIG. 1(b) is a diagram for explaining the operation of a noise reduction circuit. [Figure 2] 2(a) to 2(c) are diagrams for explaining the configuration of the magnetic component of FIG. 1(a). [Figure 3] 3(a) to 3(c) are diagrams for explaining the operation of the magnetic component of FIG. 1(a). [Figure 4] 4(a) and 4(b) are diagrams for explaining the operation of the magnetic component of the comparative example. [Figure 5] FIG. 4 is a diagram schematically illustrating a circuit configuration of a power conversion device according to a second embodiment. [Figure 6] 6(a) and 6(b) are diagrams for explaining the configuration of the magnetic component of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] (First embodiment) 1(a) shows a schematic circuit configuration of a power conversion device 1 according to a first embodiment. The power conversion device 1 is an AC / DC converter that converts AC power supplied from an AC power source AC1 to input terminals Tu and Tv into DC power by switching switching elements, and outputs the converted DC power from output terminals T1 and T2.

[0013] The use of the power conversion device 1 is not particularly limited, and it may be mounted, for example, in a charger for a drive battery of an electric vehicle. An electric vehicle is a vehicle that uses an electric motor as a driving power source, and includes, for example, an electric vehicle (Battry Electric Vehicle) or a plug-in hybrid electric vehicle (PHEV).

[0014] 1(a), the power conversion device 1 includes a first inductor L1u, a second inductor L1v, a noise reduction circuit 20, a switching circuit 30, and a control unit 36. Hereinafter, the first inductor L1u and the second inductor L1v will be collectively referred to as the inductor L1 where appropriate.

[0015] The two inductors L1 and the switching circuit 30 constitute a single-phase bridgeless PFC (Power Factor Correction) circuit. That is, the power conversion device 1 is configured by combining a single-phase bridgeless PFC circuit with a noise reduction circuit 20. A known configuration can be used for the single-phase bridgeless PFC circuit.

[0016] The switching circuit 30 includes a first switching element S1, a second switching element S2, a third switching element S3, and a fourth switching element S4. The switching circuit 30 converts power between DC power and AC power through the switching operations of the first switching element S1 to the fourth switching element S4. The first switching element S1 and the second switching element S2 are connected in series to form a u-phase first leg 32u. The connection node between the first switching element S1 and the second switching element S2 is referred to as node u1. The third switching element S3 and the fourth switching element S4 are connected in series to form a v-phase second leg 32v. The connection node between the third switching element S3 and the fourth switching element S4 is referred to as node v1. The first leg 32u and the second leg 32v are connected in parallel between the output terminal T1 and the output terminal T2 to form a full-bridge circuit. The nodes u1 and v1 can also be referred to as AC nodes. The connection node between the first switching element S1 and the third switching element S3 can be called a DC node, and the connection node between the second switching element S2 and the fourth switching element S4 can also be called a DC node.

[0017] The first switching element S1 to the fourth switching element S4 are respectively connected in anti-parallel to or formed with a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The first switching element S1 to the fourth switching element S4 may be, for example, a metal-oxide-semiconductor field-effect transistor (MOSFET) or an insulated gate bipolar transistor (IGBT). The MOSFET may be made of any material that can provide desired characteristics, such as a silicon carbide (SiC) MOSFET, a gallium nitride (GaN) MOSFET, or a silicon MOSFET.

[0018] One end of the AC power supply AC1 is connected to one end of a u-phase first inductor L1u via an input terminal Tu. The other end of the first inductor L1u is connected to a node u1 via a u-phase first transformer winding 22ub and a first transformer winding 22ua of the noise reduction circuit 20, which will be described later.

[0019] The other end of the AC power supply AC1 is connected to one end of a v-phase second inductor L1v via an input terminal Tv. The other end of the second inductor L1v is connected to a node v1 via a v-phase second transformer winding 22vb and a second transformer winding 22va of the noise reduction circuit 20, which will be described later.

[0020] The control unit 36 ​​controls the switching operations of the first switching element S1 to the fourth switching element S4 by known control so that the power conversion device 1 converts AC power into DC power.

[0021] The noise reduction circuit 20 reduces or eliminates common mode noise generated in the power conversion device 1 due to the switching operation of the switching circuit 30. The noise reduction circuit 20 includes a first common mode transformer 26a, a second common mode transformer 26b, and a capacitor circuit 28. The noise reduction circuit 20 is composed of passive elements and does not require active elements. The noise reduction circuit 20 is also called a passive common mode noise canceller (PCC).

[0022] The first common mode transformer 26a has a first core 10a, a first transformer winding 22ua, a second transformer winding 22va, and a first auxiliary winding 24a.

[0023] The second common mode transformer 26b has a second core 10b, a first transformer winding 22ub, a second transformer winding 22vb, and a second auxiliary winding 24b.

[0024] Hereinafter, the first common mode transformer 26a and the second common mode transformer 26b will be collectively referred to as the common mode transformer 26, and the first auxiliary winding 24a and the second auxiliary winding 24b will be collectively referred to as the auxiliary winding 24, where appropriate.

[0025] Each common mode transformer 26 has reverse-coupled windings. Each common mode transformer 26 is inserted into an AC line connecting an AC power supply AC1 and a switching circuit 30. Figure 1(a) shows an equivalent circuit of the common mode transformer 26. The structure of the common mode transformer 26 will be described later.

[0026] The first transformer winding 22ub and the first transformer winding 22ua are connected in series between the other end of the first inductor L1u and the node u1.

[0027] The second transformer winding 22vb and the second transformer winding 22va are connected in series between the other end of the second inductor L1v and the node v1.

[0028] One end of the first auxiliary winding 24a is connected to a node u1, and one end of the second auxiliary winding 24b is connected to a node v1.

[0029] The capacitor circuit 28 includes a first capacitor C1, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4.

[0030] The first capacitor C1 and the second capacitor C2 are connected in series between the output terminals T1 and T2, i.e., between the two DC lines. The connection node between the first capacitor C1 and the second capacitor C2 is referred to as node u2. Node u2 is connected to the other end of the first auxiliary winding 24a.

[0031] The third capacitor C3 and the fourth capacitor C4 are connected in series between the output terminal T1 and the output terminal T2. The connection node between the third capacitor C3 and the fourth capacitor C4 is referred to as node v2. The node v2 is connected to the other end of the second auxiliary winding 24b.

[0032] The first capacitor C1 to the fourth capacitor C4 each have the same capacitance value. The capacitance value can be determined appropriately through experimentation or simulation. The potentials of the nodes u2 and v2 are essentially midpoint potentials between the potentials of the output terminals T1 and T2, and are called midpoint potentials.

[0033] The noise reduction circuit 20 has substantially no effect on the differential AC current flowing through the two AC lines between the AC power supply AC1 and the switching circuit 30.

[0034] FIG. 1(b) is a diagram illustrating the operation of the noise reduction circuit 20. FIG. 1(b) shows a common-mode equivalent circuit for the u-phase. When the midpoint potential of node u2 changes due to the switching operation of the switching circuit 30, the first auxiliary winding 24a of the noise reduction circuit 20 is excited, and the first transformer winding 22ua, which is inversely coupled to the first auxiliary winding 24a, cancels out the voltage, thereby suppressing the common-mode current that is the source of common-mode noise. The common-mode current can also be suppressed in the v-phase in a similar manner.

[0035] The circuit configuration and operation of the noise reduction circuit 20 are well known, and therefore further detailed description will be omitted. The noise reduction circuit 20 can be configured based on the technology disclosed in, for example, the document "Ohara et al., 'Passive Common Noise Canceller Capable of Canceling Common-Mode Voltage Generated by an Inverter,' IEEJ Transactions on Electrical Engineering, Vol. 142, 2022."

[0036] 2(a) to 2(c), what differs from known configurations is that the first inductor L1u, the second inductor L1v, the first common mode transformer 26a, and the second common mode transformer 26b are integrally configured as a magnetic component 40. In the magnetic component 40, the first inductor L1u and the first common mode transformer 26a are configured using a common first core 10a, and the second inductor L1v and the second common mode transformer 26b are configured using a common second core 10b.

[0037] 2(a) to 2(c) are diagrams illustrating the configuration of the magnetic component 40 of FIG. 1(a). As shown in FIGS. 2(a) to 2(c), a Cartesian coordinate system is defined, consisting of an x-axis, a y-axis, and a z-axis. The x-axis extends in the arrangement direction of the outer leg portion 14, the center leg portion 12, and the outer leg portion 16 (described later). The y-axis extends in the extension direction of the center leg portion 12. The x-axis and y-axis are mutually orthogonal. The z-axis is perpendicular to the x-axis and y-axis and extends in the arrangement direction of the first core 10a and the second core 10b. The positive direction of each of the x-axis, y-axis, and z-axis is defined as the direction of the arrow in FIG. 2(a), and the negative direction is defined as the direction opposite to the arrow. Here, the positive side of the x-axis is sometimes referred to as the "right," the negative side of the x-axis is sometimes referred to as the "left," the positive side of the y-axis is sometimes referred to as the "up," and the negative side of the y-axis is sometimes referred to as the "down."

[0038] Fig. 2(a) is a perspective view showing the arrangement of the first core 10a and the second core 10b of the magnetic component 40. In Fig. 2(a), windings are not shown.

[0039] Fig. 2(b) is a cross-sectional view of the magnetic component 40 taken along the line BB in Fig. 2(a). Fig. 2(b) can also be considered a cross-sectional view of the magnetic component 40 taken along a plane parallel to the xy plane including the line BB.

[0040] Fig. 2(c) is a cross-sectional view of the magnetic component 40 taken along line CC in Fig. 2(a). Fig. 2(c) can also be considered a cross-sectional view of the magnetic component 40 taken along a plane parallel to the xz plane including line CC.

[0041] The magnetic component 40 includes a first core 10a, a second core 10b, a first inductor winding 20u, a second inductor winding 20v, a first transformer winding 22u, a second transformer winding 22v, a first auxiliary winding 24a, and a second auxiliary winding 24b. Hereinafter, the first core 10a and the second core 10b will be collectively referred to as the core 10, where appropriate.

[0042] The two cores 10 have the same shape. In the illustrated example, one core 10 is formed by combining two identical E-shaped cores 50, 50. The E-shaped core 50 has a center leg 12, a pair of outer legs 14, 16, and a base 18. The base 18 has a rectangular parallelepiped shape. The center leg 12 protrudes in the y-axis direction from near the center of the base 18 in the x-axis direction. The pair of outer legs 14, 16 are provided on both the left and right sides of the center leg 12 and protrude in the y-axis direction from both left and right ends of the base 18. The height of the center leg 12 is shorter than the height of the pair of outer legs 14, 16.

[0043] The two E-shaped cores 50, 50 are arranged so that the end faces of the center legs 12, 12 face each other, the end faces of the outer legs 14, 14 are in contact with each other, and the end faces of the outer legs 16, 16 are in contact with each other.

[0044] The first core 10a has a first center leg 12a, a pair of first outer legs 14a and 16a, and a pair of first bases 18a. The pair of first bases 18a are formed by the bases 18 of two E-shaped cores 50.

[0045] The first center leg 12a is made up of the center legs 12, 12 of the two E-shaped cores 50, 50. The first center leg 12a extends in the vertical direction between the pair of first base portions 18a, 18a and is divided by a gap 19a.

[0046] The first outer leg 14a is made up of the outer legs 14, 14 of the two E-shaped cores 50, 50. The first outer leg 14a extends in the vertical direction between the pair of first base portions 18a, 18a. The first outer leg 16a is made up of the outer legs 16, 16 of the two E-shaped cores 50, 50. The first outer leg 16a extends in the vertical direction between the pair of first base portions 18a, 18a. The pair of first outer legs 14a, 16a are provided on both the left and right sides of the first center leg 12a.

[0047] The magnetic resistance of the first center leg 12a is greater than the magnetic resistance of each of the pair of first outer legs 14a, 16a.

[0048] The second core 10b has a second center leg 12b, a pair of second outer legs 14b, 16b, and a pair of second bases 18b, 18b. The pair of second bases 18b, 18b are formed by the bases 18, 18 of two E-shaped cores 50, 50.

[0049] The second center leg 12b is made up of the center legs 12, 12 of the two E-shaped cores 50, 50. The second center leg 12b extends in the vertical direction between the pair of second base portions 18b, 18b, and is divided by a gap 19b.

[0050] The second outer leg 14b is made up of the outer legs 14, 14 of the two E-shaped cores 50, 50. The second outer leg 14b extends in the vertical direction between the pair of second base portions 18b, 18b. The second outer leg 16b is made up of the outer legs 16, 16 of the two E-shaped cores 50, 50. The second outer leg 16b extends in the vertical direction between the pair of second base portions 18b, 18b. The pair of second outer legs 14b, 16b are provided on both the left and right sides of the second center leg 12b.

[0051] The magnetic resistance of the second center leg 12b is greater than the magnetic resistance of each of the pair of second outer legs 14b, 16b.

[0052] The first core 10a and the second core 10b are arranged side by side in the z-axis direction at a predetermined interval, with the first center leg 12a and the second center leg 12b adjacent to each other, the first outer leg 14a and the second outer leg 14b adjacent to each other, and the first outer leg 16a and the second outer leg 16b adjacent to each other, and the directions in which the legs extend are substantially parallel. When viewed from the z-axis direction, the first core 10a and the second core 10b substantially overlap.

[0053] The core 10 is made of a magnetic material. Various known materials such as ferrite can be used as the magnetic material. As shown in FIG. 2(c), the cross-sectional shape of each of the center leg 12 and the outer legs 14, 16 is rectangular in this example, but is not limited thereto and may be polygonal, circular, elliptical, or the like. Each core 10 has a known shape with three legs. Each core 10 may be made based on a core of a shape other than an E-shaped core as long as it has three legs.

[0054] The first inductor winding 20u is wound around the first center leg 12a of the first core 10a. The first inductor winding 20u corresponds to the first inductor L1u in FIG. 1(a). One end 20u1 of the first inductor winding 20u is connected to, for example, the input terminal Tu in FIG. 1(a). The other end 20u2 of the first inductor winding 20u is connected to, for example, the first transformer windings 22ua and 22ub connected in series in FIG. 1(a).

[0055] The second inductor winding 20v is wound around the second center leg 12b of the second core 10b. The second inductor winding 20v corresponds to the second inductor L1v in FIG. 1(a). One end 20v1 of the second inductor winding 20v is connected to, for example, the input terminal Tv in FIG. 1(a). The other end 20v2 of the second inductor winding 20v is connected to, for example, the second transformer windings 22va and 22vb connected in series in FIG. 1(a).

[0056] For example, the number of turns of the first inductor winding 20u is equal to the number of turns of the second inductor winding 20v. The number of turns of the first inductor winding 20u and the number of turns of the second inductor winding 20v can be determined appropriately by experiment or simulation depending on the required inductance.

[0057] The first transformer winding 22u is wound n times (n is a natural number) around one first outer leg 14a and one second outer leg 14b, and is wound n times around the other first outer leg 16a and the other second outer leg 16b. In the illustrated example, n is 1. n can be determined as appropriate through experiments or simulations.

[0058] The first transformer winding 22u is configured by connecting in series a first winding portion 221u wound n times around one first outer leg 14a and one second outer leg 14b, and a second winding portion 222u wound n times around the other first outer leg 16a and the other second outer leg 16b. The first transformer winding 22u may be configured from a single electric wire.

[0059] In other words, it can be said that the number of turns of the first transformer winding 22u is divided into two equal parts, with half the number of turns wound around one first outer leg 14a and one second outer leg 14b, and further half the number of turns wound around the other first outer leg 16a and the other second outer leg 16b.

[0060] The first transformer winding 22u corresponds to the first transformer windings 22ua and 22ub connected in series in the circuit diagram of Fig. 1(a). One end 22u1 of the first transformer winding 22u is connected to, for example, node u1 in Fig. 1(a). The other end 22u2 of the first transformer winding 22u is connected to, for example, the other end of the first inductor L1u in Fig. 1(a).

[0061] The second transformer winding 22v is wound n times around one first outer leg 14a and one second outer leg 14b, and is also wound n times around the other first outer leg 16a and the other second outer leg 16b.

[0062] The second transformer winding 22v is configured by connecting in series a third winding portion 221v wound n times around one first outer leg 14a and one second outer leg 14b, and a fourth winding portion 222v wound n times around the other first outer leg 16a and the other second outer leg 16b. The second transformer winding 22v may also be configured from a single electric wire.

[0063] In other words, the number of turns of the second transformer winding 22v is divided into two equal parts, with half the number of turns wound around one first outer leg 14a and one second outer leg 14b, and further half the number of turns wound around the other first outer leg 16a and the other second outer leg 16b.

[0064] The second transformer winding 22v corresponds to the second transformer windings 22va and 22vb connected in series in the circuit diagram of Fig. 1(a). One end 22v1 of the second transformer winding 22v is connected to, for example, the node v1 in Fig. 1(a). The other end 22v2 of the second transformer winding 22v is connected to, for example, the other end of the second inductor L1v in Fig. 1(a).

[0065] 2(c), for example, the winding of the first transformer winding 22u begins at one end 22u1, extends in the z-axis direction, passes through one of the first outer legs 14a, is wound around one of the second outer legs 14b, extends in the negative direction of the z-axis, and passes through one of the first outer legs 14a. As a result, the first transformer winding 22u is wound once around one of the first outer legs 14a and one of the second outer legs 14b. Next, the first transformer winding 22u extends in the x-axis direction, passes through the other first outer leg 16a, extends in the z-axis direction, passes through the other first outer leg 16a, is wound around the other second outer leg 16b, extends in the negative direction of the z-axis, and passes through the other first outer leg 16a, and is finished at the other end 22u2. As a result, the first transformer winding 22u is wound once around the other first outer leg 16a and the other second outer leg 16b.

[0066] The second transformer winding 22v is also wound along the same path as the first transformer winding 22u, from one end 22v1 to the other end 22v2. In other words, the first transformer winding 22u and the second transformer winding 22v are wound around the first core 10a and the second core 10b along the same path.

[0067] 2(c), when viewed from the direction in which the first center leg 12a extends, the winding direction of the first winding portion 221u is the same as the winding direction of the third winding portion 221v. When viewed from the direction in which the first center leg 12a extends, the winding direction of the second winding portion 222u is the same as the winding direction of the fourth winding portion 222v. When viewed from the direction in which the first center leg 12a extends, the winding direction of the first winding portion 221u is opposite to the winding direction of the second winding portion 222u.

[0068] It can also be said that the first transformer winding 22u is wound so that the induced electromotive forces generated in the first winding section 221u and the second winding section 222u by the current flowing through the first inductor winding 20u cancel each other out, and that the induced electromotive forces generated in the first winding section 221u and the second winding section 222u by the current flowing through the second inductor winding 20v cancel each other out.

[0069] It can also be said that the second transformer winding 22v is wound so that the induced electromotive forces generated in the third winding section 221v and the fourth winding section 222v by the current flowing through the first inductor winding 20u cancel each other out, and that the induced electromotive forces generated in the third winding section 221v and the fourth winding section 222v by the current flowing through the second inductor winding 20v cancel each other out.

[0070] The first auxiliary winding 24a is wound 2n times around one first outer leg 14a and 2n times around the other first outer leg 16a. One end 24a1 of the first auxiliary winding 24a is connected to, for example, node u1 in FIG. 1(a) as described above. The other end 24a2 of the first auxiliary winding 24a is connected to, for example, node u2 in FIG. 1(a) as described above.

[0071] The second auxiliary winding 24b is wound 2n times around one second outer leg 14b and 2n times around the other second outer leg 14b. One end 24b1 of the second auxiliary winding 24b is connected to, for example, node v1 in FIG. 1(a) as described above. The other end 24b2 of the second auxiliary winding 24b is connected to, for example, node v2 in FIG. 1(a) as described above.

[0072] 2(c), for example, the first auxiliary winding 24a starts winding from one end 24a1, is wound two times around one first outer leg 14a, extends in the x-axis direction, is wound two times around the other first outer leg 16a, and finishes winding at the other end 24a2. When viewed from the direction in which the first center leg 12a extends, the winding direction of the first auxiliary winding 24a around one first outer leg 14a is opposite to the winding direction of the first auxiliary winding 24a around the other first outer leg 16a. When viewed from the direction in which the first center leg 12a extends, the winding direction of the first auxiliary winding 24a around one first outer leg 14a is the same as the winding direction of the first winding portion 221u.

[0073] The second auxiliary winding 24b starts winding from one end 24b1, is wound two times around one second outer leg 14b, extends in the x-axis direction, and is wound two times around the other second outer leg 16b before finishing at the other end 24b2. When viewed from the direction in which the first center leg 12a extends, the winding direction of the second auxiliary winding 24b around one second outer leg 14b is opposite to the winding direction of the second auxiliary winding 24b around the other second outer leg 16b. When viewed from the direction in which the first center leg 12a extends, the winding direction of the second auxiliary winding 24b around one second outer leg 14b is the same as the winding direction of the first winding portion 221u.

[0074] Thus, the turns ratio of the first transformer winding 22u, the second transformer winding 22v, and the single auxiliary winding 24 is 2n:2n:4n. This turns ratio can also be expressed as m:m:2m, where m is an even number.

[0075] 3(a) to 3(c) are diagrams for explaining the operation of the magnetic component 40 of FIG. 1(a). FIG. 3(a) schematically shows a path B1 of magnetic flux when a current flows through the first inductor winding 20u in the cross-sectional view of FIG. 2(b). A current flows from the front to the back of the page in FIG. 3(a) through the first inductor winding 20u on the left side of the first center leg 12a, and a current flows from the back to the front of the page in FIG. 3(a) through the first inductor winding 20u on the right side of the first center leg 12a. The direction of the magnetic flux is indicated by an arrow on path B1.

[0076] FIG. 3(b) shows, in the cross-sectional view of FIG. 2(c), the induced electromotive forces V1u and V2u generated in the first transformer winding 22u and the induced electromotive forces V1v and V2v generated in the second transformer winding 22v when a current I1 flows through the first inductor winding 20u in the same direction as in FIG. 3(a). The current I1 in the first inductor winding 20u flows in the direction of the arrow, i.e., from one end 20u1 to the other end 20u2. Magnetic flux flows through the first center leg 12a from the front to the back of the page in FIG. 3(b), and magnetic flux flows through the first outer legs 14a and 16a from the back to the front of the page in FIG. 3(b). Note that the second inductor winding 20v and the auxiliary winding 24 are omitted from FIG. 3(b) for clarity.

[0077] 3(b), the induced electromotive forces V1u and V2u generated in the first transformer winding 22u due to the current I1 flowing through the first inductor winding 20u are canceled out within the first transformer winding 22u. This is because the number of turns of the first winding portion 221u and the number of turns of the second winding portion 222u are equal, so the magnitudes of the induced electromotive forces V1u and V2u are substantially equal, and furthermore, the winding directions of the first winding portion 221u and the second winding portion 222u are opposite, so the directions of the induced electromotive forces V1u and V2u are opposite to each other.

[0078] Similarly, the induced electromotive forces V1v and V2v generated in the second transformer winding 22v are canceled out within the second transformer winding 22v because the number of turns of the third winding portion 221v is equal to the number of turns of the fourth winding portion 222v, and further, the winding direction of the third winding portion 221v is opposite to the winding direction of the fourth winding portion 222v.

[0079] Although not shown in the figure, the induced electromotive force generated in the first transformer winding 22u due to the current flowing through the second inductor winding 20v is also canceled out, and the induced electromotive force generated in the second transformer winding 22v due to the current flowing through the second inductor winding 20v is also canceled out.

[0080] Therefore, the currents flowing through the first inductor winding 20u and the second inductor winding 20v due to the operation of the single-phase bridgeless PFC circuit can be prevented from interfering with the operation of the noise reduction circuit 20.

[0081] 3(c) schematically shows a path B2 of magnetic flux when a current flows through the first transformer winding 22u, the second transformer winding 22v, or the first auxiliary winding 24a in the cross-sectional view of FIG. 2(b). The direction of the magnetic flux is indicated by an arrow on the path B2.

[0082] 3(c), magnetic flux generated by the current in the first transformer winding 22u and the like flows through the first outer legs 14a and 16a, which have a relatively low magnetic resistance, and does not flow through the first center leg 12a, which has a relatively high magnetic resistance. As a result, changes in magnetic flux caused by the operation of the noise reduction circuit 20 do not affect the current in the first inductor winding 20u and the second inductor winding 20v. This prevents changes in magnetic flux caused by the operation of the noise reduction circuit 20 from interfering with the operation of the first inductor L1u and the second inductor L1v, i.e., the operation of the single-phase bridgeless PFC circuit.

[0083] The magnetic resistance of the first center leg 12a may be equal to that of each of the pair of first outer legs 14a, 16a. The magnetic resistance of the second center leg 12b may also be equal. In this case, a portion of the magnetic flux flowing through the right-side first outer leg 16a passes through the upper first base portion 18a and then flows downward through the first center leg 12a. A portion of the magnetic flux flowing through the left-side first outer leg 14a passes through the lower first base portion 18a and then flows upward through the first center leg 12a. Because the magnetic fluxes flowing through these first center legs 12a cancel each other out within the first center leg 12a, even if the magnetic resistances are equal, changes in magnetic flux caused by the operation of the noise reduction circuit 20 do not affect the currents in the first inductor winding 20u and the second inductor winding 20v.

[0084] As described above, according to the embodiment, the core of the first inductor L1u and the core of the first common mode transformer 26a can be integrated into the first core 10a, and the core of the second inductor L1v and the core of the second common mode transformer 26b can be integrated into the second core 10b. Furthermore, it is possible to prevent the current in the first inductor winding 20u from interfering with the operation of the first common mode transformer 26a and the second common mode transformer 26b. It is also possible to prevent the current in the second inductor winding 20v from interfering with the operation of the first common mode transformer 26a and the second common mode transformer 26b.

[0085] This makes it possible to integrate the first inductor L1u, the second inductor L1v, the first common mode transformer 26a, and the second common mode transformer 26b into a single magnetic component 40. This reduces the space between components and the volume occupied by the multiple inductors L1 and the multiple common mode transformers 26. According to studies by the present inventors, as an example, in a 10 kW single-phase bridgeless PFC circuit, the volume occupied by the first inductor L1u, the second inductor L1v, the first common mode transformer 26a, and the second common mode transformer 26b can be reduced by approximately 25% compared to when individual components without integrated cores are implemented.

[0086] Therefore, it is possible to reduce the size of the power conversion device 1 including the noise reduction circuit 20 while maintaining electrical performance. Even if the switching operation of the switching elements becomes faster and more frequent, an increase in the size of the power conversion device 1 can be suppressed.

[0087] Now, let us consider a magnetic component 40X as a comparative example. The present inventors have recognized that when attempting to integrate the first inductor L1u, the second inductor L1v, the first common mode transformer 26a, and the second common mode transformer 26b shown in FIG. 1(a), it is likely that the configuration shown in FIGS. 4(a) and 4(b) will be reached.

[0088] 4(a) and 4(b) are diagrams illustrating the operation of a magnetic component 40X of a comparative example. FIG. 4(a) shows a cross-sectional view of the magnetic component 40X corresponding to FIG. 2(b). FIG. 4(b) shows a cross-sectional view of the magnetic component 40X corresponding to FIG. 2(c). Note that in FIG. 4(b), the second inductor winding 20v, the first auxiliary winding 24a, and the second auxiliary winding 24b are omitted for clarity.

[0089] In the comparative example, the winding methods of the first inductor winding 20u, the second inductor winding 20v, the first auxiliary winding 24a, and the second auxiliary winding 24b are the same as those in the embodiment, but the winding methods of the first transformer winding 22u and the second transformer winding 22v are different from those in the embodiment. That is, as shown in Figures 4(a) and 4(b), the first transformer winding 22u is wound twice around one first outer leg 14a and one second outer leg 14b, and is not wound around the other first outer leg 16a and the other second outer leg 16b. The second transformer winding 22v is wound twice around the other first outer leg 16a and the other second outer leg 16b, and is not wound around one first outer leg 14a and one second outer leg 14b.

[0090] Figure 4(a) also shows a schematic diagram of a path B1 of magnetic flux when a current flows through the first inductor winding 20u in the same direction as in Figure 3(a). Figure 4(b) also shows an induced electromotive force V1u generated in the first transformer winding 22u and an induced electromotive force V1v generated in the second transformer winding 22v when a current I1 flows through the first inductor winding 20u.

[0091] 4(a) and 4(b), in the comparative example, when a current flows through the first inductor winding 20u, magnetic flux is linked to each of the first transformer winding 22u and the second transformer winding 22v, and an induced electromotive force V1u is generated in the first transformer winding 22u, and an induced electromotive force V1v is generated in the second transformer winding 22v. Therefore, in the configuration of the magnetic component 40X of the comparative example, the core of the inductor L1 and the core of the common mode transformer 26 are integrated, so that the operation of the single-phase bridgeless PFC circuit affects the operation of the noise reduction circuit 20 via the first inductor winding 20u and the second inductor winding 20v.

[0092] In contrast to this, in the embodiment, the winding method of the first transformer winding 22u and the second transformer winding 22v is devised, so that, as described above, even if the cores are integrated, the operation of the single-phase bridgeless PFC circuit and the operation of the noise reduction circuit 20 are less likely to interfere with each other.

[0093] (Second embodiment) The second embodiment differs from the first embodiment in that a noise reduction circuit is combined with a three-phase bridgeless PFC circuit. The following description will focus on the differences from the first embodiment.

[0094] 5 is a schematic diagram showing a circuit configuration of a power conversion device 1A according to the second embodiment. The power conversion device 1A is a three-phase AC / DC converter that converts three-phase AC power supplied from AC power sources ACu, ACv, and ACw to input terminals Tu, Tv, and Tw into DC power by switching switching elements, and outputs the converted DC power from output terminals T1 and T2.

[0095] 5, the power conversion device 1A includes a first inductor L1u, a second inductor L1v, a third inductor L1w, a noise reduction circuit 20A, a switching circuit 30A, and a control unit 36A. The first inductor L1u, the second inductor L1v, the third inductor L1w, and the switching circuit 30A configure a three-phase bridgeless PFC circuit.

[0096] The switching circuit 30A further includes a fifth switching element S5 and a sixth switching element S6 in addition to the configuration shown in FIG. 1(a). The fifth switching element S5 and the sixth switching element S6 are connected in series to form a w-phase third leg 32w. The connection node between the fifth switching element S5 and the sixth switching element S6 is designated as node w1. The first leg 32u, the second leg 32v, and the third leg 32w are connected in parallel between the output terminal T1 and the output terminal T2. A fifth diode D5 and a sixth diode D6 are connected in antiparallel to or formed in antiparallel with the fifth switching element S5 and the sixth switching element S6, respectively.

[0097] One end of a u-phase AC power supply ACu is connected to one end of a u-phase first inductor L1u via an input terminal Tu. The other end of the first inductor L1u is connected to a node u1 via first transformer windings 22uc, 22ub, and 22ua of a noise reduction circuit 20A, which will be described later.

[0098] One end of the v-phase AC power supply ACv is connected to one end of the v-phase second inductor L1v via an input terminal Tv. The other end of the second inductor L1v is connected to a node v1 via second transformer windings 22vc, 22vb, and 22va of a noise reduction circuit 20A, which will be described later.

[0099] One end of the w-phase AC power supply ACw is connected to one end of the w-phase third inductor L1w via the input terminal Tw. The other end of the third inductor L1w is connected to a node w1 via third transformer windings 22wc, 22wb, and 22wa of the noise reduction circuit 20A, which will be described later. The other ends of the AC power supplies ACu, ACv, and ACw are connected in common.

[0100] The control unit 36A controls the switching operations of the first switching element S1 to the sixth switching element S6 by known control so that the power conversion device 1A converts three-phase AC power into DC power.

[0101] The noise reduction circuit 20A includes a first common mode transformer 26Aa, a second common mode transformer 26Ab, a third common mode transformer 26Ac, and a capacitor circuit 28A. Hereinafter, the first common mode transformer 26Aa to the third common mode transformer 26Ac will be collectively referred to as common mode transformer 26A where appropriate.

[0102] The first common mode transformer 26Aa has a first core 10a, a first transformer winding 22ua, a second transformer winding 22va, a third transformer winding 22wa, and a first auxiliary winding 24a. The first core 10a is shown in Figures 6(a) and 6(b). The second core 10b and third core 10c, which will be described later, are also similarly configured.

[0103] The second common mode transformer 26Ab has a second core 10b, a first transformer winding 22ub, a second transformer winding 22vb, a third transformer winding 22wb, and a second auxiliary winding 24b.

[0104] The third common mode transformer 26Ac has a third core 10c, a first transformer winding 22uc, a second transformer winding 22vc, a third transformer winding 22wc, and a third auxiliary winding 24c.

[0105] Each common mode transformer 26A has reverse-coupled windings and is inserted into three AC lines connecting AC power supplies ACu, ACv, and ACw to the switching circuit 30A.

[0106] The first transformer windings 22uc, 22ub, and 22ua are connected in series between the other end of the first inductor L1u and node u1. The second transformer windings 22vc, 22vb, and 22va are connected in series between the other end of the second inductor L1v and node v1. The third transformer windings 22wc, 22wb, and 22wa are connected in series between the other end of the third inductor L1w and node w1. One end of the third auxiliary winding 24c is connected to node w1.

[0107] The capacitor circuit 28A further includes a fifth capacitor C5 and a sixth capacitor C6 in addition to the configuration of FIG. 1(a). The fifth capacitor C5 and the sixth capacitor C6 are connected in series between the output terminal T1 and the output terminal T2. The connection node between the fifth capacitor C5 and the sixth capacitor C6 is designated as node w2. The node w2 is connected to the other end of the third auxiliary winding 24c. The first capacitor C1 to the sixth capacitor C6 each have the same capacitance value. The potential of the node w2 is also the midpoint potential.

[0108] The noise reduction circuit 20A does not substantially affect the AC current flowing through the three AC lines between the AC power supplies ACu, ACv, and ACw and the switching circuit 30A. On the other hand, the noise reduction circuit 20A can suppress common mode currents for each of the u-phase, v-phase, and w-phase.

[0109] The first inductor L1u, the second inductor L1v, the third inductor L1w, the first common mode transformer 26Aa, the second common mode transformer 26Ab, and the third common mode transformer 26Ac are integrally configured as a magnetic component 40A.

[0110] Figures 6(a) and (b) are diagrams for explaining the configuration of the magnetic component 40A in Figure 5. Figure 6(a) is a perspective view showing the arrangement of the first core 10a, the second core 10b, and the third core 10c of the magnetic component 40A. In Figure 6(a), windings are not shown.

[0111] Fig. 6(b) is a cross-sectional view of magnetic component 40A taken along line DD in Fig. 6(a). Fig. 6(b) can also be considered a cross-sectional view of magnetic component 40A cut along a plane parallel to the xz plane including line DD.

[0112] In addition to the configuration of the magnetic component 40 of the first embodiment, the magnetic component 40A further includes a third core 10c, a third inductor winding 20w, a third transformer winding 22w, and a third auxiliary winding 24c. Hereinafter, the first core 10a to the third core 10c will be collectively referred to as core 10 where appropriate.

[0113] The third core 10c has the same shape as the first core 10a. The third core 10c has a third center leg 12c, a pair of third outer legs 14c, 16c, and a pair of third bases 18c, 18c. The third center leg 12c extends vertically between the pair of third bases 18c, 18c and is separated by a gap 19c. The third outer leg 14c extends vertically between the pair of third bases 18c, 18c. The third outer leg 16c extends vertically between the pair of third bases 18c, 18c. The pair of third outer legs 14c, 16c are provided on both the left and right sides of the third center leg 12c. The magnetic reluctance of the third center leg 12c is greater than the magnetic reluctance of each of the pair of third outer legs 14c, 16c.

[0114] The first core 10a and the second core 10b are arranged in the same manner as in Figure 2(a). The second core 10b and the third core 10c are arranged side by side at a predetermined interval in the z-axis direction, with the second center leg 12b and the third center leg 12c adjacent to each other, the second outer leg 14b and the third outer leg 14c adjacent to each other, and the second outer leg 16b and the third outer leg 16c adjacent to each other, and the directions in which the respective legs extend are substantially parallel. When viewed from the z-axis direction, the three cores 10 substantially overlap.

[0115] The third inductor winding 20w is wound around the third center leg 12c of the third core 10c. The third inductor winding 20w corresponds to the third inductor L1w in FIG. 5. One end 20w1 of the third inductor winding 20w is connected to, for example, the input terminal Tw in FIG. 5. The other end 20w2 of the third inductor winding 20w is connected to, for example, the third transformer windings 22wa, 22wb, and 22wc connected in series in FIG. 5. For example, the first inductor winding 20u to the third inductor winding 20w each have the same number of turns.

[0116] The first transformer winding 22u is wound n times around one of the first outer legs 14a, one of the second outer legs 14b, and one of the third outer legs 14c, and is also wound n times around the other of the first outer legs 16a, the other of the second outer legs 16b, and the other of the third outer legs 16c. In the illustrated example, n is "1."

[0117] The first transformer winding 22u is configured by connecting in series a first winding portion 221u wound n times around one first outer leg 14a, one second outer leg 14b, and one third outer leg 14c, and a second winding portion 222u wound n times around the other first outer leg 16a, the other second outer leg 16b, and the other third outer leg 16c.

[0118] The first transformer winding 22u corresponds to the first transformer windings 22ua, 22ub, and 22uc connected in series in the circuit diagram of Fig. 5. One end 22u1 of the first transformer winding 22u is connected to, for example, node u1 in Fig. 5. The other end 22u2 of the first transformer winding 22u is connected to, for example, the other end of the first inductor L1u in Fig. 5.

[0119] The second transformer winding 22v is wound n times around one of the first outer legs 14a, one of the second outer legs 14b, and one of the third outer legs 14c, and is also wound n times around the other of the first outer legs 16a, the other of the second outer legs 16b, and the other of the third outer legs 16c.

[0120] The second transformer winding 22v is configured by connecting in series a third winding portion 221v wound n times around one first outer leg 14a, one second outer leg 14b, and one third outer leg 14c, and a fourth winding portion 222v wound n times around the other first outer leg 16a, the other second outer leg 16b, and the other third outer leg 16c.

[0121] The second transformer winding 22v corresponds to the second transformer windings 22va, 22vb, and 22vc connected in series in the circuit diagram of Fig. 5. One end 22v1 of the second transformer winding 22v is connected to, for example, node v1 in Fig. 5. The other end 22v2 of the second transformer winding 22v is connected to, for example, the other end of the second inductor L1v in Fig. 5.

[0122] The third transformer winding 22w is wound n times around one of the first outer legs 14a, one of the second outer legs 14b, and one of the third outer legs 14c, and is also wound n times around the other of the first outer legs 16a, the other of the second outer legs 16b, and the other of the third outer legs 16c.

[0123] The third transformer winding 22w is configured by connecting in series a fifth winding portion 221w wound n times around one of the first outer legs 14a, one of the second outer legs 14b, and one of the third outer legs 14c, and a sixth winding portion 222w wound n times around the other of the first outer legs 16a, the other of the second outer legs 16b, and the other of the third outer legs 16c.

[0124] The third transformer winding 22w corresponds to the third transformer windings 22wa, 22wb, and 22wc connected in series in the circuit diagram of Fig. 5. One end 22w1 of the third transformer winding 22w is connected to, for example, the node w1 in Fig. 5. The other end 22w2 of the third transformer winding 22w is connected to, for example, the other end of the third inductor L1w in Fig. 5.

[0125] That is, the first transformer winding 22u, the second transformer winding 22v, and the third transformer winding 22w are wound around the first core 10a, the second core 10b, and the third core 10c, respectively, via the same paths.

[0126] 6(b), when viewed from the direction in which the first center leg 12a extends, the winding direction of the first winding portion 221u, the winding direction of the third winding portion 221v, and the winding direction of the fifth winding portion 221w are the same. When viewed from the direction in which the first center leg 12a extends, the winding direction of the second winding portion 222u, the winding direction of the fourth winding portion 222v, and the winding direction of the sixth winding portion 222w are the same. When viewed from the direction in which the first center leg 12a extends, the winding direction of the first winding portion 221u and the winding direction of the second winding portion 222u are opposite.

[0127] It can also be said that the first transformer winding 22u is wound so that the induced electromotive forces generated in the first winding section 221u and the second winding section 222u by the current flowing through the first inductor winding 20u cancel each other out, the induced electromotive forces generated in the first winding section 221u and the second winding section 222u by the current flowing through the second inductor winding 20v cancel each other out, and the induced electromotive forces generated in the first winding section 221u and the second winding section 222u by the current flowing through the third inductor winding 20w cancel each other out.

[0128] It can also be said that the second transformer winding 22v is wound so that the induced electromotive forces generated in the third winding section 221v and the fourth winding section 222v by the current flowing through the first inductor winding 20u cancel each other out, the induced electromotive forces generated in the third winding section 221v and the fourth winding section 222v by the current flowing through the second inductor winding 20v cancel each other out, and the induced electromotive forces generated in the third winding section 221v and the fourth winding section 222v by the current flowing through the third inductor winding 20w cancel each other out.

[0129] It can also be said that the third transformer winding 22w is wound so that the induced electromotive forces generated in the fifth winding section 221w and the sixth winding section 222w by the current flowing through the first inductor winding 20u cancel each other out, the induced electromotive forces generated in the fifth winding section 221w and the sixth winding section 222w by the current flowing through the second inductor winding 20v cancel each other out, and the induced electromotive forces generated in the fifth winding section 221w and the sixth winding section 222w by the current flowing through the third inductor winding 20w cancel each other out.

[0130] The third auxiliary winding 24c is wound 2n times around one third outer leg 14c and 2n times around the other third outer leg 16c. One end 24c1 of the third auxiliary winding 24c is connected to, for example, node w1 in FIG. 5 as described above. The other end 24c2 of the third auxiliary winding 24c is connected to, for example, node w2 in FIG. 5 as described above.

[0131] Thus, the turns ratio of the first transformer winding 22u, the second transformer winding 22v, the third transformer winding 22w, and the single auxiliary winding 24 is 2n:2n:2n:6n. This turns ratio can also be expressed as m:m:m:3m, where m is an even number.

[0132] With this configuration, the core of third inductor L1w and the core of third common-mode transformer 26Ac can be integrated into third core 10c. This makes it possible to prevent currents flowing through first inductor winding 20u, second inductor winding 20v, and third inductor winding 20w due to operation of the three-phase bridgeless PFC circuit from interfering with the operation of noise reduction circuit 20A. It also makes it possible to prevent magnetic flux changes caused by operation of noise reduction circuit 20A from interfering with the operation of first inductor L1u, second inductor L1v, and third inductor L1w, i.e., the operation of the three-phase bridgeless PFC circuit.

[0133] This allows the first inductor L1u, the second inductor L1v, the third inductor L1w, the first common mode transformer 26Aa, the second common mode transformer 26Ab, and the third common mode transformer 26Ac to be integrated into a single magnetic component 40A. The reduction in the volume occupied by the multiple inductors L1 and the multiple common mode transformers 26A tends to be greater than in the case of a single phase.

[0134] The present invention has been described above based on the embodiments. However, the embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each treatment process, and that such modifications are also within the scope of the present invention.

[0135] For example, in the first and second embodiments, an example in which the noise reduction circuits 20 and 20A are combined with a bridgeless PFC circuit has been described. However, this is not limiting. For example, a power conversion device may be configured by combining the noise reduction circuits 20 and 20A with another power conversion circuit, such as an inverter that converts DC power to AC power. In the case of a single-phase inverter, the noise reduction circuit 20 of the first embodiment may be combined, and a first common-mode transformer 26a and a second common-mode transformer 26b may be inserted in the AC line on the output side of the inverter's switching circuit, and a capacitor circuit 28 may be connected between two DC lines on the input side of the switching circuit. The first inductor L1u and the second inductor L1v may be inserted in each of the two AC lines. Similarly, in the case of a three-phase inverter, the noise reduction circuit 20A of the second embodiment may be combined, and three common-mode transformers 26A may be inserted in the AC lines of the switching circuit, and a capacitor circuit 28A may be connected between two DC lines of the switching circuit. The first inductor L1u to the third inductor L1w may be inserted into each of the three AC lines.

[0136] Alternatively, a power conversion device may be configured by combining a noise reduction circuit with a power conversion circuit compatible with four or more phases of AC power. In this case, the number of cores 10, inductors L1, and common mode transformers 26 and 26A may be the same as the number of phases.

[0137] Furthermore, in the first and second embodiments, each inductor L1 is connected between the AC power supply and the switching circuit 30, 30A, but this is not limiting. Depending on the circuit type of the power conversion device and the function to be provided by the inductor L1, each inductor L1 may be connected to another position, such as a DC line. In this case, each inductor L1 may be connected directly to the switching circuit without any other element therebetween, or may be connected indirectly to the switching circuit via another element. [Explanation of symbols]

[0138] 1,1A...power conversion device, 10...core, 10a...first core, 10b...second core, 10c...third core, 12...center leg, 12a...first center leg, 12b...second center leg, 12c...third center leg, 14...outer leg, 14a...first outer leg, 14b...second outer leg, 14c...third outer leg, 16...outer leg, 16a...first outer leg, 16b...second outer leg, 1 6c...third outer leg, 20, 20A...noise reduction circuit, 20u...first inductor winding, 20v...second inductor winding, 20w...third inductor winding, 22u...first transformer winding, 22v...second transformer winding, 22w...third transformer winding, 24...auxiliary winding, 24a...first auxiliary winding, 24b...second auxiliary winding, 24c...third auxiliary winding, 2 6, 26A...common mode transformer, 26a, 26Aa...first common mode transformer, 26b, 26Ab...second common mode transformer, 26c, 26Ac...third common mode transformer, 28, 28A...capacitor circuit, 30, 30A...switching circuit, 40, 40A...magnetic component, 221u...first winding section, 221v...third winding section, 221w...fifth winding section, 222u...second winding section, 222v...fourth winding section, 222w...sixth winding section, C1...first capacitor, C2...second capacitor, C3...third capacitor, C4...fourth capacitor, C5...fifth capacitor, C6...sixth capacitor, L1u...first inductor, L1v...second inductor, L1w...third inductor.

Claims

1. a first core having a first center leg portion and a pair of first outer leg portions provided on both sides of the first center leg portion; a second core having a second center leg portion and a pair of second outer leg portions provided on both sides of the second center leg portion; a first inductor winding wound around the first middle leg; a second inductor winding wound around the second middle leg; a first transformer winding wound around one of the first outer legs and one of the second outer legs and also wound around the other of the first outer legs and the other of the second outer legs; a second transformer winding wound around one of the first outer legs and one of the second outer legs and also wound around the other of the first outer legs and the other of the second outer legs; A magnetic component comprising:

2. the first transformer winding includes a first winding portion wound around the one first outer leg and the one second outer leg, and a second winding portion wound around the other first outer leg and the other second outer leg, the second transformer winding includes a third winding portion wound around the one first outer leg and the one second outer leg, and a fourth winding portion wound around the other first outer leg and the other second outer leg, the first transformer winding is wound so that induced electromotive forces generated in the first winding section and the second winding section by a current flowing through the first inductor winding cancel each other out, and so that induced electromotive forces generated in the first winding section and the second winding section by a current flowing through the second inductor winding cancel each other out, the second transformer winding is wound so that induced electromotive forces generated in the third winding section and the fourth winding section by a current flowing through the first inductor winding cancel each other out, and so that induced electromotive forces generated in the third winding section and the fourth winding section by a current flowing through the second inductor winding cancel each other out.

2. The magnetic component according to claim 1.

3. the first transformer winding is wound n (n is a natural number) times around the one first outer leg and the one second outer leg, and is wound n times around the other first outer leg and the other second outer leg, the second transformer winding is wound n times around the one first outer leg and the one second outer leg, and is wound n times around the other first outer leg and the other second outer leg, a first auxiliary winding wound 2n times around the one first outer leg and wound 2n times around the other first outer leg; a second auxiliary winding wound 2n times around the one second outer leg and wound 2n times around the other second outer leg; The magnetic component according to claim 1 or 2, further comprising:

4. a third core having a third center leg portion and a pair of third outer leg portions provided on both sides of the third center leg portion; a third inductor winding wound around the third middle leg; a third transformer winding wound around the one first outer leg, the one second outer leg, and one third outer leg, and also wound around the other first outer leg, the other second outer leg, and the other third outer leg; Furthermore, the first transformer winding and the second transformer winding are wound around the one first outer leg, the one second outer leg, and the one third outer leg, respectively, and are also wound around the other first outer leg, the other second outer leg, and the other third outer leg, respectively.

2. The magnetic component according to claim 1.

5. A magnetic component; a switching circuit having a first AC node, a second AC node, a first DC node, and a second DC node, and converting power between DC power and AC power by switching operations of switching elements; a first capacitor and a second capacitor connected in series between the first DC node and the second DC node; a third capacitor and a fourth capacitor connected in series between the first DC node and the second DC node; Equipped with The magnetic component is a first core having a first center leg portion and a pair of first outer leg portions provided on both sides of the first center leg portion; a second core having a second center leg portion and a pair of second outer leg portions provided on both sides of the second center leg portion; a first inductor winding wound around the first middle leg; a second inductor winding wound around the second middle leg; a first transformer winding wound around one of the first outer legs and one of the second outer legs and also wound around the other of the first outer legs and the other of the second outer legs; a second transformer winding wound around one of the first outer legs and one of the second outer legs and also wound around the other of the first outer legs and the other of the second outer legs; a first auxiliary winding wound around the one first outer leg and also wound around the other first outer leg; a second auxiliary winding wound around the one second outer leg and the other second outer leg; and the first inductor winding and the second inductor winding are each connected to the switching circuit; the first transformer winding is connected to the first AC node; the second transformer winding is connected to the second AC node; the first auxiliary winding is connected between a connection node of the first capacitor and the second capacitor and the first AC node; the second auxiliary winding is connected between a connection node of the third capacitor and the fourth capacitor and the second AC node. A power conversion device characterized by:

Images