Three-phase high-frequency inductor with multiplexed magnetic circuit

Abstract

The application discloses a three-phase high-frequency inductor with multiplexed magnetic circuit, which comprises A, B and C phase inductor winding magnetic cores adopting a character-shaped frame structure, and the magnetic core adopts the character-shaped frame structure, which is surrounded by upper magnetic core cross beams (1), lower magnetic core cross beams (2), first magnetic core vertical columns (3), second magnetic core vertical columns (4), third magnetic core vertical columns (5) and fourth magnetic core vertical columns (6) to form left windows (10), middle windows (11) and right windows (12); the A phase magnetic flux Φa and the B phase magnetic flux Φb in the second magnetic core vertical column are in phase, and the B phase magnetic flux Φb and the C phase magnetic flux Φc in the third magnetic core vertical column are in phase; the magnetic circuit is multiplexed, the magnetic circuit of the B phase is equivalent to the magnetic circuit of the A phase and the C phase, the volume and weight of the magnetic element are reduced, the cost is reduced, the heat loss is reduced, and the heat dissipation of the magnetic element is optimized.

Description

Technical Field

[0001] This invention relates to inductors, and more particularly to a three-phase high-frequency inductor with a multiplexed magnetic circuit. Background Technology

[0002] Common three-phase PFC topologies include three-phase six-switch, Vienna topology, and their variations, as shown in the following topology structures: Figure 1 and Figure 2 As shown. Their characteristic is that the three input inductors La, Lb, and Lc are symmetrical, with identical inductance, size, and material during design. The three inductors also operate in the same way, with the same input current but a 120° phase difference. Therefore, in similar applications, to reduce the size of the magnetic core, a shared three-phase core is often chosen in the inductor design. However, in existing three-phase integrated inductors, some magnetic flux cancels out in the shared core, preventing further reduction in component size and resulting in persistently high magnetic losses.

[0003] Therefore, how to design a compact, low-magnetic-loss, and well-heat-dissipating three-phase high-frequency inductor is a technical problem that the industry urgently needs to solve. Summary of the Invention

[0004] To address the aforementioned deficiencies in the existing technology, this invention proposes a three-phase high-frequency inductor with a multiplexed magnetic circuit.

[0005] The technical solution adopted in this invention is to design a three-phase high-frequency inductor with a multiplexed magnetic circuit, including an A-phase inductor winding, a B-phase inductor winding, a C-phase inductor winding, and a magnetic core. The magnetic core adopts a U-shaped frame structure, which is formed by an upper magnetic core beam, a lower magnetic core beam, a first magnetic core column, a second magnetic core column, a third magnetic core column, and a fourth magnetic core column, creating a left window, a middle window, and a right window. The A-phase inductor winding is wound around the side walls of the left window, generating an A-phase magnetic flux Φa. The B-phase inductor winding is wound around the side walls of the middle window, generating a B-phase magnetic flux Φb. The C-phase inductor winding is wound around the side walls of the right window, generating a C-phase magnetic flux Φc. The A-phase magnetic flux Φa and the B-phase magnetic flux Φb in the second magnetic core column are in phase, and the B-phase magnetic flux Φb and the C-phase magnetic flux Φc in the third magnetic core column are in phase.

[0006] The A-phase inductor winding is divided into two sections, which are respectively wound on the upper and lower magnetic core beams at the location of the left window; the B-phase inductor winding is divided into two sections, which are respectively wound on the upper and lower magnetic core beams at the location of the middle window; the C-phase inductor winding is divided into two sections, which are respectively wound on the upper and lower magnetic core beams at the location of the right window.

[0007] In one design scheme, the A-phase inductor winding, B-phase inductor winding, and C-phase inductor winding all adopt a left-hand helical winding structure; wherein the current in the A-phase and C-phase inductor windings flows from the beginning to the end of the winding, and the current in the B-phase inductor winding flows from the end to the beginning of the winding; or the current in the A-phase and C-phase inductor windings flows from the end to the beginning of the winding, and the current in the B-phase inductor winding flows from the beginning to the end of the winding.

[0008] In another design, the A-phase, B-phase, and C-phase inductor windings all adopt a right-hand helical winding structure. The current in the A-phase and C-phase inductor windings flows from the beginning to the end of the winding, while the current in the B-phase inductor winding flows from the end to the beginning of the winding; or the current in the A-phase and C-phase inductor windings flows from the end to the beginning of the winding, while the current in the B-phase inductor winding flows from the beginning to the end of the winding.

[0009] In another design scheme, both the A-phase inductor winding and the C-phase inductor winding adopt a left-hand spiral winding structure, and the B-phase inductor winding adopts a right-hand spiral winding structure; wherein the current in the A-phase, B-phase and C-phase inductor windings all flows from the beginning to the end of the winding; or the current in the A-phase, B-phase and C-phase inductor windings all flows from the end to the beginning of the winding.

[0010] In another design, both the A-phase and C-phase inductor windings adopt a right-hand helical winding structure, while the B-phase inductor winding adopts a left-hand helical winding structure; wherein the current in the A-phase, B-phase, and C-phase inductor windings flows from the beginning to the end of the winding; or the current in the A-phase, B-phase, and C-phase inductor windings flows from the end to the beginning of the winding.

[0011] Each phase inductor winding is divided into two sections, with the two sections having the same number of turns, and are wound on the upper magnetic core beam and the lower magnetic core beam, respectively.

[0012] The beneficial effects of the technical solution provided by this invention are as follows: First, it reuses the magnetic circuit. Originally, each phase required a magnetic circuit, but through this design, it is equivalent to phase B reusing the magnetic circuits of phases A and C. Second, it reduces the size and weight of the magnetic components, making installation easier than three separate magnetic components and significantly reducing installation difficulty. Third, it reduces costs by reducing the size. Fourth, it reduces heat loss. The loss of a magnetic component is proportional to its size; reducing the size reduces the loss. The reduced magnetic flux in the reused part significantly reduces heat generation, thus optimizing the heat dissipation of the magnetic components. Attached Figure Description

[0013] The present invention will now be described in detail with reference to the embodiments and accompanying drawings, wherein:

[0014] Figure 1 This is a schematic diagram of a three-phase PFC topology;

[0015] Figure 2This is a schematic diagram of a three-phase Vienna PFC topology;

[0016] Figure 3 This is a schematic diagram of an existing three-phase high-frequency inductor structure;

[0017] Figure 4 This is a schematic diagram of the winding of the present invention, which changes the direction of the B-phase current to make the magnetic flux the same;

[0018] Figure 5 This is a schematic diagram of the winding of the present invention, which changes the winding to make the magnetic flux the same;

[0019] Figure 6 This is a schematic diagram of the temperature distribution of an existing three-phase high-frequency inductor;

[0020] Figure 7 This is a schematic diagram of the temperature distribution of the three-phase high-frequency inductor of the present invention;

[0021] Figure 8 This is a comparison diagram of the existing inductance flux curves and those of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0023] The three-phase high-frequency inductor proposed in this invention reuses the magnetic circuit by using magnetic flux cancellation in a three-phase power system, thereby reducing the effective cross-sectional area, which can reduce the volume and weight of the magnetic components, and thus reduce the cost. Reducing the volume will reduce the loss of the entire magnetic component and optimize heat dissipation.

[0024] See Figure 3 The diagram shows a schematic of an existing three-phase high-frequency inductor structure. The phase difference between each phase voltage of the three-phase power grid is 120°. Assume: , ; The magnetic flux can be obtained as follows: ; ; If the number of turns in the winding is equal, then the magnetic flux generated by the three-phase alternating current will also be the same in magnitude, with a phase difference of 120°. According to... Figure 3 In the winding method shown, the magnetic flux at the intersection of phase A and phase B is in opposite directions. Therefore, according to the rule of vector subtraction, the magnetic flux at the common core is... In this case, the volume of the magnetic flux will be reduced by 0.27 compared to a completely independent solution without a shared magnetic core, but the cross-sectional area of ​​the shared part will be separate. However, if the magnetic flux in the common section is in phase, then according to the rule of vector addition... The amplitude of the magnetic flux remains unchanged compared to the original, only the phase changes. Therefore, under this design, the effective cross-sectional area of ​​the shared magnetic core does not increase, thus reducing the volume of the magnetic component.

[0025] This invention discloses a three-phase high-frequency inductor with a multiplexed magnetic circuit, see below. Figure 4 The three-phase high-frequency inductor includes an A-phase inductor winding 7, a B-phase inductor winding 8, a C-phase inductor winding 9, and a magnetic core. The magnetic core adopts a U-shaped frame structure, which is formed by an upper magnetic core beam 1, a lower magnetic core beam 2, a first magnetic core column 3, a second magnetic core column 4, a third magnetic core column 5, and a fourth magnetic core column 6, forming a left window 10, a middle window 11, and a right window 12. The A-phase inductor winding is wound around the side walls of the left window, generating an A-phase magnetic flux Φa. The B-phase inductor winding is wound around the side walls of the middle window, generating a B-phase magnetic flux Φb. The C-phase inductor winding is wound around the side walls of the right window, generating a C-phase magnetic flux Φc. The A-phase magnetic flux Φa and the B-phase magnetic flux Φb in the second magnetic core column are in phase, and the B-phase magnetic flux Φb and the C-phase magnetic flux Φc in the third magnetic core column are in phase.

[0026] It should be noted that, for the sake of convenience, this article uses many directional and quantitative terms, such as: up and down, left, middle and right, head and tail, first, second, third and fourth. These terms are used to describe the positional relationship of each component, to facilitate comparison with the accompanying drawings, and to help people understand the present invention, but are not intended to limit the present invention.

[0027] In a preferred embodiment, the A-phase inductor winding 7 is divided into two segments, which are respectively wound around the upper magnetic core beam 1 and the lower magnetic core beam 2 at the location of the left window 10; the B-phase inductor winding 8 is divided into two segments, which are respectively wound around the upper magnetic core beam 1 and the lower magnetic core beam 2 at the location of the middle window 11; and the C-phase inductor winding 9 is divided into two segments, which are respectively wound around the upper magnetic core beam 1 and the lower magnetic core beam 2 at the location of the right window 12.

[0028] See Figure 4 One embodiment shown: the A-phase inductor winding 7, the B-phase inductor winding 8, and the C-phase inductor winding 9 all adopt a left-hand spiral winding structure; wherein the current in the A-phase and C-phase inductor windings flows from the beginning to the end of the winding, and the current in the B-phase inductor winding flows from the end to the beginning of the winding; or the current in the A-phase and C-phase inductor windings flows from the end to the beginning of the winding, and the current in the B-phase inductor winding flows from the beginning to the end of the winding.

[0029] This invention maintains the same magnetic flux direction in the common part of a three-phase shared magnetic core by changing the winding or current flow direction. Utilizing the 120° phase difference of a three-phase power grid, the amplitude of the magnetic flux in the common part remains constant, effectively reducing the core size. Figure 4Taking the second magnetic core column 4 as an example, according to the rule of vector addition... The amplitude of the magnetic flux remains unchanged compared to the original, only the phase changes. Therefore, under this design, the effective cross-sectional area of ​​the shared magnetic core does not increase, thus reducing the volume of the magnetic component. Figure 8 A comparison diagram of the existing inductor flux curves and those of the present invention is shown. This is a simulation diagram. The curve of the A-phase flux generated by the A-phase inductor winding is shown as "Φa". If the flux is subtracted in the shared second core column 4, the resulting curve is shown as "Φa-Φb", which is 1.73 times larger than Φa. If the flux is added in the shared second core column 4, the resulting curve is shown as "Φa+Φb", and the flux magnitude is the same as that of a single phase. With the present invention, the flux in the shared core column does not increase, thereby reducing the inductor volume and losses.

[0030] For schemes where the winding direction does not need to be changed, the magnetic flux of the shared core on both sides can be altered by changing the direction of the current flow in phase B. For the magnetic components, phase B can also be kept unchanged while changing the current flow directions in phases A and C. For example... Figure 4 As shown. In another embodiment, the A-phase inductor winding 7, the B-phase inductor winding 8, and the C-phase inductor winding 9 all adopt a right-hand helical winding structure, wherein the current in the A-phase and C-phase inductor windings flows from the beginning to the end of the winding, and the current in the B-phase inductor winding flows from the end to the beginning of the winding; or the current in the A-phase and C-phase inductor windings flows from the end to the beginning of the winding, and the current in the B-phase inductor winding flows from the beginning to the end of the winding.

[0031] For solutions where changing the current direction is inconvenient, the magnetic flux direction can be altered by modifying the winding method. The same effect can be achieved by simply reversing the winding direction of phase B compared to phases A and C. For example... Figure 5 As shown.

[0032] In another embodiment, both the A-phase inductor winding 7 and the C-phase inductor winding 9 adopt a left-hand spiral winding structure, and the B-phase inductor winding 8 adopts a right-hand spiral winding structure; wherein the current in the A-phase, B-phase and C-phase inductor windings all flows from the beginning to the end of the winding; or the current in the A-phase, B-phase and C-phase inductor windings all flows from the end to the beginning of the winding.

[0033] In another embodiment, both the A-phase inductor winding 7 and the C-phase inductor winding 9 adopt a right-hand spiral winding structure, and the B-phase inductor winding 8 adopts a left-hand spiral winding structure; wherein the current in the A-phase, B-phase and C-phase inductor windings flows from the beginning to the end of the winding; or the current in the A-phase, B-phase and C-phase inductor windings flows from the end to the beginning of the winding.

[0034] Following this approach, a simulation was performed on the same inductor. Under the same heat dissipation conditions and the same current input magnitude, only the direction of the input B-phase current was changed, and a significant difference was found in the final losses and heat dissipation. Figure 6 Temperature distribution according to Figure 3 The temperature distribution under the current flow. Figure 7 Temperature distribution is according to Figure 4 The temperature distribution under the current flow direction is shown. Comparing the temperatures under these two conditions, it can be seen that the temperature of the central magnetic core decreased by 18°C ​​after changing the current direction, which in turn led to a certain degree of temperature decrease in the entire inductor.

[0035] In a three-phase power grid, magnetic component systems that share three-phase power can be designed using this approach. In the part with a shared magnetic core, the magnetic flux is canceled out as much as possible by changing the direction of the magnetic flux. In simple terms, this can be achieved by making the current flow direction of phase B different, or by making the winding of phase B different.

[0036] Each phase inductor winding is divided into two sections, with the two sections having the same number of turns, and are wound on the upper magnetic core beam 1 and the lower magnetic core beam 2, respectively.

[0037] The above embodiments are merely illustrative and not intended to be limiting. Any equivalent modifications or alterations made without departing from the spirit and scope of this application should be included within the scope of the claims of this application.

Claims

1. A three-phase high-frequency inductor with a multiplexed magnetic circuit, comprising an A-phase inductor winding (7), a B-phase inductor winding (8), a C-phase inductor winding (9), and a magnetic core, characterized in that: The magnetic core adopts a zig-shaped frame structure, which is formed by the upper magnetic core beam (1), the lower magnetic core beam (2), the first magnetic core column (3), the second magnetic core column (4), the third magnetic core column (5), and the fourth magnetic core column (6) to form a left window (10), a middle window (11), and a right window (12); the A-phase inductor winding (7) is wound around the side wall of the left window (10) to generate A-phase magnetic flux Φa, the B-phase inductor winding (8) is wound around the side wall of the middle window (11) to generate B-phase magnetic flux Φb, and the C-phase inductor winding (9) is wound around the side wall of the right window (12) to generate C-phase magnetic flux Φc. The second magnetic core column (4) is a shared magnetic column for phases A and B, wherein Φa and Φb are in phase and cancel each other out. The third magnetic core column (5) is a shared magnetic column for phases B and C, wherein Φb and Φc are in phase and cancel each other out, thereby realizing the reuse of the magnetic circuits of phases A and C in phase B. The A-phase inductor winding (7), B-phase inductor winding (8), and C-phase inductor winding (9) are all divided into two sections with the same number of turns. The two sections are wound on the upper magnetic core beam (1) and the lower magnetic core beam (2) at the corresponding window positions, forming a symmetrical winding structure. The coordination between the winding method and the current flow direction ensures that the magnetic flux in the common magnetic column is in phase, specifically through any of the following methods: Method 1: The three-phase inductor windings A, B, and C all adopt a left-hand helical winding structure. The current of the A and C phase inductor windings flows from the beginning to the end, and the current of the B phase inductor winding flows from the end to the beginning; or the current of the A and C phase inductor windings flows from the end to the beginning, and the current of the B phase inductor winding flows from the beginning to the end. Method 2: All three phase inductor windings A, B, and C adopt a right-hand helical winding structure. The current in the A and C phase inductor windings flows from the beginning to the end, and the current in the B phase inductor winding flows from the end to the beginning; or the current in the A and C phase inductor windings flows from the end to the beginning, and the current in the B phase inductor winding flows from the beginning to the end. Method 3: The A and C phase inductor windings adopt a left-hand spiral winding structure, and the B phase inductor winding adopts a right-hand spiral winding structure. The current of the three phase inductor windings A, B, and C all flows from the beginning to the end; or all flows from the end to the beginning. Method 4: The A and C phase inductor windings adopt a right-hand helical winding structure, and the B phase inductor winding adopts a left-hand helical winding structure. The current of the three phase inductor windings A, B, and C all flows from the beginning to the end; or all flows from the end to the beginning.

2. The three-phase high-frequency inductor with a multiplexed magnetic circuit as described in claim 1, characterized in that: The A-phase inductor winding (7) is divided into two sections, which are wound on the upper magnetic core beam (1) and the lower magnetic core beam (2) at the location of the left window (10), respectively; the B-phase inductor winding (8) is divided into two sections, which are wound on the upper magnetic core beam (1) and the lower magnetic core beam (2) at the location of the middle window (11), respectively; the C-phase inductor winding (9) is divided into two sections, which are wound on the upper magnetic core beam (1) and the lower magnetic core beam (2) at the location of the right window (12), respectively.

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