Four-phase different name end coupling magnetic integrated inductor

Abstract

The application discloses a four-phase different-name end coupling magnetic integrated inductor, which comprises an upper cover plate, a lower cover plate, four magnetic columns and four windings; the upper cover plate and the lower cover plate are of the same shape, and the four magnetic columns are of the same shape; the four magnetic columns are uniformly distributed in a horizontal direction around a vertical connecting line of a center point of the upper cover plate and a center point of the lower cover plate; the upper cover plate covers upper surfaces of the four magnetic columns, and the lower cover plate covers lower surfaces of the four magnetic columns; the four-phase different-name end coupling magnetic integrated inductor further comprises a partition air gap; the four windings are of the same structure and are wound on the four magnetic columns respectively to form four-phase inductors which are magnetically coupled; after current excitation is applied to the four windings, magnetic fluxes generated in the four magnetic columns are of the same direction. The four-phase winding different-name end coupling makes the magnetic fluxes generated in the upper cover plate of the magnetic core and the lower cover plate of the magnetic core have the same direction, so that the four-phase inductors can be reduced to a certain extent. The four-phase different-name end coupling magnetic integrated inductor is favorable for reducing inductance current ripple and in turn reducing winding loss, and can improve current uniformity and rated value of the four-phase inductors.

Description

Technical Field

[0001] This invention relates to the field of magnetic integration technology, and in particular to a four-phase non-terminal coupled magnetic integrated inductor. Background Technology

[0002] With the rapid development of industries such as aerospace, electric vehicles, new energy power generation, and green data centers, high efficiency, high power density, and lightweight miniaturization have become new trends in the future development of switching power supplies. The focus of switching power supply development is largely on energy saving, loss reduction, and size reduction in converters. However, magnetic components typically account for about 30% of the total power supply volume, which is detrimental to improving power density.

[0003] There are two main methods to reduce the size of magnetic devices. One is high frequency. However, to reduce core losses and allow for margin, magnetic cores are generally derated at high frequencies, resulting in low core utilization. Furthermore, high frequencies are limited by the converter's operating conditions, thus restricting the miniaturization of magnetic components. The other method is magnetic integration technology. Thanks to advancements in electronic module design and magnetic technology, miniaturization and high-efficiency design of magnetic components have become possible. Currently, magnetic integration technology is an effective solution for reducing the size and parasitic parameters of magnetic components, addressing the increasingly urgent demand for miniaturization and thinner designs in switching power supplies. Meanwhile, gallium nitride high electron mobility transistors (GaN HEMTs), with their high electron mobility, high switching frequency, and low on-resistance, have become a potential advantage for high-frequency power converters. In addition, the emergence of advanced magnetic materials and high-precision magnetic device fabrication technologies allows PCB planar magnetic devices to offer more flexible design options, higher magnetic material utilization efficiency, smaller size, lower magnetic flux density, lower magnetic device losses, and higher power density compared to traditional magnetic devices, providing a new option for magnetic integration design.

[0004] Verification has shown that, compared to inductors coupled at the same terminal, applying inductors coupled at opposite terminals to GaN-based interleaved parallel switching power supplies can reduce magnetic material losses by 40%, thereby improving the power density and efficiency of the converter. To reduce current ripple in switching converters and improve overall converter performance, multiphase interleaved parallel technology based on GaN devices has become an inevitable design trend. Traditional two-phase switching converters need to expand the number of phases to four or more. However, the traditional reverse-coupling structure based on EE or EI type magnetic cores can only be applied to two-phase converters and is not suitable for multiphase converters. Wang Laili et al. proposed a novel four-phase inductor design with opposite terminals. This design has a symmetrical magnetic structure, which can effectively solve the problem of uneven magnetic flux density in the magnetic core. However, this scheme has problems such as redundant magnetic column numbers, large magnetic column flux density, and low core utilization. Furthermore, the core volume is large, making it inconvenient to use. Summary of the Invention

[0005] The object of the present invention is to provide a four-phase opposite-terminal-coupled magnetic integrated inductor, which reduces the volume of magnetic devices, decreases the magnetic flux density of magnetic devices, and improves the utilization rate of magnetic cores by using the opposite-terminal coupling method.

[0006] The technical solution for achieving the object of the present invention is as follows:

[0007] A four-phase opposite-terminal-coupled magnetic integrated inductor includes an upper cover plate, a lower cover plate, four magnetic columns, and four windings; the upper cover plate, the lower cover plate, and the four magnetic columns are all made of magnetic materials; the upper cover plate and the lower cover plate have the same shape, and the four magnetic columns have the same shape; the four magnetic columns are evenly distributed horizontally at equal distances around the vertical connection line of the center points of the upper cover plate and the lower cover plate; the upper cover plate covers the upper surfaces of the four magnetic columns, and the lower cover plate covers the lower surfaces of the four magnetic columns; it further includes a first partition air gap, which is provided between the upper cover plate and the upper surfaces of the four magnetic columns, or between the lower cover plate and the lower surfaces of the four magnetic columns, or the first partition air gap horizontally partitions the four magnetic columns into upper magnetic columns and lower magnetic columns respectively; the four windings have the same structure and are respectively wound around the four magnetic columns to form a magnetically coupled four-phase inductor; after current excitation is applied to the four windings, the magnetic flux directions generated in the four magnetic columns are the same.

[0008] Furthermore, the four magnetic columns are cubes, and their cross-sections are squares; after the four magnetic columns are evenly distributed horizontally at equal distances around the vertical connection line of the center points of the upper cover plate and the lower cover plate, their horizontal outer envelope is also a square; the perimeters of the upper cover plate and the lower cover plate both form a "hui" character shape with the horizontal outer envelope.

[0009] Furthermore, it further includes a second partition air gap; if the first partition air gap is provided between the upper cover plate and the upper surfaces of the four magnetic columns, then the second partition air gap is provided between the lower cover plate and the lower surfaces of the four magnetic columns; if the first partition air gap is provided between the lower cover plate and the lower surfaces of the four magnetic columns, then the second partition air gap is provided between the upper cover plate and the upper surfaces of the four magnetic columns; if the first partition air gap horizontally partitions the four magnetic columns into upper magnetic columns and lower magnetic columns respectively, then the second partition air gap is provided between the upper cover plate and the upper surfaces of the four magnetic columns, or the second partition air gap is provided between the lower cover plate and the lower surfaces of the four magnetic columns.

[0010] Furthermore, it further includes a second partition air gap and a third partition air gap; if the first partition air gap is provided between the upper cover plate and the upper surfaces of the four magnetic columns, then the second partition air gap is provided between the lower cover plate and the lower surfaces of the four magnetic columns, and the third partition air gap horizontally partitions the four magnetic columns into upper magnetic columns and lower magnetic columns respectively.

[0011] Furthermore, the winding is composed of copper foil wound around the periphery of the magnetic column, and an insulator is provided between turns.

[0012] Furthermore, the winding is composed of enameled wire, Litz wire, or printed circuit board wound around the periphery of the magnetic post.

[0013] Furthermore, the four windings are subjected to current excitations in the same phase.

[0014] Furthermore, the four windings are designated as the first, second, third, and fourth windings in either a clockwise or counterclockwise direction; the first winding is applied with a current excitation phase of... The phase of the current excitation applied to the second winding is... The phase of the current excitation applied to the third winding is... The phase of the current excitation applied to the fourth winding is in, Zero phase,

[0015] Furthermore, the four windings are designated as the first, second, third, and fourth windings in either a clockwise or counterclockwise direction; the first winding is applied with a current excitation phase of... The phase of the current excitation applied to the second winding is... The phase of the current excitation applied to the third winding is... The phase of the current excitation applied to the fourth winding is in, Zero phase, and All are greater than 0° and less than or equal to 360°. Furthermore,

[0016] The beneficial effects of this invention are that the four-phase, opposite-terminal coupled magnetic integrated inductor, through the opposite-terminal coupling of the four-phase windings, ensures that the magnetic flux generated by the four-phase inductor current in the upper and lower core cover plates is in the same direction, thereby achieving a certain degree of flux reduction. Compared to four-phase, same-terminal coupled magnetic integrated inductors and four independent inductors, this invention is beneficial for reducing inductor current ripple, thereby reducing winding losses, while also improving the current sharing and rated value of the four-phase inductor current and the transient response speed of the four-phase inductor current. Since the windings can be wound with copper foil, enameled wire, Litz wire, etc., or using printed circuit boards, the space occupied by the windings is reduced. Furthermore, apart from the four magnetic pillars, there are no extra support pillar structures or magnetic material structures between the upper and lower core cover plates, effectively reducing the volume of the four-phase, opposite-terminal coupled magnetic integrated inductor, lowering manufacturing costs, and improving the efficiency and power density of magnetic components. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of Example 1.

[0018] Figure 2This is an exploded view of Example 1. The following are the markings in the figure: upper cover plate 1, lower cover plate 2, first magnetic column 31, second magnetic column 32, third magnetic column 33, fourth magnetic column 34, first phase inductor winding 41, second phase inductor winding 42, third phase inductor winding 43, and fourth phase inductor winding 44.

[0019] Figure 3 This is a schematic diagram of the current direction in Example 1.

[0020] Figure 4 This is a magnetic flux distribution diagram of the upper cover plate in Example 1.

[0021] Figure 5 This is a magnetic flux distribution diagram of the lower cover plate in Example 1.

[0022] Figure 6 The waveform diagram of the winding current (first type of current excitation phase) in Example 1 is shown.

[0023] Figure 7 The waveform diagram of the winding current (second current excitation phase) in Example 1 is shown.

[0024] Figure 8 The waveform diagram of the winding current (third type of current excitation phase) in Example 1 is shown.

[0025] Figure 9 This is a schematic diagram of Example 1 applied to a four-phase parallel Buck converter.

[0026] Figure 10a This is a timing diagram of the first current excitation phase when Example 1 is applied to a four-phase parallel Buck converter.

[0027] Figure 10b This is a timing diagram of the second current excitation phase when Example 1 is applied to a four-phase parallel Buck converter.

[0028] Figure 10c This is a timing diagram of the third current excitation phase when Example 1 is applied to a four-phase parallel Buck converter.

[0029] Figure 11 This is an exploded view of Example 2. The diagram is labeled as follows: upper magnetic core cover 1, lower magnetic core cover 2, first lower magnetic column 31A, second lower magnetic column 32A, third lower magnetic column 33A, fourth lower magnetic column 34A, first upper magnetic column 31B, second upper magnetic column 32B, third upper magnetic column 33B, fourth upper magnetic column 34B, first phase inductor winding 41, second phase inductor winding 42, third phase inductor winding 43, and fourth phase inductor winding 44. Detailed Implementation

[0030] This invention provides a four-phase, non-uniformly coupled magnetic integrated inductor, comprising an upper cover plate, a lower cover plate, four magnetic pillars, and four windings; the upper cover plate, lower cover plate, and four magnetic pillars are all made of magnetic material; the upper cover plate and lower cover plate have the same shape, and the four magnetic pillars have the same shape; the four magnetic pillars are evenly distributed laterally at equal intervals around the vertical line connecting the center point of the upper cover plate and the center point of the lower cover plate; the upper cover plate covers the upper surface of the four magnetic pillars, and the lower cover plate covers the lower surface of the four magnetic pillars; it also includes a first partition air gap, disposed between the upper cover plate and the upper surface of the four magnetic pillars, or between the lower cover plate and the lower surface of the four magnetic pillars, or the first partition air gap laterally partitions the four magnetic pillars into upper and lower magnetic pillars respectively; the four windings have the same structure and are respectively wound on the four magnetic pillars to form a magnetically coupled four-phase inductor; after current excitation is applied to the four windings, the magnetic flux generated in the four magnetic pillars has the same direction.

[0031] The magnetic pillars can be set to different shapes, such as circular, elliptical, or teardrop-shaped cross-sections. The upper and lower cover plates simply cover the upper and lower surfaces of all the magnetic pillars.

[0032] A second isolation air gap can also be provided. The two isolation air gaps can be respectively located between the upper cover plate and the upper surface of the four magnetic pillars, and between the lower cover plate and the lower surface of the four magnetic pillars; alternatively, one isolation air gap can be located between the upper cover plate and the upper surface of the four magnetic pillars, while the other isolation air gap separates the four magnetic pillars into upper and lower magnetic pillars; or one isolation air gap can be located between the lower cover plate and the lower surface of the four magnetic pillars, while the other isolation air gap separates the four magnetic pillars into upper and lower magnetic pillars. By providing the first and second isolation air gaps, the overall volume of the four-phase dissimilarly coupled magnetic integrated inductor can be reduced, increasing the power density. Simultaneously, the magnetic induction intensity in the upper and lower cover plates and the four magnetic pillars of the four-phase dissimilarly coupled magnetic integrated inductor can be further reduced, effectively reducing the possibility of magnetic device saturation and increasing the rated value of the inductor winding current excitation. Furthermore, the magnetic flux at the air gap edges can be effectively reduced, thereby reducing the eddy current loss of the four-phase dissimilarly coupled magnetic integrated inductor and improving device efficiency.

[0033] A second and third isolation air gap can also be provided. These three air gaps are respectively located between the upper cover plate and the upper surface of the four magnetic pillars, between the lower cover plate and the lower surface of the four magnetic pillars, and a third air gap separates the four magnetic pillars into upper and lower magnetic pillars. By setting the first, second, and third isolation air gaps, the power density of the four-phase dissimilarly coupled magnetic integrated inductor can be improved. Simultaneously, the heat generated on the four magnetic pillars can be distributed more evenly, which helps improve the thermal performance of the four-phase dissimilarly coupled magnetic integrated inductor. Furthermore, it can effectively suppress the radiation of the magnetic field to the surrounding environment, reduce electromagnetic interference, and improve the electromagnetic compatibility characteristics of the four-phase dissimilarly coupled magnetic integrated inductor.

[0034] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0035] Embodiment 1:

[0036] As Figure 1 、 Figure 2 shown, the four-phase opposite-terminal-coupled magnetic integrated inductor of this embodiment includes:

[0037] A magnetic core upper cover plate 1, a magnetic core lower cover plate 2, four magnetic columns 3 (marked as 31, 32, 33, 34 in the figure), and a four-phase inductor winding 4 (marked as 41, 42, 43, 44 in the figure). Among them, the magnetic core upper cover plate 1 and the magnetic core lower cover plate 2 have the same shape.

[0038] The four magnetic columns 3 are located between the magnetic core upper cover plate 1 and the magnetic core lower cover plate 2, the four magnetic columns 3 are symmetrically distributed, and the outer envelope forms a zigzag structure with the edges of the magnetic core upper cover plate 1 and the magnetic core lower cover plate 2; while playing a supporting role between the magnetic core upper cover plate 1 and the magnetic core lower cover plate 2, it provides a symmetric magnetic flux path for the four-phase inductor current.

[0039] The four-phase inductor windings 4 are respectively wound around one of the four magnetic columns 3. The inductor windings 4 wound on the four magnetic columns 3 have the same and symmetric structure. The number of turns of the inductor winding on each magnetic column is determined according to the inductance value of the inductor, and can be set to a fractional number of turns. The four-phase windings 4 are conductors passing through the space between the magnetic core upper cover plate 1 and the magnetic core lower cover plate 2 except for the magnetic column around which they are wound. The current flowing through each phase winding generates magnetic flux in the magnetic column around which the winding is wound, the magnetic core upper cover plate 1, and the magnetic core lower cover plate 2.

[0040] The magnetic core upper cover plate 1 and the magnetic core lower cover plate 2 have the same shape and size, and are both square structures. The four magnetic columns 3 are cubes with a square cross-section, and are evenly distributed at equal horizontal distances along the vertical connection line around the center point of the magnetic core upper cover plate 1 and the center point of the magnetic core lower cover plate 2. At the same time, the horizontal outer envelope of the four magnetic columns 3 is also square, and the perimeters of the magnetic core upper cover plate 1 and the magnetic core lower cover plate 2 both form a "zigzag" with the horizontal outer envelope. There is at least one partition air gap between the four magnetic columns 3 and the magnetic core upper cover plate 1 and the magnetic core lower cover plate 2. Between the magnetic core upper cover plate 1 and the magnetic core lower cover plate 2, except for the four magnetic columns 3, there is no other support column structure or magnetic material structure.

[0041] The self-inductance value and mutual-inductance value of the four-phase winding 4 depend on the number of turns of the winding, the air gap between the four magnetic columns 3 and the magnetic core upper cover plate 1 and the lower cover plate 2, the cross-sectional area of the magnetic column, the thickness of the magnetic core upper cover plate 1 and the lower cover plate 2, and the magnetic material.

[0042] Figure 3 For the direction of the current excitation of the four-phase opposite-terminal-coupled magnetic integrated inductor winding. Apply the excitation in the direction shown in Figure 3 shown, the magnetic fluxes generated by the four-phase inductor windings 4 are mutually reduced in the magnetic circuits of the magnetic core upper cover plate 1 and the magnetic core lower cover plate 2, as Figure 4 , Figure 5 As shown.

[0043] Table 1 shows the winding coupling coefficient diagram of the four-phase, non-polar coupled magnetic integrated inductor under the above conditions in finite element simulation. It can be seen that there is magnetic coupling between the four-phase inductor windings 4, and the magnetic coupling coefficients between adjacent phases and diagonally opposite phases are different.

[0044] Table 1

[0045] Winding 1 Winding 2 Winding 3 Winding 4 Winding 1 1 -0.31753 -0.28712 -0.3203 Winding 2 -0.31753 1 -0.32078 -0.28643 Winding 3 -0.28712 -0.32078 1 -0.31771 Winding 4 -0.3203 -0.28643 -0.31771 1

[0046] The four-phase inductor winding 4 is one of copper foil, enameled wire, Litz wire, or printed circuit board wound around the four magnetic pillars 3. If copper foil is used, insulation should be placed between the turns to prevent short circuits.

[0047] When applying current excitation, the current excitation phase of winding 1 can be... Set as zero phase, and the current excitation phase of other windings and All angles must be greater than 0° and less than or equal to 360°.

[0048] As a preferred option, such as Figure 6 As shown, the current excitation phase applied to the four-phase winding 4 is the same. When external factors cause a small phase difference and instantaneous value difference in the excitation of the four-phase inductor windings, the coupling effect of the opposite ends of the integrated magnetic device windings can maintain a high current sharing of the four-phase inductor current. The same current excitation phase can reduce the computing power pressure on the converter controller and overcome the influence of different parasitic parameters of the four-phase inductor windings, making it suitable for low-voltage, high-current converter topologies.

[0049] Another way to set the current excitation phase is, for example Figure 7 As shown, in the clockwise direction, in the four-phase winding 4, the current excitation phase of winding 1 is set. The phase is zero, and the current excitation phase on winding 2 is... The current excitation phase on winding 3 is The current excitation phase on winding 4 is This current excitation phase causes the magnetic flux generated by the four-phase inductor winding 4 to be mutually reduced in the magnetic circuit of the upper core cover plate 1 and the lower core cover plate 2, which helps to reduce inductor current ripple, reduce winding current stress, reduce the size of the integrated inductor core, and is beneficial to thermal management and packaging design.

[0050] Another way to set the current excitation phase is, for example Figure 8 As shown, in the four-phase winding 4, the current excitation phase of winding 1 is set. The phase is zero, and the current excitation phase on winding 2 is zero. The phase is zero, and the current excitation phase on winding 3 is... The current excitation phase on winding 4 is This current excitation phase combines the characteristics of the two aforementioned current excitation phases, which can alleviate the computing power pressure on the controller to a certain extent, while also reducing inductor current ripple and improving the current sharing of the four-phase inductor current. This is beneficial for reducing the size of magnetic components and increasing their power density.

[0051] like Figure 9 As shown, a four-phase parallel Buck converter is applied to a magnetically integrated inductor with four different-named terminals.

[0052] Figure 10a , Figure 10b and Figure 10c This is a timing diagram for a four-phase parallel Buck converter with a four-phase inductor winding coupled with a magnetically integrated inductor. It includes the voltage waveforms of the four-phase inductor windings and the current waveforms of the first-phase inductor winding.

[0053] Example 2:

[0054] like Figure 11 As shown, in this embodiment, the four magnetic pillars 3 are divided into upper and lower parts. The lower magnetic pillars 31A, 32A, 33A, and 34A are connected to the lower cover plate 2 of the magnetic core, while the upper magnetic pillars 31B, 32B, 33B, and 34B are connected to the upper cover plate 1 of the magnetic core. An air gap is provided between the lower magnetic pillars 31A, 32A, 33A, and 34A and the upper magnetic pillars 31B, 32B, 33B, and 34B. This single air gap between the upper and lower magnetic pillars allows for a more uniform magnetic flux distribution in the four magnetic pillars, increases leakage flux, and reduces the coupling coefficient between the four-phase inductor windings. This is beneficial for increasing the equivalent decoupling inductance values ​​of each of the four-phase windings, reducing the losses of the four-phase inductor windings, and improving the working efficiency of the four-phase dissimilarly coupled magnetic integrated inductor. Furthermore, it also improves the anti-magnetic saturation capability of the upper and lower cover plates and the four magnetic pillars, reducing the electromagnetic interference of the four-phase dissimilarly coupled magnetic integrated inductor.

Claims

1. A four-phase, non-terminal coupled magnetic integrated inductor, characterized in that, It includes an upper cover plate, a lower cover plate, four magnetic columns and four windings; the upper cover plate, the lower cover plate and the four magnetic columns are all made of magnetic materials; the upper cover plate and the lower cover plate have the same shape, and the four magnetic columns have the same shape; the four magnetic columns are evenly distributed horizontally at equal distances around the vertical line connecting the center points of the upper cover plate and the lower cover plate; the upper cover plate covers the upper surfaces of the four magnetic columns, and the lower cover plate covers the lower surfaces of the four magnetic columns; it further includes a first partition air gap, which is arranged between the upper cover plate and the upper surfaces of the four magnetic columns, or between the lower cover plate and the lower surfaces of the four magnetic columns, or the first partition air gap transversely partitions the four magnetic columns into upper magnetic columns and lower magnetic columns respectively; the four windings have the same structure and are respectively wound around the four magnetic columns to form a magnetically coupled four-phase inductor; after current excitation is applied to the four windings, the magnetic flux directions generated in the four magnetic columns are the same; the four windings are set as the first, second, third and fourth windings in the clockwise or counterclockwise direction; the current excitation phase applied to the first winding is φ1, the current excitation phase applied to the second winding is φ2, the current excitation phase applied to the third winding is φ3, and the current excitation phase applied to the fourth winding is φ4; wherein, φ1 and φ2 are zero phases, and φ3 = φ4 = 180°.

2. The four-phase, non-terminal coupled magnetic integrated inductor as described in claim 1, characterized in that, The four magnetic columns are cubes, and their cross-sections are squares; after the four magnetic columns are evenly distributed horizontally at equal distances around the vertical line connecting the center points of the upper cover plate and the lower cover plate, their horizontal outer envelope is also a square; the perimeters of the upper cover plate and the lower cover plate both form a "return" shape with the horizontal outer envelope.

3. The four-phase, dissimilarly coupled magnetic integrated inductor as described in claim 1, characterized in that, It further includes a second partition air gap; If the first partition air gap is arranged between the upper cover plate and the upper surfaces of the four magnetic columns, then the second partition air gap is arranged between the lower cover plate and the lower surfaces of the four magnetic columns; If the first partition air gap is arranged between the lower cover plate and the lower surfaces of the four magnetic columns, then the second partition air gap is arranged between the upper cover plate and the upper surfaces of the four magnetic columns; If the first partition air gap transversely partitions the four magnetic columns into upper magnetic columns and lower magnetic columns respectively, then the second partition air gap is arranged between the upper cover plate and the upper surfaces of the four magnetic columns, or the second partition air gap is arranged between the lower cover plate and the lower surfaces of the four magnetic columns.

4. The four-phase, dissimilarly coupled magnetic integrated inductor as described in claim 1, characterized in that, It further includes a second partition air gap and a third partition air gap; if the first partition air gap is arranged between the upper cover plate and the upper surfaces of the four magnetic columns, then the second partition air gap is arranged between the lower cover plate and the lower surfaces of the four magnetic columns, and the third partition air gap transversely partitions the four magnetic columns into upper magnetic columns and lower magnetic columns respectively.

5. The four-phase, non-terminal coupled magnetic integrated inductor as described in claim 1, characterized in that, The winding is composed of copper foil wound around the periphery of the magnetic column, and an insulator is arranged between turns.

6. The four-phase, dissimilarly coupled magnetic integrated inductor as described in claim 1, characterized in that, The winding is composed of enameled wire, Litz wire or printed circuit board wound around the periphery of the magnetic column.

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