EP4662686A1

EP4662686A1 - Flux shaping inductor structures for reduced high-frequency losses

Info

Publication number: EP4662686A1
Application number: EP24711699.9A
Authority: EP
Inventors: Jizheng Qiu; Kartik Iyer
Original assignee: Tesla Inc
Current assignee: Tesla Inc
Priority date: 2023-02-06
Filing date: 2024-02-05
Publication date: 2025-12-17
Also published as: JP2026503776A; CN120677538A; WO2024167847A1; KR20250125423A

Abstract

A flux-shaping inductor structure for reduced high-frequency losses is proposed. The inductor structure may include a top core, a bottom core, and one or more center posts disposed between the top core and the bottom core. The inductor structure may also include a winding, at least portion of the winding disposed between the top core and the bottom core. The top core may include at least one top flux shaping plate that vertically overlaps at least a portion of the winding.

Description

FLUX SHAPING INDUCTOR STRUCTURES FOR REDUCED HIGH-FREQUENCY

LOSSES

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Patent Application No. 63/483,434 titled “FLUX SHAPING INDUCTOR STRUCTURES FOR REDUCED HIGH-FREQUENCY LOSSES” and filed on February 6, 2023, the disclosure of which is hereby incorporated herein by reference in its entirety.

BACKGROUND

Field of the Invention

[0002] The present disclosure relates to flux-shaping inductor structures for reduced high- frequency losses.

Background

[0003] Magnetic components, such as electronic transformers or inductors, generally include conductors (such as windings) wound around cores. They come in many shapes and sizes and can serve different functions (e.g., energy storage, enabling a converter soft-switching operation).

[0004] Conventional high-power, high-frequency inductor designs are usually built with core structures having a single air gap. The flux-density distribution in them is highly non- uniform and the energy density is low, causing a relatively higher energy loss and a larger footprint design. Recently, different multi-gap core structures have been proposed with potcores. One example is found in: “J. Schafer, D. Bortis and J. W. Kolar, “Novel Highly Efficient/Compact Automotive PCB Winding Inductors Based on the Compensating Air gap Fringing Field Concept,” in IEEE Transactions on Power Electronics, vol. 35, no. 9, pp. 9617- 9631, Sept. 2020, doi: 10. 1109/TPEL.2020.2969295.” However, the structures disclosed in the paper are difficult to manufacture and assemble because they consist of multiple annular rings of different radii. SUMMARY

[0005] The embodiments disclosed herein each have several aspects, no single one of which is solely responsible for the disclosure’s desirable attributes. Without limiting the scope of this disclosure, its more prominent features will now be briefly discussed. After considering this discussion, and particularly after reading the section entitled “Detailed Description,” one will understand how the features of the embodiments described herein provide advantages over existing inductor structures.

[0006] One aspect is an inductor structure that comprises a top core comprising at least a top center flux shaping plate, a bottom core, a center post vertically disposed between the top center flux shaping plate and the bottom core, and a winding disposed between the top core and the bottom core and surrounding the center post, where the center flux shaping plate may partially overlap at least a portion of the winding.

[0007] In the above inductor structure, the inductor structure further comprises an enclosure enclosing the top core, the bottom core, and the winding.

[0008] In the above inductor structure, the top core further comprises a first top flux shaping plate and a second top flux shaping plate disposed on opposite sides of the top center flux shaping plate.

[0009] In the above inductor structure, a first top air gap is disposed between the first top flux shaping plate and the top center flux shaping plate, and a second air gap is disposed between the top center flux shaping plate and the second top flux shaping plate.

[0010] In the above inductor structure, the top core further comprises a first additional top flux shaping plate disposed between the top center flux shaping plate and the first top flux shaping plate and a second additional top flux shaping plate disposed between the top center flux shaping plate and the second top flux shaping plate.

[0011] In the above inductor structure, the inductor structure further comprises a heat sink disposed below the bottom core.

[0012] In the above inductor structure, the winding is integrated into a printed circuit board.

[0013] In the above inductor structure, the winding comprises a plurality of winding layers.

[0014] In the above inductor structure, winding is disposed at a middle point of the top core and the bottom core. [0015] In the above inductor structure, the winding is disposed in proximity to the bottom core.

[0016] In the above inductor structure, a portion of the winding is disposed outside of the inductor structure.

[0017] Another aspect is an inductor structure that comprises a top core comprising a top center flux shaping plate, a first top flux shaping plate, and a second top flux shaping plate, a bottom core comprising a bottom center flux shaping plate, a first bottom flux shaping plate, and a second bottom flux shaping plate, a center post vertically disposed between the top center flux shaping plate and the bottom center flux shaping plate, and a winding disposed between the top core and the bottom core and surrounding the center post.

[0018] In the above inductor structure, a first top air gap is disposed between the first top flux shaping plate and the top center flux shaping plate.

[0019] In the above inductor structure, a second air gap is disposed between the top center flux shaping plate and the second top flux shaping plate.

[0020] In the above inductor structure, a first bottom air gap is disposed between the first bottom flux shaping plate and the bottom center flux shaping plate.

[0021] In the above inductor structure, a second air gap is disposed between the bottom center flux shaping plate and the second bottom flux shaping plate.

[0022] In the above inductor structure, the top core further comprises a first additional top flux shaping plate disposed between the top center flux shaping plate and the first top flux shaping plate and a second additional top flux shaping plate disposed between the top center flux shaping plate and the second top flux shaping plate.

[0023] In the above inductor structure, the bottom core further comprises a first additional bottom flux shaping plate disposed between the bottom center flux shaping plate and the first bottom flux shaping plate and a second additional bottom flux shaping plate disposed between the bottom center flux shaping plate and the second bottom flux shaping plate.

[0024] In the above inductor structure, the winding comprises a plurality of winding layers.

[0025] In the above inductor structure, the winding is disposed at a middle point of the top core and the bottom core. [0026] Any of the features of an aspect is applicable to all aspects identified herein. Moreover, any of the features of an aspect is independently combinable, partly or wholly with other aspects described herein in any way, e.g., one, two, or three or more aspects may be combinable in whole or in part. Further, any of the features of an aspect may be made optional to other aspects.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The foregoing and other features of the disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through the use of the accompanying drawings.

[0028] FIG. 1 illustrates a simplified schematic diagram of an example high-frequency inductor and transformer design.

[0029] FIG. 2 illustrates examples of inductor structures with flux shaping according to some embodiments.

[0030] FIG. 3A illustrates an example of a cross-sectional view of an enclosed pot core structure with flux shaping according to some embodiments.

[0031] FIG. 3B illustrates an example perspective view of the enclosed pot core structure of FIG. 3A according to some embodiments.

[0032] FIG. 3C illustrates anear-field distribution of the enclosed pot core structure of FIG.

3A according to some embodiments.

[0033] FIG. 3D illustrates comparative stray magnetic fields.

[0034] FIG. 3E illustrates a graph of an Ohmic loss comparison layer-layer for inductor devices having the same inductance and same footprint.

[0035] FIG. 4A, FIG. 4B, and FIG. 4C illustrate an example of an open EE inductor structure with flux shaping on top and bottom cores according to some embodiments.

[0036] FIG. 4D illustrates flux lines for the open EE inductor structure shown in FIGs. 4A-

4C in a two-dimensional simulation. [0037] FIG. 4E, FIG. 4F, and FIG. 4G illustrate an example of an open EE inductor structure with flux shaping plates on top and bottom cores according to some embodiments. Reference numbers are added.

[0038] FIG. 4H and FIG. 41 illustrate another example of an open EE inductor structure with flux shaping plates formed on top and bottom cores according to some embodiments.

[0039] FIG. 5A, FIG. 5B, and FIG. 5C illustrate another example of an open EE inductor structure with flux shaping formed on top cores only according to some embodiments.

[0040] FIG. 5D illustrates flux lines for the open EE inductor structure shown in FIGs. 5A- 5C in a two-dimensional simulation.

[0041] FIG. 5E, FIG. 5F, and FIG. 5G illustrate another example of an open EE inductor structure with flux shaping formed on top cores only according to some embodiments.

[0042] FIG. 5H illustrates another example of an open EE inductor structure with flux shaping formed on top cores only according to some embodiments.

[0043] FIG. 6A, FIG. 6B, and FIG. 6C illustrate an assembly of a multi-gap EE design.

[0044] FIG. 6D illustrates a pot core structure.

[0045] FIG. 7A illustrates a flux density distribution of a wire-wound inductor structure with a single air gap.

[0046] FIG. 7B and FIG. 7C illustrate an example of a wire-wound flux-shaping inductor structure with a multi-gap design on two side legs according to some embodiments.

[0047] FIG. 7D illustrates a flux density distribution of the wire-wound flux-shaping inductor structure shown in FIGs. 7B and 7C according to some embodiments.

[0048] FIG. 7E, FIG. 7F, and FIG. 7G illustrate another example of wire-wound fluxshaping inductor structure with a multi-gap design on all legs according to some embodiments.

[0049] FIG. 7H illustrates a flux density distribution of the wire-wound flux-shaping inductor structure shown in FIGs. 7E-7G according to some embodiments.

[0050] FIG. 8A illustrates a toroid inductor with a single air gap toroidal core.

[0051] FIG. 8B illustrates a toroid inductor with a multi air gap toroidal core according to some embodiments. [0052] FIG. 8C illustrates a current density distribution of the toroid inductor with a multi air gap toroidal core show n in FIG. 8B according to some embodiments.

[0053] Embodiments of the present disclosure and their advantages are best understood by referring to the detailed description that follows. It should be appreciated that like reference numerals are used to identify like elements illustrated in one or more of the figures, wherein showings therein are for purposes of illustrating embodiments of the present disclosure and not for purposes of limiting the same.

DETAILED DESCRIPTION

[0054] Provided herein are various embodiments of electronic inductors having an enclosed pot core structure with a flux shaping plate on a core center post. The inductor structures in an open EE core (e.g., the core having EE shape) configuration can potentially generate significant stray magnetic fields, which can lead to electromagnetic compatibility (EMC) issues on nearby components. To address these deficiencies, various embodiments are provided to minimize straying the magnetic fields. Specifically, the present disclosure provides various embodiments, such as the enclosed pot core structure with a flux shaping plate on the core center post. This structure can keep the strong magnetic fields confined within the core structures and, with a minimum stray field present at the same time, can provide the benefit of reduced high-frequency conduction loss in copper due to flux shaping.

[0055] According to various embodiments, a multi-gap EE structure described herein may include plates that are of the same size, allowing simpler manufacturing and easy assembly. In addition, in some embodiments, the proposed structures include an enclosed pot core structure with a flux shaping plate, which can solve the stray magnetic field issue (from magnetic structures) and improve conventional inductor designs.

[0056] Some embodiments may include open EE core structures with 0, 1, 2, ... , n plates on the top and bottom cores. Some embodiments may include open EE core structures with 0, 1, 2, ... , n plates on the top core only. Some embodiments may include a wire-wound fluxshaping inductor structure with distributed air gaps. Some embodiments may include a toroid inductor with a multi air gap toroidal core.

[0057] In some embodiments, the open EE inductor structure has air gaps with or without ferrite plates at strategic locations that allow the magnetic flux to be re-shaped to minimize high-frequency AC resistance and, hence, the conduction losses in copper. The open EE inductor structures can have gaps or plates either on the top core only or on both the top and bottom core. The existence of air gap/flux shaping plates on both the top and bottom cores allows flux shaping for windings from both sides. However, since the presence of an air gap on a bottom core plate may induce significant stray losses on a heat sink surface due to the close proximity to the core bottom plate, this structure can be useful for designs where there is no heat sink present.

[0058] In comparison, open EE inductor structures with gaps/plates on the top core only may have flux shaping on windings from one side only. However, since there is no air gap in the bottom core plate, there may be minimal losses in the heat sink due to stray fields.

[0059] Existing multi-gap pot core structures require multiple annular rings of different radii, which need to be manufactured and assembled together. In comparison, embodiments of the multi-gap EE structure described herein may include plates that are of the same size, allowing a simpler manufacturing and ease of assembly. Moreover, the open EE structure can also allow the windings to be placed very close to a heat sink at locations where there is no core present. This may, however, lead to some induced losses in a heat sink.

[0060] The wire-wound flux-shaping inductor structure with distributed air gaps can use square/rectangular plates to improve the energy density by virtue of a more uniform flux density in the core due to multiple air gaps. This results in a smaller footprint compared to existing structures with a single air gap. The multi-gap inductor design can also be envisioned with a toroidal core, enabling similar benefits of reduced footprint and lower loss compared to designs with a single air gap.

[0061] Various embodiments can be used for one or more of: onboard chargers in an electric vehicle, a stationary storage (such as power wall, megapack, or superchargers), an autonomous driving hardware, or any power electronic converter that requires energy' storage and has soft-switching requirements. Various embodiments can also cover all the different concepts/structures that can be used for any power converter to be designed for any of the above applications. In some embodiments, core structures can be made with a magnetic material, such as ferrite and powder core. Various embodiments are advantageous over inductors with a single air gap or no air gap designed using low permeability materials, which are less efficient designs without flux shaping features or designs featuring flux shaping but with significant near-field. According to various embodiments, multi-gap designs can result in a smaller footprint, which helps significantly improve the converter power density. Furthermore, planar high-power high-frequency inductors can significantly increase power capability with lower costs, which can more efficiently produce components for electric vehicles or for energy storage devices.

[0062] FIG. 1 illustrates a schematic example of a high-frequency inductor and transformer design 100. In some embodiments, the high-frequency inductor design 100 can include an inductor structure 110 (e. g. , for high-power and high-frequency applications) and a transformer structure 120. However, as shown in FIG. 1, the inductor design 100 can be used in a resonant converter application. In some embodiments, each of the inverter structure 110 and the transformer structure 120 can be implemented as a discrete component. Furthermore, with new multi-level soft-switching inverter designs that do not require isolation and/or turns ratio change, discrete high-power and high-frequency inductors will be required.

[0063] FIG. 2 illustrates examples of various inductor structures 200 with flux shaping according to some embodiments. The inductor structures with flux shaping may include a flux shaping plate on a center post in an enclosed pot core 210 (Example 1; see, for example, FIGs. 3A and 3B). The inductor structures with flux shaping may also include two or more flux shaping plates (0, 1 , 2, . .. . , n) on the top and bottom cores in an open EE structure 220 (Example 2; see, for example, FIGs. 4A-4C and 4E-4I). The inductor structures with flux shaping may further include two or more flux shaping plates (0, 1, 2, ... ., n) only on the top core in an open EE structure 230 (Example 3; see, for example, FIGs. 5A-5C and 5E-5I). The inductor structures with flux shaping may further include a multi-gap on some or all core legs using Litz wires 240 (Example 4; see, for example, FIGs. 7B and 7C, and 7E-7G). The inductor structures with flux shaping may further include a toroid core with a multi-gap design using foil/Litz wires 250 (Example 5; see, for example, FIG. 8B). The above designs are only examples, and the inductor structures with flux shaping may include other designs.

[0064] FIG. 3A illustrates an example cross-sectional view of an enclosed pot core structure 300 with flux shaping plate 310 according to some embodiments. FIG. 3B illustrates an example perspective view of the enclosed pot core structure in various shapes according to some embodiments. FIG. 3C illustrates a near-field distribution of the enclosed pot core structure of FIG. 3 A according to some embodiments. FIG. 3D illustrates comparative stray magnetic fields. FIG. 3E illustrates a graph of Ohmic loss comparison layer-layer for the same inductance and same footprint. [0065] Referring to FIG. 3 A, the enclosed pot core structure 300 can include a flux shaping plate 310 disposed on the top of the center post 312. In some embodiments, the flux shaping plate 310 can form a top core. In some embodiments, the flux shaping plate 310 can have a width sized to at least partially vertically overlap one or more of a first winding portion 330 or a second winding portion 340. In some examples, the width of the flux shaping plate 310 can be larger than the width of the center post 312. In some embodiments, the center post 312 can be vertically disposed on the bottom core 314. In some examples, the bottom core 314 can include the side walls 314A, 314B (hereinafter, the bottom core is generally referred including the side walls 314A, 314B). The winding (e.g., winding including the first winding portion 330 and the second winding portion 340_ can be disposed between the flux shaping plate 310 and the bottom core 314. In some cases, enclosure 316 can be used to enclose the flux shaping plate 310 (e.g., the top core), the center post 312, the bottom core 314, and the winding (e.g., winding including the first winding portion 330 and the second winding portion 340. FIG. 3B illustrates examples of various shapes of the inductor structure 300. For example, the inductor structure can have a circular shape structure, as shown in FIG. 3B-1. The inductor structure can also have a rectangular shape structure, as shown in FIG. 3B-2. Even though such structures have different shapes, these structures can include various shapes of the enclosure 316, the flux shaping plate 310, the winding 350 of FIG. 3B-1 (only shown in FIG. 3B-1, and FIG. 3B-2 can include PCD winding, which is not shown in FIG. 3B-2), the center post 312, and the botom core 314.

[0066] As shown in the near-field distribution of FIG. 3C, the enclosed pot core structure 300 can provide a minimum stray magnetic field, for example, by using the flux shaping plate 310 that can block at least some stray magnetic field. For example, as shown in FIG. 3C, most of the magnetic field is confined wdthin the inductor structure, such as the enclosed pot core structure 300 shown in FIG. 3A. As further shown in FIG. 3D, compared to a conventional design (350) that does not include a flux shaping plate, the current density is significantly more uniform (360) in the enclosed pot core structure 300, including a flux shaping plate. In addition, the current densify of the enclosed pot core structure 300, including a flux shaping plate having an un-optimized shape (370), can also have a significantly uniform current densify compared to the conventional design (350). Thus, the simulation results illustrated in FIGs. 3C and 3D show the minimum stray magnetic field by using the flux shaping plate. Referring to FIG. 3E, the enclosed pot core structure 300 can also have a reduced ohmic loss when a flux shaping plate 310 is used. For example, each layer turn (each value of x-axis of FIG. 3E) corresponds to ohmic loss in high frequency (e.g., 272KHz) with or without the flux shaping plate and at a low frequency, such that each bar corresponds to relative layer turn, the right bar (382) can represent the ohmic loss without the flux shaping plate at the high frequency, the center bar (384) can represent the ohmic loss with the flux shaping plate at the high frequency, and the left bar (386) can represent the ohmic loss at the low frequency. As illustrated in FIG. 3E, the ohmic loss can be increased at a high frequency. As further illustrated in FIG. 3E, the increscent of the ohmic loss at the high frequency can be minimized by implementing the flux shaping plate, as shown in the comparison result between the bar 382 (without implementing the flux shaping plate) and the bar 384 (with implementing the flux shaping plate) which provides a minimized ohmic loss. In some embodiments, a structure with enclosing the pot core structure, such as the enclosed pot core structure 300, can be utilized for designs that can be incorporated with external components, such as a heatsink/a cold place, a metal cover, and the like that a near-filed can be a concern.

[0067] FIG. 4A illustrates a 2-D view of open EE inductor structure 400, FIG. 4B illustrates an exploded view of the open EE inductor structure 400, and FIG. 4C illustrates an assembled view of the open EE inductor structure 400. FIG. 4A, FIG. 4B, and FIG. 4C illustrate an example of an open EE inductor structure 400 with flux shaping formed on top and bottom cores according to some embodiments. FIG. 4D illustrates flux lines for the open EE inductor structure shown in FIGs. 4A-4C in a two-dimensional simulation according to some embodiments. FIG. 4E, FIG. 4F, and FIG. 4G illustrate an example of an open EE inductor structure 450 with flux shaping plates on top and bottom cores according to some embodiments. FIG. 4H and FIG. 41 illustrate another example of an open EE inductor structure 480 with flux shaping plates on top and bottom cores according to some embodiments.

[0068] Referring to FIGs. 4A-4C, the open EE inductor structure 400 can include a top core 410, a bottom core 430, and a PCB winding 420 interposed between the top core 410 and the bottom core 430. The top core 410 may include a top center flux shaping plate 414 disposed or coupled to a top portion of the center post 418. In some embodiments, the top core 410 may also include a first top flux shaping plate 412 and a second top flux shaping plate 416. In some examples, the first top flux shaping plate 412 and the second top flux shaping plate 416 are disposed on opposing sides of the center top flux shaping plate 414. The top core 410 of the open EE inductor structure 400 may further include two top air gaps 422 A, 422B. For example, a first top air gap 422A can be formed between the first top flux shaping plate 412 and the top center flux shaping plate 414. Furthermore, a second top air gap 422B can be formed between the second top flux shaping plate 416 and the top center flux shaping plate 414.

[0069] As further shown in FIGs. 4A-4C, the bottom core 440 may include a bottom center flux shaping plate 434 disposed on or coupled to a bottom portion of the center post 418. The bottom core 430 may include a bottom center flux shaping plate 434 disposed or coupled to a bottom portion of the center post 418. In some embodiments, the bottom core 430 may also include a first bottom flux shaping plate 432 and a second bottom flux shaping plate 436. In some examples, the first bottom flux shaping plate 432 and the second bottom flux shaping plate 436 are disposed on opposing sides of the center bottom flux shaping plate 434. The bottom core 430 of the open EE inductor structure 400 may further include two bottom air gaps 424A, 424B. For example, a first bottom air gap 424A can be formed between the first bottom flux shaping plate 432 and the bottom center flux shaping plate 434. Furthermore, a second bottom air gap 424B can be formed between the second bottom flux shaping plate 436 and the bottom center flux shaping plate 434. In some embodiments, the open EE inductor structure 400 can include a total of three top flux shaping plates (e.g., the first top flux shaping plate 412, the center top flux shaping plate 414, and the second top flux shaping plate 416) and a total of three bottom shaping plates (e.g., the first bottom flux shaping plate 432, the center bottom flux shaping plate 434, and the second bottom flux shaping plate 436), each of which at least partially vertically overlaps the winding 420 (e.g., PCB winding). FIG. 4C illustrates an example of an assembled view of the EE inductor structure 400. For example, the assembled EE inductor structure 400 can include the top core 410 (having the first top flux shaping plate 412, the center top flux shaping plate 414, and the second top flux shaping plate 416), the bottom core 430 (having the first bottom flux shaping plate 432, the center bottom flux shaping plate 434, and the second bottom flux shaping plate 436), the center post 418, and the winding 420 (e.g., PCB winding). As illustrated in FIG. 4C, the winding 420 can surround the center post 418. In some examples, a portion 420A of the winding 420 may not be included in the EE inductor structure 400.

[0070] FIG. 4D illustrates flux lines for one side of the open EE inductor structure 400 shown in FIGs. 4A-4C in a two-dimensional simulation according to some embodiments. As shown in FIG. 4D, flux lines of one side of the open EE inductor structure 400 may be substantially parallel to the winding layers (e.g., Layers (422)). This design may be advantageous over an inductor structure that does not include a flux shaping plate, whose flux line is substantially perpendicular to the winding layers, such that a stray magnetic field or AC winding loss can be minimized at high frequencies. Eight winding layers illustrated in FIG. 4D are merely examples, and the present disclosure is not limited thereto. For example, more than or less than eight winding layers may be used.

[0071] FIGs. 4E-4G illustrate a 2-D view, an exploded view, and an assembled view of an example of an open EE inductor structure 450 with flux shaping plates on top and bottom cores according to some embodiments of open EE inductor structure 400, respectively. Referring to FIGs. 4E-4G, the open EE inductor structure 450 can include two additional top flux shaping plates 452 on the top core 410 and two additional bottom flux shaping plates 462 on the bottom core 430. In some embodiments, the open EE inductor structure 450 can include total five top flux shaping plates (e.g., a first top flux shaping plate 412, a first additional top flux shaping plate 452A, a center top flux shaping plate 414, a second additional top flux shaping plate 452B, and a second top flux shaping plate 416) and total five bottom shaping plates (e.g., a first bottom flux shaping plate 432, a first additional bottom flux shaping plate 462A, a center bottom flux shaping plate 434, a second additional bottom flux shaping plate 462B, and a second bottom flux shaping plate 436), each of which at least partially vertically overlaps the winding 420.

[0072] In some embodiments, the top core 410 may include a first top flux shaping plate 412, a first additional top flux shaping plate 452A, a center top flux shaping plate 414, a second additional top flux shaping plate 452B, and a second top flux shaping plate 416. In some examples, the two plates (the first top flux shaping plate 412 and the first additional top flux shaping plate 452A) and the other two plates (the second top flux shaping plate 416 and the second additional top flux shaping plate 452B) are disposed on opposing sides of the center top flux shaping plate 414. In some embodiments, the top core 410 can include air gaps 454A- 454D. For example, a first top air gap 454A can be formed between the first top flux shaping plate 412 and the first additional top flux shaping plate 452 A; a second top air gap 454B can be formed between the first additional top flux shaping plate 452A and the center top flux shaping plate 414; a third top air gap 454C can be formed between the center top flux shaping plate 414 and the second additional top flux shaping plate 452B; and a fourth top air gap 454D can be formed between the second additional top flux shaping plate 452B and the second top flux shaping plate 416.

[0073] FIG. 4E illustrates a 2-D view of open EE inductor structure 450, and FIG. 4F illustrates an exploded view of the open EE inductor structure 450. As further shown in FIGs. 4E-4F, in some embodiments, the bottom core 430 may include a first bottom flux shaping plate 432, a first additional bottom flux shaping plate 462A, a center bottom flux shaping plate 434, a second additional bottom flux shaping plate 462B, and a second bottom flux shaping plate 436. In some examples, two plates (the first bottom flux shaping plate 432 and the first additional bottom flux shaping plate 462A) and another two plates (the second botom flux shaping plate 436 and the second additional botom flux shaping plate 462B) are disposed on opposing sides of the center botom flux shaping plate 434. In some embodiments, the botom core 430 can include air gaps 456A-456D. For example, a first botom air gap 456A can be formed between the first botom flux shaping plate 432 and the first additional bottom flux shaping plate 462A; a second botom air gap 456B can be formed between the first additional botom flux shaping plate 462A and the center botom flux shaping plate 434; a third botom air gap 456C can be formed between the center botom flux shaping plate 434 and the second additional botom flux shaping plate 462B; and a fourth air botom gap 454D can be formed between the second additional botom flux shaping plate 462B and the second botom flux shaping plate 436. Thus, the open EE inductor structure 450 can include four top air gaps 454A-454D and four botom air gaps 456A-456D. A stray magnetic field or AC winding loss can be minimized at high frequencies in this design.

[0074] FIG. 4G illustrates an example of an assembled view of the open EE inductor structure 450. For example, the assembled open EE inductor structure 450 can include the top core 410 (having the first top flux shaping plate 412, the first additional top flux shaping plate 452A, the center top flux shaping plate 414, the second additional top flux shaping plate 452B, and the second top flux shaping plate 416), the botom core 430 (having the first bottom flux shaping plate 432, the first additional botom flux shaping plate 462A, the center botom flux shaping plate 434, the second additional botom flux shaping plate 462B, and the second botom flux shaping plate 436), the center post 418, and the winding 420 (e.g., PCB winding). As illustrated in FIG. 4G, the winding 420 can surround the center post 418. In some examples, a portion 420A of the winding 420 may not be included in the open EE inductor structure 450.

[0075] FIG. 4H illustrates another example of open EE inductor structure 480 with flux shaping plates formed on the top core 410 and botom core 430 according to some embodiments. Referring to FIGs. 414 and 41, the open EE inductor structure 480 can include four additional top flux shaping plates (482A, 482B, 482C, and 482D) on the top core 410 and four additional botom flux shaping plates (492A, 492B, 492C, and 492D) on the botom core 430. According to this design, the open EE inductor structure 480 can include a total of seven top flux shaping plates and a total of seven botom shaping plates, each of which at least partially vertically overlaps the PCB winding. For example, the top core 410 can include a first top flux shaping plate 412, a first additional top flux shaping plate 482A, a second additional top flux shaping plate 482B, a center top flux shaping plate 414, a third additional top flux shaping plate 482C, a fourth additional top flux shaping plate 482D, and a second top flux shaping plate 416. Likewise, the bottom core 430 can include a first bottom flux shaping plate 432, a first additional bottom flux shaping plate 492A, a second additional bottom flux shaping plate 492B, a center bottom flux shaping plate 434, a third additional bottom flux shaping plate 462C, a fourth additional bottom flux shaping plate 462D, and a second bottom flux shaping plate 436. As a result, the open EE inductor structure 480 can include six top air gaps. For example, the six top air gaps can be disposed (1) between the first top flux shaping plate 412 and the first additional top flux shaping plate 482A; (2) between the first additional top flux shaping plate 482A and the second additional top flux shaping plate 482B; (3) between the second additional top flux shaping plate 482B and the center top flux shaping plate 414; (4) between the center top flux shaping plate 414 and the third additional top flux shaping plate 482C; (5) between the third additional top flux shaping plate 482C and the fourth additional top flux shaping plate 482D; and (6) between the fourth additional top flux shaping plate 482D and the second top flux shaping plate 416. Furthermore, the six bottom air gaps can be disposed (1) between the first bottom flux shaping plate 432 and the first additional bottom flux shaping plate 492A; (2) between the first additional bottom flux shaping plate 492 A and the second additional bottom flux shaping plate 492B; (3) between the second additional bottom flux shaping plate 492B and the center bottom flux shaping plate 434; (4) between the center bottom flux shaping plate 434 and the third additional bottom flux shaping plate 462C; (5) between the third additional bottom flux shaping plate 462C and the fourth additional bottom flux shaping plate 462D; and (6) between the fourth additional bottom flux shaping plate 462D and the second bottom flux shaping plate 436. In some embodiments, the winding 420 can be disposed of between the top core 410 and the bottom core 430. In these embodiments, the winding 420 can surround the center post 418.

[0076] In some embodiments, as illustrated in FIG. 41, the example of open EE inductor structure 480 illustrated in FIG. 4H can further include multiple plates 494 in each side wall of the bottom core 430 and multiple coils 496 that surround the center post 418.

[0077] The above inductor structures illustrated in FIGs. 4A-4I are merely examples, and the present disclosure is not limited thereto. For example, more than seven top flux shaping plates and/or seven bottom shaping plates can be provided. Also, more than six top air gaps and/or more than six bottom air gaps can be provided. [0078] FIGs. 5A-5C illustrate a 2-D view, an exploded view, and an assembled view of an example of an open EE inductor structure 500 with flux shaping formed on top cores only according to some embodiments, respectively. Referring to FIGs. 5A-5C, the open EE inductor structure 500 can include atop core 510, a bottom core 530, and a PCB winding 520, generally interposed between the top core 510 and the bottom core 530. The top core 410 may include three flux shaping plates 512-516. The open EE inductor structure 500 may include two top air gaps 522 formed between the center flux shaping plate 514 and the side flux shaping plates 512 and 516. The bottom core 530 does not include a flux shaping plate. The open EE inductor structure 500 may not include a bottom air gap. A heat sink/cold plate 540 may be provided below the bottom core 530. According to this design, the open EE inductor structure 500 can include total three top flux shaping plates, each of which at least partially vertically overlaps the PCB winding 520. FIG. 5C illustrates an example of an assembled view of the EE inductor structure 500. For example, the assembled EE inductor structure 500 can include the top core 510 (having the first top flux shaping plate 512, the center top flux shaping plate 514, and the second top flux shaping plate 516), the bottom core 530, the center post 518, and the winding 520 (e.g., PCB winding). As illustrated in FIG. 5C, the winding 520 can surround the center post 518. In some examples, a portion 520A of the winding 520 may not be included in the EE inductor structure 500.

[0079] FIG. 5D illustrates flux lines for the open EE inductor structure shown in FIGs. 5 A- 5C in a two-dimensional simulation. As shown in FIG. 5D, flux lines 524 of the open EE inductor structure 500 may be substantially parallel to the winding 520 (e.g., winding layers). This design may be advantageous over a conventional inductor structure that does not include a flux shaping plate, whose flux line is substantially perpendicular to the winding layers, such that a stray magnetic field or AC winding loss can be minimized at high frequencies.

[0080] FIG. 5E, FIG. 5F, and FIG. 5G illustrate another example of an open EE inductor structure 550 with flux shaping formed on top cores only according to some embodiments. Referring to FIGs. 5E-5G, the open EE inductor structure 550 can include two additional top flux shaping plates 552 formed only on the top core. According to this design, the open EE inductor structure 550 can include a total of five top flux shaping plates 552, each of which at least partially vertically overlaps the PCB winding. As a result, the open EE inductor structure 550 can include a total of four top air gaps 554 (only one top air gap has a designated lead line and reference numeral in FIG. 5E). This design may be used to shape the electromagnetic fields generated by the PCB winding. In some embodiments, a heatsink 540 can be disposed (e.g., assembled) at the bottom of the bottom core. The heatsink 540 can help with cooling the core/windings. The present disclosure does not limit the types and/or number of heatsinks. These types and/or number of heatsinks can be determined based on specific applications.

[0081] FIGs. 5E-5G illustrate a 2-D view, an exploded view, and an assembled view of an example of an open EE inductor structure 550 with flux shaping plates on top cores according to some embodiments of open EE inductor structure 500, respectively. Referring to FIGs. 5E- 5G, the open EE inductor structure 550 can include two additional top flux shaping plates 552 on the top core 510. In some embodiments, the open EE inductor structure 550 can include a total of five top flux shaping plates (e.g., a first top flux shaping plate 512, a first additional top flux shaping plate 552A, a center top flux shaping plate 514, a second additional top flux shaping plate 552B, and a second top flux shaping plate 516), each of which at least partially vertically overlaps the winding 420. The open EE inductor structure 550 may be configured to minimize straying the electromagnetic fields generated by the PCB winding from the open EE inductor structure 550. In some embodiments, a heatsink 540 at the bottom of the open EE inductor structure 550 can be assembled to cool the core/windings.

[0082] In some embodiments, as illustrated in FIGs. 5E and 5F, the top core 510 may include a first top flux shaping plate 512, a first additional top flux shaping plate 552A, a center top flux shaping plate 514, a second additional top flux shaping plate 552B, and a second top flux shaping plate 516. In some examples, the two plates (the first top flux shaping plate 512 and the first additional top flux shaping plate 552A) and the other two plates (the second top flux shaping plate 516 and the second additional top flux shaping plate 552B) are disposed on opposing sides of the center top flux shaping plate 514. In some embodiments, the top core 510 can include air gaps 554A-554D. For example, a first top air gap 554A can be formed between the first top flux shaping plate 512 and the first additional top flux shaping plate 552A; a second top air gap 554B can be formed between the first additional top flux shaping plate 552A and the center top flux shaping plate 514; a third top air gap 554C can be formed between the center top flux shaping plate 514 and the second additional top flux shaping plate 552B; and a fourth top air gap 554D can be formed between the second additional top flux shaping plate 552B and the second top flux shaping plate 416.

[0083] FIG. 5G illustrates an example of an assembled view of the open EE inductor structure 550. For example, the assembled open EE inductor structure 550 can include the top core 510 (having the first top flux shaping plate 512, the first additional top flux shaping plate 552A, the center top flux shaping plate 514, the second additional top flux shaping plate 552B, and the second top flux shaping plate 516), the center post 518, a bottom core 530, and the winding 520 (e.g., PCB winding). As illustrated in FIG. 5G, the winding 520 can surround the center post 518. In some examples, a portion 520A of the winding 520 may not be included in the open EE inductor structure 550.

[0084] FIG. 5H illustrates another example of open EE inductor structure 580 with flux shaping plates formed on the top core 510 and bottom core 530 according to some embodiments. Referring to FIG. 5H, the open EE inductor structure 580 can include four additional top flux shaping plates (582A, 582B, 582C, and 582D) on the top core 510. According to this design, the open EE inductor structure 580 can include a total of seven top flux shaping plates, each of which at least partially vertically overlaps the PCB winding. For example, the top core 510 can include a first top flux shaping plate 512, a first additional top flux shaping plate 582A, a second additional top flux shaping plate 582B, a center top flux shaping plate 514, a third additional top flux shaping plate 582C, a fourth additional top flux shaping plate 582D, and a second top flux shaping plate 516. As a result, the open EE inductor structure 580 can include six top air gaps. For example, the six top air gaps can be disposed (1) between the first top flux shaping plate 512 and the first additional top flux shaping plate 582A; (2) between the first additional top flux shaping plate 582A and the second additional top flux shaping plate 582B; (3) between the second additional top flux shaping plate 582B and the center top flux shaping plate 514; (4) between the center top flux shaping plate 514 and the third additional top flux shaping plate 582C; (5) between the third additional top flux shaping plate 582C and the fourth additional top flux shaping plate 582D; and (6) between the fourth additional top flux shaping plate 582D and the second top flux shaping plate 516. In some embodiments, the winding 520 can be disposed between the top core 510 and the bottom core 530. In these embodiments, the winding 520 can surround the center post 518.

[0085] The above inductor structures illustrated in FIGs. 5A-5H are merely examples, and the present disclosure is not limited thereto. For example, more than a total of seven top flux shaping plates can be provided. Also, more than six top air gaps can be provided.

[0086] FIG. 6A, FIG. 6B, and FIG. 6C illustrate an ease of assembly of a multi-gap EE design 600 compared to a pot core structure 650 shown in FIG. 6D. For example, as shown in FIG. 6A, the open EE inductor structure 600, which has various multi-gap EE designs, can be assembled with accurate spacing of the plates 625. For example, an example of multi-gap EE design 600 shown in FIG. 6A, FIG.6B, and FIG. 6C can be assembled with gaps 610, gaps 620, and gaps 630, respectively. Given that these gaps 610, 620 can arise between straight parallel plates 625, it may maintain an equal spacing with a consistent air gap across all the plates 625.

[0087] Referring to FIG. 6D, the conventional multi-gap pot core design 650 requires different radii annular rings 640 being assembled. In the FIG. 6D design, it may be difficult to ensure the same air gap lengths throughout the diameter of the ring.

[0088] FIG. 7A illustrates a flux density distribution of a conventional wire-wound inductor structure with a single air gap. As shown in FIG. 7A, the wire-wound inductor structure with a single air gap can drop a magnetic field (e.g., as shown in 702) and thus may store less energy overall (as shown in 704).

[0089] FIG. 7B and FIG. 7C illustrate an example wire-wound flux-shaping inductor structure 700 with a multi-gap design on two vertical side legs 710 and 720 according to some embodiments. In this embodiment, only two vertical legs 710, 720 can include multi-gaps 730. Although FIG. 7B shows a certain number of gaps 730 on the vertical legs 10, 720, the present disclosure does not limit the number of gaps. In some embodiments, multi-gaps can be formed on the horizontal legs, such as horizontal legs 740, 750. In some embodiments, as illustrated in FIG. 7C, wires can be wounded on the horizontal gaps and vertical gaps of the inductor structure shown in FIG. 7B. This embodiment may provide more efficient manufacturing compared to the embodiment of FIGs. 7E-7G, where multi-gaps are formed on all legs.

[0090] FIG. 7D illustrates a flux density distribution of the wire-wound flux-shaping inductor structure shown in FIGs. 7B and 7C according to some embodiments. As shown in FIG. 7D, the flux density distribution of the wire-wound flux-shaping inductor structure 700 shows an improved magnetic field for more storage compared to the FIG. 7 A design.

[0091] FIG. 7E, FIG. 7F, and FIG. 7G illustrate another example of wire-wound fluxshaping inductor structure 750 with a multi -gap design on all legs according to some embodiments. As illustrated in FIG. 7E, the multiple number of air gaps 730 can be formed in the vertical legs 710, 720 and the horizontal legs 740, 750. As shown in FIG. 7F, the wires 760 can be wounded in each of the vertical legs 710, 720 and the horizontal legs 740, 750. FIG. 7F can be referred to as a Litz wire winding, and FIG. 7G shows a prototype sample. As shown in FIG. 7G, the multiple number of air gaps 730 can be formed in the vertical legs 710, 720 and the horizontal legs 740, 750. In addition, the wires 760 can be wounded in each of the vertical legs 710, 720 and the horizontal legs 740, 750. [0092] FIG. 7H illustrates a flux density distribution of the wire-wound flux-shaping inductor structure 750 shown in FIGs. 7E-7G according to some embodiments. As shown in FIG. 7H, the wire-wound flux-shaping inductor structure 750 can provide a substantially more uniform flux density distribution and can store more energy due to multiple air gaps on all legs compared to the FIG. 7B embodiment.

[0093] FIG. 8A illustrates a toroid inductor 800 with a single air gap 810 toroidal core. FIG. 8B illustrates a toroid inductor 850 with a multi air gap toroidal core according to some embodiments. The toroid inductor 800 can include a large single air gap 810. In some embodiments, as illustrated in FIG. 8B, the toroid inductor 850 can include smaller multi-air gaps 820.

[0094] FIG. 8C illustrates a current density distribution of the toroid inductor 850 with a multi air gap toroidal core shown in FIG. 8B according to some embodiments. As shown in FIG. 8C, the toroid inductor 850, including the smaller multi-air gaps 860 can provide a more uniform current density distribution compared to the toroid inductor 800, including the large single air gap 810, so as to reduce high-frequency winding loss and increase a stored energy density.

[0095] Features, materials, characteristics, or groups described in conjunction with a particular aspect, embodiment, or example are to be understood to be applicable to any other aspect, embodiment or example described in this section or elsewhere in this specification unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The protection is not restricted to the details of any foregoing embodiments. The protection extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0096] Furthermore, certain features that are described in this disclosure in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable sub combination. Moreover, although features may be described above as acting in certain combinations, one or more features from a claimed combination can, in some cases, be excised from the combination, and the combination may be claimed as a sub combination or variation of a sub combination.

[0097] Moreover, while operations may be depicted in the drawings or described in the specification in a particular order, such operations need not be performed in the particular order shown or in sequential order, or that all operations be performed, to achieve desirable results. Other operations that are not depicted or described can be incorporated in the example methods and processes. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the described operations. Further, the operations may be rearranged or reordered in other implementations. Those skilled in the art will appreciate that in some embodiments, the actual steps taken in the processes illustrated and/or disclosed may differ from those shown in the figures. Depending on the embodiment, certain of the steps described above may be removed, others may be added. Furthermore, the features and attributes of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure. Also, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described components and systems can generally be integrated together in a single product or packaged into multiple products. For example, any of the components for an energy storage system described herein can be provided separately, or integrated together (e.g., packaged together, or attached together) to form an energy storage system.

[0098] For purposes of this disclosure, certain aspects, advantages, and novel features are described herein. Not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the disclosure may be embodied or carried out in a manner that achieves one advantage or a group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

[0099] Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and/or steps. Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, and/or steps are included or are to be performed in any particular embodiment.

[00100] Conjunctive language such as the phrase “at least one of X, Y, and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be either X, Y, or Z. Thus, such conjunctive language is not generally intended to imply that certain embodiments require the presence of at least one of X, at least one of Y, and at least one of Z.

[00101] Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result.

[00102] The scope of the present disclosure is not intended to be limited by the specific disclosures of embodiments in this section or elsewhere in this specification, and may be defined by claims as presented in this section or elsewhere in this specification or as presented in the future. The language of the claims is to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during the prosecution of the application, which examples are to be construed as nonexclusive.

[00103] While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosure. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the systems and methods described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure. Accordingly, the scope of the present inventions is defined only by reference to the appended claims.

Claims

WHAT IS CLAIMED IS:

1. An inductor structure comprising: a top core comprising at least a top center flux shaping plate; a bottom core; a center post vertically disposed between the top center flux shaping plate and the bottom core; and a winding disposed between the top core and the bottom core and surrounding the center post, the center flux shaping plate partially overlapping at least a portion of the winding.

2. The inductor structure of Claim 1, further comprising an enclosure enclosing the top core, the bottom core, and the winding.

3. The inductor structure of Claim 1 or 2, wherein the top core further comprises a first top flux shaping plate and a second top flux shaping plate disposed on opposite sides of the top center flux shaping plate, wherein a first top air gap is disposed between the first top flux shaping plate and the top center flux shaping plate, and wherein a second air gap is disposed between the top center flux shaping plate and the second top flux shaping plate.

4. The inductor structure of Claim 3, wherein the top core further comprises: a first additional top flux shaping plate disposed between the top center flux shaping plate and the first top flux shaping plate; and a second additional top flux shaping plate disposed between the top center flux shaping plate and the second top flux shaping plate.

5. The inductor structure of any of Claims 1-4, further comprising a heat sink disposed below the bottom core.

6. The inductor structure of any of Claims 1-5, wherein the winding is integrated into a printed circuit board.

7. The inductor structure of any of Claims 1-6, wherein the winding comprises a plurality of winding layers.

8. The inductor structure of any of Claims 1-7, wherein the winding is disposed at a middle point of the top core and the bottom core.

9. The inductor structure of any of Claims 1-7, wherein the winding is disposed in proximity to the bottom core.

10. The inductor structure of any of Claims 1-9, wherein a portion of the winding is disposed outside of the inductor structure.

11. An inductor structure comprising: a top core comprising a top center flux shaping plate, a first top flux shaping plate, and a second top flux shaping plate; a bottom core comprising a bottom center flux shaping plate, a first bottom flux shaping plate, and a second bottom flux shaping plate; a center post vertically disposed between the top center flux shaping plate and the bottom center flux shaping plate; and a winding disposed between the top core and the bottom core and surrounding the center post.

12. The inductor structure of Claim 11, wherein a first top air gap is disposed between the first top flux shaping plate and the top center flux shaping plate, and wherein a second air gap is disposed between the top center flux shaping plate and the second top flux shaping plate.

13. The inductor structure of Claim 11 or 12, wherein a first bottom air gap is disposed between the first bottom flux shaping plate and the bottom center flux shaping plate, and wherein a second air gap is disposed between the bottom center flux shaping plate and the second bottom flux shaping plate.

14. The inductor structure of any of Claims 11-13, wherein the top core further comprises: a first additional top flux shaping plate disposed between the top center flux shaping plate and the first top flux shaping plate; and a second additional top flux shaping plate disposed between the top center flux shaping plate and the second top flux shaping plate, and wherein the bottom core further comprises: a first additional bottom flux shaping plate disposed between the bottom center flux shaping plate and the first bottom flux shaping plate; and a second additional bottom flux shaping plate disposed between the bottom center flux shaping plate and the second bottom flux shaping plate.

15. The inductor structure of any of Claims 11-14, wherein the winding comprises a plurality of winding layers.

16. The inductor structure of any of Claims 11-15, wherein the winding is disposed at a middle point of the top core and the bottom core.