Polyphase coupled inductance and single-stage high step-down converter

Abstract

This application relates to a multiphase coupled inductor and a single-stage high-step-down converter. The multiphase coupled inductor includes a main flux magnetic component and windings. The multiphase coupled inductor has a cavity in which the main flux magnetic component is located. The main flux magnetic component includes a first central core and at least two first side cores, with the first central core located between the first side cores. The two ends of the first central core and the first side cores are respectively connected to the two sides of the cavity. The windings include at least two first windings and at least two second windings, with the first windings and second windings interleaved. The first windings and second windings enter from both sides of the first side cores and are wound around the first central core. The winding directions of the first windings and second windings are opposite, enabling a fully coupled inductor structure with both forward and reverse directions in a single-stage data center power supply scenario.

Description

Technical Field

[0001] This application relates to the field of magnetic component technology, and in particular to a multiphase coupled inductor and a single-stage high-step converter. Background Technology

[0002] With the development of Internet technology, data centers have become a high-energy-consuming industry, accounting for more than 3% of the total electricity consumption of the whole society.

[0003] To reduce the additional losses generated in the intermediate stage of traditional multi-stage step-down power supply schemes, the mainstream approach currently adopts a single-stage high step-down structure as the power supply scheme for new data centers. This is achieved by using a system structure with the primary side in series and the secondary side in parallel to withstand the high voltage stress on the primary side and the high current stress on the secondary side. However, this approach restricts the excitation mode of the secondary inductor winding, limiting it to be consistent with that of the primary side. This makes it impossible to use the multi-phase step-down interleaved parallel technology in multi-stage schemes, and therefore, it is impossible to reduce the output current ripple through phase shifting.

[0004] It is evident that the inductor structure of traditional technology still cannot meet the requirements of multi-phase step-down interleaved parallel connection for single-stage high step-down ratio power supply schemes. Summary of the Invention

[0005] Therefore, it is necessary to provide a multiphase coupled inductor and a single-stage high step-down converter that can meet the requirements of a single-stage high step-down power supply scheme, addressing the aforementioned technical problems.

[0006] Firstly, this embodiment provides a multiphase coupled inductor, which includes a main magnetic flux magnetic component and windings, wherein:

[0007] The multiphase coupled inductor has a cavity, and the main magnetic flux component is located in the cavity;

[0008] The main magnetic flux magnetic component includes a first central magnetic core and at least two first side magnetic cores. The first central magnetic core is located between the first side magnetic cores, and the two ends of the first central magnetic core and the first side magnetic cores are respectively connected to the two sides of the chamber.

[0009] The winding includes at least two first windings and at least two second windings, the first windings and the second windings are interleaved and coupled, the first windings and the second windings enter from both sides of the first side magnetic core and are wound around the first central magnetic core; the winding directions of the first windings and the second windings are opposite.

[0010] In one embodiment, the multiphase coupled inductor further includes a secondary magnetic flux component, which includes at least two second side magnetic cores, and the primary magnetic flux component includes two end magnetic plates; the second side magnetic cores are respectively connected to both ends of the two end magnetic plates to form the cavity; the first central magnetic core and the first side magnetic cores are respectively connected to the middle of the two end magnetic plates.

[0011] In one embodiment, air gaps are uniformly distributed between the first central magnetic cores, between the first side magnetic cores, between the second side magnetic cores, and between the second side magnetic cores and the end face magnetic plate, and the air gaps correspond to the air gaps between the windings.

[0012] In one embodiment, the windings include four first windings and four second windings; the main magnetic flux magnetic component includes six first side magnetic cores and three first central magnetic cores; the auxiliary magnetic flux magnetic component includes six second side magnetic cores; and there are four air gaps between the windings, corresponding to the air gaps of the three first central magnetic cores of the main magnetic flux magnetic component.

[0013] In one embodiment, the air gap size is less than 0.1 mm.

[0014] In one embodiment, the cross-sectional area of ​​the first central magnetic core is the sum of the cross-sectional areas of the two first side magnetic cores.

[0015] In one embodiment, the winding is made of Litz wire or copper strip material.

[0016] In one embodiment, the first winding is wound clockwise around the first central magnetic core, and the second winding is wound counterclockwise around the first central magnetic core.

[0017] Secondly, this embodiment provides a single-stage high-step-out converter, which includes a square wave inverter, an input series-output parallel transformer, a rectifier output unit, a controller, and the aforementioned multiphase coupled inductor, wherein:

[0018] The square wave inverter is connected to the input series-output parallel transformer, the input series-output parallel transformer is connected to the rectifier output unit, the rectifier output unit is connected to the winding of the multiphase coupled inductor, and the controller is connected to the input series-output parallel transformer and the rectifier output unit respectively.

[0019] The controller is used to control the rectifier output unit to excite the winding based on the positive or negative value of the output voltage of the input series-output parallel transformer.

[0020] In one embodiment, the circuit of the square wave inverter adopts one of the following topologies: full-bridge topology, half-bridge topology, and switched capacitor topology.

[0021] The aforementioned multiphase coupling resistor and single-pole high-dropout converter includes a cavity within the multiphase coupling inductor, where the main magnetic flux component is located. The main magnetic flux component comprises a first central magnetic core and at least two first side magnetic cores, with the first central magnetic core positioned between the first side magnetic cores. The two ends of the first central and first side magnetic cores are connected to opposite sides of the cavity. The windings include at least two first windings and at least two second windings, with the first and second windings interleaved. The first and second windings enter from opposite sides of the first side magnetic cores and are wound around the first central magnetic core. The winding directions of the first and second windings are opposite, enabling a fully coupled inductor structure with mixed forward and reverse coupling in a single-pole data center power supply scenario. This achieves full integration of all phase inductors, reducing output current ripple through phase shifting in a single-stage high-dropout structure. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a multiphase coupled inductor in one embodiment;

[0023] Figure 2 An exploded view of the multiphase coupled inductor structure in another embodiment;

[0024] Figure 3 This is a schematic diagram of the winding structure in another embodiment;

[0025] Figure 4 This is a schematic diagram of the structure of a multiphase coupled inductor in another embodiment;

[0026] Figure 5 An exploded view of the multiphase coupled inductor structure in another embodiment;

[0027] Figure 6 This is a schematic diagram of the structure of a multiphase coupled inductor magnetic component in another embodiment;

[0028] Figure 7 This is a schematic diagram of the winding structure in another embodiment;

[0029] Figure 8 This is a magnetic flux density distribution diagram of a multiphase coupled inductor in another embodiment;

[0030] Figure 9 This is a circuit diagram of a single-stage high-buck converter in one embodiment;

[0031] Figure 10 Here is a ripple gain diagram for different coupling coefficients in another embodiment;

[0032] Figure 11 The current waveform of a multiphase coupled inductor is shown in another embodiment. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0034] It should be noted that when a component is described as "mounted on" another component, it can be directly on the other component or there may be an intermediate component. When a component is described as "set on" another component, it can be directly set on the other component or there may be an intermediate component. When a component is described as "fixed to" another component, it can be directly fixed to the other component or there may be an intermediate component.

[0035] In one embodiment, such as Figure 1 and Figure 2 As shown, this embodiment provides a multiphase coupled inductor, the multiphase coupled inductor 1 including a main magnetic flux magnetic component 11 and windings, wherein:

[0036] The multiphase coupled inductor 1 has a cavity, and the main magnetic flux magnetic component 11 is located in the cavity;

[0037] The main magnetic flux magnetic component 11 includes a first central magnetic core 112 and at least two first side magnetic cores 111. The first central magnetic core 112 is located between the first side magnetic cores 111, and the two ends of the first central magnetic core 112 and the first side magnetic cores 111 are respectively connected to the two sides of the chamber.

[0038] The winding includes at least two first windings 13 and at least two second windings 14, the first windings 13 and the second windings 14 are interleaved and coupled, the first windings 13 and the second windings 14 enter from both sides of the first side magnetic core 111 and are wound around the first middle magnetic core 112; the winding directions of the first windings 13 and the second windings 14 are opposite.

[0039] The main magnetic flux component 11 is used to provide the main magnetic flux path generated when the current-carrying winding is working, when the winding is carrying current.

[0040] The cavity of the multiphase coupled inductor 1 may have an air gap to avoid magnetic saturation and to better control the inductance. The cavity may have a protrusion corresponding to one end of the first central magnetic core 112 and one end of the first side magnetic core 111. The protrusion at one end of the cavity can provide for the winding of a winding.

[0041] An air gap may also be provided between the first central magnetic core 112 and the first side magnetic core 111. The size of each air gap may be equal or may be set according to the actual situation.

[0042] The first side magnetic core 111 is disposed on the front and rear sides of the first central magnetic core 112. The first central magnetic core 112 and the first side magnetic core 111 can be cylindrical, cuboid, or other magnetic core shapes, which are not limited in this article.

[0043] The first winding 13 and the second winding 14 are interleaved, meaning that the first winding 13 and the second winding 14 are wound alternately. For example, if the first winding includes L1 and L2 and the second winding includes L3 and L4, then they are wound alternately in the order of L1, L3, L2, and L4. The relative positions of L1 and L2, and L3 and L4 can be adjusted according to the actual situation, or the winding order can be determined starting from the second winding.

[0044] The first winding 13 and the second winding 14 enter from both sides of the first side magnetic core 111 and are wound around the first middle magnetic core 112. Alternatively, the first winding 13 may enter from the lower side of the first side magnetic core 111 and wind upwards, winding clockwise around the first middle magnetic core 112, and exiting from the lower side of the other end of the first side magnetic core 111. The second winding 14 may enter from the upper side of the first side magnetic core 111 and wind downwards, winding counterclockwise around the first middle magnetic core 112. The first winding 13 can be wound from the bottom of the first side core 111 and wound upwards, clockwise around the first middle core 112, and led out from the bottom of the first side core 111 at the other end; or the second winding 13 can enter from the bottom of the first side core 111 and be wound upwards, clockwise around the first middle core 112, and led out from the bottom of the first side core 111 at the other end; the first winding 14 can enter from the top of the first side core 111 and be wound downwards, counterclockwise around the first middle core 112, and led out from the top of the first side core 111 at the other end. Figure 3 As shown, an air gap is left between the first winding 13 and the second winding 14, and a first central magnetic core 112 is provided in the air gap. The first winding 13 and the second winding 14 are wound around the first central magnetic core 112.

[0045] This embodiment provides a multiphase coupled inductor with a cavity in which the main magnetic flux magnetic component is located. The main magnetic flux magnetic component includes a first central magnetic core and at least two first side magnetic cores. The first central magnetic core is located between the first side magnetic cores, and the two ends of the first central magnetic core and the first side magnetic cores are respectively connected to the two sides of the cavity. The winding includes at least two first windings and at least two second windings. The first windings and second windings are interleaved and enter from both sides of the first side magnetic cores and are wound around the first central magnetic core. The winding directions of the first windings and second windings are opposite, which can realize a fully coupled inductor structure with mixed forward and reverse coupling in a single-pole data center power supply scenario. This achieves full integration of all phase inductors and can reduce output current ripple under a single-stage high-dropout structure.

[0046] like Figure 2 As shown, in one embodiment, the multiphase coupled inductor further includes a secondary magnetic flux component 12, which includes at least two second side magnetic cores 122, and the main magnetic flux component 11 includes two end face magnetic plates 121; the second side magnetic cores 122 are respectively connected to the two ends of the two end face magnetic plates 121 to form the cavity; the first middle magnetic core 112 and the first side magnetic cores 111 are respectively connected to the middle of the two end face magnetic plates 121.

[0047] The auxiliary flux magnetic component 12 surrounds the space around the main flux magnetic component 11 and the winding, providing a return flux path when the current-carrying winding is operating. The second side core 122 can be disposed on the upper and lower sides of the first central core 112 and the first side core 111. The number of second side cores 122 can be the same as the number of first side cores 111. The length of the second side core 122 on the same side can be equal to the length of both the first central core 112 and the first side core 112.

[0048] The end face magnetic plate 121 may be provided with protrusions corresponding to the first middle magnetic core 112, the first side magnetic core 111 and the second side magnetic core 122. A single protrusion of the end face magnetic plate 121 can provide for the winding of a winding.

[0049] A chamber can be formed by connecting the second side magnetic core 122 with the end face magnetic plate 121. This chamber can contain an air gap, which can be located at the connection point between the second side magnetic core 122 and the end face magnetic plate 121.

[0050] This embodiment provides a multiphase coupled inductor, which consists of a secondary magnetic flux component composed of at least two second side magnetic cores. The cavity is formed by the end face magnetic plates of the secondary magnetic flux component and the primary magnetic flux component. This allows for the structural design of the multiphase coupled inductor cavity, which breaks down the cavity of the multiphase coupled inductor into simpler components, thereby reducing the production cost of the multiphase coupled inductor.

[0051] In one embodiment, air gaps 15 are uniformly distributed between the first central magnetic cores 112, between the first side magnetic cores 111, between the second side magnetic cores 122, and between the second side magnetic cores 122 and the end face magnetic plate 121, and the air gaps 15 correspond to the air gaps between the windings.

[0052] In a multiphase coupled inductor, if there are multiple first central magnetic cores 112, multiple first side magnetic cores 111 on the same side, or multiple second side magnetic cores 122 on the same side, then air gaps 15 are uniformly distributed between the first central magnetic cores 112. These air gaps 15 correspond to the air gaps between the first side magnetic cores 111 and between the second side magnetic cores. An air gap 15 also exists between the second side magnetic cores 122 and the end face magnetic plate 121. This air gap corresponds to the air gap between the first winding 13 and the second winding 14 within the multiphase coupled inductor.

[0053] In addition, there is an air gap between the first central magnetic core 112 and the first side magnetic core 111 and the second side magnetic core 122. The size of the air gap can be the same or different based on the actual situation.

[0054] Traditional air-gap structures are single-gap structures. When there are more than two first windings 13 and second windings 14 in a multiphase coupled inductor, the air gaps of the first central core 112, the first side core 111, and the second side core 122 are determined based on the air gaps between the windings, thus achieving a distributed air-gap structure. In a specific embodiment, a single air-gap structure requires an air gap size of 0.2 mm, which can be evenly divided based on the number of air gaps between the windings. For example, when the number of air gaps is 4, there are four air gaps, each with a size of 0.05 mm.

[0055] This embodiment provides a multiphase coupled inductor that, through a distributed air gap structure, can divide a large air gap into multiple small air gaps compared to a traditional single air gap structure, thereby achieving the technical effect of reducing magnetic field leakage and winding losses.

[0056] like Figure 4 and Figure 5As shown, this embodiment provides an 8-phase interleaved coupling inductor structure. In one embodiment, the windings include four first windings 13 and four second windings 14; the main flux magnetic component 11 includes six first side magnetic cores 111 and three first middle magnetic cores 112; the auxiliary flux magnetic component 12 includes six second side magnetic cores 122; there are four air gaps 15 between the windings, corresponding to the air gaps 15 of the three first middle magnetic cores 112 of the main flux magnetic component 11.

[0057] Among them, such as Figure 6 As shown, the six first side magnetic cores 111 are divided into two parts, located on the front and rear sides of the three first middle magnetic cores 112 respectively, and their lateral positions correspond to the first middle magnetic cores 112. The six second side magnetic cores 122 are divided into two parts, located on the upper and lower sides of the three first middle magnetic cores 112 respectively, and their longitudinal positions correspond to the first middle magnetic cores 112.

[0058] In the winding structure, each of the first winding 13 and second winding 14 is wound on the protrusions of the two end face magnetic plates 121. Adjacent first windings 13 and second windings 14 are grouped together, resulting in individual first windings 13 and second windings 14, as well as three winding groups. There are air gaps 15 between the three winding groups, and there are also air gaps 15 between the winding groups and the individual first windings 13 and second windings 14, for a total of four air gaps.

[0059] like Figure 7 This is a schematic diagram of the multiphase coupled inductor winding structure of this embodiment, including four first windings 13 and four second windings 14. The first windings 13 enter from the bottom and are wound upwards, and exit from the bottom of the other end. The second windings 14 enter from the top and are wound downwards, and exit from the top of the other end. The first windings 13 and the second windings 14 are alternately coupled. The first windings 13 and the second windings 14 are positively coupled, and the first windings 13 and the second windings 14 are negatively coupled.

[0060] like Figure 8 The diagram shows the magnetic flux distribution when the multiphase coupled inductor of this embodiment is in operation. When the first winding 13 is energized, the generated magnetic flux is horizontal to the left, and when the second winding 14 is energized, the generated magnetic flux is horizontal to the right.

[0061] This embodiment provides a multiphase coupled inductor, which is an 8-phase interleaved coupled inductor that can realize a fully integrated inductor structure with mixed forward and reverse coupling. It achieves full integration of all phase inductors and can meet the inductor requirements of single-level data center power supply scenarios.

[0062] In one embodiment, the air gap size is less than 0.1 mm.

[0063] It is understandable that by adjusting the size of the air gap between the windings and between the magnetic cores, the inductance and coupling coefficient of the multiphase coupled inductor can be controlled.

[0064] While keeping the leakage inductance Lk constant, i.e., the dynamic characteristics unchanged, the steady-state equivalent inductance can be altered by changing the coupling coefficient k. By controlling the air gap size within a preset range, the desired current ripple can be obtained. Accordingly, in a specific embodiment, the coupling coefficient can be between -0.3 and 0.7.

[0065] This embodiment provides a multiphase coupled inductor that can improve the quality of current ripple by controlling the range of air gap size.

[0066] In one embodiment, the cross-sectional area of ​​the first central magnetic core 112 is the sum of the cross-sectional areas of the two first side magnetic cores 111.

[0067] In this multiphase coupled inductor, both the first central magnetic core 112 and the first side magnetic core 111 are cuboid cores. The length and height of the first central magnetic core 112 and the first side magnetic core 111 can be equal, or they can be set to different dimensions based on actual conditions. When there are N first central magnetic cores 112 in the multiphase coupled inductor, the dimensions of several first central magnetic cores 112 are equal, and N is greater than or equal to 2. Correspondingly, when there are N first central magnetic cores 112 in the multiphase coupled inductor, the dimensions of several first side magnetic cores 111 are also equal, and N is greater than or equal to 2.

[0068] This embodiment provides a multiphase coupled inductor. By setting the cross-sectional area of ​​the first central magnetic core to be the sum of the cross-sectional areas of the two first side magnetic cores, the magnetic flux density in the multiphase coupled inductor can be kept similar, thereby balancing the magnetic flux and achieving the technical effect of reducing magnetic loss.

[0069] In one embodiment, the winding is made of Litz wire or copper strip material.

[0070] The Litz wire is made of multiple independently insulated conductors twisted or braided together. The copper strip material can be copper wire.

[0071] In one embodiment, the first winding 13 is wound clockwise around the first central magnetic core 112, and the second winding 14 is wound counterclockwise around the first central magnetic core 112.

[0072] The clockwise and counterclockwise perspectives are based on the perspective that the inlets of the first winding 13 and the second winding 14 are located on the left. The winding of the positive and negative windings can be achieved by winding the first winding 13 clockwise and the second winding 14 counterclockwise.

[0073] Based on the same inventive concept, this application also provides a single-stage high-dropout converter for using the aforementioned multiphase coupled inductor. Specific limitations in one or more single-stage high-dropout converter embodiments provided below can be found in the limitations regarding the multiphase coupled inductor above, and will not be repeated here.

[0074] In one embodiment, such as Figure 9 As shown, a single-stage high-step-down converter is provided, including a square wave inverter, an input series-output parallel transformer, a rectifier output unit, a controller, and a multi-phase coupled inductor, wherein:

[0075] The square wave inverter is connected to the input series-output parallel transformer, the input series-output parallel transformer is connected to the rectifier output unit, the rectifier output unit is connected to the winding of the multiphase coupled inductor, and the controller is connected to the input series-output parallel transformer and the rectifier output unit respectively.

[0076] The controller is used to control the rectifier output unit to excite the winding based on the positive or negative value of the output voltage of the input series-output parallel transformer.

[0077] The square wave inverter is used to convert DC power into AC power. The input-series-output-parallel transformer is used to realize the high-voltage series input on the primary side and the low-voltage parallel output on the secondary side.

[0078] The multiphase coupled inductor used in this embodiment is an 8-phase interleaved coupled inductor, wherein the first winding 13 enters and is wound from the lower side of the first side magnetic core 111, and the second winding 14 enters and is wound from the upper side of the first side magnetic core 111.

[0079] The rectifier output unit includes multiple switching transistors, each connected to a corresponding winding. When the secondary coil of the input-series-output-parallel transformer induces a voltage with positive at the top and negative at the bottom, the controller controls the upper switching transistor of the winding to turn off and the lower switching transistor to turn on based on the voltage of the secondary coil, thus energizing the inductance of the first winding 13. When the secondary coil induces a voltage with positive at the bottom and negative at the top, the controller controls the lower switching transistor of the winding to turn off and the upper switching transistor to turn on based on the voltage of the secondary coil, thus energizing the inductance of the second winding 14. When the voltage induced in the secondary coil is 0, the controller controls both the upper and lower switching transistors to turn on, at which point both the first winding 13 and the second winding 14 are in demagnetization mode.

[0080] The controller can be a control chip built into a single-stage high-step converter, or a control unit in the power supply system to perform overall control of the power supply system, including the single-stage high-step converter. Other control units are also possible, but this article does not limit them.

[0081] This embodiment provides a single-stage high-step-out converter that, through a square wave inverter, an input series-output parallel transformer, a switching transistor, and a multi-phase coupled inductor, can realize coupled inductor excitation under a single-stage power supply architecture in a data center, achieving a combination of single-stage high-step-out structure and multi-phase step-out interleaved parallel technology.

[0082] In one embodiment, the circuit of the square wave inverter may employ one of the following topologies: full-bridge topology, half-bridge topology, and switched-capacitor topology.

[0083] To more clearly illustrate the technical solution of this application, a detailed embodiment is also provided. This embodiment provides an 8-phase interleaved coupled inductor, including a main flux magnetic component, a secondary flux magnetic component, a positive winding, and a negative winding.

[0084] The main magnetic flux component consists of multiple rectangular magnetic cores with air gaps between them, providing a path for the main magnetic flux generated by the winding. It also includes two end-face magnetic plates. The secondary magnetic flux component consists of multiple Class II magnetic cores with air gaps between them, providing a path for the return magnetic flux generated by the winding. The positive winding enters from below and is wound clockwise. When excited, the generated magnetic flux is horizontally to the left, and the positive windings are positively coupled to each other. The negative winding enters from above and is wound quasi-clockwise. When excited, the generated magnetic flux is also horizontally to the right. Therefore, the negative windings are positively coupled to each other, but negatively coupled to the positive winding.

[0085] Among them, the air gap between the cuboid cores of the main magnetic flux magnetic component and the air gap between the two types of cores of the auxiliary magnetic flux magnetic component are located between the windings and have equal widths.

[0086] The winding material can be Litz wire, copper strip, or other materials.

[0087] To achieve the benefits of a single-stage power supply architecture in a data center and to implement a single-stage high-step converter, the coupled inductor is driven using the following topology:

[0088] The primary side uses a square wave inverter circuit, specifically a full-bridge topology, half-bridge topology, switched capacitor topology, etc.; the intermediate transformer uses a matrix transformer to provide high-voltage series input on the primary side and low-voltage parallel output on the secondary side.

[0089] like Figure 9As shown, the secondary-side rectification adopts an inductor-based current-doubling rectification structure. When the secondary coil induces a voltage with positive at the top and negative at the bottom, the switch at the upper end of the winding is turned off, and the switch at the lower end is turned on, thus exciting the upper inductor (i.e., the forward winding, marked as L1, 3, 5, 7 in the circuit diagram). When the secondary coil induces a voltage with positive at the bottom and negative at the top, the switch at the lower end of the winding is turned off, and the switch at the upper end is turned on, thus exciting the lower inductor (i.e., the reverse winding, marked as L2, 4, 6, 8 in the circuit diagram). When the secondary coil has 0 voltage, both the upper and lower switches are turned on, and both types of inductor windings are in demagnetization mode.

[0090] It is understandable that the inductance and its coupling coefficient can be controlled by adjusting the air gap between the central and edge magnetic pillars. While keeping the leakage inductance Lk constant (i.e., the dynamic characteristics unchanged), the steady-state equivalent inductance can be altered by changing the coupling coefficient k. The values ​​of inductances L1 and L2 are 120 / (1+k)nH. A parameter scan of k from -1 to 0 represents complete reverse coupling to the discrete components; the magnitude of the resulting ripple is then compared. Figure 10 It is known that as the reverse coupling coefficient increases, the peak-to-peak value of the ripple decreases. However, once the coupling coefficient increases to a certain extent, the benefit of reducing ripple becomes limited. Based on experience and practical considerations, the optimal value for the coupling coefficient k is -0.3 to -0.7.

[0091] Based on finite element simulation, the inductance matrix of the 8-phase interleaved coupled inductor in this embodiment is as follows:

[0092]

[0093] The current waveform of the coupled inductor can be obtained using circuit simulation software, as shown below. Figure 11 As shown, coupling interleaving is achieved, which reduces steady-state ripple.

[0094] On the other hand, the winding impedance extracted by finite element method can be used to estimate the loss of the 8-phase interleaved inductor under a 200A load condition:

[0095] Loss 8ph =2.19W

[0096] Therefore, it can be seen that the 8-phase interleaved coupling inductor provided in this embodiment can effectively reduce winding losses.

[0097] The multiphase interleaved coupling inductor provided in this embodiment has a cavity in the multiphase coupling inductor, and the main magnetic flux magnetic component is located in the cavity; the main magnetic flux magnetic component includes a first central magnetic core and at least two first side magnetic cores, the first central magnetic core is located between the first side magnetic cores, and the two ends of the first central magnetic core and the first side magnetic cores are respectively connected to the two sides of the cavity. The winding includes at least two first windings and at least two second windings, with the first and second windings interleaved. The first and second windings enter from both sides of the first side magnetic core and are wound around the first central magnetic core, respectively. The winding directions of the first and second windings are opposite, which can realize a fully coupled inductor structure with mixed forward and reverse coupling in a single-pole data center power supply scenario. This achieves full integration of all phase inductors and reduces output current ripple under a single-stage high-dropout structure. By setting a distributed air gap structure in the multi-phase interleaved coupled inductor, magnetic field leakage and winding losses can also be reduced. By modularizing the magnetic core and using distributed air gaps, the expansion difficulty of the multi-phase interleaved coupled inductor is reduced, and the usability of the multi-phase interleaved coupled inductor is improved.

[0098] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0099] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A multiphase coupled inductor, characterized in that, The multiphase coupled inductor includes a main flux magnetic component and windings, wherein: The multiphase coupled inductor has a chamber; The main magnetic flux magnetic component includes three first central magnetic cores and six first side magnetic cores. The first central magnetic cores are located between the first side magnetic cores, and the first central magnetic cores and the first side magnetic cores are located in the cavity. The multiphase coupled inductor also includes a secondary magnetic flux magnetic component, which includes six second side magnetic cores. The main magnetic flux magnetic component includes two end-face magnetic plates. The second side magnetic cores are respectively connected to both ends of the two end-face magnetic plates to form the cavity. The first central magnetic cores and the first side magnetic cores are respectively connected to the middle of the two end-face magnetic plates. The winding includes four first windings and four second windings. The first windings and second windings are interleaved and coupled. The first windings and second windings enter from both sides of the first side magnetic core and are wound around the first central magnetic core. The winding directions of the first windings and second windings are opposite.

2. The multiphase coupled inductor according to claim 1, characterized in that, Air gaps are evenly distributed between the first central magnetic cores, between the first side magnetic cores on the same side, between the second side magnetic cores on the same side, and between the second side magnetic core and the end face magnetic plate. The air gaps correspond to the gaps between the windings.

3. The multiphase coupled inductor according to claim 2, characterized in that, The air gap size is less than 0.1 mm.

4. The multiphase coupled inductor according to claim 1, characterized in that, Both the first central magnetic core and the first side magnetic core are cuboid magnetic cores with equal length and height; the cross-sectional area of ​​the first central magnetic core in the length and height directions is the sum of the cross-sectional areas of the two first side magnetic cores in the length and height directions.

5. The multiphase coupled inductor according to claim 1, characterized in that, The winding is made of Litz wire or copper strip material.

6. The multiphase coupled inductor according to claim 1, characterized in that, The first winding is wound clockwise around the first central magnetic core, and the second winding is wound counterclockwise around the first central magnetic core.

7. A single-stage high-step converter, characterized in that, The single-stage high-step converter includes a square wave inverter, an input series-output parallel transformer, a rectifier output unit, a controller, and a multiphase coupled inductor as described in any one of claims 1 to 6, wherein: The square wave inverter is connected to the input series-output parallel transformer, the input series-output parallel transformer is connected to the rectifier output unit, the rectifier output unit is connected to the winding of the multiphase coupled inductor, and the controller is connected to the input series-output parallel transformer and the rectifier output unit respectively. The controller is used to control the rectifier output unit to excite the winding based on the positive or negative value of the output voltage of the input series-output parallel transformer.

8. The single-stage high-step converter according to claim 7, characterized in that, The circuit of the square wave inverter adopts one of the following topologies: full-bridge topology, half-bridge topology, and switched capacitor topology.

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