Integrated magnetic components

Abstract

Integrated magnetic components are disclosed. The invention relates to integrated magnetic components for switched mode power converters comprising a transformer having two transformer core elements and at least one choke core element. Each core element comprises two outer legs and a flange connecting the outer legs to form a U-shaped core element. Each choke core element is adjacent to the flange of one of the transformer core elements. The integrated magnetic component comprises a first choke winding arranged on a central leg of the choke core element and a second choke winding arranged on another central leg of the choke core element, wherein either (i) a primary winding is interconnected with the choke windings to reduce core losses by magnetic flux compensation in order to increase power density or (ii) a secondary winding is interconnected with the choke windings to reduce core losses by magnetic flux compensation in order to increase power density.

Description

Technical Field

[0001] This invention relates to an integrated magnetic component for a switch-mode power converter. The integrated magnetic component includes a transformer comprising two transformer core elements. The integrated magnetic component also includes at least one choke core element. Each of the core elements includes first and second outer legs and a flange connecting the outer legs to form a U-shaped core element. The transformer core elements are arranged to form an O-shaped core element. Each choke core element is adjacent to a flange of one of the transformer core elements. The transformer further includes a primary winding and a secondary winding arranged on the legs of the transformer core elements. Furthermore, the transformer includes a first air gap arranged in the magnetic flux path between the transformer core elements. The integrated magnetic component further includes at least one second air gap in the magnetic flux path between the transformer core elements and the choke core element. Background Technology

[0002] Switch-mode power supplies, as a major component of telecommunications and commercial systems, frequently have specified dimensions and electrical performance, as well as reliability and cost. With increasing demands for power density and efficiency—critical characteristics of power converters—the requirements for these evaluation characteristics are particularly stringent for inductive components. One way to increase power density and efficiency is by integrating inductive components. Transformers and inductors can be integrated into a single magnetic structure, which then reduces cost and increases power density and power efficiency.

[0003] Among the power converters with integrated magnetic components, LLC resonant converters are strongly recommended, as they can generate high efficiency and high-quality EMI while operating at high switching frequencies. US6344979 B1 discloses an isolated type DC-DC converter that isolates the voltage of a DC power source and outputs DC power to the load, such as... Figure 1 As shown in the diagram, it comprises an LLC converter according to the prior art, which uses three magnetic components: a series resonant inductor, a parallel resonant inductor, and a two-winding or three-winding transformer. This converter additionally results in at least three windings and several interconnections due to the number of discrete magnetic components (which leads to higher size and cost), negatively impacting efficiency.

[0004] Another type of power converter with integrated magnetic components that is highly recommended is the soft-switching converter.

[0005] In recent years, efforts have been made to integrate all three magnetic components into a single component for LLC resonant converters. US 2008 0224 809 discloses an integrated magnetic structure ( Figure 2This contributes to increased power density and efficiency. Core element losses are reduced by flux compensation in the mutual core element flanges, and copper losses are minimized by reducing the interconnection between the resonant choke and the transformer. Mutual core element flanges imply increased power density.

[0006] While LLC converters offer all the benefits in terms of efficiency and EMI, they also have some drawbacks. Overcurrent protection is required in many applications. US 2011 0255 321 discloses an LLC resonant converter capable of overcurrent protection. However, this circuitry implies even more discrete magnetic components and more interconnections, which significantly increases size and compromises efficiency gain. Furthermore, the aforementioned structure disclosed in US 2008 0224 809 is unsuitable for such complex converters with more than one filter choke, and especially unsuitable for converters with split resonant chokes. Distributing inductive components across more than one magnetic component not only minimizes losses and increases size but also degrades EMI quality. Summary of the Invention

[0007] The objective of this invention is to create an integrated magnetic component for switching power supplies that belongs to the technical field initially mentioned, which allows for the integration of more inductive components, has increased power density and therefore reduced losses, without negatively impacting EMI quality.

[0008] The solution of the present invention is defined by the features of Example 1 of this solution. According to the present invention, the integrated magnetic component includes a first choke winding disposed on one core post of a choke core element and a second choke winding disposed on another core post of the choke core element. One of the primary winding and the secondary winding is connected between the choke windings. This means that either the primary winding is connected in series between the choke windings or the secondary winding is connected in series between the choke windings. If one of the primary or secondary windings is connected between the choke windings, the other of the primary or secondary windings can also be connected in series between additional choke windings. The windings of the integrated magnetic component are interconnected to reduce core element losses through flux compensation in order to increase power density.

[0009] Integrated magnetic components are generally associated with switch-mode power converters and specifically with DC / DC and AC / DC power converters.

[0010] The windings mentioned above are connected in a manner that minimizes the magnetic flux through the core element (correspondingly, the magnetic flux through different parts of the core element caused by different windings will at least partially compensate for each other). By reducing the magnetic flux (and correspondingly the magnetic flux density through the core element), losses are reduced. In particular, the winding direction and number of windings are adapted to minimize the magnetic flux through the flanges caused by different windings. Moreover, the windings are connected such that the magnetic flux in the parallel core columns is distributed so that the magnetic flux density in the core columns is similar across the parallel core columns.

[0011] Integrated magnetic components may also include additional windings, which must also be connected in such a way that the losses of the magnetic core elements are minimized.

[0012] Preferably, the core element integrating the magnetic components can be used as an assembly block, and in particular, standardized assembly blocks can be used. If the assembly block has two core pillars, standardized U-shaped, UR-shaped, or similar core elements can be used. If the core element has three core pillars, standardized E-shaped or similar core elements with three core pillars are preferably used. A non-exhaustive list includes three-pillar core elements, such as E-shaped, ER-shaped, and PQ-shaped core elements.

[0013] Magnetic core elements may be understood as abstract component blocks, although preferably they represent structural component blocks consisting of a single element or assembled from different sub-component blocks (like I-shaped magnetic core elements). For example, structural magnetic core elements (such as U-shaped magnetic core elements) may be arranged from three I-shaped magnetic core elements, or E-shaped magnetic core elements may be arranged from four I-shaped magnetic core elements or one U-shaped magnetic core element and one I-shaped magnetic core element. By considering magnetic core elements as abstract component blocks, they are understood as blocks that allow for the final arrangement of magnetic core elements to realize magnetic circuits, although the same structure can also be implemented by other structural elements. For example, an O-shaped shape formed by two transformer magnetic core elements can also be arranged from an I-shaped magnetic core element defining the flange of the first transformer magnetic core element and a U-shaped magnetic core element adjacent to the I-shaped magnetic core element, thereby providing the core post of the first transformer magnetic core element and the core post of the second transformer element, as well as the flange of the second transformer element. Furthermore, the shape formed by the two transformer core elements, resembling the number 8, can be arranged by an I-shaped core element defining the flange of the first transformer core element and an E-shaped core element adjacent to the I-shaped core element, thereby providing the core post of the first transformer core element and the core post of the second transformer core element, as well as the flange of the second transformer core element.

[0014] Two-column core elements are particularly advantageous when windings must be adapted for high currents, which involves the use of spacious windings. This is especially true if integrated magnetic components are provided for power converters adapted to be connected to low-voltage input sources such as batteries or DC power supplies (e.g., 12, 24, or 48V). Conversely, integrated magnetic components with three-column core elements may be more advantageous if power is provided for connections to higher voltages, such as to the household grid, for example, to a 400V household network.

[0015] In the sense that specific portions of the surfaces of the magnetic core elements are in contact with each other, the magnetic core elements are adjacent or connected. However, as will be described later, air gaps or any other material may be arranged between the magnetic core elements in order to adjust the magnetic properties of the magnetic components.

[0016] The magnetic flux path between two core elements is understood as a low-resistivity path provided by the core pillars between the flanges of two adjacent core elements. The air gap in the flux path can be located anywhere within the flux path defined by the core pillars of the two adjacent core elements: between two facing core pillars, between the core pillars of the core elements, or between a flange and a core pillar, where the flange and core pillar can be the same or different core elements. In ferrite core elements with high reluctance, the air gap is typically a concentrated air gap filled with air or any other material with low magnetic permeability, usually perpendicular to the core pillar. However, the air gap can also be distributed, which is achieved by using a powder core made of a material containing iron or an iron alloy.

[0017] The first air gap in the flux path between the transformer core elements allows for adjustment of the transformer's magnetic characteristics. Specifically, it allows for adjustment of the parallel inductance of the primary or secondary transformer windings. Similarly, the second air gap allows for adjustment of the magnetic properties of the choke core elements. It allows for adjustment of the series resonant inductance of the choke winding.

[0018] Each choke core element is adjacent to the flange of the adjacent transformer core element. The core elements are preferably arranged such that the core posts of the core elements are arranged linearly in rows such that the core post of one of the two transformer core elements is adjacent to the core post of the other two transformer core elements, and the core post of at least one of the choke core elements is adjacent to the flange of the adjacent transformer core element on the flange side opposite to the corresponding core post of the adjacent transformer core element.

[0019] It should be noted that the integrated magnetic components are preferably arranged in a plane.

[0020] It should also be noted that the core post and flange are preferably arranged at a right angle, which simplifies the structure and manufacture of the integrated magnetic components.

[0021] The integrated magnetic component according to the invention allows for increased power density in complex magnetic circuits by reducing core element losses, while maintaining high EMI quality. The complex magnetic circuit can include at least four windings: the primary and secondary windings of a transformer, and first and second choke windings, thus providing a basis for implementing complex switch-mode power converters with at least four dual-series resonant inductors and a transformer with at least one primary winding and one secondary winding. It further provides a cost-saving implementation of the magnetic component for switch-mode power converters.

[0022] In a preferred embodiment of the invention, the integrated magnetic component comprises at least two choke core elements. In this embodiment, a second air gap is located in the flux path between one of the transformer core elements and the first of the two choke core elements. The integrated magnetic component further comprises at least one third air gap located in the flux path between the other of the transformer core elements and the second of the two choke core elements. Here, a first choke winding is arranged on the first choke core element and a second choke winding is arranged on the second choke core element to reduce the air gap edge field by splitting the choke windings across the two choke core elements.

[0023] By distributing the choke coils on two choke core elements and simultaneously distributing the air gap on two choke core elements, the edge field is reduced and thus the loss is reduced.

[0024] Another advantage of this embodiment is that the integrated magnetic components will have an improved transient response.

[0025] In a beneficial embodiment, the integrated magnetic component comprises exactly two choke core elements. This allows for a planar arrangement of the core elements while simultaneously distributing the air gap across the two choke core elements.

[0026] In another advantageous embodiment of the invention, each core element further includes a central core post arranged between the outer core posts of the core elements, such that the outer core post, central core post, and flange of each core element form a shape like E, and wherein the central core posts of the transformer core elements face each other, such that the two transformer core elements form a core element of shape like 8. The central core post of each choke core element abuts the flange of the adjacent transformer core element on the side opposite to the central core post of the adjacent transformer core element.

[0027] Preferably, the central core posts of the stacked magnetic core elements are arranged in rows. The central core posts are preferably adjacent to the flanges of adjacent magnetic core elements at right angles.

[0028] In a preferred embodiment, the transformer winding is wound around the central core post of the transformer core element, and the choke winding is wound around the central core post of the choke core element.

[0029] The advantage of this embodiment is that fewer windings and fewer connections are inevitable and involve such low costs.

[0030] In another advantageous embodiment of the invention, the windings are arranged on the outer core posts of the respective U-shaped magnetic core elements. The windings may be divided into first and second winding portions. At least one of the windings or at least one of the first winding portions is arranged on at least one first outer core post, while at least another of the windings or one of the second winding portions is arranged on a second outer core post opposite to the at least one first outer core post. Furthermore, two of the windings or winding portions are connected in series, having the same number of turns and winding direction, such that the current through the series-connected windings or winding portions results in a magnetomotive force acting in the same direction. This direction is defined with respect to the closed magnetic circuit to which the two opposing outer core posts belong.

[0031] Alternatively, the windings may be wound only on the outer core posts, or both on the outer core posts and the center core post. If the core element has three core posts—two outer core posts and one center core post—the transformer windings may also be wound on the center core element and the choke windings wound around the outer core posts, or vice versa.

[0032] The winding may also be wound around the flange of the magnetic core element.

[0033] In a preferred embodiment, the choke winding and the transformer winding connected between the first and second choke windings are implemented with a single conductor to avoid additional leads between the windings.

[0034] A continuous connection established between the choke winding and the primary or secondary winding of the transformer via a single wire (and correspondingly, a single connector) reduces the total number of welded ends and thus reduces copper losses. Furthermore, it simplifies the manufacturing process and therefore reduces the cost of integrating magnetic components.

[0035] In some embodiments, it may be advantageous to first mount the transformer and / or choke windings onto the core posts of the core elements before assembling the core elements. In such cases, it may be advantageous to connect only the windings after assembling the core elements. The connection between the choke windings and one of the first or second transformers may be achieved by providing leads for the respective windings and, for example, by soldering them to a circuit board.

[0036] In an additional preferred embodiment with integrated magnetic components, the primary and / or secondary windings of the transformer are split into a first split transformer winding and a second split transformer winding. A first end of the first split transformer winding is connected to a first end of an electronic component, preferably a capacitive element. Further, a first end of the second split transformer winding is connected to a second end of the electronic component, and the second end of the second split transformer winding is connected to a first and a second choke winding, respectively.

[0037] This embodiment is particularly suitable for the magnetic components of integrated resonant switching converters (such as LLC converters). Therefore, it allows an LLC converter with overcurrent protection, featuring two series resonant inductors, two parallel inductors, and a transformer, to be integrated onto a single integrated magnetic component with high power density. The resonant series capacitor of the LLC circuit can be connected between the primary portions of the split transformer windings, in parallel with the clamping circuit for overcurrent protection.

[0038] Furthermore, other electronic components may be connected between the transformer windings, such as resistive elements for damping purposes or shunt resistors for measuring input or output current.

[0039] Instead of electronic components, the center tap can be connected to the first end of the split transformer winding.

[0040] In another embodiment of the integrated magnetic component, at least one of the air gaps is arranged parallel to the flange of the core element of the integrated magnetic component.

[0041] Parallel arrangement not only simplifies sizing and manufacturing but also reduces the cost of integrating magnetic components. However, in some cases, it may be beneficial to arrange at least one air gap with the flanges of the core element at an angle other than zero, especially if the core post is not arranged at right angles with respect to the flanges of the core element.

[0042] Preferably, the surface of the permeable material defining the air gap in the core element is planar. However, due to other factors, they may have uneven surfaces, such as concave surfaces, for the purpose of reducing edge effects at the air gap boundary.

[0043] In particular, if sintered or cast magnetic core elements are used, economical manufacturing is not limited to the air gap of the flange of the magnetic core element parallel to the integrated magnetic components.

[0044] In another preferred embodiment of the invention, an air gap is arranged between corresponding adjacent magnetic core elements.

[0045] This means that the air gap is positioned at the connection point between the core elements. An advantage of this embodiment is that the air gap can be milled within the core post or incorporated using prefabricated core elements, where the length of the core post has been adjusted. The air gap is preferably milled before assembling the corresponding core elements. The air gap can be filled with any suitable material or left empty. Filling the air gap with a non-permeable material increases the mechanical stability of the integrated magnetic components.

[0046] Air gaps can also be integrated between the core posts of a magnetic core element or between the core post and the flange. Furthermore, more than one air gap can be integrated into the core post of a magnetic core element. This reduces air gap edge artifacts.

[0047] In conjunction with or as an alternative to a centralized air gap, a distributed air gap can also be applied by specifically using powder material on the core element or a portion thereof for the core post. Distributed air gaps (correspondingly, powder core elements) are preferred when energy must be stored for operation in regions of high magnetoresistivity and high saturation flux density.

[0048] In an advantageous embodiment of the invention, the arrangement of the transformer core elements and the choke core elements is symmetrical about the axis of the core column parallel to the core elements.

[0049] The symmetrical arrangement of magnetic core elements involves a symmetrical distribution of magnetic flux in the circuit and thus reduces losses. In particular, the compensation of magnetic flux through the flanges of transformer core elements adjacent to choke core elements can be maximized. Symmetrical arrangement also reduces production costs and facilitates assembly.

[0050] However, under the same circumstances, it may be advantageous to choose a structure that is asymmetrical about the axis of the core column parallel to the core element. This may be because the space available for integrating the magnetic components is not conducive to a symmetrical arrangement. In some cases, the magnetic components of the power converter to be implemented are not adapted for such a mirror-symmetrical implementation. Furthermore, thermal constraints may require an asymmetrical arrangement if, for example, one half of the circuit is exposed to a higher temperature.

[0051] In another advantageous embodiment of the integrated magnetic component according to the invention, the arrangement of the transformer core element and the choke core element is symmetrical about an axis parallel to the flange of the core element, and in particular the air gap is symmetrical about said axis.

[0052] This embodiment has the following particular advantage: the two choke coils are symmetrically inducted, which significantly increases the performance of the integrated magnetic components.

[0053] However, and here, spatial constraints may necessitate the use of an arrangement that does not conform to axisymmetry with respect to the parallelism of the flanges of the core elements. This is the case, for example, if the number of choke core elements is unpaired. Moreover, the magnetic components of the power converter to be implemented may not be adapted for such a mirror-symmetric implementation, for example, if different values ​​are required for the series inductors.

[0054] The present invention further relates to a switch-mode power converter that includes an integrated magnetic component according to any of the embodiments mentioned in the description.

[0055] In a preferred embodiment, the switch-mode power converter is an LLC resonant converter.

[0056] In another preferred embodiment, the switch-mode power converter is a soft-switching converter.

[0057] Switch-mode power converters inherit all the advantages of the magnetic components mentioned above; this applies to LLC resonant converters as well as soft-switching converters.

[0058] The present invention also relates to a method for providing an integrated magnetic component, comprising the steps of: a) Provide two transformer core elements and one or two choke core elements; each of the core elements is U-shaped, comprising two outer core pillars and a flange. b) A transformer is formed by arranging two transformer core elements as O-shaped core elements, arranging the primary and secondary windings on the core column of the transformer core elements, and providing at least one air gap in the magnetic flux path between the transformer core elements. c) Arrange the choke core elements such that each adjacent transformer core element in the choke core element has a flange, while providing at least one second air gap in the flux path between the transformer core element and the choke core element. and through steps d) A series connection is provided between the first choke winding, the primary or secondary winding of the transformer, and the second choke winding, such that one of the primary and secondary windings of the transformer is connected at one end to the first choke winding and at the other end to the second choke winding, the first choke winding is arranged on the central core of the first choke core element, and the second choke winding is arranged on the central core of the second choke core element, wherein either (i) the primary winding is interconnected with the choke winding to reduce core losses through flux compensation in order to increase power density, or (ii) the secondary winding is interconnected with the choke winding to reduce core losses through flux compensation in order to increase power density.

[0059] Other beneficial embodiments and combinations of features arise from the following detailed description and the technical solutions to be protected. Attached Figure Description

[0060] The accompanying drawings, used to illustrate the embodiments, show: Figure 1 A schematic diagram of a prior art LLC resonant converter is shown in patent US6344979 B1; Figure 2 The integrated magnetic structure shown in patent US20080224809; Figure 3 Circuit configuration of an LLC resonant converter with overcurrent protection using a split resonant choke (LLC converter in patent US20110255321A1); Figure 4 A schematic diagram of a first preferred embodiment of an integrated magnetic component for an LLC resonant converter with overcurrent protection using a split resonant choke; Figure 5 Figure 4 The magnetoresistive model of the integrated magnetic components presented in the paper; Figure 6 The current in series resonant chokes, the current in parallel resonant chokes and the primary winding current, as well as the magnetic flux density in the core components of transformers and chokes and in their respective flanges. Figure 7 A schematic circuit of a soft-switching converter with a split second filter choke; Figure 8 A second embodiment of integrating magnetic components is used for integrating, such as Figure 7 The magnetic components of the soft-switching converter with a split second filter choke shown are illustrated. Figure 9 Figure 8 The magnetoresistive model of the integrated magnetic structure presented in the paper; Figure 10 The voltage and current of the secondary transformer windings, as well as the magnetic flux density in the core components of the transformer and choke, and in the mutual flanges; Figure 11 A schematic diagram of the third embodiment of the present invention is provided by a tool for... Figure 4 and Figure 8 The integrated magnetic components are constructed using stacked EE magnetic core elements or similar three-pillar magnetic core elements, the difference being the air gap arrangement in the longitudinal magnetic flux path; Figure 12 A schematic diagram of the fourth embodiment of the present invention is provided by a tool for... Figure 4 and Figure 8 The integrated magnetic components are constructed using stacked EE magnetic core elements or similar three-pillar magnetic core elements, the difference being the air gap arrangement in the longitudinal magnetic flux path; Figure 13A schematic diagram of a fifth embodiment of the integrated magnetic component according to the present invention; the integrated magnetic component comprises four U-shaped magnetic core elements or similar two-pillar magnetic core elements stacked in parallel, for use as... Figure 3 The LLC resonant converter shown in the figure; Figure 14 A schematic diagram of a sixth embodiment of the integrated magnetic component according to the present invention; the integrated magnetic component comprises four U-shaped magnetic core elements or similar two-pillar magnetic core elements stacked in parallel, for use as... Figure 7 The soft-switching converter shown; Figure 15 A schematic diagram of a seventh preferred embodiment of the integrated magnetic component according to the present invention; the integrated magnetic component comprises three U-shaped magnetic core elements or similar two-pillar magnetic core elements stacked in parallel, for use according to Figure 3 LLC resonance; Figure 16 A schematic diagram of eight preferred embodiments of the integrated magnetic component according to the present invention, having three U-shaped magnetic core elements or similar two-pillar magnetic core elements stacked in parallel; used for, for example Figure 7 The soft-switching converter shown; Figures 17a), 17b), and 17c can be alternatively derived from those used for Figure 15 and Figure 16 The integrated magnetic components are constructed using stacked U-shaped magnetic core elements or similar two-pillar magnetic core elements.

[0061] In the diagram, the same parts are given the same reference labels. Detailed Implementation

[0062] The LLC resonant converter circuit 10 includes a resonant capacitor Cr and a series resonant inductor. L r A parallel resonant inductor L m And a two-winding or three-winding transformer 4 (depending on the selected rectifier at the output of the LLC converter). According to Figure 1 In the example, transformer 4 includes a primary winding P, a first-stage winding S1, and a second-stage winding S2. This converter additionally results in at least three windings and several interconnections due to the increased number of discrete magnetic components (which lead to higher size and cost), negatively impacting efficiency.

[0063] Figure 2 The integrated magnetic component 20 is integrated according to Figure 1 The three magnetic components of the circuit (i.e., the series resonant inductor Lr, the parallel resonant inductor Lm, and the transformer 4) are integrated into a single magnetic component 20, which helps to increase... Figure 1The power density of the LLC series-parallel converter is increased. Core element losses are reduced by means of flux compensation in the mutual core element flanges 21, and copper losses are minimized by reducing the interconnections between the windings of the integrated magnetic components 20. The mutual core element flanges 21 also imply an increase in power density.

[0064] according to Figure 2 The integrated magnetic component is constructed using three E-shaped core elements: a choke core element E1, a first transformer core element E2, and a second transformer core element E3. The two transformer core elements E2 and E3 face each other with their core posts, forming an 8-shaped transformer core element. A transformer air gap 41.23 is positioned between the two central core posts of transformer core elements E2 and E3. The third choke core element E1 is stacked on the flange of the first transformer core element E2, such that its outer core post abuts against the flange of the first transformer core element E2 on the side opposite to the outer core post of the first transformer core element E2. The central core post of the choke core element E3 faces the center of the flange of the transformer core element E2 on the side opposite to the center. The choke air gap 41.1 is located between the flange of the first transformer core element E2 and the central core post of the choke core element E1. Figure 2 The diagram shows the primary winding P of a transformer, which is wound around the central core post of the first transformer core element E2, while the first and second secondary windings S1 and S2 are wound around the central core post of the second transformer core element E3. However, the primary winding P and the first and second secondary windings S1 and S2 can also be wound around the central core posts of both transformer core elements (i.e., around the central core posts of the first transformer core element E2 and the second transformer core element E3), thus the primary winding P and the first and second secondary windings S1 and S2 of the transformer S are arranged in layers.

[0065] The series resonant inductor Lr of the circuit is defined by a choke winding 23 wound around the central core of the choke core element E1 and a choke air gap 41.1 between the central core and the flange of the transformer core element. The choke winding is connected in series with the primary winding P of the transformer.

[0066] Upstream of the integrated magnetic component 20, according to Figure 2 The LLC converter further includes an H-bridge converter with four switches Q11, Q12, Q21, and Q22, and a resonant capacitor Cr. At the output of the integrated magnetic component 20, a full-wave center-tapped rectifier with diodes D1, D2, and a filter capacitor Cout is connected to the secondary portion of the transformer 4 at load connection points 7a, 7b, and 7c. It should be noted that a half-bridge converter with two switches can also be used upstream of the integrated magnetic component 20 instead of an H-bridge converter with four switches.

[0067] However, according to Figure 2 Magnetic components are not allowed to be integrated Figure 3 The circuit configuration shown (an LLC resonant converter with overcurrent protection (OCP) using a split resonant choke) includes magnetic components.

[0068] However, the circuit can be integrated by means of a first embodiment of the integrated magnetic component 103 according to the present invention.

[0069] In the drawings below, similar elements in different embodiments are indicated by similar figures (distinguished by the hundreds digit) if they are depicted in different drawings.

[0070] Figure 3 An AC-to-DC converter 100 is shown, comprising an LLC converter unit 101 having a rectifier stage (not shown), a full bridge (not shown), and a split resonant choke. The resonant LLC circuit with the split resonant choke includes a series resonant capacitor Cr, two series resonant inductors Lr1 and Lr2, two parallel resonant inductors Lm1 and Lm2, and a split transformer 104. All five inductive components Lr1, Lr2, Lm1, Lm2, and 104 are implemented on an integrated magnetic component 103 according to the invention. The split transformer 104 includes a first transformer 105a having a first primary winding P1 and a second primary winding S1, and a second transformer 105b having a second primary winding P2 and a second secondary winding S2.

[0071] The output of LLC converter unit 101 is connected to a first connection point 102a and a second connection point 102b of the integrated magnetic component 103 according to the invention. At a third connection point 102c of the integrated magnetic component 103, a first primary winding P1 is connected with its first end to the first terminal of a series resonant capacitor Cr. Similarly, at a fourth connection point 102d of the integrated magnetic component 103, a second primary winding P2 is connected with its first end to the second terminal of the series resonant capacitor Cr. The second ends of the primary windings P1 and P2 are connected to the corresponding first ends of series resonant inductors Lr1 and Lr2. The series resonant inductors Lr1 and Lr2 are themselves connected to the converter outputs of the integrated magnetic component 103 at the first and second connection points 102a and 102b. Parallel inductors Lm1 and Lm2 are arranged in parallel with the first and second primary windings P1 and P2 of the first and second transformers 105a and 105b. According to US20110255321A1, a diode clamping circuit is connected in parallel to a series resonant capacitor Cr between the third and fourth connection points 102c and 102d of the integrated magnetic component 103. The secondary portion of the split transformer 104 of the integrated magnetic component 103 circuit includes three connection points for connecting a center-tapped full-wave rectifier. The anodes of diodes D1 and D2 of the center-tapped full-wave rectifier are connected to the first and second load connection points 107a and 107b. A filter capacitor Cout is connected at one end to the cathodes of the respective diodes D1 and D2, and at the other end to the center tap of the split transformer 104 in the third load connection point 107c. Alternatively, a full-wave bridge rectifier can be used. In a later example, a single secondary winding can be used between the first and second load connection points 107a and 107b, thus using a single multi-winding transformer.

[0072] Figure 4 The diagram shows a first embodiment of the integrated magnetic component 103 according to the present invention. It allows for... Figure 3 The LLC converter using a split resonant choke shown is integrated into a single integrated magnetic component. The integrated magnetic component 103 comprises four E-shaped core elements: a first transformer core element E2, a second transformer core element E3, a first choke core element E1, and a second choke core element E4. Each of the core elements E1, E2, E3, and E4 includes a first outer core post 120a, a second outer core post 120b, a center core post 121, and a flange 122.

[0073] Two transformer core elements E2 and E3 are arranged in a shape resembling an 8, with their first outer core posts 120a.2 and 120a.3, their second outer core posts 120b.2 and 120b.3, and their center core posts 121.2 and 121.3 facing each other. A transformer air gap 141.23 is arranged between the two center core posts 121.2 and 121.3 of the first transformer core element E2 and the second transformer core element E3. A first choke core element E1 is stacked on the flange 122.2 of the first transformer core element E2, such that its first outer core post 120a.1 and its second outer core post 120b.1 are adjacent to the flange 122.2 of the first transformer core element E2 on the side opposite to the outer core posts 120a.2 and 120b.2. The central core post 121.1 of the choke core element E1 faces the center of the flange 122.2 of the first transformer core element E2 on the side opposite to the central core post 121.2 of the first transformer core element E2. The air gap 141.1 of the first choke is placed between the flange 122.2 of the first transformer core element E2 and the central core post 121.1 of the choke core element E1.

[0074] The second choke core element E4 is stacked on the flange 122.3 of the second transformer core element E3, such that its first outer core post 120a.4 and its second outer core post 120b.4 are adjacent to the flange 122.3 of the second transformer core element E3 on the side opposite to the outer core posts 120a.3 and 120b.3 of the second transformer core element E3. The center core post 121.4 of the second choke core element E4 faces the center of the flange 122.3 of the second transformer core element E3 on the side opposite to the center core post 121.3 of the second transformer core element E3. The second choke air gap 141.4 is placed between the flange 122.3 of the second transformer core element E3 and the center core post 121.4 of the second choke core element E4.

[0075] Air gaps 141.1, 141.4, and 141.23 can be achieved by grinding the corresponding center cores 121.1, 121.2, 121.3, or 121.4. They can be filled with air or any other material with low magnetic permeability.

[0076] In order to Figure 4 More clearly, the first primary winding P1 of transformer 104 (see...) Figure 3 The second primary winding P2 of transformer 104 is wound around the central core post 121.2 of the first transformer core element E2. Figure 3The first stage winding S1 is wound around the center post 121.2 of the first transformer core element E2, and the second stage winding S2 of the transformer 104 is wound around the center post 121.3 of the second transformer core element E3.

[0077] Preferably, however, the first primary winding P1, the second primary winding P2, the first secondary winding S1 and the second secondary winding S2 of the transformer 104 are all wound around the central core posts of the two transformer core elements E2 and E3 (i.e. around the central core post 121.2 of the first transformer core element E2 and the central core post 121.3 of the second transformer core element E3). Thus, the primary windings P1 and P2 and the secondary windings S1 and S2 of the transformer 104 are stacked in layers. For example, the primary windings P1 and P2 of the transformer are surrounded by the secondary windings S1 and S2 of the transformer 104, or vice versa.

[0078] The secondary windings S1 and S2 are connected in series, and the first and second secondary windings S1 and S2 of the transformer have the same winding direction.

[0079] This connection is preferably achieved by using the same wire for both windings, thus avoiding copper losses caused by the soldered interconnection between the two secondary windings S1 and S2. The second end of the first primary winding S1 is connected to the first load connection point 107a with a free end, and the second end of the second secondary winding S2 is connected to the second load connection point 107b with a free end. A center tap 106 is arranged on the wire between the secondary windings S1 and S2 and is connected to the third load connection point 107c of the integrated magnetic component 103.

[0080] The air gap 141.23 of the transformer allows for the parallel inductors Lm1 and Lm2 to be connected in the resonant LLC circuit. A first choke winding 123 is wound around the center post 121.1 of the first choke core element E1; however, a second choke winding 124 is wound around the center post 121.4 of the second choke core element E4. The first choke winding 123 is connected between the first end of the primary winding P1 of the transformer 104 and the first connection point 102.a (see [link to transformer 104]). Figure 3 Similarly, the second choke winding 124 is connected between the first end of the second primary winding P2 of the transformer 104 and the second connection point 102.b (see [link]). Figure 3 The connection between the choke windings 123 and 124 and the primary windings P1 and P2 of the transformer windings is achieved by using a single conductor.

[0081] All the windings of the magnetic components connected to the primary section of the transformer (correspondingly, the choke windings 123, 124 and the primary windings P1, P2) are wound around the central core posts 121.1, 121.2, 121.3, 121.4 of the respective core elements, with the central core posts arranged in rows. Furthermore, all windings have the same winding direction, so the current through the aforementioned series-connected windings generates central magnetic fluxes 131.1, 131.2, 131.3, 131.4 pointing in the same direction through the central core posts of the four core elements E1, E2, E3, and E4. Therefore, the first external magnetic fluxes 130a.1, 130a.2, 130a.3, and 130a.4 through the first outer core pillars 120a.1, 120a.2, 120a.3, and 120a.4 of the corresponding magnetic core elements, and the second external magnetic fluxes 130b.1, 130b.2, 130b.3, and 130b.4 through the second outer core pillars 120b.1, 120b.2, 120b.3, and 120b.4 of the corresponding magnetic core elements, are oriented in the opposite direction to the central magnetic fluxes 131.1, 131.2, 131.3, and 131.4. Since the external magnetic fluxes 130a.1, 130a.2, 130a.3, 130a.4, 130b.1, 130b.2, 130b.3, 130b.4 through the first and second outer core columns are opposite to the central magnetic fluxes 131.1, 131.2, 131.3, 131.4, the flange magnetic fluxes 132a.2 and 132b.2 through the flange of the first transformer core element E2 and the flange magnetic fluxes 132.2 and 132.3 through the flange of the second transformer core element E3 are reduced by flux cancellation, thus resulting in increased power density and reduced copper loss and core element loss.

[0082] The second terminal of the first primary winding P1 of transformer 104 and the second terminal of the second primary winding P2 of transformer 104 (see...) Figure 3 The capacitors Cr and Cr are respectively connected to the third connection point 102c and the fourth connection point 102d of the integrated magnetic component 103. The series resonant capacitor Cr is connected to the third and fourth connection points 102c and 102d of the integrated magnetic component 103 with its two ends connected.

[0083] The first series resonant inductance Lr1 of the circuit is defined by the choke winding 123 wound around the central core post 121.1 of the first choke core element E1 and the first choke air gap 141.1 between the flange 122.2 of the transformer core element and the central core post 121.1. The choke winding 123 is connected in series with the first primary winding P1 of the transformer 104 (see...). Figure 3 ).

[0084] Similarly, the second series resonant inductance Lr2 of the circuit is defined by the choke winding 124 wound around the center post 121.4 of the second choke core element E4 and the second choke air gap 141.4 between the center post 121.4 of the second choke winding E4 and the flange 122.3 of the second transformer core element E3. The second choke winding 124 is connected in series with the second primary winding P2 of the transformer 104 (see...). Figure 3 ).

[0085] Upstream of the integrated magnetic component 103, the LLC converter includes a full-bridge converter with a switching network of four switches Q11, Q12, Q21, and Q22. The switching network provides a square voltage output from the DC input voltage Vdc between the first and second connection points 102a, 102b of the integrated magnetic component. The DC input voltage Vdc can be provided by a rectifier circuit, such as an AC / DC power factor correction (PFC) converter. Instead of the full-bridge converter with the four-switch switching network, a half-bridge rectifier with two switches can also be used.

[0086] Downstream of the integrated magnetic component 103, at the output of the integrated magnetic component 103, a center-tapped full-wave rectifier is provided and the center-tapped full-wave rectifier is connected to load connection points 107a, 107b, 107c.

[0087] Figure 5 The first embodiment according to the present invention is shown. Figure 4 The magnetoresistive model 150 of the integrated magnetic component 103 is shown. The flanges 122.1, 122.2, 122.3, and 122.4 of all core elements E1, E2, E3, and E4 are considered identical and are composed of flange magnetoresistive R. B This indicates that the outer core posts 120a.1, 120a.4, 120b.1, and 120b.4 of the choke inductor core elements E1 and E4 are considered to be the same. LF Specify the reluctance of the outer core posts 120a.1, 120a.4, 120b.1, and 120b.4 of the choke core elements E1 and E4, and R LC Specify the reluctance of the corresponding center cores 121.1 and 121.4 for the corresponding choke core elements E1 and E4. The reluctance of the center cores 121.1 and 121.4 includes the corresponding air gaps (141.1 and 141.4) defined by the center cores 121.1 and 121.4.

[0088] Furthermore, transformer core components E2 and E3 are considered to be the same. TF The reluctance R of each of the outer core columns 120a.2, 120a.3, 120b.2, and 120b.3 of the transformer core elements E2 and E3 is... TCIt is the magnetic reluctance of each of its central core pillars 121.2 and 121.3 (including its portion on the air gap 141.23 in the magnetic flux path between the first and second transformer core elements E2 and E3). The current i through the first and second choke windings 123 and 124 and the transformer primary windings P1 and P2. p They are considered to be the same. Furthermore, the current i flowing through the secondary windings S1 and S2... s They are considered the same. The number of turns in the winding is: N for the first choke winding. L1 For the second choke winding, N L2 For the primary transformer winding N P And for the transformer secondary winding as N S N L1 and N L2 Considered equal: N L1 =N L2 =N L .

[0089] Figure 5 The magnetoresistive model 150 shown will then be analyzed considering only the primary winding S1. After mathematically describing the magnetoresistive model 140 and applying Faraday's law to all windings, some equations calculate the inductance matrix of the integrated component, which is calculated as follows: in N L1 = N L2 = N L / 2, R L = 2· R LC + R LF + R B and R T = 2· R TC + R TF .

[0090] Elements calculated using the inductance matrix, primary L 11 Secondary self-sensing L 22 and mutual induction M 12 ,transformer π Model parameters, primary leakage inductance L r Magnetized inductorL m and equivalent primary turns N pn They were described as Winding N p However, transformer 104 exhibits... N pn Turns. By introducing an air gap 141.23 into the central core posts 121.2 and 121.3, the effective number of primary turns is increased. N pn Becomes more than the actual number of turns N p Higher, which allows for reduced primary copper loss.

[0091] For high-permeability, low-saturation magnetic flux density materials with no air gap in the flange and outer core pillar, only R TC >> R TF , R B and R LC >> R LF , R B The gapped transformer and resonant inductor are decoupled and the primary leakage inductance is reduced. L r Magnetized inductor L m and equivalent primary turns N pn Simplified to: .

[0092] Figure 6 The diagram shows the first and second series resonant inductors ( L r1 and L r2 ) current i Lr and through the primary winding ( P 1 and P 2 ) current i p The curve. These currents are sinusoidal and pass through a parallel resonant inductor ( L m1 and L m2 ) current i LmThe curve is triangular. The central core of the inductor core element ( R LC , Figure 5 (Induced) magnetic flux density B L The current is sinusoidal and resonant with the current of the series resonant inductor. i Lr Proportional. The central core column of the transformer core element ( R TC , Figure 5 (Induced) magnetic flux density B T It is triangular and connected to the primary current. i p Proportional. Transformer core components E 2 and E 3 flange ( R B , Figure 5 Magnetic flux density in ) B c The curve comes from B L and B T The difference between them is also sinusoidal.

[0093] Figure 7 An electrical diagram of an AC-to-DC converter 200 is shown, which includes a soft-switching converter unit 201 and a soft-switching circuit having two series output inductors Ls1 and Ls2, a parallel inductor Lm, and a transformer 204. All these magnetic components are implemented by means of an integrated magnetic component 203 according to a second embodiment of the invention. Figure 7 The circuit includes a soft-switching converter unit 201 with two outputs (e.g., as proposed in US 6'862'195B). The outputs are connected to a first connection point 202a and a second connection point 202b of an integrated magnetic component 203 implementing the soft-switching circuit. The integrated magnetic component includes a first load connection point 207a and a second load connection point 207b for connecting an H-bridge full-wave rectifier comprising four diodes D11, D12, D21, D22 and a filter capacitor Cout.

[0094] The integrated magnetic component 203 implements a transformer 204 comprising a primary winding P and a secondary winding S, a parallel inductor Lm, and a first series output inductor Ls1 and a second series output inductor Ls2. The primary winding P of the transformer 204 is connected between a first connection point 202a and a second connection point 202b, in parallel with the parallel inductor Lm. The first series output inductor Ls1 is connected between a first end of the secondary winding S of the transformer 204 and a first load connection point 207a, and the second series output inductor Ls2 is connected between a second end of the secondary winding S of the transformer 204 and a second load connection point 207b. Instead of an H-bridge rectifier with four diodes, a rectifier with a center tap and two diodes can also be used. In this case, the integrated magnetic component must include a third load connection point with taps connected between the split secondary windings of the transformer 204.

[0095] exist Figure 8 The integrated magnetic component 203 according to the present invention is described in more detail below. Figure 8 A schematic drawing of the integrated magnetic component 203 according to the present invention is shown. Figure 8 Integrated magnetic component 203 and Figure 4 Similar to the integrated magnetic component 103. It also includes a first transformer core element E2, a second transformer core element E3, a first choke core element E1, and a second choke core element E4. Since the arrangement of the core elements in this embodiment is the same as that in the first embodiment of the present invention, according to Figure 4 The description of the arrangement of the four magnetic core elements E1, E2, E3, and E4 can be applied by adding one to the hundreds digit of the reference number.

[0096] exist Figure 8 In the middle, the first half of the primary winding P of transformer 204 (see...) Figure 7 The primary winding is wound around the central core post 221.2 of the first transformer core element E2, and the second half of the primary winding is wound around the central core post 221.3 of the second transformer core element E3.

[0097] Similarly, the first half of the secondary winding S is wound around the central core post 221.2 of the first transformer core element E2, and the second half of the winding S of the transformer 204 is wound around the central core post 221.3 of the second transformer core element E3. The two halves of the secondary winding are connected in series and have the same winding direction.

[0098] Preferably, the primary winding P and the secondary winding S of transformer 204 are wound around the central core posts of two transformer core elements E2 and E3 (i.e., around the central core post 221.2 of the first transformer core element E2 and the central core post 221.3 of the second transformer core element E3), thereby the primary winding P and the secondary winding S of transformer 204 are arranged in layers, and the primary winding P of transformer 204 is surrounded by the secondary winding S of transformer 204, or vice versa.

[0099] The first choke output winding 223 is connected to the first end of the secondary winding S of transformer 204 (see...). Figure 7 The second output choke winding 224 is connected between the first load connection point 207.a and the second output choke winding 224. Similarly, the second output choke winding 224 is connected to the other end of the secondary winding S of the transformer 204 (see [link to transformer 204]). Figure 7 Between the secondary winding S of the transformer winding and the output choke windings 223 and 224, as well as between the two halves of the secondary winding S, can be achieved using a single conductor. This avoids copper losses due to soldered interconnections.

[0100] Air gap 241.23 is ground into the center core posts 221.2 and 221.3 of transformer core elements E2 and E3 to set the parallel input inductance Lm. The first output choke winding 223 is wound around the center core post 221.1 of the first choke core element E1, while the second output choke winding 224 is wound around the center core post 221.4 of the second choke core element E4. According to... Figure 7 The first output filter inductance value Ls1 of the circuit is set by the first choke air gap 241.1 between the center core post 221.1 of the first choke core element E1 and the flange 222.2 of the first transformer core element E2. The air gap 241.1 also prevents the core element from saturating. Similarly, according to Figure 7 The second output filter inductor Ls2 of the circuit is set by the second choke air gap 241.4 between the center core 221.4 of the second choke core element E4 and the flange 222.3 of the second transformer core element E3. Furthermore, the second choke air gap 241.4 prevents the core element from saturating. Therefore, the output choke inductance is split across the two core elements.

[0101] According to Figure 4 Similar to an LLC resonant converter, a switching network of four switches Q11, Q12, Q21, and Q22 provides a square voltage output from the DC input voltage Vdc to the first and second connection points 202a and 202b of the integrated magnetic components. The DC input voltage can be provided by a rectifier circuit, such as an AC / DC power factor correction (PFC) converter.

[0102] Downstream of the integrated magnetic component 203, at the output of the integrated magnetic component 203, a full-wave rectifier is provided and the full-wave rectifier is connected to load connection points 207a, 207b.

[0103] Similar to the first embodiment of the present invention ( Figure 4 The integrated magnetic components of the transformer are connected to the secondary portion of the transformer. All windings of the magnetic components (correspondingly, choke windings 223, 224 and secondary windings S1, S2) are wound around the central core posts 221.1, 221.2, 221.3, 221.4 of the respective magnetic core elements, which are arranged in rows. Furthermore, all windings have the same winding direction, so the current through the series-connected windings generates central magnetic fluxes 231.1, 231.2, 231.3, 231.4 pointing in the same direction through the central core posts 221.1, 221.2, 221.3, 221.4 of the four magnetic core elements E1, E2, E3, and E4. Therefore, the orientation of the magnetic flux through other parts of the magnetic core elements is also similar to that of the first embodiment. Specifically, the flange fluxes 232a.2 and 232b.2 through the flange of the first transformer core element E2, and the flange fluxes 232a.3 and 232b.3 through the flange of the second transformer core element are reduced by flux cancellation, thus resulting in an increase in power density and a reduction in copper loss and core element loss.

[0104] exist Figure 9 The diagram shows a corresponding magnetoresistive model 250 of the proposed structure of the integrated magnetic component 203 according to the invention, used for integrating the input parallel inductor Lm, transformer 204, and two output filter inductors Ls1 and Ls2. The flanges of all core elements E1, E2, E3, and E4 are considered identical and are composed of magnetoresistive R. B This indicates that inductor core components E1 and E4 are considered to be the same. R LF It is the magnetic reluctance of each outer core post and R LC This refers to the magnetic reluctance of the central core column (including its corresponding air gaps 241.1 and 241.4). Transformer core elements E2 and E3 are considered to be the same. R TF It is the magnetic reluctance of each outer core post and R TC It is the reluctance of the central core column (including its air gap 241.23). The current through the primary winding S is the primary current i. p Furthermore, the current through the transformer secondary winding P and the output choke windings 223 and 224 is considered to be the same and is designated as the secondary current i. s The number of turns for the transformer's primary winding P, secondary winding S, first output choke winding, and second output choke winding are N, respectively. P NS N L1 and N L2 N L1 and N L2 They are considered equal.

[0105] The following analysis will be conducted. Figure 9 The magnetoresistive model is shown. After mathematically describing the magnetoresistive model and applying Faraday's law to all windings, several equations are calculated to produce the inductance matrix of the integrated component, which is calculated as follows: in N L1 = N L2 = N L / 2, R L =2· R LC + R LF + R B and R T = 2· R TC + R TF .

[0106] Elements calculated using the inductance matrix, primary L 11 Secondary self-sensing L 22 and mutual induction M 12 ,transformer π Model parameters, magnetizing inductance L m Secondary leakage L r and equivalent number of secondary turns N sn They were described as Winding N s Turns, but the transformer exhibits N sn Turns. The effective number of secondary turns is increased by introducing an air gap 241.23 into the flux path defined by the central core posts 221.2 and 221.3. N sn Becomes more than the actual number of turns N s Higher, which allows for reduced secondary copper losses.

[0107] For high-permeability, low-saturation magnetic flux density materials with no air gap in the flange and outer core pillar, only R TC >> R TF , R B and R LC >> R LF , R B The gapped transformer and output filter inductor are decoupled and the primary leakage inductance is reduced. L r Magnetized inductor L m and equivalent primary turns N pn Simplified to: .

[0108] Figure 10 The diagram shows the output voltage Vs, the current Is through the secondary transformer winding S, and the center cores (221.3, ) of the transformer core elements E2 and E3. Figure 8 B T , Figure 9 In the choke core elements E1 and E4, the center core posts (221.1, 221.4) are... Figure 8 B L , Figure 9 In the context of transformer core elements (222.2, 222.3), and the mutual flanges (correspondingly, the flanges of the transformer core elements (222.2, 222.3), Figure 8 B c , Figure 9 The direction (run) of the magnetic flux density curve in (). For example Figure 10 The diagram shows the transformer secondary winding current. i s The curve is triangular and corresponds to the magnetic flux density B. L Proportional. The central core pillar of the choke core element (221.1, 221.4, ... Figure 8 ; R LC , Figure 9 The (induced) magnetic flux density B in ) L It is triangular and connected to the secondary current. i s Proportional. The central core column of the transformer core components (221.2, 221.3, ... Figure 8 ; R TC , Figure 9 (Induced) magnetic flux density B TThe flanges (222.2, 222.3) of transformer core components E2 and E3 are trapezoidal. Figure 8 , R B , Figure 9 Magnetic flux density in ) B C The curve comes from B L and B T The difference between them. The flanges of the transformer core components (222.2, 222.3, ... Figure 8 The magnetic flux density B in ) C This is reduced, thus minimizing the losses of the magnetic core components.

[0109] like Figure 11 The illustration depicts a third embodiment of the integrated magnetic component 303 according to the invention, in which the air gap can also be distributed along all three core posts of any magnetic core element. The distribution of the air gap along the core posts of the magnetic core element reduces the negative impact of the air gap edge field and can also prevent wear of the magnetic core element, for example, by inserting a flat layer of material with low magnetic permeability.

[0110] This is similar to the first embodiment of the integrated magnetic component 103 ( Figure 4 The second embodiment of the integrated magnetic component 203 Figure 8 In contrast, the air gaps 141.1, 141.23, 141.4, 241.1, 241.23, and 241.4 are individual air gaps arranged in the central core pillars (121.1, 121.2, 121.3, 121.4, 221.1, 221.2, 221.3, and 221.4) of the magnetic core elements E1, E2, E3, and E4, which generate a higher edge field.

[0111] The air gaps in the flux path between the first / second choke core element E1 / E4 and the first / second transformer core element E2 / E3 are distributed on three core posts: central air gaps 341.1 and 341.4, which are arranged between the central core posts 321.1 / 321.4 of the first / second choke core element E1 / E4 and the first / second transformer core element E2 / E3; first outer air gaps 340a.1 / 340a.4, which are arranged between the first outer core posts 320a.1 / 320a.4 of the first / second choke core element E1 / E4 and the first / second transformer core element E2 / E3; and second outer air gaps 340b.1 and 340b.4, which are arranged between the second outer core posts 320b.1 / 320b.4 of the first / second choke core element E1 / E4 and the first / second transformer core element E2 / E3.

[0112] Similarly, the air gaps in the magnetic flux path between the first transformer core element E2 and the second transformer core element E3 are distributed as follows: a central air gap 341.23 is arranged between the central core pillars 321.2 and 321.3 of the first transformer core element E2 and the second transformer core element E3; a first outer air gap 340a.23 is arranged between the first outer core pillar 320a.2 of the first transformer core element E2 and the first outer core pillar 320a.3 of the second transformer core element E3; and a second outer air gap 340b.23 is arranged between the second outer core pillar 320b.2 of the first transformer core element E2 and the second outer core pillar 320b.3 of the second transformer core element E3.

[0113] Figure 12 A fourth embodiment of the integrated magnetic component 403 according to the present invention is shown. The arrangement of the transformer core elements E2 and E3 and the choke core elements E1 and E4 is similar to that of the previous embodiments; however, in Figure 12 In this embodiment, the air gap is distributed along the central core post of the respective core element to reduce AC losses in the winding. The air gap between the central core posts 421.2 and 421.3 of the transformer core elements E2 and E3 is segmented by the inserted I-shaped core element I23, thereby defining a first central air gap 441.2 between the central core post 421.2 of the first transformer core element E2 and the I-shaped core element I23, and a second central air gap 441.3 between the central core post 421.3 of the second transformer core element E3. The third air gap 441.1 in the magnetic flux path between the first choke core element E1 and the first transformer core element is defined by the distance between the central core post 421.1 of the first choke element and the I-shaped core element I1 adjacent to the flange of the first transformer core element E2. Similarly, the fourth air gap 441.4 in the magnetic flux path between the second choke core element E4 and the second transformer core element E3 is defined by the distance between the central core post 421.4 of the first choke element and the third I-shaped core element I4 adjacent to the flange of the second transformer core element E3.

[0114] Figure 13 and Figure 14 Two other embodiments of the invention are shown. Both embodiments have the same core element structure using four U-shaped core elements, each of which includes a flange, a first outer core post, and a second outer core post. The U-shaped core elements are: a first transformer core element U2, a second transformer core element U3, a first choke core element U1, and a second choke core element U4. Each of these core elements includes first and second outer core posts. The following description of the core elements applies to both embodiments (correspondingly, Figure 13 and 14 (Examples); however, when it involves Figure 14 In this case, the third digit of the reference number above must be increased by one.

[0115] Two transformer core elements U2 and U3 face each other with their first outer core posts 520a.2 and 520a.3 and their second outer core posts 520b.2 and 520b.3, forming an O-shaped transformer core element. A first transformer air gap 540a.23 is arranged between the first two outer core posts 520a.2 and 520a.3 of the first transformer core element U2 and the second transformer core element U3. A second transformer air gap 540b.23 is arranged between the second two outer core posts 520b.2 and 520b.3 of the first transformer core element U2 and the second transformer core element U3.

[0116] The first choke core element U1 is stacked on the flange 522.2 of the first transformer core element U2, such that its first outer core post 520a.1 and its second outer core post 520b.1 are adjacent to the flange 522.2 of the first transformer core element U2 on the side opposite to the outer core posts 520a.2 and 520b.2 of the first transformer core element U2.

[0117] The first choke air gap 540a.1 is placed between the flange 522.2 of the first transformer core element U2 and the first outer core post 520a.1 of the first choke core element U1. The second choke air gap 540b.1 is placed between the flange 522.2 of the first transformer core element U2 and the second outer core post 520b.1 of the first choke core element U1.

[0118] The third choke air gap 540a.4 is placed between the flange 522.3 of the second transformer core element U3 and the first outer core post 520a.4 of the second choke core element U4. Furthermore, the fourth choke air gap 540b.4 is placed between the flange 522.3 of the second transformer core element U3 and the second outer core post 520b.4 of the second choke core element U4.

[0119] according to Figure 13 Embodiments of the integrated magnetic component 503 are implemented according to Figure 3 An integrated magnetic component of an LLC converter with a split resonant choke. It includes first and second resonant choke windings 523, 524, thereby implementing... Figure 3The equivalent circuit diagram shown includes first and second resonant inductors Lr1 and Lr2. The first resonant choke winding 523 comprises series-connected first choke winding portions 523a.1 and 523b.1, which are wound around the first outer core post 520a.1 and the second outer core post 520b.1 of the first choke core element U1, respectively. The first choke air gap 540a.1 and the second choke air gap 540b.1 allow setting the inductance value of the first series resonant inductor Lr1 and also prevent core element saturation. The second resonant choke winding 524 comprises series-connected second choke winding portions 524a.1 and 524b.1, which are wound around the first outer core post 520a.4 and the second outer core post 520b.4 of the second choke core element U4, respectively. The third choke air gap 540a.3 and the fourth choke air gap 540.4 allow setting the inductance value of the second series resonant inductor Lr2 and also prevent saturation. The first split transformer 105a ( Figure 3 The primary winding P1 and secondary winding S1 of the transformer are wound around the connected transformer core elements U2 and the first outer core posts 520a.2 and 520a.3 of U2. In the same manner, the second split transformer 105b ( Figure 3 The primary winding P2 and secondary winding S2 of the transformer are wound on the second outer core posts 520b.2 and 520b.3 of the connected transformer core elements U2 and U3. The air gaps 540a.23 of the first transformer and 540b.23 of the second transformer are set according to... Figure 3 The equivalent circuit consists of parallel resonant inductors Lm1 and Lm2. A first resonant choke winding 523 is connected in series to the primary winding P1 of the first split transformer, and a second resonant choke winding 524 is connected in series to the primary winding P2 of the second transformer. The first resonant choke winding 523 is connected to the first connection point 502a of the integrated magnetic component 503, while the second resonant choke winding is connected to the second connection point of the integrated magnetic component 503. The free ends of the primary windings P1 and P2 of the first and second split transformers 105a and 105b are connected to the ends of the series resonant capacitor Cr. The winding direction is selected such that the mutual inductance flux in the flanges of the first and second transformer core elements is minimized.

[0120] according to Figure 14 An embodiment of the integrated magnetic component 603 includes a primary winding P and a secondary winding S, a parallel inductor Lm, and a first series output inductor Ls1 and a second series output inductor Ls2, according to... Figure 7 The magnetic components of a soft-switching converter.

[0121] Integrated magnetic component 603 and for implementation according to Figure 3The integrated magnetic component 503 of the LLC resonant converter with split chokes is very similar. Instead of the choke windings 523, 524 connected to the primary portion of the transformer, it includes first and second output choke windings 623, 624 connected to the secondary winding S of the transformer, thereby implementing… Figure 7 The equivalent circuit diagram shown includes first and second series output inductors Ls1 and Ls2. The first series output choke winding 623 comprises series-connected first output choke winding portions 623a.1 and 623b.1, which are wound around the first outer core post 620a.1 and the second outer core post 620b.1 of the first choke core element U1, respectively. The first choke air gap 640a.1 and the second choke air gap 640b.1 allow setting the inductance value of the first series output inductor Ls1 and also prevent saturation. The second output choke winding 624 comprises series-connected second output choke winding portions 624a.1 and 624b.1, which are wound around the first outer core post 620a.4 and the second outer core post 620b.4 of the second choke core element U4, respectively. The third choke air gap 640a.4 and the fourth choke air gap 640b.4 allow setting the inductance value of the second series output inductor Ls2 and also prevent saturation.

[0122] The primary winding P is split into a first part P1 and a second part P2 connected in series. In order to... Figure 14 As illustrated more clearly, the first part P1 is wound only around the first outer core post 620a.2, and the second part P2 is wound around the second outer core post 620b.2 of the first transformer core element U2. Similarly, the secondary winding S of the transformer is split into a first part S1 and a second part S2, with the first part S1 wound around the first outer core post 620a.3 and the second part S2 wound around the second outer core post 620b.3 of the second transformer core element U3.

[0123] Preferably, the first part P1 of the primary winding P and the first part S1 of the secondary winding S are wound around the first outer core post 620a.2 of the first transformer core element U2 and the first outer core post 620a.3 of the second transformer core element U3, and the windings of the first part P1 of the primary winding P and the first part S1 of the secondary winding S are arranged in layers.

[0124] Similarly, the second part P2 of the primary winding P and the second part S2 of the secondary winding S are wound around the second outer core post 620b.2 of the first transformer core element U2 and the second outer core post 620b.3 of the second transformer core element U3, and the windings of the second part P2 of the primary winding P and the second part S2 of the secondary winding are arranged in layers.

[0125] The air gaps 640a.23 of the first transformer and 640b.23 of the second transformer are set according to... Figure 7 The equivalent circuit has parallel resonant inductors Lm1 and Lm2.

[0126] The first output choke winding 623 is connected to the first load connection point 607a via the free end of the first winding portion 623a.1 and to the first split primary winding S1 via the free end of the second winding portion 623b.1. Similarly, the second output choke winding 624 is connected to the second load connection point 607b via the free end of the first winding portion 624a.4 and to the first split secondary winding S2 via the free end of the second winding portion 624b.4. The winding direction is selected such that the mutual inductance flux in the flanges 622.2 and 622.3 of the first and second transformer core elements is minimized. The split primary winding P is connected to connection points 602a and 602b for connecting a soft-switching converter comprising a full bridge with switches Q11, Q12, Q21, and Q22.

[0127] Figure 15 The fifth embodiment of the present invention is shown in the figure. This embodiment, which integrates the magnetic component 703, is also implemented according to... Figure 3 The magnetic components of the LLC resonant circuit. It uses three U-shaped magnetic core elements, each of which includes a flange, a first outer core post, and a second outer core post. The core element structure corresponds to... Figure 13 The illustrated embodiment has a magnetic core element structure; however, it does not include a second choke core element, but only includes first and second transformer core elements U2 and U3 and a first choke core element U1. A first resonant choke winding 723 is wound around the first outer core post 720a.1 of the first choke core element U1, and a second choke winding 724 is wound around the same choke core element U1, but around the second outer core post 720b.1 of the first choke core element U1. The first choke winding 723 is connected at one end to a first input connection point 702a and at the other end to a first split transformer 105a. Figure 3 The free end of the first primary winding P1. The second choke winding 724 is connected at one end to the second input connection point 702b and at the other end to the second split transformer 105b. Figure 3 The free end of the second primary winding P2 of the transformer. The arrangement of the transformer windings and... Figure 4 The arrangement of the transformer windings in the third embodiment of the integrated magnetic component 503 shown is the same. In summary: [The text abruptly ends here, likely due to an incomplete sentence or missing information.] Figure 13 Compared with the integrated magnetic component 504, according to Figure 15 The series resonant inductance of the integrated magnetic component 703 is not split on two different magnetic core elements, thus reducing the total number of magnetic core elements and therefore also reducing costs.

[0128] Figure 16 This illustrates a sixth embodiment of the integrated magnetic component 803 according to the present invention. Like the previous embodiments of the integrated magnetic component 703, the integrated magnetic component 803 comprises three U-shaped magnetic core elements, but its implementation... Figure 7 The schematic diagram of the soft-switching converter shown illustrates the magnetic components. It includes the arrangement of transformer core elements U2 and U3 and transformer windings P1, P2, S1, and S2, including the connections between the transformer windings P1, S1, P2, and S2. Figure 14 The same applies to the embodiment shown. Therefore, the primary winding portions P1 and P2 are connected in series, and the secondary winding portions S1 and S2 are also connected in series. For certain design specifications, the primary winding portions P1 and P2 may be connected in parallel. This also applies to the secondary winding portions S1 and S2.

[0129] The integrated magnetic component 803 contains only one choke core element U1, which is stacked on the flange 822.3 of the second transformer core element U3, and the second choke core element U4 of the integrated magnetic component 603 is stacked on the flange of the second transformer core element U3 (e.g., Figure 14 Similar to (shown in the diagram). The first output choke winding 823 is wound around the first outer core post 820a.1 of the first choke core element and is connected to the first load connection point 807a with one end and to the free end of the first portion S1 of the secondary winding of the transformer with the second end. The second choke winding 824 is wound around the second outer core post 820b.1 of the first choke core element U1, with its free end connected to the second load connection point 807b and its other end connected to the free end of the second portion S2 of the secondary winding. Therefore, the series output inductance Ls is not split on two different choke core elements but on two different core posts of a single choke core element. The first choke air gap 840a.1 and the second choke air gap 840b.1 between the first choke core element U1 and the second transformer core element U2 set the inductance values ​​of LS1 and LS2 and prevent the core element from saturating.

[0130] Using three U-shaped magnetic core elements and four U-shaped magnetic core elements respectively Figures 13 to 16 The integrated magnetic component described herein can also be constructed using other basic magnetic core elements as component blocks and then U-shaped magnetic core elements. The following example shows how an integrated magnetic component using three U-shaped magnetic core elements can be constructed using U-shaped and I-shaped basic elements.

[0131] exist Figure 17aIn this configuration, the first U-shaped choke core element U1 is constructed from an I-shaped core element base element 950 and a U-shaped core element base element 951 whose core post faces the I-shaped core element base element 950. This core post defines a first outer core post 920a.1 and a second outer core post 920b.1 of the first U-shaped choke core element U1. The I-shaped core element base element 950 defines a flange 922.1 of the first choke core element U1. The flange of the U-shaped core element base element 951 represents a flange 922.2 of the first transformer core element U2.

[0132] exist Figure 17b In the first transformer core element U2, the I-shaped magnetic core element base element 952 defines the flange 922.2 of the first transformer core element U2, while the end of the outer core post 954 of the U-shaped magnetic core element base element 953 defines the core post of the first transformer core element U2.

[0133] exist Figure 17c In the design, the I-shaped magnetic core element base element 955 defines the flange 922.3 of the second transformer magnetic core element U3, while the end of the outer core post 957 of the U-shaped magnetic core element base element 956 defines the core post of the second transformer magnetic core element U3.

[0134] In summary, it should be noted that the present invention creates integrated magnetic components for switching power supplies, allowing the integration of multiple inductive components, achieving increased power density, and thus reducing core element losses. The present invention further creates switch-mode power converters including such magnetic components and corresponding methods.

Claims

1. Integrated magnetic component for a switched mode power converter, comprising a transformer comprising two transformer core elements, the integrated magnetic component further comprising at least one choke core element, each of said core elements comprising first and second outer legs and a flange connecting the outer legs, each of said core elements further comprising a center leg arranged between the outer legs of said core element, such that the outer legs, the center leg and the flange of each core element form an E-like shape, the two transformer core elements being arranged to form a core element shaped like an 8, with the center legs of the transformer core elements facing each other, each choke core element abutting the flange of one of the transformer core elements, with the center leg of each choke core element abutting the flange of the adjacent transformer core element on the side opposite to the center leg of said adjacent transformer core element, the transformer comprising a primary winding and a secondary winding arranged on the center legs of the transformer core elements, the transformer comprising a first air gap arranged in the magnetic flux path between the transformer core elements, the integrated magnetic component further comprising at least a second air gap in the magnetic flux path between one of the transformer core elements and a first one of said choke core elements, and a third air gap arranged in the magnetic flux path between the other of said transformer core elements and a second one of said two choke core elements, wherein the integrated magnetic component comprises a first choke winding arranged on the center leg of the first choke core element and a second choke winding arranged on the center leg of the second choke core element, in order to reduce air gap fringe fields by splitting the choke winding over the two choke core elements, wherein one of the primary winding and the secondary winding is connected between the choke windings, and wherein either (i) the primary winding is interconnected with the choke windings to reduce core losses by magnetic flux compensation in order to increase power density, or (ii) the secondary winding is interconnected with the choke windings to reduce core losses by magnetic flux compensation in order to increase power density.

2. Integrated magnetic component according to claim 1, wherein the transformer windings are wound around the center legs of the transformer core elements, and the choke windings are wound around the center legs of the choke core elements.

3. Integrated magnetic component according to any of claims 1-2, the choke windings and the transformer winding connected between the first and second choke windings being implemented with a single wire to avoid additional leads between the windings.

4. Integrated magnetic component according to any of claims 1-2, wherein the primary winding and / or the secondary winding of the transformer are split into a first split transformer winding and a second split transformer winding, a first end of said first split transformer winding being connected to a first end of an electronic component which is a capacitive element Cr, and a first end of said second split transformer winding being connected to a second end of said electronic component, the second ends of said split transformer windings being connected to the first, second choke windings, respectively.

5. The integrated magnetic component according to any of claims 1-2, wherein at least one of the air gaps is arranged parallel to the flanges of the magnetic core elements of the integrated magnetic component.

6. The integrated magnetic component according to any of claims 1-2, wherein the air gaps are arranged between respective adjacent magnetic core elements.

7. The integrated magnetic component according to claim 2, the arrangement of transformer magnetic core elements and choke magnetic core elements being mirror-symmetrical about an axis parallel to the flanges of the magnetic core elements, the air gaps being symmetrical with respect to said axis.

8. A switched mode power converter comprising an integrated magnetic component according to any of the preceding claims 1-7.

9. The switched mode power converter according to claim 8, wherein the switched mode power converter is an LLC resonant converter.

10. The switched mode power converter according to claim 8, wherein the switched mode power converter is a soft-switching converter.

11. A method of providing an integrated magnetic component, comprising the steps of: a. providing two transformer magnetic core elements, two choke magnetic core elements; each of the magnetic core elements being E-shaped, comprising two outer legs, a center leg arranged between the outer legs and a flange, b. forming a transformer by arranging the two transformer magnetic core elements as E-shaped magnetic core elements, arranging a primary winding and a secondary winding on the center leg of the transformer magnetic core elements and providing at least one air gap in the magnetic flux path between the transformer magnetic core elements, c. arranging the choke magnetic core elements such that each of the choke magnetic core elements is adjacent to the flange of one of the transformer magnetic core elements, while providing a second air gap in the magnetic flux path between one of the two transformer magnetic core elements and a first of the two choke magnetic core elements and a third air gap in the magnetic flux path between the other of the two transformer magnetic core elements and a second of the two choke magnetic core elements, and d. providing a series connection between a first choke winding, the primary or the secondary winding of the transformer and a second choke winding, such that one of the primary winding and the secondary winding of the transformer is connected with one end to the first choke winding and with the other end to the second choke winding, the first choke winding being arranged on the center leg of the first choke magnetic core element and the second choke winding being arranged on the center leg of the second choke magnetic core element, wherein either (i) the primary winding is interconnected with the choke winding to reduce magnetic core losses by magnetic flux compensation in order to increase power density, or (ii) the secondary winding is interconnected with the choke winding to reduce magnetic core losses by magnetic flux compensation in order to increase power density.

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