Multi-phase system including power converter with through outcoupling

Abstract

The invention relates to a multiphase system comprising a power converter having at least two branches and a filtering device connected to the at least two branches of the power converter, the filtering device consisting of at least two inductors, each inductor consisting of a turn wound around a magnetic material. The magnetic material is disposed within at least one printed circuit board comprising a connection of the inductors, and the filtering device further comprises an electrically conductive material surrounding the at least two inductors, a first terminal of each inductor being respectively connected to one branch of a power converter, and a second terminal of each inductor being respectively connected to the other branch of the power converter. And one terminal of the conductive material is connected to a second terminal of the inductor.

Description

Technical Field

[0001] The present invention generally relates to through-output coupled inductors. Background Art

[0002] Recent advances in semiconductor technology, especially wide bandgap devices (WBG), have paved the way for more compact power electronic systems. WBG switches have better dynamic performance compared to silicon switches, so power converters can now operate at higher switching frequencies. This directly alleviates the constraints on inductive and capacitive filtering devices. Combined with the power converter interleaving technology, which is often used for high current applications, the volume and weight of magnetic components have been significantly reduced in the past few years. The interleaved structure consists of parallel cells (also called branches). The driving signal of each branch is phase-shifted. In particular, the phase shift can be evenly distributed according to the number of branches. If this condition is met, the HF voltage is virtually divided by N due to the apparent frequency N.Fsw (Fsw is the switching frequency of the power converter), and the structure can reduce the output current ripple by N. 2 times (N is the number of branches). This allows the current rating of the semiconductor to be reduced by distributing the design constraints over multiple devices. In interleaved converters with filtered output voltages, the filtering devices are a significant part of the converter weight. The traditional solution is to use separate inductors, but this solution adds significant weight and the conception of the magnetics is also critical.

[0003] Meanwhile, since no significant improvements have been observed in magnetic materials, designers have no choice but to determine the optimal trade-off between saturation magnetic field and core losses.

[0004] Conventional inductors involve a superposition of a direct current (DC) or low frequency (LF) field component and a high frequency (HF) component. Magnetic saturation is the most critical issue to address when targeting smaller inductors. It is also obvious that the DC / LF and HF magnetic fields can be handled independently, since the high frequency induced magnetic field B HF The evolution of the magnetic permeability is independent of the low frequency or DC induced magnetic field B DC / LF This is not the case.

[0005] exist Figure 1a In the example given in , the magnetization curve of the inductor may result in saturation of the inductive field.

[0006] exist Figure 1a Middle, B LF represents the LF induction field, B DC represents the DC induced field, H LF represents the LF magnetic field, H DC Represents a DC magnetic field.

[0007] Based on these observations, compensating the LF / DC flux and operating the inductor in both magnetic quadrants is as follows Figure 1b The best option shown. By doing this, the saturation constraints related to the LF / DC fields are alleviated, which means that the inductor is now designed almost as a transformer with only HF components. One advantage of this solution is that the design inductor (except for copper losses) is completely decoupled from the current flowing through the device. This demagnetization method can be performed by magnetically coupling at least two inductors with similar currents flowing through them.

[0008] Then, the reduction of the LF / DC magnetic field can be achieved by adjusting the coupling factor between at least two inductors. Good coupling is associated with reduced B LF / DC value, but also accompanied by N·F sw In fact, the leakage inductance is responsible for the N·F flowing in all branches. sw The current harmonics are filtered under the filter device and minimum values ​​are mandatory to avoid generating HF losses, which could lead to unacceptable loss levels and possibly damage to the filter device. Summary of the invention

[0009] The present invention aims to provide a filtering device in an interleaved structure of a converter consisting of a straight-through output coupled inductor designed using PCB-based technology.

[0010] Basically, each inductor is wound as a solenoid, where the turns are located in the longer dimension of the device. Depending on the inductance requirements, the target AC resistance and the overall capacitive behavior, several layers of conductors can be considered. The windings of multiple so-called solenoids are located on a single substrate. Both the substrate and the windings act as a frame to embed the first part of the magnetic circuit of each inductor. The coupling to the output current is performed by a compensating turn made of a foil made of a conductive material.

[0011] Optionally, two plates made of magnetic material are implemented at the top and bottom to close the unit magnetic circuit.

[0012] To this end, the present invention relates to a multiphase system comprising a power converter having at least two branches and filtering means connected to the at least two branches of the power converter, the filtering means consisting of at least two inductors, each inductor consisting of turns wound around a magnetic material, characterized in that the magnetic material is arranged in at least one printed circuit board comprising the connections of the inductors, and the filtering means also comprises a conductive material surrounding the at least two inductors, a first terminal of each inductor being connected to a branch of the power converter, respectively, and one terminal of the conductive material being connected to a second terminal of the inductor.

[0013] Thus, in this configuration, the two inductors are magnetically coupled through the conductive material for frequencies up to N·Fsw (N being the number of branches), and decoupled for other frequencies, then providing effective filtering.

[0014] According to particular features, the filtering device comprises a printed circuit board having at least two cavities for placing respectively each of the at least two magnetic materials.

[0015] The printed board thus acts as a frame for assembling and mechanically maintaining the filter device and embedding the magnetic core. Thus, if additional layers are required in the above-mentioned printed circuit board, this frame can be used for the lamination process.

[0016] According to particular features, the printed circuit board also comprises two spaces for each cavity for winding the inductor around the magnetic core.

[0017] The printed circuit board thus also acts as a yoke for the inductor without any prerequisites regarding winding technology, but requires winding directly on the printed circuit board.

[0018] According to particular features, said printed circuit board also comprises two spaces for each cavity for inserting said inductor wound around said magnetic core.

[0019] Therefore, according to this feature, the winding can be manufactured separately and installed on the printed board by inserting through the space. This makes it possible to use a dedicated manufacturer to design the winding without the need for a printed circuit board, making the process more versatile.

[0020] According to a specific feature, the filtering device includes a first printed circuit board, a second printed circuit board and a third printed circuit board, the third printed circuit board having at least two cavities for placing each of at least two magnetic materials respectively, the first printed circuit board and the second printed circuit board having conductors, the conductors of the first printed circuit board and the conductors of the second printed circuit board are electrically connected and form a winding of the inductor.

[0021] Therefore, the design can benefit from a cost-effective and simplified PCB process. Furthermore, additional features such as PCB embedded sensors can be implemented in conjunction with the windings on the printed circuit board.

[0022] According to particular features, said conductive material surrounding said at least two inductors has a U-shape.

[0023] Therefore, the component can be easily manufactured. In addition, the input and output of the conductor will be located on the same side (opposite sides of the U-bend), which simplifies the overall mechanical design and the required interconnections.

[0024] According to a particular feature, the filtering means are surrounded by the magnetic element.

[0025] The invention also relates to a method for manufacturing a multiphase system comprising a power converter having at least two branches and a filtering device connected to the at least two branches of the power converter, the filtering device consisting of at least two inductors, characterized in that the method comprises the following steps:

[0026] - placing magnetic material in at least one printed circuit board including the connections of said inductor;

[0027] - providing each inductor with a turn wound around the magnetic material;

[0028] - placing a conductive material around the at least two inductors;

[0029] - connecting the filtering means by connecting a first terminal of each inductor to a branch of the power converter respectively and connecting one terminal of the conductive material to the second terminal of the inductor.

[0030] The characteristics of the invention will emerge more clearly on reading the following description of an exemplary embodiment, which is produced with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] [ Figure 1a ]

[0032] Figure 1a Represents the magnetization curve of the filter arrangement in the interleaved structure of the converter.

[0033] [ Figure 1b ]

[0034] Figure 1b Represents the magnetization curve of a filtering arrangement in an interleaved structure of a converter comprising a through-output coupled inductor according to the invention.

[0035] [ Figure 2 ]

[0036] Figure 2 An embodiment of an interleaved structure realizing a converter comprising filtering means consisting of a through-output coupled inductor according to the invention is shown.

[0037] [ Figure 3 ]

[0038] Figure 3 A more detailed embodiment of an interleaved structure realizing a converter comprising filtering means consisting of a through-output coupled inductor according to the invention is shown.

[0039] [ Figure 4 ]

[0040] Figure 4 A first embodiment of the realization of two inductors of the filtering device using a printed circuit board is shown.

[0041] [ Figure 5 ]

[0042] Figure 5 A second embodiment showing the implementation of an inductor of a filtering device implemented using a printed circuit board.

[0043] [ Figure 6 ]

[0044] Figure 6 A first embodiment of a through-output coupled inductor according to the present invention is shown.

[0045] [ Figure 7 ]

[0046] Figure 7 The architecture of a system for making a filtering device in an interleaved structure of a converter including a through-output coupled inductor is shown.

[0047] [ Figure 8 ]

[0048] Figure 8 An algorithm for making a filtering arrangement in an interleaved structure of a converter including a through output coupled inductor is presented. DETAILED DESCRIPTION

[0049] Figure 2 An embodiment of an interleaved structure realizing a converter comprising a filtering device according to the invention is shown.

[0050] exist Figure 2 In the embodiment of the present invention, the converter comprises N branches. The switch Q 11 and Q 12 is the switch of the first branch 1 and is connected to a first terminal of the inductor L1.

[0051] Switch Q i1 and Q i2 is the switch of the i-th branch and is connected to the inductor L i The first terminal of the switch Q N1 and Q N2 is the switch of the Nth branch N and is connected to the inductor L N The first terminal.

[0052] Inductor L1, L i and L N The second terminal is connected to the inductor L' N The first terminal of the inductor L' NThe second terminal is connected to the inductor L' i The first terminal of the inductor L' i The second terminal of is connected to the first terminal of the inductor L'1. Figure 2 As shown in the figure, inductors L1 and L'1 are magnetically coupled, and inductor L i and L' i magnetic coupling, and the inductor L N and L' N Magnetic coupling.

[0053] Each magnetic device (here marked as L i ) is coupled to the output current I ∑ Another magnetic device L' i .

[0054] When the magnetic devices are coupled, this theoretically results in L i The inductor is connected via L' i Indirect magnetic coupling is achieved by using a phase-to-phase arrangement. With this arrangement, only one phase has to be coupled to the output conductor, increasing the design freedom or releasing layout constraints on the magnetic components. By doing so, the LF / DC flux can be canceled or partially compensated depending on the turns ratio.

[0055] More precisely, if Figure 3 As shown in FIG, inductors L1 and L'1 are magnetically coupled through magnetic material M1. i and L' i Through the magnetic material M i magnetic coupling, and the inductor L N and L' N Through the magnetic material M N Magnetic coupling. Depending on the required loss level, the magnetic materials M1 to M2 are implemented using a toroidal core geometry made of magnetic materials such as ferrite, nanosilicate or iron powder. N .

[0056] Figure 4 A first embodiment of the realization of two inductors of the filtering device using a printed circuit board is shown.

[0057] exist Figure 4 In the embodiment, each inductor L1 or L N Both are wound as a solenoid with the turns located in the longer dimension of the filtering device. Inductor L1 or L N The terminal has an electrical connection Co, which is for example part of a copper layer of a printed circuit board PCB.

[0058] For each inductor L1 or L N , the printed circuit board includes a magnetic material M1 or M placed therein NThe cavity of the inductor L1 or L2 can be considered according to the inductance requirements, target AC resistance and overall capacitance behavior. N The wire in Figure 4 The embodiment is represented by a thick black line and is wound around the magnetic material. The wound inductor and magnetic material are placed in the corresponding cavities C1 and C of the printed circuit board. N In a variant, the magnetic material is placed in the corresponding cavities C1 and C N and the inductor L1 or L N Due to the space Sp1, Sp N , Sp'1 and Sp' N And around the magnetic material, these spaces are Figure 4 The holes shown with dashed lines are extended.

[0059] Both PCB and winding are used as embedded magnetic material M1 or M N framework.

[0060] Figure 5 A second embodiment shows the implementation of an inductor of a filtering device implemented using a printed circuit board.

[0061] exist Figure 5 In the embodiment, the inductor L i The inductor L is implemented using a plurality of printed circuit boards PCB1, PCB2 and PCB3. i .

[0062] The printed circuit PCB3 includes a magnetic material M for placement i cavity.

[0063] The printed circuit board PCB1 includes an insulating layer on which a conductive layer is provided, and is a castellated board or includes a flexible terminal.

[0064] The printed circuit board PCB2 includes an insulating layer on which a conductive layer is provided, and is a half-perforated board or includes a flexible terminal.

[0065] The insulating layer of the printed circuit board PCB2 is disposed on the bottom of the printed circuit PCB3 , and the insulating layer of the printed circuit board PCB1 is disposed on the top of the printed circuit PCB3 .

[0066] Inductor L i Made of: Conductive layer L of printed circuit board PCB1 i1 , flexible terminal or half hole (castellation) L i2 and L i8 ; Welding L i3 and L i9 ; Via hole L of printed circuit board PCB3 i4and L i10 Conductive layer L of printed circuit board PCB1 i7 , flexible terminal or half hole L i6 and L i11 ; and welding L i5 and L i12 .

[0067] Figure 6 denoted a through output coupled inductor according to the present invention.

[0068] According to the present invention, the compensating turn L' is realized by using a conductive foil (copper or aluminum). N The single conductor is designed to be implemented to compensate the LF magnetic field in each unit inductor. In a possible implementation, the compensating turn L' N It is composed of part L' Na , L' Nb and L' Nc Made in a U-shape, which corresponds to a single compensating turn. In a multiple compensating turn configuration, the winding can be designed with concentric foils or metal pieces folded to obtain a solenoid-like geometry. The choice of either solution depends on the rated current and the target AC resistor value. Regardless of the chosen geometry, the compensating turn L' N The main turn L to be coupled N Above.

[0069] In a possible implementation, the compensating turns L'1 or L' i Only part L' Nb and L' Nc composition.

[0070] Finally, the magnetic circuit is closed with top, side and bottom magnetic plates Sh. For example, the magnetic plates Sh are composed of two C-shaped plates or a C-shaped plate and an I-shaped plate.

[0071] Figure 7 The architecture of a system for making a filtering device in an interleaved structure of a converter including a through-output coupled inductor is shown.

[0072] The system 70 has an architecture based on components connected by a bus 801 and a processor 800 controlled by a program, for example. Figure 8 As disclosed in.

[0073] The bus 701 links the processor 700 to a read-only memory ROM 702 , a random access memory RAM 703 , and an input / output I / O IF interface 705 .

[0074] The input-output I / O IF interface 705 enables control of different devices for producing filtering means including through-output coupled inductors.

[0075] The memory 703 contains registers which are intended to receive Figure 8 The variables and instructions of the program related to the algorithm disclosed in.

[0076] Read-only memory or possibly flash memory 702 contains Figure 8 When the system 70 is powered on, these programs are loaded into the random access memory 703. Alternatively, the program can also be executed directly from the ROM memory 702.

[0077] The system 70 may be implemented in software by executing a set of instructions or a program by a programmable computing machine, such as a PC (personal computer), a DSP (digital signal processor), or a microcontroller; or in hardware by a machine or dedicated component, such as an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit).

[0078] In other words, the system 70 includes: a circuit; or a device including a circuit, so that the system 70 performs the same Figure 8 Programs related to the algorithms disclosed in .

[0079] Figure 8 An algorithm for making a filtering arrangement in an interleaved structure of a converter including a through output coupled inductor is presented.

[0080] The present algorithm discloses a method for manufacturing a multi-phase system, which includes a power converter having at least two branches and a filtering device connected to the at least two branches of the power converter.

[0081] At step S80, magnetic material is disposed within at least one printed circuit board including connections of an inductor.

[0082] In step S81, each turn of the inductor is wound around a magnetic material.

[0083] In a variant of implementation, each turn of the inductor is wound around a magnetic material and is arranged in at least one printed circuit board comprising the connections of the inductor.

[0084] In step S82, a conductive material is provided around at least two inductors.

[0085] At step S83 , the filtering device is connected by connecting a first terminal of each inductor to one branch of the power converter respectively and connecting one terminal of the wire to a second terminal of the inductor.

[0086] Of course, many modifications may be made to the embodiments of the invention described above without departing from the scope of the invention.

Claims

1. A multiphase system comprising a power converter having at least two branches and a filtering device connected to the at least two branches of the power converter, the filtering device consisting of at least two inductors, each inductor consisting of turns wound around a magnetic material, characterized in that The magnetic material is arranged in at least one printed circuit board including the connection of the inductors, and the filtering device also includes a conductive material surrounding the at least two inductors, the first terminal of each inductor is respectively connected to a branch of the power converter, and one terminal of the conductive material is connected to the second terminal of the inductor.

2. The multiphase system according to claim 1, characterized in that The filtering device includes a printed circuit board having at least two cavities for placing each of at least two magnetic materials, respectively.

3. The multiphase system according to claim 2, characterized in that The printed circuit board also includes two spaces for each cavity, the two spaces being used to wind the inductor around the magnetic core.

4. The multiphase system according to claim 2, characterized in that The printed circuit board further includes two spaces for each cavity, the two spaces being used to insert a magnetic core and the inductor wound around the magnetic core.

5. The multiphase system according to claim 1, characterized in that The filtering device includes a first printed circuit board, a second printed circuit board and a third printed circuit board, the third printed circuit board having at least two cavities for placing each of at least two magnetic materials respectively, the first printed circuit board and the second printed circuit board having conductors, the conductors of the first printed circuit board and the conductors of the second printed circuit board are electrically connected and form a winding of the inductor.

6. The multiphase system according to claim 5, characterized in that The conductive material surrounding the at least two inductors has a U-shape.

7. A method for manufacturing a multiphase system, the multiphase system comprising a power converter having at least two branches and a filtering device connected to the at least two branches of the power converter, the filtering device consisting of at least two inductors, characterized in that The method comprises the following steps: - placing magnetic material in at least one printed circuit board including the connections of said inductor; - providing each inductor with a turn wound around the magnetic material; - placing a conductive material around the at least two inductors; - connecting the filtering means by connecting a first terminal of each inductor to a branch of the power converter respectively and connecting one terminal of the conductive material to a second terminal of the inductor.

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