Inductor-transformer integrated magnetic coupling ripple transfer channel magnetic core structure

Abstract

The invention discloses a magnetic core structure of an inductance-transformer integrated magnetic coupling ripple transfer channel. The magnetic core structure comprises at least two flat plates arranged in parallel, decoupling side columns oppositely connected to the edges of the two sides of the flat plates and at least two winding columns arranged between the two opposite decoupling side columns. A coil is wound on the wrapping post, and a post shaft is perpendicular to the direction of the plane of the flat plate; the at least two wrapping posts are arranged along the arrangement direction of the opposite decoupling side posts and are directly connected with the flat plate at one end, and air gaps are arranged between the wrapping posts and the flat plate at the other end. As the primary self-inductance coil and the secondary self-inductance coil on the winding post II are tightly coupled, the ripple elimination condition can be met only by adjusting the number of turns of the primary self-inductance coil and the secondary self-inductance coil on the winding post II to be the same, and accurate matching of electrical parameters of the magnetic coupling ripple transfer channel is realized. And the design of the magnetic core of the magnetic coupling ripple transfer channel is greatly simplified while the switching ripple damping capability of the magnetic coupling ripple transfer channel is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of power electronics, and in particular relates to an inductor-transformer integrated magnetic coupling ripple transfer channel core structure. Background Art

[0002] With the advancement of power technology, power electronic converters have been widely used due to their superior power conversion characteristics. During the power conversion process, the rapid switching action of the switching devices within the power electronic converter introduces high-frequency voltage or current ripple excitation into the system. This ripple is primarily concentrated at the switching frequency and its multiples, propagating through the system as wideband electromagnetic harmonic interference, with even more complex impacts in the frequency domain. A large number of distributed power sources, energy storage, or nonlinear loads are connected to the power system via power electronic converters. Due to the nonlinear switching characteristics of power electronic converters, these converters can introduce severe harmonic pollution to the power system, including low-frequency harmonics, high-frequency switching ripple, and even higher-frequency electromagnetic harmonics. Therefore, filters are required at the input or output ports of the power electronic converter to suppress the high-frequency ripple introduced by the switching modulation.

[0003] Taking grid-connected inverters as an example, most current systems enhance the filtering performance of their filters. Common filters include L filters, LC filters, and LCL filters. Compared to L and LC filters, LCL filters offer a high-frequency attenuation rate of -60dB / dec, providing superior high-frequency current ripple suppression. They also require smaller inductance values, significantly reducing system cost and size. To further reduce filter size, researchers have proposed a magnetically coupled ripple transfer technology based on coupled inductors. This technology integrates two inductors into a single magnetic core through magnetic integration. This shared magnetic circuit transfers the switching ripple of the main power channel to an auxiliary branch, eliminating the switching ripple in the main power channel. However, this technology's ripple elimination capability relies heavily on parameter matching of the coupled inductors in the magnetically coupled ripple transfer channel. Currently, parameter matching of coupled inductors requires simultaneous adjustment of the core air gap length and winding turns ratio. This requires customized design of magnetic components and results in poor consistency, making it difficult to implement in practical engineering applications. Summary of the Invention

[0004] The main purpose of the present invention is to improve the magnetic coupling ripple transfer technology and provide an inductor-transformer integrated magnetic coupling ripple transfer channel core structure, which can achieve precise parameter matching.

[0005] The present invention provides an inductor-transformer integrated magnetically coupled ripple transfer channel core structure, comprising at least two parallel flat plates, decoupling side posts connected to opposite edges of the flat plates, and at least two winding posts arranged between the two opposite decoupling side posts.

[0006] A coil is wound on the winding post, and the post axis is perpendicular to the plane of the flat plate; at least two winding posts are arranged along the opposite decoupling side post arrangement direction, and are directly connected to the flat plate at one end but with an air gap between them and the flat plate at the other end.

[0007] The technical effect achieved by the above arrangement: The air gap reluctance differs significantly from the core reluctance. The proposed invention achieves its technical effect by exploiting this difference between the core and air gap reluctances, thus requiring an air gap. Direct connection means the side legs and plate are integral, without an air gap. Because the core reluctance is much smaller than the air gap reluctance, magnetic flux can be decoupled by this difference in reluctance.

[0008] Furthermore, the decoupling side column includes a decoupling side column 1 and a decoupling side column 2;

[0009] The flat plate includes a flat plate 1 and a flat plate 2;

[0010] The winding pole includes a winding pole 1 and a winding pole 2;

[0011] Both ends of the decoupling side column 1 and the decoupling side column 2 are directly connected to the flat plate 1 and the flat plate 2 respectively. The winding column 1 and the winding column 2 are directly connected to the flat plate 2 but an air gap is set between them and the flat plate 1.

[0012] Furthermore, the decoupling side column, the flat plate and the winding column are made of a soft magnetic material with high magnetic permeability. High magnetic permeability means a magnetic permeability of about 100 or more.

[0013] Furthermore, the soft magnetic material with high magnetic permeability is, for example, a ferrite material.

[0014] Furthermore, the coil includes a primary self-inductance coil and a secondary self-inductance coil;

[0015] The primary self-inductance coil is wound in series on winding poles 1 and 2 in opposite directions. The secondary self-inductance coil is wound on winding pole 2 in the same winding direction as the primary self-inductance coil on the winding pole. The relationship between the number of turns of the primary and secondary self-inductance coils on winding pole 2 satisfies:

[0016] N p2 =N s2

[0017] Among them, N p2 and N s2 are the turns of the primary and secondary self-inductance coils on the second winding column respectively.

[0018] Furthermore, the two decoupling side columns have the same size, the two winding columns have the same size, and the two flat plates have the same size.

[0019] Furthermore, the decoupling side columns have the same width as the connected flat plate.

[0020] The above arrangement achieves the following technical effect: ensuring that the reluctance of the same part of the core is the same, such as the reluctance of the two decoupling side legs.

[0021] Furthermore, the primary self-inductance coil is selected as a PCB winding with a width of 2.5 mm and a thickness of 0.07 mm, a current resistance value of 6 A effective value, and a self-inductance value of 31.4 μH.

[0022] Furthermore, the secondary side self-inductance coil is selected as a PCB winding with a width of 2.5 mm and a thickness of 0.07 mm, a current carrying value of 6 A effective value, and a self-inductance value of 15.1 μH.

[0023] Furthermore, the winding column is selected to be a "runway" structure, which is spliced by two semicircles with a radius r of 3 mm and a rectangle with a length l of 6 mm and a width w of 12 mm.

[0024] Furthermore, the decoupling side column is selected to be a rectangle with a length of 5 mm and a width of 30 mm.

[0025] Furthermore, the flat plate is selected to be a rectangle with a length of 34 mm and a width of 30 mm.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention proposes an inductor-transformer integrated magnetically coupled ripple transfer channel core structure. By decoupling the side legs and air gaps, the primary winding of winding leg one and the secondary winding of winding leg two are loosely coupled, eliminating mutual induction flux. Therefore, the mutual induction flux between the primary and secondary windings is generated solely by the tightly coupled primary and secondary windings on winding leg two. Therefore, the switching ripple elimination condition can be met by simply adjusting the number of turns of the primary and secondary windings wound on the same winding leg to be the same, achieving precise matching of electrical parameters and reducing the difficulty of core design. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the magnetically coupled ripple transfer channel of the inductor-transformer integration proposed in the present invention;

[0029] Figure 2 The magnetic core structure of the inductor-transformer integrated magnetic coupling ripple transfer channel proposed by the present invention;

[0030] Figure 3 The circuit diagram of the present invention applied to a single-phase inverter.

[0031] Figure 4 This is a typical circuit modulation strategy diagram of the present invention;

[0032] Figure 5The equivalent magnetic circuit of the inductor-transformer integrated magnetic coupling ripple transfer channel magnetic core structure designed by the present invention;

[0033] Figure 6 The magnetic core size designed in the embodiment of the present invention;

[0034] Figure 7 The primary and secondary inductance matrices of the magnetic core structure proposed in the present invention;

[0035] Figure 8 Schematic diagram of the magnetic coupling ripple transfer channel in the prior art. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0037] In the description of this embodiment, it should be noted that when terms such as "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", and "outside" appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings. It is only for the convenience of describing this embodiment and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on this embodiment.

[0038] Example 1:

[0039] The magnetic core structure of the inductor-transformer integrated magnetic coupling ripple transfer channel proposed in this embodiment is as follows: Figure 2 As shown, the core is made of high permeability soft magnetic material. The core structure and air gap position are as shown in Figure 2 shown.

[0040] The circuit diagram of this embodiment when the present invention is applied to a single-phase inverter is as follows: Figure 3 As shown. Using sinusoidal pulse width modulation (SPWM) Figure 3 The four switching devices S1-S4 in the single-phase inverter shown in FIG are pulse-width modulated, and the modulation strategy is as follows: Figure 4 shown. Figure 4 Medium V r is the modulation signal, the control signal output by the closed-loop controller; V c is a triangular carrier wave, used to modulate the signal V r Comparison generates the driving sequence of the switching device. r >V c When S1 is driven at a high level and S2 is driven at a low level, S1 is turned on and S2 is turned off. r <V cWhen -V r >V c When -V r <V c When , the driving voltage of S4 is high and the driving voltage of S3 is low, then S4 is turned on and S3 is turned off;

[0041] The core structure includes two decoupling side columns, two plates, two winding columns and primary and secondary self-inductance coils. The single-phase inverter parameters used are: dc 400V, v g The AC voltage is 220V RMS and 50Hz, and the capacitor C au The peak current is 6.42A and the power is 1KW.

[0042] The decoupling side legs are directly connected to the plate, with no air gap at the interface. An air gap is provided between the winding legs and the plate. The air gap reluctance differs significantly from the core reluctance. The proposed invention exploits this difference in core and air gap reluctance to achieve the proposed technical invention, thus requiring an air gap. Direct connection means the side legs and plate are integral, without an air gap. Because the core reluctance is much smaller than the air gap reluctance, magnetic flux can be decoupled through this difference in reluctance.

[0043] The primary self-inductance coil is wound in series on winding poles 1 and 2 in opposite directions. The secondary self-inductance coil is wound on winding pole 2 in the same direction as the primary self-inductance coil on winding pole 2. The primary and secondary self-inductance coils on winding pole 2 are arranged in an alternating pattern. One end of the primary self-inductance coil is connected to the corresponding end of the secondary self-inductance coil and connected to the midpoint of the inverter switches S1 and S2; the other end of the primary self-inductance coil is connected to one end of the AC voltage; the other end of the secondary self-inductance coil is connected to the capacitor C au Connected; capacitor C au The other end of the AC voltage is connected to each other and connected to the midpoint of the inverter switches S3 and S4.

[0044] In this example, the primary self-inductance coil is a 2.5mm wide, 0.07mm thick PCB winding with a current rating of 6A RMS and a self-inductance of 31.4µH. The secondary self-inductance coil is a 2.5mm wide, 0.07mm thick PCB winding with a current rating of 6A RMS and a self-inductance of 15.1µH. The winding post is a "runway" structure consisting of two semicircles with a radius r of 3mm joined by a rectangle with a length l of 6mm and a width w of 12mm. The decoupling post is a rectangle with a length of 5mm and a width of 30mm. The flat plate is a rectangle with a length of 34mm and a width of 30mm.

[0045] The design of the core size is related to the power level, desired inductance, core material, etc. The size designed in the present invention is a set of parameters selected according to the power level. There are other preferred sizes that can achieve the same electrical parameters.

[0046] The following combination Figures 1 to 6 Introduce the specific application of the present invention:

[0047] Figure 4 This is a schematic diagram of single-phase inverter modulation. Assume that the current of the primary self-inductance is i g , the current of the secondary side self-inductance is i au The number of turns of the primary self-inductance coil on the winding column is N p1 , the number of turns on winding pole 2 is N p2 The number of turns of the secondary self-inductance coil on the winding column 2 is N s2 The sum of the air gap magnetic resistance and the core magnetic resistance of the winding column is R1, the core magnetic resistance between the decoupling side column and the winding column is R2, and the core magnetic resistance of the magnetic plate between the two winding columns is R3.

[0048] Figure 5 This is the equivalent magnetic circuit of the inductor-transformer integrated magnetically coupled ripple transfer channel core structure designed by the present invention. It should be noted that any processes or parameters not specifically described below can be understood or implemented by those skilled in the art by referring to existing technologies.

[0049] Since the positive and negative half cycles of AC voltage work on the same principle, only the positive half cycle is analyzed. Figure 4 For the modulation strategy shown in Figure 1, during the periods t0~t1 and t2~t3, the inverter mathematical model is:

[0050]

[0051] Where, the primary inductance L1=L p +L, secondary inductance L2=L s .

[0052] During t1~t2 and t3~t4, the inverter mathematical model is:

[0053]

[0054] For ease of analysis, the duty cycle signal is normalized. Let the duty cycle of the switch S1 after normalization be d. According to the inductor volt-second balance principle, we can obtain:

[0055]

[0056] According to the above formula, we can further deduce

[0057]

[0058] Substituting formula (4) into formula (1) and formula (2) yields:

[0059]

[0060] From formula (5), it can be seen that there is a common factor in the current slope expression of the primary self-inductance coil. As long as this factor is zero, the ripple can be minimized, that is:

[0061]

[0062] Since the core material is a soft magnetic material with high magnetic permeability, the core magnetic permeability is much greater than the air gap magnetic permeability, so the core magnetic resistance R2 and R3 are much smaller than R1. Figure 5 It can be seen that due to the tight coupling between the primary self-inductance coil and the secondary self-inductance coil on the winding column 2 and the number of winding turns N p2 =N s2 Therefore, the primary and secondary self-inductances and mutual inductances obtained by the winding column are the same, which can meet the ripple elimination condition L s =M, part of the primary self-inductance wire on the winding column forms the primary self-inductance L. Since the primary self-inductance coils are connected in series, the total primary inductance value L1=L p +L.

[0063] The solution proposed in this invention is verified using the Ansys simulation experiment platform. The core size is as follows: Figure 6 As shown, the number of turns of the primary self-inductance coil is N p1 =6,N p2 =6, the number of turns of the secondary self-inductance coil is N s2 =6, the simulation results are as follows Figure 7 shown. Figure 7 The figure shows the primary and secondary inductance matrices (Pri represents the primary inductance, Sec represents the secondary inductance). It can be seen that the mutual inductance and the secondary inductance are almost the same, achieving precise matching of the electrical parameters of the magnetically coupled ripple transfer channel.

[0064] This embodiment also provides an inductor-transformer integrated magnetic coupling ripple transfer channel, which is applicable to the magnetic core structure described above. Figure 8 The original magnetic coupling ripple transfer channel composed of weak coupling inductor and auxiliary capacitor is transformed into a magnetic coupling ripple transfer channel composed of integrated inductor-transformer and auxiliary capacitor, such as Figure 1As shown, the two-port filter includes an integrated inductor-transformer and an auxiliary capacitor. Figure 1 The integrated inductor-transformer shown here splits the original weakly coupled inductor into a tightly coupled inductor and a series inductor, then integrates them through magnetic circuit decoupling, improving core utilization and reducing size. Furthermore, compared to weakly coupled inductors, tightly coupled inductors simplify ripple transfer conditions and achieve precise parameter matching.

[0065] Among them, the condition for achieving ripple elimination is the secondary side self-inductance L s Equal to the mutual inductance M. Where M is defined as the transformer primary self-inductance L p and the secondary side self-inductance L s The mutual induction between.

[0066] The primary and secondary inductance coils on the winding column 2 are tightly coupled. To achieve the ripple elimination condition, the relationship between the number of turns of the primary and secondary self-inductance coils on the winding column 2 is adjusted to meet the following relationship: N p2 =N s2 Among them, N p2 and N s2 are the turns of the primary and secondary self-inductance coils on the second winding column respectively.

[0067] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features being referred to. Thus, features specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0068] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0069] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0070] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. Throughout this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0071] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. An inductor-transformer integrated magnetically coupled ripple transfer channel core structure, characterized in that: The invention comprises at least two parallel flat plates, decoupling side posts connected to the edges of both sides of the flat plates, and at least two winding posts arranged between the two opposite decoupling side posts. A coil is wound on the winding post, and the post axis is perpendicular to the plane of the flat plate; at least two winding posts are arranged along the opposite decoupling side post arrangement direction, and are directly connected to the flat plate at one end but with an air gap between them and the flat plate at the other end.

2. The inductor-transformer integrated magnetically coupled ripple transfer channel core structure according to claim 1, characterized in that: The decoupling side column includes a decoupling side column 1 and a decoupling side column 2; The flat plate includes a flat plate 1 and a flat plate 2; The winding pole includes a winding pole 1 and a winding pole 2; Both ends of the decoupling side column 1 and the decoupling side column 2 are directly connected to the flat plate 1 and the flat plate 2 respectively. The winding column 1 and the winding column 2 are directly connected to the flat plate 2 but an air gap is set between them and the flat plate 1.

3. The inductor-transformer integrated magnetically coupled ripple transfer channel core structure according to claim 2, characterized in that: The decoupling side columns, flat plates and winding columns are made of soft magnetic materials with high magnetic permeability.

4. The inductor-transformer integrated magnetically coupled ripple transfer channel core structure according to claim 3, characterized in that: The soft magnetic material with high magnetic permeability is, for example, ferrite material.

5. The inductor-transformer integrated magnetically coupled ripple transfer channel core structure according to claim 2, characterized in that: The coil includes a primary self-inductance coil and a secondary self-inductance coil; The primary self-inductance coil is wound in series on winding poles 1 and 2 in opposite directions. The secondary self-inductance coil is wound on winding pole 2 in the same winding direction as the primary self-inductance coil on the winding pole. The relationship between the number of turns of the primary and secondary self-inductance coils on winding pole 2 satisfies: N p2 = N s2 in, N p2 and N s2 are the turns of the primary and secondary self-inductance coils on the second winding column respectively.

6. The inductor-transformer integrated magnetically coupled ripple transfer channel core structure according to claim 2, characterized in that: The two decoupling side posts are the same size, the two winding posts are the same size, and the two flat plates are the same size.

7. The inductor-transformer integrated magnetically coupled ripple transfer channel core structure according to claim 2, characterized in that: The decoupling jambs have the same width as the connected slabs.

8. The inductor-transformer integrated magnetically coupled ripple transfer channel core structure according to claim 2, characterized in that: The primary self-inductance coil is a PCB winding with a width of 2.5 mm and a thickness of 0.07 mm, a current carrying value of 6 A effective value, and a self-inductance value of 31.4 µH.

9. The inductor-transformer integrated magnetically coupled ripple transfer channel core structure according to claim 8, characterized in that: The secondary side self-inductance coil is selected as a PCB winding with a width of 2.5 mm and a thickness of 0.07 mm, a current carrying value of 6 A effective value, and a self-inductance value of 15.1 μH.

10. The inductor-transformer integrated magnetically coupled ripple transfer channel core structure according to claim 9, characterized in that: The winding column is selected as a "racetrack" structure, consisting of two radii r 3mm semicircle with a length of l 6mm wide w It is a 12mm rectangular splicing; The decoupling side column is selected to be a rectangle with a length of 5 mm and a width of 30 mm; The flat plate is selected to be a rectangle with a length of 34 mm and a width of 30 mm.

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