An alternating current wound core and direct current laminated core combined orthogonal controllable reactor

Abstract

This invention provides an orthogonal controllable reactor combining an AC wound core and a DC stacked core, relating to the field of power equipment technology. The orthogonal controllable reactor of this invention includes an AC core and a DC core; wherein the AC core is a closed wound core structure made of continuously conductive magnetic material; the DC core consists of two identical C-shaped cores; each core column of the C-shaped core is a stacked core structure made of magnetically conductive sheets. This invention allows the AC and DC magnetic flux to intersect perpendicularly without obstruction in the same two-dimensional plane of the AC core, eliminating the influence of seams in the AC main magnetic circuit and improving the magnetic flux coupling state; simultaneously, by utilizing the characteristics of the DC-side stacked core, high leakage magnetic resistance is constructed, effectively suppressing leakage of the AC main magnetic flux to the DC side, maintaining the orthogonal decoupling characteristics of AC and DC. This invention significantly widens the effective adjustment range of the inductance and greatly reduces the core operating losses of the equipment.

Description

Technical Field

[0001] This invention relates to the field of power equipment technology, specifically to an orthogonal controllable reactor combining an AC wound core and a DC stacked core. Background Technology

[0002] With the continuous expansion of power systems and the large-scale integration of new energy sources and nonlinear loads, the problems of harmonic pollution and power quality facing the power grid are becoming increasingly prominent. Controllable reactors, with their continuously adjustable impedance, play a crucial role in dynamically filtering harmonics and improving power quality. Among them, orthogonal controllable reactors utilize the spatial orthogonality mechanism of AC and DC magnetic fields to achieve electromagnetic decoupling, offering advantages such as low harmonic content and continuous, smooth inductance adjustment.

[0003] However, traditional orthogonal controllable reactors mostly employ a stacked core structure, which has two inherent structural defects: First, the rectangular stack of silicon steel sheets inevitably introduces seams into the magnetic circuit, disrupting the continuity of the magnetic circuit and increasing the air gap reluctance; second, because the AC and DC magnetic circuits are spatially orthogonal, when the DC control flux enters the orthogonal region, it must penetrate the silicon steel sheet perpendicularly along the normal direction, weakening the effective component of the applied DC magnetic field in this region, making it difficult for the orthogonal region to reach a deep magnetic saturation state. This ultimately leads to low inductance regulation sensitivity, limited effective regulation range, and high core losses in traditional power equipment. Summary of the Invention

[0004] The purpose of this invention is to provide an orthogonal controllable reactor that combines an AC wound core and a DC stacked core, in order to solve the technical problems of existing stacked core orthogonal controllable reactors where there are seams in the main magnetic circuit and the DC control flux needs to penetrate the silicon steel sheet in the orthogonal region perpendicularly along the normal direction, resulting in difficulty in achieving deep magnetic saturation in the orthogonal region, limited inductance adjustment range, and high core loss.

[0005] To achieve the above objectives, the present invention provides an orthogonal controllable reactor combining an AC core and a DC core, comprising an AC core and a DC core; the AC core and the DC core are perpendicularly stacked in space to form a cross-shaped orthogonal controllable reactor. The AC core is a closed wound core structure made of continuous conductive magnetic material; The DC core uses two identical C-type cores; each C-type core is composed of multiple core columns spliced ​​together, with seams at the splicing points; each core column is a stacked core structure made of magnetically conductive sheets.

[0006] According to the present invention, an orthogonal controllable reactor combining an AC wound core and a DC stacked core is provided, wherein two air gaps of the same size are respectively provided in the middle part of the two core columns on both sides of the AC core.

[0007] According to the present invention, an orthogonal controllable reactor combining an AC wound core and a DC stacked core is provided, which further includes two AC windings and two DC windings; the two AC windings are respectively wound on the two core columns of the AC core as the working windings of the orthogonal controllable reactor; the two DC windings are respectively wound on the two core columns of the DC core as the control windings of the orthogonal controllable reactor.

[0008] According to the present invention, an orthogonal controllable reactor combining an AC wound core and a DC stacked core is provided, wherein the two air gaps are located at the middle of the two AC windings respectively.

[0009] According to the present invention, an orthogonal controllable reactor combining an AC wound core and a DC stacked core is provided, wherein the same-name terminals of the two AC windings are connected in series with the beginning and end connected, and the same-name terminals of the two DC windings are connected in series with the beginning and end connected.

[0010] According to the present invention, an orthogonal controllable reactor combining an AC wound core and a DC stacked core is provided, wherein the two AC windings have the same number of turns and the two DC windings have the same number of turns.

[0011] According to the present invention, an orthogonal controllable reactor combining AC wound core and DC stacked core is provided. Each C-type core includes three core columns, referred to as the first core column, the second core column and the third core column respectively. The first core column and the third core column are perpendicular to the two ends of the second core column, and the DC winding is disposed on the second core column.

[0012] According to the present invention, an orthogonal controllable reactor combining an AC wound core and a DC stacked core is provided, wherein the conductive tape is anisotropic silicon steel tape.

[0013] According to the present invention, an orthogonal controllable reactor combining an AC wound core and a DC stacked core is provided, wherein the magnetic material is a silicon steel sheet.

[0014] According to the present invention, an orthogonal controllable reactor combining an AC core and a DC core is provided, wherein the overlap of the AC core and the DC core forms an orthogonal region in which the AC and DC magnetic fields are orthogonal; in the orthogonal region, the plane of the magnetic magnetic material is perpendicular to the plane of the magnetic sheet.

[0015] Compared with the prior art, the present invention has at least the following technical effects: 1. The introduction of a wound core structure made of continuous conductive magnetic material (such as silicon steel tape) on the AC side eliminates the influence of seams and improves the magnetic flux coupling state in the orthogonal region; 2. The DC side retains the stacked core form made of magnetically conductive sheets (such as silicon steel sheets), which suppresses AC leakage flux and takes into account the overall orthogonal decoupling characteristics. 3. Thanks to the increased magnetic saturation depth in the orthogonal region and the effective suppression of leakage flux, the effective adjustment range of inductance is significantly widened, and the operating loss of the equipment core is greatly reduced. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] In the attached diagram: Figure 1 This is a schematic diagram of the orthogonal controllable reactor combining AC wound core and DC stacked core of the present invention. Figure 2 This is a schematic diagram of the spatial topology of the orthogonal region of the orthogonal controllable reactor of the present invention; Figure 3 This is a schematic diagram of the nonlinear equivalent magnetic circuit model of the orthogonal controllable reactor of the present invention; Figure 4 This is a schematic diagram of a traditional stacked core orthogonal controllable reactor. Figure 5 This is a comparison curve of the inductance regulation characteristics between the novel topology of this invention and the traditional topology; Figure 6 This is a comparison curve of the core loss characteristics between the new topology of this invention and the traditional topology. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0019] The following detailed description of some embodiments of the present invention will be provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0020] Please see Figure 1This invention provides an orthogonal controllable reactor combining an AC wound core and a DC stacked core, comprising a DC core and an AC core. The AC core and DC core are spatially perpendicularly stacked to form a cross-shaped orthogonal controllable reactor. In terms of spatial structure, this orthogonal controllable reactor adopts an orthogonal structure of AC and DC cores. The AC core is a closed wound core structure made of continuous conductive magnetic material, for example, tightly wound anisotropic silicon steel strip following the direction of magnetic field lines, forming a seamless closed wound core structure. The DC core consists of two identical C-shaped cores. Each C-shaped core is composed of multiple core columns spliced ​​together, with seams at the splicing points. Each core column is a stacked core structure made of magnetically conductive sheets, for example, manufactured using a silicon steel sheet stacking process.

[0021] It should be noted that the DC core is orthogonally positioned between the DC and AC cores in the middle, forming a cross-shaped orthogonal controllable reactor. In particular, due to the inherent material properties of oriented silicon steel sheets—high permeability when unsaturated and low permeability when saturated—the core of conventional magnetically saturated reactors is highly susceptible to abrupt saturation.

[0022] To overcome this problem, in this embodiment of the invention, two air gaps of the same size are respectively provided in the middle of the two core columns on both sides of the AC core. The introduction of this air gap can effectively optimize the overall equivalent magnetization curve of the AC core, thereby making the inductance adjustment characteristics have better linearity. The silicon steel sheet lamination structure retained in the DC core utilizes its joint characteristics to construct high leakage magnetic resistance, which is used to suppress the leakage of AC main magnetic flux to the DC side, prevent additional hysteresis loss, and thus maintain the orthogonal decoupling characteristics of the AC and DC magnetic field spaces of this invention.

[0023] Specifically, the orthogonal controllable reactor also includes two AC windings and two DC windings. The two AC windings are wound on both sides of the AC core, serving as the working windings of the orthogonal controllable reactor. The two AC windings have the same number of turns, and their corresponding terminals are connected in series. Furthermore, two air gaps are located in the middle of each of the two AC windings. The two DC windings are wound on both sides of the DC core, serving as the control windings of the orthogonal controllable reactor. The two DC windings have the same number of turns, and their corresponding terminals are connected in series.

[0024] In some embodiments, each C-type core includes three core posts, referred to as the first core post, the second core post, and the third core post, respectively; the first core post and the third core post are perpendicular to the two ends of the second core post, and the DC winding is disposed on the second core post.

[0025] like Figure 2As shown, the overlap of the AC core and the DC core forms an orthogonal region where the AC and DC magnetic fields are orthogonal. Within the orthogonal region, the AC magnetic flux and the DC magnetic flux intersect perpendicularly without obstruction in the same two-dimensional plane of the AC core. At the orthogonal region, the plane where the magnetic magnetic material is located is perpendicular to the plane where the magnetic magnetic sheet is located.

[0026] like Figure 1 As shown, AC windings are wound around the two core columns on both sides of the AC core. W AC1 , W AC2 DC windings are wound on both sides of the core column of the DC core. W DC1 , W DC2 The AC section is integrated into the circuit to form the main body of the orthogonal controllable reactor. The specific structure of the core in the orthogonal region of this invention is as follows: Figure 2 As shown, Figure 2 It visually demonstrates the connection and magnetic flux direction of AC wound iron core and DC stacked iron core in the orthogonal region.

[0027] The core working mechanism of the orthogonal controllable reactor of this invention is as follows: When the DC flux enters the orthogonal region, due to the core winding process used in the AC core, the DC and AC fluxes intersect perpendicularly within the two-dimensional plane of the same silicon steel sheet, avoiding the resistance of the normal direction penetrating the insulating coating of the silicon steel sheet. This allows the orthogonal region to enter a deep magnetic saturation state under the same DC current. Simultaneously, the laminated silicon steel sheet structure of the DC core has seams and interlayer insulation, effectively blocking the leakage path of the AC main flux to the DC core, maintaining the orthogonal decoupling characteristics of AC and DC.

[0028] according to Figure 1 The structure of the orthogonal controllable reactor shows its equivalent magnetic circuit as follows: Figure 3 As shown. Figure 3 middle, F ac , F dc These are alternating current magnetomotive force and direct current magnetomotive force, respectively. R a1 , R a2 These represent the total magnetic reluctance of the non-orthogonal regions and the magnetic reluctance of a single orthogonal region in an alternating magnetic circuit, respectively. R leak This refers to the leakage reluctance when AC leakage flux flows into the DC core through the orthogonal region. R d1 , R d2 These represent the total reluctance of the non-orthogonal regions in a DC magnetic circuit and the equivalent reluctance of a single orthogonal region on the DC side, respectively. R gThe total magnetic reluctance of the air gap is denoted as .

[0029] Considering the symmetrical saturation characteristics of ferromagnetic materials, their magnetization curves are completely symmetrical about the origin. Therefore, the magnetization curve of the iron core can be approximated as a function of magnetic flux. For independent variables, magnetomotive force F The magnetomotive force is an odd function of the dependent variable. Its Taylor expansion, retaining the odd-order terms, yields the magnetomotive force. F With magnetic flux The nonlinear mapping relationship can be expressed as: (1) In the formula, a 1. a 3. a 5 and a m These are all characteristic coefficients determined by the reactor's topological geometry and the inherent properties of the ferromagnetic material. To balance the mathematical rigor and physical intuition of the theoretical derivation, the following values ​​were selected: m =3 for dimensionality reduction simplification.

[0030] The method described above, based on the Taylor expansion of odd functions, can also be used to map and represent the magnetic field strength of the material itself. H With magnetic induction intensity B The magnetization relationship. Combined with Ampere's circuital law. F = N i = H l ( N The number of coil turns. i (The current flowing through the coil) and the flux continuity theorem = B S The above equation can be reconstructed into a relationship between magnetic field strength and magnetic induction: (2) In the formula, b 1= a 1 S / l , b 3= a 3 S 3 / l ; l The equivalent magnetic circuit length of the iron core. S This represents the effective cross-sectional area of ​​the iron core.

[0031] Within the orthogonal region, the AC main magnetic flux density Ba ( t It is considered as a vector that evolves sinusoidally with respect to the fundamental frequency, while the DC magnetic flux density is... B d It is spatially perpendicular to the direction of alternation and remains constant. Based on the spatial geometric composition relationship of the magnetic field vector, the total composite magnetic flux density vector within the orthogonal region is... B total ( t )satisfy: (3) (4) In the formula, B am The amplitude of the AC main magnetic flux density, B d This represents the amplitude of the DC magnetic flux density. ω Let ω be the fundamental angular frequency and t be the time. In equation (3), i and j represent two orthogonal direction vectors, respectively.

[0032] Substituting equation (3) into equation (4), and expanding it, we can further extract the magnetic field component along the AC main magnetic path to obtain the magnetic field strength in the AC direction. H a ( t )for: (5) The power reduction formula for trigonometric functions sin 3 ( ωt )=3sin( ωt ) / 4-sin(3 ωt Substituting 4 / 4 into equation (5), and ignoring higher-order components such as the third harmonic within the allowable error range in engineering, the fundamental magnetic field strength can be extracted as follows: (6) Based on this, the equivalent dynamic permeability of the orthogonal region in the AC direction can be derived. μ a2 Permeability of the non-orthogonal region of the alternating current core μ a1 They are respectively: (7) By combining the magnetic circuit geometry parameters, the corresponding magnetic reluctance can be obtained: (8) In the formula, l a1 and l a2 These represent the total magnetic path length in the non-orthogonal region of the AC core and the magnetic path length in a single orthogonal region, respectively. μ 0 represents the permeability of free space.

[0033] On the other hand, since the leakage of AC magnetic flux into the DC core is inevitable, let the amplitude of the AC leakage flux density leaking into the DC core be... B leak Since the leakage flux is closed along the DC magnetic circuit, it is related to the DC main magnetic flux density. B d They exhibit a collinear superposition relationship in space. Therefore, the total magnetic flux density inside the DC iron core is... B d ( t This can be represented as: (9) Magnetic field strength in the non-orthogonal region of a DC core H d1 ( t )for: (10) In the formula, c 1. c 3 represents the magnetization polynomial coefficients determined by the material and structure of the non-orthogonal region of the DC core. Expanding and power-reducing the cubic terms, and filtering out higher-order distortion components, yields: (11) This allows us to extract the static bias permeability of the non-orthogonal region on the DC side. μ d1 With AC leakage flux and dynamic permeability μ d_leak They are respectively: (12) The equivalent leakage magnetic resistance expression can then be given as: (13) like Figure 3 As shown, in the total AC equivalent magnetic circuit, the leakage magnetic reluctance is connected in parallel with the magnetic reluctance of the orthogonal region, and then in series with the magnetic reluctance of the AC non-orthogonal region. Based on the above derivation, the total AC equivalent magnetic reluctance... R eq for: (14) According to Ampere's circuital law, the total alternating magnetomotive force... F a The equilibrium equation is: (15) Therefore, the formula for calculating the equivalent inductance is derived as follows: (16) In the formula, N ac This refers to the number of turns in a single-sided AC winding.

[0034] To verify the effectiveness of the above theoretical support and structural design, a finite element simulation model was established in this embodiment of the invention, and the new topology (the orthogonal controllable reactor proposed in this invention) was compared with the traditional topology (…). Figure 4 A comparative analysis was conducted on the existing stacked core orthogonal controllable reactor shown. To ensure the rigor of the comparative experiment, the external spatial dimensions of the cores of both were set to be completely identical. The specific model parameters and simulation boundary conditions were configured as follows: the spatial dimensions of both topologies were 250mm×250mm×300mm, the core cross-section was 50mm×50mm, and the single-sided air gap length was 1mm. Anisotropic 30Q130 silicon steel sheets were used as the material. In terms of winding parameters, considering the differences in the initial state of the magnetic circuit caused by different core manufacturing processes, to ensure that the two topologies could have the same initial equivalent inductance value as a comparison benchmark under the initial condition of 0 DC current, the number of turns of the AC winding on one side of the traditional topology and the new topology were set to 88 turns and 100 turns, respectively. The number of turns of the DC winding on one side was uniformly kept at 50 turns. In the simulation test, the current amplitude flowing into the AC winding was set to 10A, and the current flowing into the DC winding was set to 0 to 20A. A comparison of inductor regulation characteristics and core loss characteristics is as follows: Figure 5 , Figure 6 As shown in the figure. The results clearly demonstrate that the orthogonal controllable reactor combining AC wound core and DC stacked core of the present invention has a larger inductance adjustment range and significantly reduced core loss under rated operating conditions (DC control current of 10A) compared with the traditional stacked core orthogonal controllable reactor.

[0035] In summary, this invention provides an orthogonal controllable reactor combining an AC wound core and a DC stacked core, comprising an AC core and a DC core; the AC and DC cores are spatially perpendicularly stacked to form a cross-shaped orthogonal controllable reactor; the AC core is a closed wound core structure made of continuously conductive magnetic material; the DC core uses two identical C-shaped cores; each C-shaped core is composed of multiple core columns spliced ​​together, with seams at the splicing points; each core column is a stacked core structure made of magnetically conductive sheets. This invention allows the AC and DC magnetic flux to intersect perpendicularly without obstruction in the same two-dimensional plane of the AC core, eliminating the influence of seams in the AC main magnetic circuit and improving the magnetic flux coupling state; simultaneously, by utilizing the characteristics of the DC-side stacked core, high leakage magnetic resistance is constructed, effectively suppressing leakage of the AC main magnetic flux to the DC side, maintaining the orthogonal decoupling characteristics of AC and DC. This invention significantly widens the effective adjustment range of the inductance and greatly reduces the core operating losses of the equipment.

[0036] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the embodiments disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. It should be understood that the invention is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. An orthogonal controllable reactor combining an AC wound core and a DC stacked core, characterized in that, It includes an AC core and a DC core; the AC core and the DC core overlap perpendicularly to each other in space to form a cross-shaped orthogonal controllable reactor; The AC core is a closed wound core structure made of continuous conductive magnetic material. The DC core uses two identical C-type cores; each C-type core is composed of multiple core columns spliced ​​together, with seams at the splicing points; each core column is a stacked core structure made of magnetically conductive sheets.

2. The orthogonal controllable reactor combining an AC wound core and a DC stacked core according to claim 1, characterized in that, The two sides of the AC core have two air gaps of the same size in the middle of the core columns.

3. The orthogonal controllable reactor combining an AC wound core and a DC stacked core according to claim 2, characterized in that, It also includes two AC windings and two DC windings; the two AC windings are respectively wound on both sides of the core column of the AC core, serving as the working windings of the orthogonal controllable reactor; the two DC windings are respectively wound on both sides of the core column of the DC core, serving as the control windings of the orthogonal controllable reactor.

4. The orthogonal controllable reactor combining an AC wound core and a DC stacked core according to claim 3, characterized in that, The two air gaps are located in the middle of the two AC windings, respectively.

5. The orthogonal controllable reactor combining an AC wound core and a DC stacked core according to claim 3, characterized in that, The same-name terminals of the two AC windings are connected in series, with the ends connected end to end. The same-name terminals of the two DC windings are also connected in series, with the ends connected end to end.

6. The orthogonal controllable reactor combining an AC wound core and a DC stacked core according to claim 3, characterized in that, The two AC windings have the same number of turns, and the two DC windings have the same number of turns.

7. The orthogonal controllable reactor combining an AC wound core and a DC stacked core according to claim 3, characterized in that, Each C-type iron core includes three iron core columns, referred to as the first iron core column, the second iron core column, and the third iron core column, respectively; the first iron core column and the third iron core column are perpendicular to the two ends of the second iron core column, and the DC winding is disposed on the second iron core column.

8. The orthogonal controllable reactor combining an AC wound core and a DC stacked core according to claim 1, characterized in that, The conductive tape is anisotropic silicon steel tape.

9. The orthogonal controllable reactor combining an AC wound core and a DC stacked core according to claim 1, characterized in that, The magnetically conductive sheet is a silicon steel sheet.

10. The orthogonal controllable reactor combining an AC wound core and a DC stacked core according to claim 1, characterized in that, The overlap of the AC core and the DC core forms an orthogonal region where the AC and DC magnetic fields are orthogonal; in the orthogonal region, the plane of the magnetic magnetic material is perpendicular to the plane of the magnetic sheet.

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