Three-phase integrated inductor and power electronic converter

Abstract

The utility model belongs to the technical field of power electronics, and particularly relates to a three-phase integrated inductor and a power electronic converter, which comprise two first magnetic columns, four second magnetic columns and three windings, the two first magnetic columns are arranged in parallel, and the four second magnetic columns are arranged between the two second magnetic columns in parallel at intervals to form a structure shaped like a Chinese character'mu '. The magnetic conductivity of the first magnetic columns is smaller than that of the second magnetic columns, the three windings are correspondingly located between every two adjacent second magnetic columns, a single winding is divided into two winding structures and correspondingly wound on the two first magnetic columns, the two winding structures of the single winding are connected in series, and the two winding structures of the single winding are connected in parallel. And magnetic lines of force formed on the first magnetic columns wound by the two winding structures are arranged towards the same direction. According to the utility model, the trend of magnetic lines generated by the three windings can be better controlled, effective decoupling is realized, the hottest point temperature of the inductor is reduced, the magnetic lines are prevented from being counteracted, the normal operation of the power electronic converter is ensured, and the number of turns of the windings is smaller.

Description

Technical Field

[0001] The utility model belongs to the technical field of power electronics, and particularly relates to a three-phase integrated inductor and a power electronic converter. Background Art

[0002] In the AC side of a power electronic converter, three independent inductors are usually used as filtering components. Since the inductors are independent of each other and have no magnetic connection, a large amount of magnetic core is used. At the same time, due to the lack of magnetic flux cancellation between the independent inductors, the loss of the magnetic core is also large. This will result in a relatively large overall volume and total weight of the three inductors, and the production material cost is relatively high. During the mass production stage, the three inductors need independent casings for independent potting, which reduces the efficiency of inductor mass production and the production cost is also relatively high. At present, some integrated inductors are proposed in the prior art. Although they can reduce the volume and weight, there are problems such as too high inductor temperature caused by over-concentration of local heat, and strong mutual inductance is likely to exist between the three phases, resulting in unequal equivalent inductances of each phase. When the same-phase winding is divided into several parts for layout, the magnetic lines of force of these parts may cancel each other out, thus affecting the normal operation of the power electronic converter. Summary of the Utility Model

[0003] The technical problem to be solved by the utility model is to provide a three-phase integrated inductor and a power electronic converter that can reduce the volume and weight while achieving effective decoupling, reduce the hottest point temperature of the inductor while avoiding the situation of mutual cancellation of the magnetic circuits of the two winding structures of the same phase, ensure the normal operation of the power electronic converter and make the number of turns of the winding smaller.

[0004] The content of the utility model provides a three-phase integrated inductor, including two first magnetic posts, four second magnetic posts and three windings. The two first magnetic posts are arranged in parallel, and the four second magnetic posts are arranged in parallel and spaced between the two second magnetic posts to form a rectangular structure with a hole in the middle. And the magnetic permeability of the first magnetic post is less than that of the second magnetic post. The three windings are respectively located between two adjacent second magnetic posts. Each single winding is divided into two winding structures, and is respectively wound around the two first magnetic posts. The two winding structures of each single winding are connected in series, and the magnetic lines of force formed by the two winding structures on the first magnetic posts they wind around are arranged in the same direction.

[0005] Furthermore, among the three windings, the vector directions of the magnetic lines of force generated by two adjacent windings on the shared second magnetic post differ by 120°.

[0006] Furthermore, an air gap is provided between the first magnetic post and the second magnetic post.

[0007] Furthermore, the two first magnetic posts and the four second magnetic posts are adhesively fixed.

[0008] Furthermore, the cross-sectional shapes of the first magnetic column, the second magnetic column, and the winding wire are any one of a circle, an ellipse, a kidney shape, and a polygon.

[0009] Furthermore, the shapes and sizes of the two first magnetic columns are the same, and the shapes and sizes of the four second magnetic columns are the same.

[0010] Furthermore, the first magnetic column is a single-piece integral magnetic column structure, or is formed by bonding two or more first sub-magnetic columns with the same cross-sectional shape and size.

[0011] Furthermore, the second magnetic column is a single-piece integral magnetic column structure, or is formed by bonding two or more second sub-magnetic columns with the same cross-sectional shape and size.

[0012] Furthermore, the single winding structure in a single winding is an integral winding structure, or is formed by connecting two or more winding sub-structures in series.

[0013] The present utility model also provides a power electronic converter, which is provided with the above-mentioned three-phase integrated inductor.

[0014] The beneficial effects of the present utility model are that the three-phase integrated inductor only needs two first magnetic columns and four second magnetic columns, and the required number of magnetic columns is small. The magnetic cores and windings of the three phases can be integrated in the same housing, and the volume, weight, and potting amount can be greatly reduced, and the production efficiency can be improved, while reducing the material and labor costs.

[0015] It can better control the direction of the magnetic force lines generated by the three windings, effectively ensuring that among the magnetic force line one, the magnetic force line two, and the magnetic force line three, only the magnetic paths of the adjacent two magnetic induction lines coincide within the shared second magnetic column, and the magnetic paths within the first magnetic column do not coincide, ensuring that the magnetic force line one, the magnetic force line two, and the magnetic force line three do not generate mutual inductance with each other, and more effectively realizing the decoupling of each phase inductor from each other, making the equivalent inductance of each phase equal, thereby more reliably ensuring the normal operation of the power electronic converter.

[0016] By winding each phase of the winding into two winding structures around different first magnetic columns, the heat of the winding and the magnetic core is more dispersed and the heat dissipation surface is larger, reducing the hottest point temperature of the inductor. On the one hand, it can ensure the normal operation of the converter, and on the other hand, it also reduces the requirements for the heat dissipation device of the inductor. Since the two winding structures of each winding are in a series connection relationship in the circuit and the magnetic force lines generated by the two winding structures on the first magnetic column they surround are in the same direction, the magnetic force lines of the two winding structures will be superimposed in the same direction, avoiding the situation where the magnetic paths of the two winding structures of the same phase cancel each other out. Under the condition of a determined magnetic core scheme, it can ensure the normal operation of the power electronic converter and make the number of winding turns smaller. Description of the Drawings

[0017] Figure 1 This is a schematic structural diagram of the present utility model.

[0018] Figure 2 This is a schematic diagram of the magnetic circuit formed by the three windings of the present utility model.

[0019] Figure 3 For the present utility model Figure 2 Magnetic field line vector diagram of the magnetic circuit.

[0020] Figure 4 For the present utility model Figure 3 Schematic diagram of vector superposition of two of the magnetic field lines.

[0021] Figure 5 This is a schematic diagram of the magnetic circuit of the two winding structures in a single winding of the present utility model.

[0022] In the figure: 1, the first magnetic column; 2, the second magnetic column; 3, the winding; 31, the winding structure; 301, magnetic field line one; 302, magnetic field line two; 303, magnetic field line three; 304, vector sum. Specific embodiments

[0023] As Figures 1-5 shown, the present utility model provides a three-phase integrated inductor, including two first magnetic columns 1, four second magnetic columns 2 and three windings 3. The two first magnetic columns 1 are arranged in parallel, and the four second magnetic columns 2 are arranged between the two second magnetic columns 2. The four second magnetic columns 2 are spaced between the two first magnetic columns 1, and the four second magnetic columns 2 are parallel to each other and perpendicular to the two first magnetic columns 1, jointly forming a square-eye structure. Among them, the magnetic permeability of the first magnetic column 1 is less than that of the second magnetic column 2.

[0024] The three windings 3 are correspondingly located between two adjacent second magnetic columns 2. A single winding 3 is divided into two winding structures 31 and is correspondingly wound around the two first magnetic columns 1. Specifically, as Figure 1As shown, the first winding 3 is located between the first second magnetic column 2 and the second second magnetic column 2 arranged from top to bottom, and the two winding structures 31 of the first winding 3 are respectively wound on the area between the two first magnetic columns 1 located between the first second magnetic column 2 and the second second magnetic column 2; the second winding 3 is located between the second second magnetic column 2 and the third second magnetic column 2 arranged from top to bottom, and the two winding structures 31 of the second winding 3 are respectively wound on the area between the two first magnetic columns 1 located between the second second magnetic column 2 and the third second magnetic column 2; the third winding 3 is located between the third second magnetic column 2 and the fourth second magnetic column 2 arranged from top to bottom, and the two winding structures 31 of the third winding 3 are respectively wound on the area between the two first magnetic columns 1 located between the third second magnetic column 2 and the fourth second magnetic column 2. The two winding structures 31 of a single winding 3 are connected in series, and the magnetic lines of force formed by the two winding structures 31 on the first magnetic column 1 wound thereon are arranged in the same direction. The two first magnetic columns 1 and the four second magnetic columns 2 together form a three-phase magnetic core. A single winding 3 forms a single-phase winding, and three windings 3 form a three-phase winding.

[0025] The three-phase integrated inductor provided by the utility model only requires two first magnetic columns 1 and four second magnetic columns 2, and the number of magnetic columns required is small. The magnetic cores and windings 3 of the three phases can be integrated in the same housing, and the volume, weight, and amount of glue injection can be greatly reduced, and the production efficiency can be improved, while reducing material and labor costs.

[0026] Since the magnetic permeability of the second magnetic column 2 is higher than that of the first magnetic column 1, it can be ensured that the magnetic lines of force generated by each winding 3 will follow the magnetic path of the second magnetic column 2 with higher magnetic permeability as much as possible, thereby better controlling the direction of the magnetic lines of force generated by the three windings 3. Specifically, the magnetic lines of force generated by the first winding 3 will follow the magnetic path of the second magnetic column 2 with higher magnetic permeability as much as possible. Figure 2 The magnetic circuit of the first second magnetic column 2 and the second second magnetic column 2 arranged from top to bottom forms a magnetic circuit as shown in FIG. Figure 2 The closed magnetic field line 301 shown in the figure; the magnetic field lines generated by the second winding 3 will be as far as possible along the Figure 2 The magnetic circuit of the second second magnetic column 2 and the third second magnetic column 2 arranged from top to bottom forms a magnetic circuit as shown in FIG. Figure 2 The closed magnetic field line 2 302 shown; the magnetic field line generated by the third winding 3 will be as far as possible along Figure 2 The magnetic circuit of the third second magnetic column 2 and the fourth second magnetic column 2 arranged from top to bottom forms a magnetic circuit as shown in FIG. Figure 2 The closed magnetic force line 3 303 is shown. Among the magnetic force lines 1 301, 2 302 and 303, only the magnetic circuits in the second magnetic column 2 with higher magnetic permeability and shared by the user overlap, and there is no overlap in the magnetic circuits in the first magnetic column 1 with lower magnetic permeability. That is, it can be ensured that the magnetic force line 1 301 and the magnetic force line 2 302 only overlap in Figure 2There is a common magnetic path in the second second magnetic column 2 arranged from top to bottom, avoiding the existence of a common magnetic path in the two first magnetic columns 1, and there is also no common magnetic path between the magnetic line 1 301 and the magnetic line 3 303; the magnetic line 2 302 and the magnetic line 3 303 only exist in Figure 2 There is a common magnetic path in the third second magnetic column 2 arranged from top to bottom, avoiding the existence of a common magnetic path in the two first magnetic columns 1, so as to effectively ensure that the magnetic line 1 301, the magnetic line 2 302, and the magnetic line 3 303 do not generate mutual inductance with each other, effectively realizing the decoupling of each phase inductance from each other, making the equivalent inductance of each phase equal, and thus more reliably ensuring the normal operation of the power electronic converter.

[0027] By dividing the winding 3 of each phase into two winding structures 31 and winding them on different first magnetic columns 1, the heat of the winding 3 and the magnetic core is more dispersed and the heat dissipation surface is larger, reducing the hottest point temperature of the inductor. On the one hand, it can ensure the normal operation of the converter, and on the other hand, it also reduces the requirements for the heat dissipation device of the inductor. Since the two winding structures 31 of each winding 3 are in a series connection relationship in the circuit and the magnetic lines generated by these two winding structures 31 on the first magnetic column 1 they surround are in the same direction, as Figure 5 shown, the magnetic lines of its two winding structures 31 will be superimposed in the same direction, avoiding the situation where the magnetic paths of the two winding structures 31 of the same phase cancel each other out. Under the condition that the magnetic core scheme is determined, it can ensure the normal operation of the power electronic converter and make the number of turns of the winding 3 smaller.

[0028] As Figure 2 shown, the magnetic line 1 301 is clockwise, the magnetic line 2 302 is counterclockwise, and the magnetic line 3 303 is clockwise. In the present invention, the phase differences of the three-phase power supply are mutually 120°, so that among the three windings 3, the vector directions of the magnetic lines generated by two adjacent windings 3 on the shared second magnetic column 2 are mutually 120°. Specifically, among the three windings 3, the vector direction of the magnetic line 301 generated by the first winding 3 from top to bottom and the magnetic line 2 302 generated by the second winding 3 on the shared second magnetic column 2, and the vector direction of the magnetic line 2 302 generated by the second winding 3 and the magnetic line 3 303 generated by the third winding 3 on the shared second magnetic column 2 are specifically as Figure 3 shown, mutually 120°. Taking the magnetic line 1 301 and the magnetic line 2 302 as an example, the vector sum 304 after the superposition of the magnetic line 1 301 and the magnetic line 2 302 is as Figure 4As shown, the sum of the magnetic field line vectors with a 120° mutual difference after superposition is smaller than that of the magnetic field line vectors with a 60° mutual difference after superposition. The core loss generated after superposition is lower, achieving the effect of further reducing the core temperature. At the same time, under the condition that the core material is determined, the threshold value for the magnetic field lines to reach saturation in the core is fixed. Therefore, compared with the 60° mutual difference method, the 120° mutual difference method makes the shared second magnetic column 2 of the adjacent two-phase windings 3 less likely to saturate.

[0029] An air gap is provided between the first magnetic column 1 and the second magnetic column 2 to meet the corresponding inductance requirements. Preferably, the two first magnetic columns 1 and the four second magnetic columns 2 are adhesively fixed. When adhesively fixing, it is convenient to add an air gap to adjust the parameters according to the actual inductance requirements.

[0030] In the present utility model, the cross-sectional shapes of the first magnetic column 1 and the second magnetic column 2 are any one of a circle, an ellipse, a kidney shape, and a polygon. The cross-sectional shape of the wire of the winding 3 is also any one of a circle, an ellipse, a kidney shape, and a polygon. In specific applications, it can be selected according to the actual design scheme and production requirements. In the present utility model, preferably, the shapes and sizes of the two first magnetic columns 1 are the same, and the shapes and sizes of the four second magnetic columns 2 are the same. Therefore, there are only two categories of magnetic columns applied in a single inductor, which is beneficial to the standardization of materials and production and assembly.

[0031] The first magnetic column 1 is a single-piece integral magnetic column structure, that is, a single first magnetic column 1 is an independent individual, or the first magnetic column 1 is formed by bonding two or more first sub-magnetic columns with the same cross-sectional shape and size. The second magnetic column 2 is a single-piece integral magnetic column structure, that is, a single second magnetic column 2 is an independent individual, or the second magnetic column 2 is formed by bonding two or more second sub-magnetic columns with the same cross-sectional shape and size. The single winding structure 31 in a single winding 3 is an integral winding structure, or the single winding structure 31 is formed by connecting two or more winding sub-structures in series. In specific applications, it can be selected according to the actual design scheme and production requirements.

[0032] The present utility model also provides a power electronic converter provided with the three-phase integrated inductor as described above. Due to the provision of the above three-phase integrated inductor, the decoupling of each phase inductor is realized, the equivalent inductance of each phase is equal, and the hottest point temperature of the inductor is lower, and the operation reliability of the power electronic converter is higher.

[0033] Those of ordinary skill in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; under the concept of this application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments in this application as described above, and for the sake of brevity, they are not provided in detail.

[0034] One or more embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of this application shall be included within the scope of protection of this application.

Claims

1. A three-phase integrated inductor, characterized in that: It includes two first magnetic posts (1), four second magnetic posts (2) and three windings (3). The two first magnetic posts (1) are arranged in parallel. The four second magnetic posts (2) are arranged in parallel at intervals between the two first magnetic posts (1), forming a rectangular frame structure with a hole in the middle. And the magnetic permeability of the first magnetic post (1) is less than that of the second magnetic post (2). The three windings (3) are correspondingly located between two adjacent second magnetic posts (2). Each winding (3) is divided into two winding structures (31), and is correspondingly wound around the two first magnetic posts (1). The two winding structures (31) of each winding (3) are connected in series, and the magnetic force lines formed by the two winding structures (31) on the first magnetic posts (1) they wind around are arranged in the same direction.

2. The three-phase integrated inductor according to claim 1, characterized in that: Among the three windings (3), the vector directions of the magnetic force lines generated by two adjacent windings (3) on the shared second magnetic post (2) are mutually different by 120°.

3. The three-phase integrated inductor according to claim 1 or 2, characterized in that: An air gap is provided between the first magnetic post (1) and the second magnetic post (2).

4. The three-phase integrated inductor according to claim 3, characterized in that: The two first magnetic posts (1) and the four second magnetic posts (2) are bonded and fixed.

5. The three-phase integrated inductor according to claim 4, characterized in that: The cross-sectional shapes of the wires of the first magnetic post (1), the second magnetic post (2) and the winding (3) are any one of a circle, an ellipse, a kidney shape, and a polygon.

6. The three-phase integrated inductor according to claim 4 or 5, characterized in that: The two first magnetic posts (1) have the same shape and size, and the four second magnetic posts (2) have the same shape and size.

7. The three-phase integrated inductor according to claim 6, characterized in that: The first magnetic post (1) is a single-piece integral magnetic post structure, or is formed by bonding two or more first sub-magnetic posts with the same cross-sectional shape and size.

8. The three-phase integrated inductor according to claim 6, characterized in that: The second magnetic post (2) is a single-piece integral magnetic post structure, or is formed by bonding two or more second sub-magnetic posts with the same cross-sectional shape and size.

9. The three-phase integrated inductor according to claim 6, characterized in that: Each winding structure (31) in each winding (3) is an integral winding structure, or is formed by connecting two or more winding sub-structures in series.

10. A power electronic converter, characterized in that: A three-phase integrated inductor as described in any one of claims 1-9 is provided.

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