CN205039034U - Three -phase magnetic metal powder core structure of symmetry effective air gap - Google Patents

Abstract

The utility model discloses a three-phase metal magnetic powder core structure with a symmetrical equivalent air gap, which comprises an upper yoke and a lower yoke which are arranged in balance and have the same shape and size. Between the upper yoke and the lower yoke, a vertical There are three core columns on the upper yoke and the lower yoke, and coils are wound on the core columns. In practical applications, the size and structure of the three core columns are the same. At the three vertices of the triangle, the equivalent air gaps of the three phases of the three-phase metal magnetic powder core structure are equal. The structure of the utility model is ingenious and practical. The three core columns are arranged equidistantly in pairs, so that the equivalent air gap of each phase of the three-phase reactor is equal to ensure that the inductance unbalance of the three-phase reactor is less than 4%. The technical scheme of the utility model can obtain a three-phase magnetic powder core structure, and realizes the manufacture of a low-cost, small-volume miniature and light-weight three-phase reactor by using the magnetic powder core structure.

Description

A Three-phase Metal Magnetic Powder Core Structure with Symmetrical Equivalent Air Gap

technical field

The utility model relates to the field of metal magnetic powder core reactors, in particular to a three-phase metal magnetic powder core structure with symmetrical equivalent air gaps.

Background technique

Metal magnetic powder cores are usually mixed with corresponding magnetic material powder and binder, and made into corresponding shapes through molding, curing and other processes, so as to be suitable for various inductors, especially for EMI/RFI filter inductors, high frequency and low loss requirements inductors etc. Because the material of the metal magnetic powder core is mixed with a large amount of non-magnetic substances, the air gap is distributed in the magnetic core, and the magnetic field energy is distributed and stored in the entire magnetic core, which avoids the strong electromagnetic radiation and high frequency generated by the concentrated air gap. loss.

Since the structure of the metal magnetic powder core determines that its air gap is basically evenly distributed in the core, it has excellent performance when applied to a single-phase inductor structure, but when applied to a three-phase reactor structure, the asymmetrically distributed air gap It seriously affects the balance of the inductance of the three-phase reactor. This is because the core structure of the commonly used three-phase reactor is a three-phase three-column structure. If a metal magnetic powder core is used as the iron core of the three-phase reactor, there are also air gaps evenly distributed in the upper and lower yokes. The structure of the core column shows that the magnetic path length of the two phases A and C (that is, the left and right phases) is greater than that of the B phase (central phase), so that the equivalent air gap of the A and C phases in the metal magnetic powder core is much larger than that of the B phase. The size of the air gap has a great influence on the inductance. The difference in the equivalent air gap of the three phases will cause the unbalance of the inductance of the three-phase reactor to exceed the range, even exceeding 30%. Therefore, at present, the metal magnetic powder core is not used to make a three-phase reactor structure in the industry.

In practical applications, under some special requirements, three-phase metal powder core inductors need to be used. At present, the common practice in the industry is to decompose the three-phase metal powder core inductors into three single-phase inductors, and each single-phase inductor It is made of ring-shaped or square-shaped metal magnetic powder core, and then three single-phase inductors are connected to form a three-phase inductor. This production method decomposes the three-phase inductance into three single-phase inductances, which greatly increases the cost, volume, loss, and production hours of the product, which is not conducive to the miniaturization, low cost, low loss of the product and the energy saving and reduction advocated by the country. consumption concept.

Therefore, the prior art still needs to be improved and developed.

Utility model content

The purpose of this utility model is to provide a three-phase metal magnetic powder core structure with symmetrical equivalent air gap, aiming to make the equivalent air gap of each phase of the three-phase reactor structure equal, so that the metal magnetic powder core can be applied to three-phase In the reactor structure.

The three stems of the traditional three-phase inductor structure are generally arranged in a planar arrangement. When the metal magnetic powder core structure is applied to the three-phase inductor structure, the three stems arranged in a planar arrangement lead to AC two-phase in the three-phase inductor structure. There is a large difference in the equivalent air gap between phase B and phase B, which directly affects the balance of the three-phase inductance, and in severe cases, the unbalance of the three-phase inductance exceeds 30%.

In order to make the three-phase equivalent air gaps of the three-phase inductance structure equal, the utility model proposes the following technical proposal: a three-phase metal magnetic powder core structure with a symmetrical equivalent air gap, including a balanced upper yoke with the same shape and size And the lower yoke, between the upper yoke and the lower yoke, there are three core columns perpendicular to the upper yoke and the lower yoke, and coils are wound on the core columns. In practical applications, the size and structure of the three core columns Consistent, the three core pillars are distributed equidistantly in pairs, respectively arranged at the three vertices of the equilateral triangle, so that the equivalent air gaps of the three phases of the three-phase metal magnetic powder core structure are equal. The upper yoke and the lower yoke are respectively fixedly connected to the upper and lower end faces of the three core posts to form a magnetic flux circuit. In this structure proposed by the utility model, the magnetic circuit lengths of the ABC three-phase three-phase inductance structure are completely equal. Therefore, its three-phase equivalent air gap is basically completely equal, ensuring that the inductance of the three phases is completely equal, improving the stability of the metal magnetic powder core three-phase inductance structure, and making the inductance of the metal magnetic powder core three-phase reactor unbalanced. less than 4%.

Specifically, the stem is one of a cylindrical stem, a rectangular parallelepiped stem or a polygonal stem. In practical applications, the core column is preferably a cylindrical core column. This is because the cylindrical core column structure has a more uniform internal air gap distribution, and the three-phase reactor structure obtained has a higher three-phase equivalent air gap proximity. The balance of the inductance of the three-phase reactor is higher.

However, when the cylindrical stem is used, different sizes of the cylindrical stem need to correspond to different molds, so too many molds are required, which greatly increases the production cost and reduces the convenience and flexibility of production. In specific applications, the core column is preferably a hexagonal core column composed of equilateral triangular parts set by multiple monomers bonded by epoxy glue. Improve the balance of the three phases; at the same time save copper wires and space, reduce production costs and product volume. The hexagonal core column structure proposed by the utility model only needs to produce a plurality of equilateral triangular parts of the same size during specific production, and then assemble to obtain hexagonal core column structures of different sizes. These equilateral triangular parts are assembled to obtain other regular polygonal core column structures, which have strong flexibility and are applicable to products of different sizes.

Furthermore, in order to facilitate the bonding of the bonding surfaces of the metal magnetic powder cores, grooves are provided on the sides of the equilateral triangular parts provided by each monomer. After a plurality of equilateral triangular parts are combined to form a stem, inside the stem Form a circular groove. Before assembly, apply epoxy glue to the grooves on the sides of the equilateral triangular parts and on the sides. When the sides of two adjacent equilateral triangular parts are combined and pressed together, the epoxy glue will be squeezed out On the outside or squeezed into the circular groove in the middle, the equilateral triangular parts set by each monomer are firmly bonded together to improve the reliability of their combination.

The structure of the upper yoke and the lower yoke is introduced below.

The upper yoke and the lower yoke are one of circular, equilateral triangle or Y-shaped. Further, a cavity is provided at the center of the upper yoke and the lower yoke. The arrangement of the cavity is beneficial to saving materials and at the same time is beneficial to improving the smoothness of the magnetic flux circuit. In practical applications, the cavity is a circle or an equilateral triangle. Preferably, the cavity is an equilateral triangle. This arrangement makes the three-phase magnetic flux circuits of the three-phase reactor more clear, ensures that the lengths of the magnetic circuits are completely equal, thereby ensuring that the equivalent air gaps of the three phases are consistent, and further reduces the three-phase flux loop. The unbalance degree of the inductance of the phase reactor.

In a specific application, the shape of the upper yoke and the lower yoke is preferably an equilateral triangle. At this time, the equivalent magnetic circuit length of each phase of the iron core structure is the shortest. Under the same conditions, the shorter the magnetic circuit length, the higher the inductance. At the same time, the equilateral triangular upper and lower yoke structures can be easily combined with the core column to improve the stability of the overall structure while ensuring the smoothness and stability of the magnetic flux circuit. At the same time, since the magnetic flux of each phase flows to the other two phases through both sides of the triangle at the same time, the cross-sectional area of each side of the equilateral triangle of the upper yoke and the lower yoke only needs half of the cross-sectional area of the core column to achieve The same magnetic flux density reduces the cost.

Further, the structure of the upper yoke and the lower yoke of the equilateral triangle is composed of a plurality of single cuboids, and the middle part of the equilateral triangular yoke forms an equilateral triangular cavity. Multiple single cuboids can be combined to form equilateral triangular yoke structures of different sizes according to actual needs, which improves the flexibility and convenience of yoke structure production, reduces the number of molds, and reduces production costs. At the same time, the upper yoke or lower yoke of this structure has three connection end faces, which correspond to the upper and lower end faces or intersecting sides of the three core columns respectively. The three-phase equivalent air gap is closer, and the inductance of the three-phase reactor Quantity balance is better.

Beneficial effects of the utility model: the utility model has an ingenious and practical structure, and the three core columns are arranged equidistantly in pairs, so that the equivalent air gap of each phase of the three-phase reactor is equal, and the inductance of the three-phase reactor is guaranteed to be equal. The balance degree is less than 4%, and a series of optimization schemes are proposed to make the magnetic circuit more optimized, the processing mold universal, the cost lower, and the bonding more reliable. Through the technical scheme of the utility model, a three-phase magnetic powder core structure can be obtained, and a low-cost, small-volume miniature and light-weight three-phase reactor can be manufactured by using the magnetic powder core structure.

Description of drawings

Fig. 1 is a structural schematic diagram of a three-phase metal magnetic powder core structure in which the transverse yoke adopts a disk structure with a symmetrical equivalent air gap.

Fig. 2 is a top view of a three-phase metal magnetic powder core structure with a regular hexagonal core pillar structure.

Fig. 3 is a top view of a three-phase metal magnetic powder core structure with a ring structure used in the cross yoke.

Fig. 4 is a top view of a three-phase metal magnetic powder core structure with a solid equilateral triangle structure for the yoke.

Fig. 5 is a top view of a three-phase metal magnetic powder core structure with an equilateral triangle structure provided with a cavity in the yoke.

Fig. 6 is a top view of the structure of the upgraded composite three-phase metal magnetic powder core in Fig. 5 .

Fig. 7 is a top view of the structure of the upgraded composite three-phase metal magnetic powder core in Fig. 6 .

Figure 8 is a top view of an equilateral triangular member.

FIG. 9 is a top view of a stem composed of equilateral triangular parts in FIG. 8 .

detailed description

In order to make the purpose, technical solution and advantages of the utility model more clear and definite, the utility model will be further described in detail below with reference to the accompanying drawings and examples.

Example 1

This embodiment discloses a three-phase metal magnetic powder core structure with a symmetrical equivalent air gap, as shown in Figure 1, including an upper cross-yoke 110 and a lower cross-yoke 120 that are balanced in shape and size, and the upper cross-yoke Between 110 and the lower cross-yoke 120 , three stems 200 are arranged perpendicular to the upper cross-yoke 110 and the lower cross-yoke 120 (respectively forming phase A, phase B and phase C), and coils 300 are wound on the stems 200 . In practical applications, the size and structure of the three stems 200 are the same, and the three stems 200 are distributed equidistantly in pairs, and are respectively arranged at the three vertices of an equilateral triangle. This arrangement makes the structure of the three-phase metal magnetic powder core The equivalent air gaps of the three phases are equal.

In practical applications, the core column 200 or the upper yoke 110 and the lower yoke 120 can be made by using a single magnetic powder core, or by stacking multiple magnetic powder cores (fixed by epoxy glue). The magnetic powder core is mixed with corresponding magnetic material powder and binder, and molded into a preset shape (such as ring, cylinder, bar, etc.) through molding and solidification. According to the different materials, magnetic powder cores are mainly divided into sendust magnetic powder cores, silicon-iron magnetic powder cores, iron-silicon-nickel magnetic powder cores, high-flux iron-nickel magnetic powder cores, iron-nickel-molybdenum magnetic powder cores, etc.

The upper yoke 110 and the lower yoke 120 are respectively fixedly connected to the upper and lower end surfaces of the three stems 200 to form a magnetic flux circuit. The structure of this embodiment is suitable for different magnetic powder cores, and can make the three-phase inductance structure The magnetic circuit lengths of the three phases of ABC are completely equal, so the equivalent air gaps of the three phases are also basically completely equal, ensuring that the inductance of the three phases is completely equal, and improving the stability of the three-phase inductance structure. The unbalance of the three-phase inductance of the three-phase reactor manufactured by using the three-phase metal magnetic powder core structure of this embodiment is less than 4%.

Example 2

Referring to Fig. 2, this embodiment is basically the same as Embodiment 1, the difference is that the stem 200 of this embodiment is a regular hexagonal stem, and each regular hexagonal stem is composed of 6 equilateral triangular parts set by a single unit 210, this setting structure sets the equilateral triangular parts into a standard part. It does not need to use different molds to produce stem columns of different sizes, but only needs to use equilateral triangular parts for arbitrary assembly, which improves production efficiency. At the same time, the production cost is reduced. The unbalance of the three-phase inductance of the three-phase reactor manufactured by using the three-phase metal magnetic powder core structure of this embodiment is less than 4%.

Example 3

Referring to Fig. 3, this embodiment is basically the same as Embodiment 2, the difference is that a circular cavity 130 is arranged in the middle of the upper yoke 110 and the lower yoke 120 of this embodiment (that is, the upper yoke 110 and the lower yoke 120 Adopting a ring structure), the setting of the cavity 130 is conducive to dissipating the heat of the coil upwards and saving materials, and at the same time is beneficial to improving the smoothness of the magnetic flux circuit. The unbalance of the three-phase inductance of the three-phase reactor manufactured by using the three-phase metal magnetic powder core structure of this embodiment is less than 3%.

Example 4

Referring to Fig. 4, this embodiment is basically the same as Embodiment 2, the difference is that the upper cross-yoke 110 and the lower cross-yoke 120 of this embodiment are arranged in solid equilateral triangles, this arrangement, compared with Embodiment 2 The circular structure in the reactor saves more materials, and at the same time there are fewer redundant blanks, and the air gaps are more concentrated. The three-phase reactor structure obtained has a higher three-phase equivalent air gap proximity. The unbalance of the three-phase inductance of the three-phase reactor manufactured by using the three-phase metal magnetic powder core structure of this embodiment is less than 3%.

Example 5

Referring to Fig. 5, this embodiment is basically the same as Embodiment 4, the difference is that an equilateral triangle cavity 130 is arranged at the center of the upper yoke 110 and the lower yoke 120 of this embodiment, and the upper yoke 110 and the lower yoke The yokes 120 are all composed of three single cuboids 140 arranged in an equilateral triangle (the single cuboids 140 are cuboid metal magnetic powder core structures). Compared with the structure of Example 4, this arrangement saves more materials, and at the same time, the three-phase magnetic flux circuit is more clear, ensuring that the lengths of the three-phase magnetic circuits are completely equal, thereby ensuring that the equivalent air gaps of the three phases are consistent, and further reducing the three-phase flux. The unbalance degree of phase reactor inductance. On the other hand, the distance between any two of the three core columns 200 is the shortest, and the magnetic induction is the best, and the magnetic flux of each phase flows to the other two phases through the adjacent two sides of the triangle at the same time, so the upper yoke 110 and the lower yoke 120 The cross-sectional area of each side of the equilateral triangle only needs half of the cross-sectional area of the stem 200 to achieve the same magnetic flux density and reduce the cost. The unbalance of the three-phase inductance of the three-phase reactor manufactured by using the three-phase metal magnetic powder core structure of this embodiment is less than 2%.

Example 6

Referring to Fig. 6, this embodiment is basically the same as Embodiment 5, the difference is that each side column of the upper yoke 110 and the lower yoke 120 of this embodiment is composed of four single cuboids 140, correspondingly, the core The column 200 is composed of 24 equilateral triangular members 210 arranged in one piece. This setting structure makes the single cuboid 140 form a standard part. For the upper yoke 110 and the lower yoke 120 of different sizes, it only needs to use different cuboids 140 for assembly, which improves production efficiency and reduces production. Cost; In addition, this arrangement structure increases the power capacity of the reactor. The unbalance of the three-phase inductance of the three-phase reactor manufactured by using the three-phase metal magnetic powder core structure of this embodiment is less than 3%.

Example 7

Referring to Fig. 7, this embodiment is basically the same as Embodiment 6, the difference is that each side column of the upper yoke 110 and the lower yoke 120 of this embodiment is composed of 6 single cuboids 140, and the core column 200 It is composed of 30 equilateral triangular parts 210 arranged separately to form a quasi-parallelogram structure, and only 3 equilateral triangular bodies need to be added at the junction of the core column 200 and the upper yoke 110 or the lower yoke 120 to supplement. The unbalance of the three-phase inductance of the three-phase reactor manufactured by using the three-phase metal magnetic powder core structure of this embodiment is less than 3%.

Referring to Fig. 8, grooves 501 are provided on the three sides of the equilateral triangular parts 210 used in the above-mentioned embodiments 2 to 7. After a plurality of equilateral triangular parts 210 are assembled to form a stem, the stem A circular groove 502 (see FIG. 9 ) is formed inside. Before assembly, apply epoxy glue to the grooves on the sides of the equilateral triangular parts and on the sides. When the sides of two adjacent equilateral triangular parts are combined and pressed together, the epoxy glue will be squeezed out On the outside or squeezed into the circular groove in the middle, the equilateral triangular parts set by each monomer are firmly bonded together to improve the reliability of their combination.

It should be understood that the application of the present utility model is not limited to the above examples, and those skilled in the art can improve or change according to the above description, and all these improvements and changes should belong to the protection of the appended claims of the present utility model scope.

Claims (9)

1. A three-phase metal magnetic powder core structure with a symmetrical equivalent air gap, including an upper yoke and a lower yoke that are balanced in shape and size, between the upper yoke and the lower yoke, perpendicular to the upper yoke The yoke and the lower cross yoke are provided with three core columns, and coils are wound on the core columns. At the three vertices of the side triangle, the three-phase equivalent air gaps of the three-phase metal magnetic powder core structure are equal. 2 . The three-phase metal magnetic powder core structure with symmetrical and equivalent air gaps according to claim 1 , wherein the core pillar is one of a cylindrical core pillar, a rectangular parallelepiped core pillar or a polygonal core pillar. 3 . The three-phase metal magnetic powder core structure with symmetrical and equivalent air gaps according to claim 2 , wherein the stem is a hexagonal stem. 4 . 4. The three-phase metal magnetic powder core structure with symmetrical and equivalent air gaps according to claim 3, characterized in that, the core column is composed of a plurality of equilateral triangular parts arranged in a single body. 5. The three-phase metal magnetic powder core structure of symmetrical equivalent air gap according to claim 4, characterized in that grooves are arranged on the three sides of the equilateral triangular part, and a plurality of equilateral triangular parts After being combined to form a stem, a circular groove is formed inside the stem. 6 . The three-phase metal magnetic powder core structure with symmetrical and equivalent air gaps according to claim 1 , wherein the upper yoke and the lower yoke are one of circular, equilateral triangle or Y-shaped. 7 . The symmetrical and equivalent air gap three-phase metal magnetic powder core structure according to claim 6 , wherein a cavity is provided at the center of the upper yoke or the lower yoke. 7 . 8 . The symmetrical and equivalent air gap three-phase metal magnetic powder core structure according to claim 7 , wherein the cavity is a circular cavity or an equilateral triangular cavity. 9. The three-phase metal magnetic powder core structure with symmetrical equivalent air gap according to claim 7, characterized in that, the upper yoke or the lower yoke is an equilateral triangular yoke, and the equilateral triangular yoke The three sides are respectively composed of a plurality of single cuboids, and the middle part of the equilateral triangular yoke forms an equilateral triangular cavity.