Annular transformer capable of adjusting leakage inductance

Abstract

The utility model discloses an annular transformer capable of adjusting leakage inductance. The annular transformer comprises an annular iron core, a primary coil, a secondary coil, an upper rubber mat and a lower rubber mat, the upper rubber mat, the annular iron core and the lower rubber mat jointly define a filling cavity for filling epoxy resin; the secondary coil comprises a plurality of wires, and each wire comprises a winding area, an extension area and a wire tail area which are integrally formed; the winding area surrounds the annular iron core, the extension area is located at the bottom of the annular iron core, and the winding area and the extension area are matched together and cover the bottom of the primary coil; and the end part of the winding area and the end part of the wire tail area are close to each other. According to the annular transformer capable of adjusting the leakage inductance, the leakage inductance can be adjusted according to actual needs, and high flexibility is achieved; and on the premise that the using amount of insulating materials is reduced and the installation and operation efficiency is improved, the outer diameter size of the transformer is not influenced, the actual use requirement is met, and the defects in the prior art are overcome.

Description

Technical Field

[0001] The utility model relates to the technical field of transformers, in particular to a toroidal transformer with adjustable leakage inductance. Background Art

[0002] Transformers are commonly used components in circuits, which can realize functions such as voltage conversion, impedance conversion, isolation and voltage stabilization. Toroidal transformers are a type of transformers. They use a toroidal core, and the entire core is seamlessly rolled, which gives them good output characteristics and anti-interference capabilities. They are widely used in computers, medical equipment, telecommunications, instruments, lighting and other fields.

[0003] The toroidal transformer is mainly composed of an iron core, a primary coil and a secondary coil. The existing toroidal transformer is generally a toroidal transformer without leakage inductance, so the secondary coil of the toroidal transformer is usually a full turn. However, in some special application fields, such as solar inverters, the secondary coil of the toroidal transformer is required to be a non-integer turn to meet its leakage inductance requirements.

[0004] Since the secondary coil is wound in a non-full circle, during the winding process of the existing leakage inductance toroidal transformer, when the wire tail area of ​​the secondary coil is at a certain distance from the wire head area of ​​the secondary coil, it extends from the side of the transformer to the wire head area of ​​the secondary coil, and then the internal potting epoxy resin of the toroidal core is filled to achieve the purpose of fixing the transformer, effectively reducing the vibration of the coil during its operation, thereby reducing noise and shock. However, since the wire tail area of ​​the secondary coil extends from the side of the transformer to the wire head area of ​​the secondary coil, a large gap exists at the bottom of the toroidal transformer. Before potting the epoxy resin, a large amount of insulating material needs to be used to fill the unwound part of the bottom of the toroidal transformer to prevent the epoxy resin from leaking to the bottom of the transformer during the filling of the epoxy resin. The filling of a large amount of insulating material not only leads to a waste of raw materials, but also seriously affects the installation and operation efficiency. In addition, since the wire tail area of ​​the secondary coil extends from the side of the transformer to the wire head area of ​​the secondary coil, the outer diameter of the transformer becomes larger, which is not conducive to the subsequent installation and application of the transformer. Utility Model Content

[0005] The purpose of the utility model is to provide a toroidal transformer with adjustable leakage inductance, which can not only adjust the size of the leakage inductance according to actual needs and has high flexibility; it can also reduce the use of insulating materials and improve installation and operating efficiency without affecting the outer diameter of the transformer, thereby meeting actual use needs and overcoming the shortcomings of the prior art.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] A toroidal transformer with adjustable leakage inductance comprises an annular iron core, a primary coil, a secondary coil, an upper rubber pad and a lower rubber pad; the annular iron core is a hollow structure, the primary coil is wound around the annular iron core, and the secondary coil is wound around the outside of the primary coil;

[0008] The upper rubber pad is arranged on the inner upper part of the annular iron core, and the edge of the upper rubber pad abuts against the secondary coil; the lower rubber pad is arranged on the bottom of the secondary coil, and the lower rubber pad abuts against the secondary coil; the upper rubber pad, the annular iron core and the lower rubber pad together form a filling cavity for filling epoxy resin;

[0009] The secondary coil includes a plurality of conductive wires, and the conductive wires include an integrally formed winding area, an extension area, and a wire tail area; the winding area surrounds the annular core, the extension area is located at the bottom of the annular core, and the winding area and the extension area cooperate with and cover the bottom of the primary coil;

[0010] An end of the winding area and an end of the wire tail area are close to each other.

[0011] Furthermore, the winding area includes a wire head section and a surrounding section which are connected in sequence, an end of the wire head section and an end of the wire tail section are close to each other, and the surrounding section is connected to the extension area.

[0012] Further, the wire end section includes a bonding branch section and a wire end branch section connected in sequence, the bonding branch section is connected to the surrounding section, and the bonding branch section is located at the upper part of the outer side wall of the annular core; the wire end branch section and the bonding branch section are perpendicular to each other;

[0013] The wire tail area includes a fitting section and a wire tail section connected in sequence, the fitting section is connected to the extension area, and the fitting section is located at the lower part of the outer side wall of the annular iron core; the wire tail section and the fitting section are perpendicular to each other, and the end of the wire tail section is close to the wire head branch section.

[0014] Furthermore, the outer side of the extension area of ​​the wire closest to the hollow structure among the plurality of wires is located on the same vertical line as the outer side wall of the primary coil.

[0015] Furthermore, the winding area covers 60-70% of the outer side wall area of ​​the annular core.

[0016] Furthermore, at least four wires are provided.

[0017] Furthermore, it also includes a bolt and a nut, the end of the bolt passes through the lower rubber pad, the hollow structure and the upper rubber pad in sequence from bottom to top, and the end of the bolt protrudes from the top of the upper rubber pad, and the nut is threadedly connected to the end of the bolt.

[0018] Furthermore, it also includes a first air permeable layer and a second air permeable layer, wherein the first air permeable layer is arranged between the annular core and the primary coil;

[0019] The second air permeable layer is disposed between the primary coil and the secondary coil.

[0020] Furthermore, it also includes a first insulating layer and a second insulating layer, wherein the first insulating layer is arranged between the annular core and the first air permeable layer;

[0021] The second insulating layer is disposed between the primary coil and the second air-permeable layer.

[0022] The technical solution provided by the embodiments of the present application may have the following beneficial effects:

[0023] 1. The upper rubber pad, the annular core and the lower rubber pad together form a filling cavity for filling epoxy resin. By filling the inside of the transformer with epoxy resin, the coil vibration during its operation is effectively reduced, thereby reducing noise and preventing shock. At the same time, epoxy resin has good dielectric properties and thermal conductivity, which is beneficial to improving the thermal conductivity and heat dissipation performance of the transformer.

[0024] 2. The conductor includes an integrally formed winding area, an extension area and a wire tail area, and the winding area surrounds the annular core; the extension area is located at the bottom of the annular core, and the winding area and the extension area cooperate to completely cover the bottom of the primary coil, so that the leakage inductance can be adjusted according to actual needs, with high flexibility. In addition, compared with the existing secondary coil whose wire tail area extends from the side of the transformer to the winding area of ​​the secondary coil, resulting in a large gap at the bottom of the annular transformer, and a large amount of insulating material is required to fill the unwound area at the bottom of the annular transformer before encapsulating the epoxy resin, the winding method of the secondary coil 3 of the technical solution greatly reduces the required insulating material, thereby improving installation and operation efficiency. At the same time, because the winding area and the extension area cooperate and cover the bottom of the primary coil, the outer diameter of the transformer is not affected, which is conducive to the subsequent installation and application of the transformer. In addition, the ends of the tail area and the end of the tail area are close to each other, which is conducive to the secondary coil to be connected at the end. The secondary coil can not only reduce the voltage of the transformer to the required range, but also play the role of mutual compensation of the secondary coil 3, effectively solving the problem of grid voltage fluctuation and improving the stability of the grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The utility model is a cross-sectional view of a toroidal transformer with adjustable leakage inductance.

[0026] Figure 2The utility model is a partial structural diagram of a toroidal transformer with adjustable leakage inductance.

[0027] Figure 3 It is a cross-sectional view of a partial structural diagram of a toroidal transformer with adjustable leakage inductance according to the utility model.

[0028] Figure 4 It is another cross-sectional view of a partial structural diagram of a toroidal transformer with adjustable leakage inductance according to the utility model.

[0029] Among them: annular iron core 1, primary coil 2, secondary coil 3, winding area 31, wire end section 311, fitting branch section 3111, wire end branch section 3112, surrounding section 312, extension area 32, wire tail area 33, fitting section 331, wire tail section 332, upper rubber pad 4, lower rubber pad 5, bolt 6 and nut 7. DETAILED DESCRIPTION

[0030] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0031] The technical solution provides a toroidal transformer with adjustable leakage inductance, comprising a toroidal core 1, a primary coil 2, a secondary coil 3, an upper rubber pad 4 and a lower rubber pad 5; the toroidal core 1 is a hollow structure, the primary coil 2 is wound on the toroidal core 1, and the secondary coil 3 is wound outside the primary coil 2;

[0032] The upper rubber pad 4 is arranged at the inner upper part of the annular core 1, and the edge of the upper rubber pad 4 abuts against the secondary coil 3; the lower rubber pad 5 is arranged at the bottom of the secondary coil 3, and the lower rubber pad 5 abuts against the secondary coil 3; the upper rubber pad 4, the annular core 1 and the lower rubber pad 5 together form a filling cavity for filling epoxy resin;

[0033] The secondary coil 3 includes a plurality of conductive wires, and the conductive wires include an integrally formed winding area 31, an extension area 32, and a wire tail area 33; the winding area 31 surrounds the annular core 1, the extension area 32 is located at the bottom of the annular core 1, and the winding area 31 and the extension area 32 cooperate with and cover the bottom of the primary coil 2;

[0034] The end of the winding area 31 and the end of the wire tail area 33 are close to each other.

[0035] In order to overcome the technical defects of the prior art that a large amount of insulating materials are needed for filling, which not only leads to the waste of raw materials, but also seriously affects the installation and operation efficiency. At the same time, since the wire tail area of ​​the secondary coil extends from the side of the transformer to the wire head area of ​​the secondary coil, the outer diameter of the transformer becomes larger, and the subsequent installation and application of the transformer are not utilized, the technical solution proposes a toroidal transformer with adjustable leakage inductance, such as Figures 1 to 4 As shown, it includes an annular iron core 1, a primary coil 2 and a secondary coil 3, an upper rubber pad 4 and a lower rubber pad 5. The annular iron core 1 is a hollow structure, and the primary coil 2 is wound on the annular iron core 1; the secondary coil 3 is wound on the outside of the primary coil 2. When the primary coil 2 is energized, a magnetic field will be formed on the annular iron core 1, and the magnetic field will cause an electromotive force to be generated in the secondary coil 3, thereby realizing voltage conversion.

[0036] Furthermore, the upper rubber pad 4 is arranged at the inner upper part of the annular core 1, and the edge of the upper rubber pad 4 is against the secondary coil 3; the lower rubber pad 5 is arranged at the bottom of the secondary coil 3, and the lower rubber pad 5 is against the secondary coil 3; the upper rubber pad 4, the annular core 1 and the lower rubber pad 5 together form a filling cavity for filling epoxy resin. By filling the interior of the transformer with epoxy resin, the coil vibration during its operation is effectively reduced, thereby reducing noise and preventing shock; at the same time, the epoxy resin has good dielectric properties and thermal conductivity, which is beneficial to improving the thermal conductivity and heat dissipation performance of the transformer.

[0037] Furthermore, the secondary coil 3 includes a plurality of conductors, and the conductors include an integrally formed winding area 31, an extension area 32, and a wire tail area 33. The winding area 31 surrounds the annular core 1; the extension area 32 is located at the bottom of the annular core 1, and the winding area 31 and the extension area 32 cooperate to completely cover the bottom of the primary coil 2, so that the leakage inductance can be adjusted according to actual needs, with high flexibility. In addition, compared with the existing secondary coil 3, the wire tail area 33 extends from the side of the transformer to the winding area 31 of the secondary coil, resulting in a large gap at the bottom of the annular transformer, and a large amount of insulating material is required to fill the unwound part of the bottom of the annular transformer before the epoxy resin is poured, the winding method of the secondary coil 3 of the technical solution greatly reduces the insulating material required, thereby improving the installation and operation efficiency. At the same time, because the winding area 31 and the extension area 32 cooperate and cover the bottom of the primary coil 2, the outer diameter of the transformer is not affected, which is conducive to the subsequent installation and application of the transformer. In addition, the ends of the wire tail area 33 and the ends of the wire tail area 33 are close to each other, which is conducive to the secondary coil 3 to achieve the tail connection. The secondary coil 3 can not only reduce the voltage of the transformer to a required range, but also play a role in the tail compensation of the secondary coil 3, effectively solving the problem of grid voltage fluctuations and improving the stability of the grid.

[0038] It should be noted that the structure of the primary coil 2 is a common structure of the primary coil 2 of a toroidal transformer in the prior art, and will not be described in detail here.

[0039] To further explain, the winding area 31 includes a wire head segment 311 and a surrounding segment 312 which are connected in sequence, an end of the wire head segment 311 and an end of the wire tail area 33 are close to each other, and the surrounding segment 312 is connected to the extension area 32 .

[0040] In a preferred embodiment of the present technical solution, by providing the wire end section 311 and the surrounding section 312, the winding area of ​​the surrounding section 312 can be adjusted according to actual needs, thereby adjusting the size of the leakage inductance and improving the flexibility of the device.

[0041] Further, the wire end section 311 includes a bonding branch section 3111 and a wire end branch section 3112 which are connected in sequence, the bonding branch section 3111 is connected to the surrounding section 312, and the bonding branch section 3111 is located at the upper part of the outer side wall of the annular core 1; the wire end branch section 3112 and the bonding branch section 3111 are perpendicular to each other;

[0042] The wire tail area 33 includes a fitting section 331 and a wire tail section 332 which are connected in sequence, the fitting section 331 is connected to the extension area 32, and the fitting section 331 is located at the lower part of the outer wall of the annular core 1; the wire tail section 332 is perpendicular to the fitting section 331, and the end of the wire tail section 332 is close to the wire head branch section 3112.

[0043] In a preferred embodiment of the present technical solution, the bonding branch segment 3111 is located at the upper part of the outer wall of the annular core 1, and the bonding segment 331 is located at the lower part of the outer wall of the annular core 1. The bonding branch segment 3111 and the bonding segment 331 are used to basically wrap the outer wall of the primary coil 22, thereby improving the voltage stability of the transformer; at the same time, the end of the tail segment 332 and the end of the head segment 3112 are close to each other, which is more conducive to the voltage dropping to the required range, meeting the voltage requirements of different loads, and improving the stability of the power grid.

[0044] To further illustrate, the outer side of the extension area 32 of the wire closest to the hollow structure among the plurality of wires is located on the same vertical line as the outer side wall of the primary coil 2 .

[0045] In a preferred embodiment of the present technical solution, the outer side of the extension area 32 of the wire closest to the hollow structure is located on the same vertical line as the outer side wall of the primary coil 2. Figure 4 As shown, there is no gap between the bottom of the transformer and the hollow structure of the annular core 1, and there is no need to fill the gap with insulating material before pouring the epoxy resin, thus saving raw materials.

[0046] To further explain, the winding area 31 covers 60-70% of the outer wall area of ​​the annular core 1 .

[0047] In a preferred embodiment of the present technical solution, by limiting the outer wall area of ​​the winding area 31 covering the annular core 1, the leakage inductance of the annular transformer is made 40 to 70 microhenries, which better meets the actual application requirements.

[0048] It is further specified that at least four wires are provided.

[0049] In a preferred embodiment of the present technical solution, by limiting the number of wires, it is avoided that when the number of wires is too small, more insulating material needs to be used for filling before epoxy resin encapsulation, which causes an increase in cost.

[0050] Further description, it also includes a bolt 6 and a nut 7, the end of the bolt 6 passes through the lower rubber pad 5, the hollow structure and the upper rubber pad 4 from bottom to top, and the end of the bolt 6 protrudes from the top of the upper rubber pad 4, and the nut 7 is threadedly connected to the end of the bolt 6.

[0051] In a preferred embodiment of the present technical solution, the upper rubber pad 4 and the lower rubber pad 5 are further fixed by arranging bolts 6 and nuts 7 to improve the stability of the transformer.

[0052] Further, it further comprises a first air permeable layer and a second air permeable layer, wherein the first air permeable layer is arranged between the annular core 1 and the primary coil 2;

[0053] The second air permeable layer is disposed between the primary coil 2 and the secondary coil 3 .

[0054] In a preferred embodiment of the present technical solution, by providing a first breathable layer (not shown in the figure) and a second breathable layer (not shown in the figure), it is beneficial to improve the heat dissipation effect of the transformer. At the same time, the first breathable layer can be used to protect the primary coil 2 and the second breathable layer can be used to protect the secondary coil 3, thereby avoiding scratches on the surfaces of the primary coil 2 and the secondary coil 3 during the winding process.

[0055] Preferably, the first air permeable layer and the second air permeable layer are both made of non-woven fabrics.

[0056] Further, it further comprises a first insulating layer and a second insulating layer, wherein the first insulating layer is arranged between the annular core 1 and the first air permeable layer;

[0057] The second insulating layer is disposed between the primary coil 2 and the second air-permeable layer.

[0058] The installation and operation of the internal components of the transformer are usually in a relatively harsh environment such as high temperature and high humidity. Therefore, in a preferred embodiment of the present technical solution, by providing a first insulating layer (not shown in the figure) and a second insulating layer (not shown in the figure), the support and protection of the first insulating layer and the second insulating layer are used to increase the firmness and durability of the structure, which is beneficial for its use in harsh environments; at the same time, the first insulating layer and the second insulating layer can also improve the insulation and high voltage resistance of the transformer, thereby increasing the service life of the transformer.

[0059] Preferably, the first insulating layer and the second insulating layer are both made of polyester film.

[0060] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0061] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps described in these embodiments do not limit the scope of the utility model. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0062] In the description of the present utility model, it needs to be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present utility model; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0063] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0064] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the utility model.

[0065] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0066] The technical principle of the present invention is described above in combination with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the protection scope of the present invention in any way. Based on the explanations here, technicians in this field can think of other specific implementation methods of the present invention without creative work, and these methods will fall within the protection scope of the present invention.

Claims

1. A toroidal transformer with adjustable leakage inductance, characterized in that: It includes an annular iron core, a primary coil, a secondary coil, an upper rubber pad and a lower rubber pad; the annular iron core is a hollow structure, the primary coil is wound on the annular iron core, and the secondary coil is wound outside the primary coil; The upper rubber pad is arranged on the inner upper part of the annular iron core, and the edge of the upper rubber pad abuts against the secondary coil; the lower rubber pad is arranged on the bottom of the secondary coil, and the lower rubber pad abuts against the secondary coil; the upper rubber pad, the annular iron core and the lower rubber pad together form a filling cavity for filling epoxy resin; The secondary coil includes a plurality of conductive wires, and the conductive wires include an integrally formed winding area, an extension area, and a wire tail area; the winding area surrounds the annular core, the extension area is located at the bottom of the annular core, and the winding area and the extension area cooperate with and cover the bottom of the primary coil; An end of the winding area and an end of the wire tail area are close to each other.

2. The toroidal transformer with adjustable leakage inductance according to claim 1, characterized in that: The winding area includes a wire head section and a surrounding section which are connected in sequence, an end of the wire head section and an end of the wire tail area are close to each other, and the surrounding section is connected to the extension area.

3. The toroidal transformer with adjustable leakage inductance according to claim 2, characterized in that: The wire end section includes a bonding branch section and a wire end branch section which are connected in sequence, the bonding branch section is connected to the surrounding section, and the bonding branch section is located at the upper part of the outer side wall of the annular core; the wire end branch section and the bonding branch section are perpendicular to each other; The wire tail area includes a fitting section and a wire tail section connected in sequence, the fitting section is connected to the extension area, and the fitting section is located at the lower part of the outer side wall of the annular iron core; the wire tail section and the fitting section are perpendicular to each other, and the end of the wire tail section is close to the wire head branch section.

4. The toroidal transformer with adjustable leakage inductance according to claim 3, characterized in that: The outer side of the extension area of ​​the wire closest to the hollow structure among the plurality of wires is located on the same vertical line as the outer side wall of the primary coil.

5. The toroidal transformer with adjustable leakage inductance according to claim 1, characterized in that: The winding area covers 60-70% of the outer side wall area of ​​the annular core.

6. The toroidal transformer with adjustable leakage inductance according to claim 1, characterized in that: At least four wires are provided.

7. The toroidal transformer with adjustable leakage inductance according to claim 1, characterized in that: It also includes a bolt and a nut, the end of the bolt passes through the lower rubber pad, the hollow structure and the upper rubber pad in sequence from bottom to top, and the end of the bolt protrudes from the top of the upper rubber pad, and the nut is threadedly connected to the end of the bolt.

8. The toroidal transformer with adjustable leakage inductance according to claim 1, characterized in that: It also includes a first air permeable layer and a second air permeable layer, wherein the first air permeable layer is arranged between the annular core and the primary coil; The second air permeable layer is disposed between the primary coil and the secondary coil.

9. The toroidal transformer with adjustable leakage inductance according to claim 8, characterized in that: It also includes a first insulating layer and a second insulating layer, wherein the first insulating layer is disposed between the annular core and the first air permeable layer; The second insulating layer is disposed between the primary coil and the second air-permeable layer.

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