Annular multi-winding balanced leakage inductance high-frequency transformer

Abstract

The invention discloses an annular multi-winding balanced leakage inductance high-frequency transformer which comprises an insulating magnetic core, a plurality of transformer windings and a leakage inductance value regulator, the insulating magnetic core is of an annular structure, the transformer windings are wound on the insulating magnetic core at intervals, the leakage inductance value regulator comprises an insulating base and an insulating leakage magnetic sheet, the insulating base is fixedly arranged in the center of the insulating magnetic core, and the insulating leakage magnetic sheet is arranged on the insulating base. The insulation magnetic leakage sheets and the transformer windings are in one-to-one correspondence and are distributed in an annular radiation mode, the ends, close to each other, of the insulation magnetic leakage sheets are arranged in the insulation base, the ends, away from each other, of the insulation magnetic leakage sheets are connected with the inner ring face of the insulation magnetic core and located between the two transformer windings, and the sizes and specifications of the insulation magnetic leakage sheets are the same or different. By controlling the size specification of each magnetic leakage sheet, each magnetic leakage sheet has different leakage inductance values, the leakage inductance values between the transformer windings can be accurately adjusted, the leakage inductance value deviation value between the transformer windings can be adjusted, and the leakage inductance value between the transformer windings can be adjusted.

Description

Technical Field

[0001] The invention relates to the technical field of transformers, and in particular to a toroidal multi-winding balanced leakage inductance high-frequency transformer. Background Art

[0002] With the continuous development of power electronics technology, high-frequency transformers are becoming increasingly important as key components for voltage conversion and electrical isolation in power electronic converters. However, high-frequency transformers currently face many challenges in design and application. On the one hand, due to the lack of regularity in the arrangement of windings, there are differences in coupling between windings, resulting in unbalanced leakage inductance. In practical applications, leakage inductance balance between windings is often required to ensure stable operation and high efficiency of power electronic converters, but the irregularity of winding arrangement makes it difficult to achieve this goal. On the other hand, when multi-winding transformers need to adjust the leakage inductance value between windings, they also face difficulties. The adjustment of leakage inductance value is affected by many factors such as the distance between windings and the structure of external magnetic materials. It is difficult for transformers with traditional structures to adjust the leakage inductance value through the magnetic core of the external structure, because this will not only change the overall structure of the transformer, but also may affect its performance and reliability.

[0003] In addition, existing patents have attempted to add an extra pair of magnetic cores on the outermost side of the transformer to design an integrated leakage inductance. However, this design method has obvious disadvantages. First, it increases the volume of space occupied by the high-frequency transformer, which is difficult to apply in some application scenarios with strict space requirements; second, the addition of the leakage inductance core increases the overall loss of the high-frequency transformer and reduces its efficiency. At the same time, the leakage inductance core will affect the distribution of current in the winding, further increasing the difficulty of estimating the winding loss and bringing new challenges to the design and optimization of the transformer. Summary of the invention

[0004] In view of this, the present invention proposes a toroidal multi-winding balanced leakage inductance high-frequency transformer, aiming to achieve effective regulation of the leakage inductance value between each transformer winding through a built-in leakage inductance value regulator.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] A toroidal multi-winding balanced leakage inductance high-frequency transformer comprises an insulating magnetic core, a transformer winding and a leakage inductance value adjuster, wherein the insulating magnetic core is an annular structure, the transformer winding is a plurality of windings and is wound at intervals on the annular surface of the insulating magnetic core, the leakage inductance value adjuster comprises an insulating base and an insulating leakage magnetic sheet, the insulating base is fixedly arranged at the center of the insulating magnetic core, the insulating leakage magnetic sheets correspond to the transformer windings one by one and are radially distributed in an annular shape, the ends of the insulating leakage magnetic sheets close to each other are spaced from each other and are all arranged in the insulating base, the ends of the insulating leakage magnetic sheets far away from each other are respectively connected to the inner annular surface of the insulating magnetic core and are located between the two transformer windings, and the size specifications of the insulating leakage magnetic sheets are the same or different.

[0007] In order to better implement the above technical solution, optionally, it is characterized in that the insulating magnetic core includes two symmetrically arranged magnetic core half rings and an insulating gasket fixedly clamped between the two end surfaces of the two magnetic core half rings, the two magnetic core half rings and the two insulating gaskets together constitute an annular structure and both are wrapped with an annular insulating shell.

[0008] Optionally, the two magnetic core half rings and the two insulating gaskets are connected by gluing.

[0009] Optionally, the annular insulating shell includes an upper insulating half shell and a lower insulating half shell buckled with the upper insulating half shell.

[0010] Optionally, the insulating magnetic leakage sheet includes a magnetic leakage sheet and a high temperature resistant insulating tape located between two ends of the magnetic leakage sheet and wrapping the magnetic leakage sheet.

[0011] Optionally, the leakage magnetic sheet is made of a metal magnetic powder core, a ferrite core, a silicon steel sheet, or an amorphous nanocrystalline material.

[0012] Optionally, the outer peripheral surface of the insulating base is provided with open grooves for inserting and fixing each insulating magnetic leakage sheet.

[0013] Optionally, a bottom plate is further included, and pins extending downward are respectively provided at both ends of each group of transformer windings, and the bottom plate is provided with pin holes for each pin to pass through.

[0014] Optionally, a tin-through plate is further included, wherein the tin-through plate is glued to the bottom surface of the base plate, and each pin hole is located on the outer side or the inner side of the tin-through plate.

[0015] Optionally, the transformer winding uses a single-wire, multi-strand Litz enameled copper wire, which is then coated with a polyimide PI film or a high-temperature resistant tape, or a multi-strand three-layer insulated wire.

[0016] Beneficial effects of the present invention:

[0017] A toroidal multi-winding balanced leakage inductance high-frequency transformer of the present invention can control the size specifications of each leakage magnetic sheet so that each leakage magnetic sheet has a different leakage inductance value, thereby accurately adjusting the leakage inductance value between each transformer winding, thereby achieving controllable leakage inductance deviation value between each transformer winding of the multi-winding transformer and adjustable leakage inductance value between each transformer winding.

[0018] The invention discloses a toroidal multi-winding balanced leakage inductance high frequency transformer, which adopts radially distributed leakage magnetic sheets, has high space occupancy rate, small volume and high power density. The toroidal multi-winding balanced leakage inductance high frequency transformer can achieve the design requirements of current 10 to 100A and single power up to 20KW. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a three-dimensional schematic diagram of a toroidal multi-winding balanced leakage inductance high-frequency transformer according to an embodiment of the present invention;

[0020] Figure 2 yes Figure 1 A top view of

[0021] Figure 3 yes Figure 1 Bottom view of

[0022] Figure 4 yes Figure 1 Exploded diagram of

[0023] Figure 5 yes Figure 1 A three-dimensional schematic diagram of a leakage inductance value adjuster at one angle;

[0024] Figure 6 yes Figure 1 A three-dimensional schematic diagram of the leakage inductance value regulator from another angle;

[0025] Reference numerals:

[0026] Insulating magnetic core 10, magnetic core half ring 11, insulating gasket 12, upper insulating half shell 131, lower insulating half shell 132, transformer winding 20, pin 21, leakage inductance value adjuster 30, leakage magnetic sheet 31, high temperature resistant insulating tape 32, insulating base 33, opening groove 331, weight-reducing through hole 332, bottom plate 40, pin hole 41, tin-through plate 50. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments, wherein the same components are represented by the same reference numerals.

[0028] See also Figures 1 to 6The embodiment of the present invention discloses a toroidal multi-winding balanced leakage inductance high-frequency transformer, which includes an insulating magnetic core 10, a transformer winding 20 and a leakage inductance value adjuster 30.

[0029] like Figure 1 As shown, the insulating core 10 is an annular structure, and the transformer windings 20 are multiple groups, which are wound on the annular surface of the insulating core 10 at intervals. Specifically, there are five groups of transformer windings 20, and the five groups of transformer windings 20 are equidistantly wound on the annular surface of the insulating core 10, with intervals between adjacent transformer windings 20. The insulating core 10 adopts an annular structure, and each transformer winding 20 adopts the same number of turns, which can effectively control the consistency of the DC resistance value of each transformer winding 20, ensure that the current distribution of each transformer winding 20 is more uniform when the transformer is working, and reduce local overheating and energy loss caused by resistance differences.

[0030] like Figure 1 , Figure 4 as well as Figure 5 As shown, the leakage inductance value adjuster 30 includes an insulating base 33 and an insulating leakage magnetic sheet. The insulating base 33 is fixedly arranged at the center of the insulating magnetic core 10. The insulating leakage magnetic sheets correspond to the transformer windings 20 one by one and are radially distributed in a ring shape. The ends of each insulating leakage magnetic sheet close to each other are spaced apart from each other and are all arranged in the insulating base 33. The ends of each insulating leakage magnetic sheet far away from each other are respectively connected to the inner annular surface of the insulating magnetic core 10 and are located between the two transformer windings 20. The size specifications of each insulating leakage magnetic sheet are the same or different.

[0031] In a toroidal multi-winding balanced leakage inductance high-frequency transformer of the present invention, a leakage inductance value adjuster 30 is arranged at the inner center of the insulating core 10. The insulating leakage magnetic sheet has a low magnetic permeability, which will change the magnetic circuit distribution of the original insulating core 10. A part of the magnetic flux will be guided by the leakage magnetic sheet 31 instead of passing through all the transformer windings 20, thereby increasing the leakage magnetic flux. Since the leakage inductance is proportional to the leakage magnetic flux, the change of the leakage magnetic flux will directly affect the leakage inductance value. At the same time, the leakage magnetic sheet 31 is arranged to add a high magnetic resistance area in the magnetic circuit. The increase in magnetic resistance will lead to a decrease in magnetic flux, especially the change of leakage magnetic flux is more obvious. The change of leakage magnetic flux will cause a corresponding change in leakage inductance value. Therefore, the leakage inductance value adjuster 30 is arranged on the inner side of the insulating core 10. By selecting insulating leakage magnetic sheets of different sizes and specifications, the leakage inductance value between each transformer winding 20 can be adjusted, thereby realizing that the leakage inductance deviation value between each transformer winding 20 of the multi-winding transformer can be controlled and the leakage inductance value between each winding of the multi-winding transformer can be adjusted.

[0032] In an embodiment of the present invention, the transformer winding 20 adopts a single-wire multi-strand combination of Leeds enameled copper wire, which is then wrapped with a polyimide PI film or a high-temperature resistant tape, or a multi-strand three-layer insulated wire. Specifically, each group of transformer windings 20 is wound with one layer, two layers or more layers of 0.1*450 film-wrapped wire. The number of turns of each group of transformer windings 20 is determined according to design requirements (9 turns in the accompanying drawings), and a space for placing the leakage magnetic sheet 31 is formed between adjacent transformer windings 20. Compared with copper foil, the Leeds enameled copper wire has a simple preparation process, free selection of the number of strands, and low high-frequency loss, which can effectively reduce the temperature rise of the high-frequency transformer during operation, reduce the weight of the transformer, and improve the heat dissipation performance and portability of the transformer.

[0033] In an embodiment of the present invention, the insulating magnetic core 10 includes two symmetrically arranged magnetic core half rings 11 and an insulating gasket 12 fixedly clamped between the two end surfaces of the two magnetic core half rings 11. The two magnetic core half rings 11 and the two insulating gaskets 12 together form an annular structure and both are wrapped with an annular insulating shell. Specifically, the magnetic ring is cut according to a certain thickness and along the diameter of the magnetic ring. The magnetic ring is preferably made of annular manganese-zinc ferrite to form two magnetic core half rings 11. The cutting thickness can be determined according to the inductance requirement. If the thickness of the insulating gasket 12 is designed to be 0.1-0.8mm or thicker, the thickness of the magnetic ring cut is greater than the thickness of the insulating gasket 12. The two magnetic core half rings 11 and the two insulating gaskets 12 are connected by gluing. The sum of the thickness of the gluing and the thickness of the insulating gasket 12 is consistent with the cut thickness, so that the two magnetic core half rings 11 and the two insulating gaskets 12 form a circular ring structure. Three layers of high temperature resistant tape are wrapped around the connection of the gasket 12, which can reinforce the connection between the two magnetic core half rings 11 and the two insulating gaskets 12, thereby improving the structural stability and reliability of the insulating magnetic core 10. Then, an annular insulating shell is sleeved on the annular structure formed by the two magnetic core half rings 11 and the two insulating gaskets 12. Specifically, the annular insulating shell includes an upper insulating half shell 131 and a lower insulating half shell 132 buckled with the upper insulating half shell 131. The buckling method can be a common method in the prior art such as upper and lower buckling, elastic covering, etc., so that the magnetic core half ring 11 is insulated and isolated from the transformer winding 20, thereby enhancing the electrical insulation performance of the transformer.

[0034] In an embodiment of the present invention, the insulating leakage magnetic sheet includes a leakage magnetic sheet 31 and a high temperature resistant insulating tape 32 located between the two ends of the leakage magnetic sheet 31 and wrapping the leakage magnetic sheet 31. The material of the leakage magnetic sheet 31 is a metal magnetic powder core or a ferrite magnetic core or a silicon steel sheet or an amorphous nanocrystalline material. The metal magnetic powder core is such as an iron silicon aluminum powder core, an iron silicon powder core, and an iron nickel powder core. The ferrite core 10 is such as a manganese zinc power material, a manganese zinc high magnetic permeability material, and a nickel zinc ferrite material. The leakage magnetic sheets 31 of different materials have different magnetic properties and electrical properties, and can be selected according to specific application requirements, thereby broadening the scope of application of the transformer.

[0035] In an embodiment of the present invention, the size specifications of the leakage magnetic sheet 31 are different, including one or more of the length, width and thickness of the leakage magnetic sheet 31. By adjusting the length, width and thickness of the leakage magnetic sheet 31, the leakage inductance value of a single leakage magnetic sheet 31 can be controlled, and then the leakage inductance value between the transformer windings 20 can be accurately adjusted, thereby improving the performance adjustment accuracy and flexibility of the transformer.

[0036] like Figure 5 and Figure 6 As shown, the outer circumferential surface of the insulating base 33 is provided with open grooves 331 for each insulating leakage magnetic sheet to be inserted and fixed. Specifically, the insulating base 33 is a cylindrical structure, and a weight-reducing through hole 332 is provided in the central axis of the insulating base 33. The weight-reducing through hole 332 is a T-shaped hole that is larger at the bottom and smaller at the top. The weight-reducing through hole 332 can be filled with fixing glue. Five open grooves 331 with open tops and sides are arranged equidistantly along the axial direction of the insulating base 33 and at intervals on the top surface of the insulating base 33. Each insulating gasket 12 is inserted in the corresponding open groove 331, so that the five insulating leakage magnetic sheets are all inserted and fixed on the insulating base 33. The provision of the insulating base 33 can effectively control the relative positions of the five insulating leakage magnetic sheets, thereby improving the accuracy and stability of the leakage inductance value adjustment.

[0037] In an embodiment of the present invention, a bottom plate 40 and a tin-through plate 50 are further included. Both ends of each group of transformer windings 20 are respectively provided with pins 21 extending downward. The bottom plate 40 is an epoxy bottom plate or an open injection mold bottom plate. The bottom plate 40 is provided with pin holes 41 for each pin 21 to pass through. The pin holes 41 can accurately locate the size of each pin 21 to facilitate direct assembly of the transformer onto the PCB board. The tin-through plate 50 is glued to the bottom surface of the bottom plate 40, and each pin hole 41 is located on the outer side or the inner side of the tin-through plate 50, so that the pins 21 and the tin-through plate 50 do not contact each other, thereby ensuring the reliability and safety of the electrical connection.

[0038] The assembly method of a toroidal multi-winding balanced leakage inductance high-frequency transformer of the present invention is as follows:

[0039] S10. Cut the magnetic ring along a diameter of the magnetic ring and at a certain thickness. The thickness of the cut magnetic ring is greater than the thickness of the insulating gasket 12. Then, glue the insulating gasket 12 to the cut surface of the magnetic core half ring 11, so that the two magnetic core half rings 11 and the two insulating gaskets 12 form a ring structure. Then, wrap three layers of tape around the connection between the magnetic core half ring 11 and the insulating gasket 12 for reinforcement. Then, put an annular insulating shell on the ring structure formed by the two magnetic core half rings 11 and the two insulating gaskets 12.

[0040] S20, evenly winding five sets of transformer windings 20 in the circumferential direction of the insulating magnetic core 10, and connecting the ends of the transformer windings 20 to the pins 21 by soldering;

[0041] S30, fixing and inserting the magnetic leakage sheet 31 on the insulating base 33;

[0042] S40 , gluing the tin-transmissive plate 50 to the bottom surface of the bottom plate 40 , fixing the insulating base 33 to the top surface of the bottom plate 40 by gluing, and gluing the magnetic leakage sheet 31 to the insulating magnetic core 10 .

[0043] S50, fix all components with glue and conduct testing.

[0044] The present invention provides a toroidal multi-winding balanced leakage inductance high-frequency transformer, which controls the size specifications of each leakage magnetic sheet 31 so that each leakage magnetic sheet 31 has a different leakage inductance value, thereby accurately adjusting the leakage inductance value between each transformer winding 20, and realizing that the leakage inductance deviation value between each transformer winding 20 of the multi-winding transformer can be controlled and the leakage inductance value between each winding of the multi-winding transformer can be adjusted. The radially distributed leakage magnetic sheet 31 has high space utilization, small volume, and high power density. The toroidal multi-winding balanced leakage inductance high-frequency transformer can achieve the design requirements of current 10 to 100A and single power up to 20KW, and is suitable for a variety of high-power and high-precision power electronic application scenarios.

[0045] The technical solution of the present invention is described in detail above in conjunction with specific embodiments, and the described specific embodiments are used to help understand the concept of the present invention. Derivations and modifications made by those skilled in the art based on the specific embodiments of the present invention also fall within the protection scope of the present invention.

Claims

1. A toroidal multi-winding balanced leakage inductance high-frequency transformer, characterized in that: It comprises an insulating magnetic core (10), a transformer winding (20) and a leakage inductance value regulator (30); The insulating magnetic core (10) has a ring-shaped structure; The transformer windings (20) are multiple and are wound at intervals on the annular surface of the insulating magnetic core (10); The leakage inductance value adjuster (30) comprises an insulating base (33) and an insulating leakage magnetic sheet. The insulating base (33) is fixedly arranged at the center of the insulating magnetic core (10). The insulating leakage magnetic sheets correspond to the transformer windings (20) one by one and are radially distributed in a ring shape. The ends of the insulating leakage magnetic sheets close to each other are spaced apart from each other and are all arranged in the insulating base (33). The ends of the insulating leakage magnetic sheets far away from each other are respectively connected to the inner annular surface of the insulating magnetic core (10) and are located between the two transformer windings (20). The size specifications of the insulating leakage magnetic sheets are the same or different.

2. The toroidal multi-winding balanced leakage inductance high-frequency transformer according to claim 1, characterized in that: The insulating magnetic core (10) comprises two symmetrically arranged magnetic core half rings (11) and an insulating gasket (12) fixedly clamped between the two end surfaces of the two magnetic core half rings (11); the two magnetic core half rings (11) and the two insulating gaskets (12) together form an annular structure and are both wrapped with an annular insulating shell.

3. The toroidal multi-winding balanced leakage inductance high-frequency transformer according to claim 2, characterized in that: The two magnetic core half rings (11) and the two insulating gaskets (12) are connected by gluing.

4. The toroidal multi-winding balanced leakage inductance high frequency transformer according to claim 3, characterized in that: The annular insulating shell comprises an upper insulating half shell (131) and a lower insulating half shell (132) buckled with the upper insulating half shell (131).

5. The toroidal multi-winding balanced leakage inductance high frequency transformer according to claim 1, characterized in that: The insulating magnetic leakage sheet comprises a magnetic leakage sheet (31) and a high temperature resistant insulating adhesive tape (32) located between two ends of the magnetic leakage sheet (31) and wrapping the magnetic leakage sheet (31).

6. The toroidal multi-winding balanced leakage inductance high frequency transformer according to claim 5, characterized in that: The material of the magnetic leakage sheet (31) is a metal magnetic powder core, a ferrite magnetic core, a silicon steel sheet, or an amorphous nanocrystalline material.

7. The toroidal multi-winding balanced leakage inductance high frequency transformer according to claim 1, characterized in that: The outer peripheral surface of the insulating base (33) is provided with open grooves (331) at intervals for inserting and fixing the insulating magnetic leakage sheets.

8. The toroidal multi-winding balanced leakage inductance high frequency transformer according to claim 1, characterized in that: It also comprises a bottom plate (40), and pins (21) extending downwards are respectively provided at both ends of each group of transformer windings (20), and the bottom plate (40) is provided with pin holes (41) for each pin (21) to pass through.

9. The toroidal multi-winding balanced leakage inductance high frequency transformer according to claim 8, characterized in that: It also comprises a tin-penetrating plate (50), wherein the tin-penetrating plate (50) is glued to the bottom surface of the bottom plate (40), and each pin hole (41) is located on the outside or inside of the tin-penetrating plate (50).

10. The toroidal multi-winding balanced leakage inductance high frequency transformer according to claim 1, characterized in that: Each transformer winding (20) is made of a single-wire, multi-strand Litz enameled copper wire, which is then coated with a polyimide PI film or a high-temperature resistant tape, or a multi-strand three-layer insulated wire.

Images