Transformer composed of a hybrid material transformer frame with high pressure resistance and heat dissipation

Abstract

A transformer is disclosed, comprising a magnetic core (7), a low-voltage side frame (3), a low-voltage side coil winding (4), a high-voltage side frame (1), a high-voltage side coil winding (2), and an outer sleeve (5) arranged from inside to outside, the high-voltage side winding (2) is wound on the outer wall of the sleeve of the high-voltage side frame (1), the low-voltage side winding (4) is wound on the outer wall of the sleeve of the low-voltage side frame (3), a bottom cover is arranged at both ends of the low-voltage side frame, the high-voltage side frame, and the outer sleeve, and the gaps between the low-voltage side frame and the high-voltage side frame, the gaps between the high-voltage side frame and the outer sleeve, and the gaps between the bottom cover and the low-voltage side frame, the high-voltage side frame, and the outer sleeve are all filled with high thermal conductivity insulating glue. Part of the heat generated by the coil winding is conducted to the chassis through the low-voltage side frame and the high-voltage side frame for heat dissipation, and the other part is transferred to the outer sleeve through the high thermal conductivity insulating glue for heat dissipation.

Description

Technical Field

[0001] The invention relates to the field of high-power magnetic element design, and in particular to a transformer composed of a mixed material transformer skeleton with high pressure resistance and high heat dissipation. Background Art

[0002] With the rapid development of power electronics technology, the application of high-power isolated switching power supplies is becoming more and more extensive. As the core component of isolated high-power switching power supplies, transformers not only play the role of electrical isolation, but also realize important functions such as voltage level conversion and energy transmission. Therefore, the performance of the transformer will directly affect the reliable and stable operation of the isolated switching power supply. In addition to reasonable design, the performance of the transformer also depends on its thermal stability and insulation characteristics.

[0003] First of all, the main factors affecting the thermal stability of the transformer are core loss and winding loss. Core loss is the power loss caused by the alternating or pulsating magnetic field of the core, which exists in the form of heat; while winding loss refers to the power loss caused by the parasitic ohmic resistance of the coil winding, which also exists in the form of heat. And the higher the operating frequency of the transformer, the greater the core loss and winding loss, and the heat generated by the transformer cannot be discharged. The heat continues to accumulate and the temperature gradually rises, which will affect the thermal stability of the transformer and cause the transformer to be damaged and the power electronic device to collapse. Secondly, when the voltage level of the transformer is high, the transformer is often damaged due to high-voltage breakdown. There are two main reasons for the high-voltage breakdown. One is the air breakdown caused by insufficient creepage distance; the other is the breakdown caused by insufficient voltage resistance of the transformer skeleton material. No matter which kind of breakdown, it will damage the transformer and cause the system to collapse.

[0004] Therefore, the thermal stability and insulation characteristics of the transformer have become the key to restricting the development of high-power power electronics. At present, the coil skeleton materials on the market are generally plastic (bakelite) or plastic (nylon). These materials can only ensure the electrical insulation between the coil and the skeleton or the coil and the copper sheet. The skeleton itself cannot conduct heat, which causes the heat to accumulate continuously, the temperature to rise, and the transformer is damaged and the system crashes. In addition, in high-voltage applications, traditional skeletons often cause breakdown due to insufficient insulation withstand voltage, thereby damaging power electronic devices. Therefore, there is an urgent need for a transformer skeleton with both good heat dissipation and insulation capabilities to enhance the thermal stability and device reliability of power electronic devices. In order to solve this problem, the present invention proposes a hybrid material transformer skeleton with high pressure resistance and strong heat dissipation. Summary of the invention

[0005] The present invention proposes a hybrid material transformer skeleton with high pressure resistance and heat dissipation, which adopts a new type of thermal conductive alumina ceramic material combined with 3D printed nylon material. The alumina ceramic material has a very high thermal conductivity coefficient and better thermal conductivity than nylon material; it has good heat resistance and can withstand extreme heat of 2000℃; its insulation performance is much higher than that of ordinary insulating plastics and plastics; its thermal expansion coefficient and dielectric constant are both low; its material has high mechanical strength and can still work under harsh conditions, which is very suitable for insulating and thermally conductive materials. Therefore, the low-voltage side skeleton adopts 3D printed nylon material, which is convenient for designing the optimal shape, and the alumina ceramic material is made into the high-voltage side skeleton of the transformer, and the heat generated by the transformer coil winding is conducted to the outside through the skeleton for heat dissipation, which helps the transformer to dissipate heat and cool down, improve its thermal stability, and reduce costs at the same time.

[0006] According to one aspect of an embodiment of the present invention, there is provided a transformer, comprising:

[0007] A low-pressure side skeleton, wherein the low-pressure side skeleton is a hollow cylinder;

[0008] A magnetic core, wherein the magnetic core is arranged in the low-voltage side frame;

[0009] A low-voltage side winding, wherein the low-voltage side winding is wound on the outer wall of the low-voltage side frame;

[0010] A high-voltage side skeleton, which is a hollow cylinder with the same structure and height as the low-voltage side skeleton, and is sleeved on the outside of the low-voltage side winding. The high-voltage side skeleton is made of insulating, high-temperature resistant, and high-thermal-conductivity non-metallic material;

[0011] A high-voltage side winding, wherein the high-voltage side winding is wound around an outer wall of the high-voltage side frame;

[0012] An outer sleeve, wherein the outer sleeve is sleeved on the outside of the high-voltage side winding; and

[0013] A bottom cover, the bottom cover is arranged on the low-voltage side frame, the high-voltage side frame, and two ends of the outer sleeve, and the bottom cover has two outlets for the wires connecting the low-voltage side winding and the high-voltage side winding to pass through;

[0014] Among them, the gap between the low-voltage side frame and the high-voltage side frame, the gap between the high-voltage side frame and the outer sleeve, and the gap between the bottom cover and the low-voltage side frame, and the gap between the high-voltage side frame and the outer sleeve are all filled with high thermal conductivity insulating glue.

[0015] In some examples, heat dissipation teeth are provided on the outer sleeve.

[0016] In some examples, the outer sleeve is made of alumina ceramic material.

[0017] In some examples, the low-pressure side frame, the high-pressure side frame, and both ends of the outer sleeve are respectively placed in three annular grooves of the bottom cover.

[0018] In some examples, the bottom cover is made of alumina ceramic material.

[0019] In some examples, the two outlets are distributed at 180°.

[0020] In some examples, the high-voltage side skeleton is made of alumina ceramic material.

[0021] In some examples, the low-pressure side frame is made of nylon material.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] (1) The present invention is used for high-power power transformers. With the help of a heat-conducting sleeve (low-voltage side frame, high-voltage side frame) or a high-thermal-conductivity insulating glue, the heat generated by the coil winding is directly or indirectly conducted to the chassis or the outer sleeve for heat dissipation. The alumina ceramic material has high insulation resistance, high temperature resistance, high thermal conductivity, and is non-metallic. It will not generate eddy currents in the magnetic field. It is an innovation of the previous plastic frame, reduces losses, improves the heat dissipation capacity of the system, and improves the thermal stability of the system.

[0024] (2) The outer sleeve of the present invention has cylindrically distributed heat dissipation serrations, which increases the contact area with the outside air and enhances the heat dissipation capacity;

[0025] (3) The present invention adopts a "sandwich" structure with inner and outer layers stacked together, which reduces the volume of the high-power transformer and improves the power density of the power electronic device;

[0026] (4) Alumina materials can be made into powder, which is easy to process, convenient for product miniaturization, high frequency, modular design and simple and compact structure;

[0027] (5) The low-voltage side and high-voltage side frames are made of traditional nylon material and new alumina ceramic material, giving full play to their respective advantages while reducing the production cost of the transformer frame. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solution of the embodiment of the present disclosure, the drawings of the embodiment are briefly introduced below.

[0029] Figure 1a A schematic diagram of a low-pressure side skeleton provided in one embodiment of the present invention.

[0030] Figure 1b A schematic diagram of a high-voltage side skeleton provided in one embodiment of the present invention.

[0031] Figure 1cA schematic diagram of an outer sleeve provided in one embodiment of the present invention.

[0032] Figure 2a A schematic diagram of a low-voltage side skeleton and a low-voltage side winding provided in one embodiment of the present invention.

[0033] Figure 2b A schematic diagram of a high-voltage side skeleton and a high-voltage side winding provided in one embodiment of the present invention.

[0034] Figure 3 A schematic diagram of a bottom cover provided by an embodiment of the present invention.

[0035] Figure 4 A schematic diagram of a magnetic core provided by an embodiment of the present invention.

[0036] Figure 5 A schematic diagram of the horizontal cross-sectional structure of a transformer composed of a hybrid material transformer skeleton with high pressure resistance and heat dissipation provided by an embodiment of the present invention.

[0037] Figure 6 A schematic diagram of a transformer composed of a hybrid material transformer skeleton with high pressure resistance and heat dissipation provided by an embodiment of the present invention.

[0038] Figure 7 A schematic diagram of a heat dissipation path of a transformer skeleton provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0039] The present invention proposes a transformer composed of a hybrid material transformer skeleton with high pressure resistance and strong heat dissipation, the transformer comprising a high-voltage side skeleton 1, a high-voltage side winding 2, a low-voltage side skeleton 3, a low-voltage side winding 4, an outer sleeve 5, two bottom covers 6 and a magnetic core 7.

[0040] like Figure 1a , 1b , 1c, the high-pressure side skeleton 1 and the low-pressure side skeleton 3 have the same structure and height, are hollow cylinders, and heat dissipation teeth are distributed on the outer sleeve 5. The high-pressure side skeleton 1 can be made of alumina ceramic material. The low-pressure side skeleton 3 can be made of nylon material, which can be obtained by 3D printing. Figure 2a , 2b The high-voltage side winding 2 is wound on the outer wall of the sleeve of the high-voltage side skeleton 1, and the low-voltage side winding 4 is wound on the outer wall of the sleeve of the low-voltage side skeleton 3.

[0041] Figure 3 The bottom cover 6 is shown. The two bottom covers 6 are hollow rings with three annular grooves 8, 9, and 10. The widths of the three annular grooves 8, 9, and 10 distributed from the outside to the inside are respectively adapted to the wall thickness of the outer sleeve 5, the sleeve wall thickness of the high-voltage side frame 1, and the sleeve wall thickness of the low-voltage side frame 3. The bottom cover 6 has two outlets 11 and 12, which are 180 degrees apart to increase the creepage distance and improve the insulation properties.

[0042] Figure 4 A magnetic core is shown, and this embodiment takes the UY42 magnetic core as an example, but is not limited to this.

[0043] The transformer of the present invention adopts a "sandwich" structure from inside to outside. The horizontal section of the transformer from inside to outside is respectively a magnetic core 7, a low-voltage side frame 3, a low-voltage side coil winding 4, a high-voltage side frame 1, a high-voltage side coil winding 2, and an outer sleeve 5. This structure can effectively reduce the leakage inductance of the transformer. The horizontal section diagram is as follows: Figure 5 As shown. The magnetic core 7 is placed in the sleeve of the low-voltage side skeleton 3, the sleeve of the high-voltage side skeleton 1 is sleeved on the outside of the low-voltage side coil 4, the outer sleeve 5 is sleeved on the outside of the high-voltage side coil 2, and the two bottom covers 6 close the two ends of the transformer. The outer sleeve 5, the high-voltage side skeleton 1, and the two ends of the low-voltage side skeleton 3 are respectively placed in the grooves 8, 9, and 10 of the two bottom covers, and the wires connecting the low-voltage side winding 4 and the high-voltage side winding 2 are led out from the outlets 11 and 12. Among them, the inner diameter of the sleeve of the low-voltage side skeleton 3 is greater than the diameter of the magnetic core 7; the inner diameter of the sleeve of the high-voltage side skeleton 1 is greater than the sum of the outer diameter of the sleeve of the low-voltage side skeleton 3 and twice the diameter of the low-voltage side coil winding 4; the inner diameter of the outer sleeve 5 is greater than the sum of the outer diameter of the sleeve of the high-voltage side skeleton 1 and twice the diameter of the high-voltage side coil winding 2; the inner diameter of the bottom cover 6 is consistent with the diameter of the magnetic core 7, and the outer diameter is consistent with the outer diameter of the outer sleeve 5. Figure 4 The assembled transformer is shown.

[0044] like Figure 7 The gaps between the sleeve of the low-voltage side skeleton 3 and the sleeve of the high-voltage side skeleton 1, the gaps between the sleeve of the high-voltage side skeleton 1 and the outer sleeve 5, and the gaps between the three sleeves and the grooves of the chassis 6 are all filled with a high thermal conductivity insulating glue 13 with a thermal conductivity coefficient of 5.0W / (m·K), which enhances heat dissipation and improves insulation capacity.

[0045] The high-voltage side skeleton 1 is made of alumina ceramic material, which makes full use of its insulation and thermal conductivity properties. Part of the heat generated by the coil winding is transferred to the chassis 6 through the sleeve for heat dissipation, and the other part is transferred to the outer sleeve 5 through the high thermal conductivity insulation glue for heat dissipation. Since the voltage resistance requirement on the low-voltage side is not high, the low-voltage side skeleton 3 is made of nylon material with low production cost. Its heat dissipation path is as follows: Figure 7 As shown by the arrows. In addition, the outer sleeve 5 and the bottom cover 6 can also be made of alumina ceramic material.

Claims

1. A transformer, characterized in that: include: A low-pressure side frame, which is a hollow cylinder and made of nylon; A magnetic core, wherein the magnetic core is arranged in the low-voltage side frame; A low-voltage side winding, wherein the low-voltage side winding is wound on the outer wall of the low-voltage side frame; A high-voltage side skeleton, which is a hollow cylinder with the same structure and height as the low-voltage side skeleton, and is sleeved on the outside of the low-voltage side winding. The high-voltage side skeleton is made of alumina ceramic material; A high-voltage side winding, wherein the high-voltage side winding is wound on the outer wall of the high-voltage side frame; An outer sleeve, wherein the outer sleeve is sleeved on the outside of the high-voltage side winding; and A disc-shaped bottom cover, the bottom cover is arranged at the two ends of the low-voltage side skeleton, the high-voltage side skeleton, and the outer sleeve, the bottom cover has a hole for inserting a magnetic core, the inner diameter of the bottom cover is consistent with the diameter of the magnetic core, the outer diameter of the bottom cover is consistent with the outer diameter of the outer sleeve, the inner diameter of the low-voltage side skeleton is larger than the diameter of the magnetic core, the inner diameter of the high-voltage side skeleton is larger than the sum of the outer diameter of the low-voltage side skeleton and twice the diameter of the winding of the low-voltage side winding, the inner diameter of the outer sleeve is larger than the outer diameter of the high-voltage side skeleton and twice the sum of the diameter of the winding of the high-voltage side winding, the bottom cover has three annular grooves adapted to the two ends of the low-voltage side skeleton, the high-voltage side skeleton and the outer sleeve, the two ends of the low-voltage side skeleton, the high-voltage side skeleton, and the outer sleeve are respectively placed in the three annular grooves, the bottom cover has two outlets for the wires connecting the low-voltage side winding and the high-voltage side winding to pass through, and the two outlets are distributed at 180°; Among them, the gap between the low-voltage side frame and the high-voltage side frame, the gap between the high-voltage side frame and the outer sleeve, and the gap between the bottom cover and the low-voltage side frame, and the gap between the high-voltage side frame and the outer sleeve are all filled with high thermal conductivity insulating glue.

2. The transformer according to claim 1, characterized in that: The outer sleeve is provided with heat dissipation teeth.

3. The transformer according to claim 1, characterized in that: The bottom cover is made of alumina ceramic material.

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