A high power density transformer

Abstract

This invention discloses a high power density transformer, comprising: a wound magnet, a first winding and a second winding wound on the wound magnet, and a first electrode and a second electrode attached to the wound magnet; the lead of the first winding extends to the first electrode, and the lead of the second winding extends to the second electrode. The wound magnet of this invention uses a low-loss, high-saturation Fe-based nanocrystalline material to reduce material loss and heat generation. Simultaneously, the high saturation characteristics of the Fe-based nanocrystalline material, together with carbonyl Fe powder, prepare a gapless transformer structure, reducing localized heat generation caused by leakage flux loss.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, and more particularly to a high power density transformer. Background Technology

[0002] With the popularization of new energy vehicles, the demand for high-power on-board chargers (OBC) is becoming increasingly urgent. The charging power has increased from the original 3.3kW to 25kW. Due to the increase in charging power, the power density of the transformer, the core component of power conversion, has increased significantly. Without redesigning the structure and materials, the transformer will generate a serious increase in heat due to losses, which will greatly increase the difficulty of heat dissipation and further deteriorate the transformer's performance, seriously affecting the normal operation of the transformer.

[0003] Therefore, existing technologies have shortcomings and need to be improved. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a high power density transformer that reduces heat generation by optimizing the material ratio and improves heat dissipation performance by optimizing the device structure design, so as to ensure that the transformer can be used normally under high power density and provide support for high-power charging of new energy vehicles.

[0005] The technical solution of the present invention is as follows: A high power density transformer is provided, comprising: a wound magnet, a first winding and a second winding respectively wound on the wound magnet, and a first electrode and a second electrode attached to the wound magnet; the lead of the first winding extends to the first electrode, and the lead of the second winding extends to the second electrode; the wound magnet is composed of: 70wt%~85wt% Fe-based nanocrystals, 15wt%-29wt% carbonyl Fe powder, and 1wt%-5 The composition of the first resin is wt%; the Fe-based nanocrystals consist of 43.0wt%~69wt% Fe, 20wt%~35wt% Ni, 6wt%~10wt% Si, 1.5wt%~4.5wt% Al, 3wt%~6wt% Mn, and 0.5wt%~1.5wt% Cu, with a particle size of 15~75µm. The Fe-based nanocrystal powder has an oxide layer of 5~15nm on its surface, and the grain size of the Fe-based nanocrystals is 30~60nm. The carbonyl Fe powder has a composite coating layer of phosphating and oxide layers on its surface, with a thickness greater than 80nm. The carbonyl Fe powder has a particle size of 5~50µm.

[0006] Further, the first resin is one or a combination of at least two of epoxy resin, phenolic resin, and silicone resin, wherein the softening temperature of the first resin is less than 70°C.

[0007] Furthermore, the high power density transformer further includes: an encapsulated magnet; the encapsulated magnet is composed of 90wt%-98wt% FeSiCr alloy material and 2wt%-10wt% second resin; the FeSiCr alloy material contains more than 8wt% Si, and is a graded material with large and small particles, wherein the large particles have a particle size of 10-15µm and account for 58wt%-78wt% of the weight of the graded material powder, and the small particles have a particle size of 2-4µm and account for 22wt%-42wt% of the weight of the graded material powder, wherein the coarse powder surface contains a composite oxide layer with a Cr and Si thickness greater than 50nm, and the fine powder surface contains a composite oxide layer with a Cr and Si thickness greater than 20nm, wherein the oxide layer structure on the particle surface is a non-single-layer structure, such as a two-layer or multi-layer structure, or a composite inlaid structure (e.g., with silicon oxide as the base layer and chromium oxide inlaid in the silicon oxide layer). The Fe oxide content in the oxide layer is less than 20wt% of the overall oxide content.

[0008] Further, the second resin is one or a combination of at least two of epoxy resin, phenolic resin, and silicone resin, wherein the softening temperature of the second resin is less than 70°C.

[0009] Furthermore, the encapsulating magnet encapsulates the winding magnet, the first winding, and the second winding into a semi-encapsulated structure. The surface of the first winding that is in the same direction as the first electrode is not encapsulated by the encapsulating magnet, and the surface of the second winding that is in the same direction as the second electrode is not encapsulated by the encapsulating magnet.

[0010] Further, the wound magnet includes: a first limiting plate, a first winding center post connected to the first limiting plate, a second limiting plate connected to the first winding center post, a second winding center post connected to the second limiting plate, and a third limiting plate connected to the second winding center post; the first winding is wound on the first winding center post, and the second winding is wound on the second winding center post; the first electrode is disposed on the first limiting plate and / or the second limiting plate, and the second electrode is disposed on the second limiting plate and / or the third limiting plate.

[0011] Furthermore, the high power density transformer further includes: an insulating layer embedded in the second limiting plate; the insulating layer is disposed between the first electrode and the second electrode; the width of the insulating layer is not less than one-third of the width of the second limiting plate.

[0012] Furthermore, the wound magnet and the insulating layer are integrally formed; the insulating layer is made of oxide ceramic or nitride ceramic.

[0013] Furthermore, the encapsulated magnet covers at least half of the side surface of the wound magnet.

[0014] Using the above-mentioned solution, the present invention provides a high power density transformer. The winding magnet uses a low-loss, high-saturation Fe-based nanocrystalline material to reduce material loss and heat generation. At the same time, the high saturation characteristics of the Fe-based nanocrystalline material, together with carbonyl Fe powder, are used to prepare a gapless transformer structure, reducing local heat generation caused by leakage magnetic loss. Furthermore, by encapsulating the magnet to form a semi-enclosed structure, leakage magnetic loss can also be reduced, thereby reducing the product size. In addition, space is reserved near the circuit board soldering point in the semi-enclosed structure to facilitate heat dissipation of the first and second windings. The insulating layer embedded in the first and second limiting plates can prevent short circuits between the first and second electrodes and also dissipate heat, thereby meeting the high power density requirements of transformers in automotive on-board charger (OBC) applications. Attached Figure Description

[0015] Figure 1 This is a bottom view schematic diagram of an embodiment of the present invention;

[0016] Figure 2 for Figure 1 Cross-sectional view of an embodiment. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0018] Please see Figure 1 and Figure 2 This invention provides a high power density transformer, comprising: a wound magnet, a first winding 21 and a second winding 22 respectively wound on the wound magnet, and a first electrode 23 and a second electrode 24 attached to the wound magnet; the lead wire of the first winding 21 extends to the first electrode 23, and the lead wire of the second winding 22 extends to the second electrode 24; the wound magnet is composed of: 70wt%~85wt% Fe-based nanocrystals, 15wt%-29wt% carbonyl Fe powder, and 1wt%-5 The composition of the first resin is wt%; the Fe-based nanocrystals consist of 43.0wt%~69wt% Fe, 20wt%~35wt% Ni, 6wt%~10wt% Si, 1.5wt%~4.5wt% Al, 3wt%~6wt% Mn, and 0.5wt%~1.5wt% Cu, with a particle size of 15~75µm. The Fe-based nanocrystal powder has an oxide layer of 5~15nm on its surface, and the grain size of the Fe-based nanocrystals is 30~60nm. The carbonyl Fe powder has a composite coating layer of phosphating and oxide layers on its surface, with a thickness greater than 80nm. The carbonyl Fe powder has a particle size of 5~50µm.

[0019] In this invention, the first resin is one or a combination of at least two of epoxy resin, phenolic resin, and silicone resin, wherein the softening temperature of the first resin is less than 70°C.

[0020] In this invention, the high power density transformer further includes: an encapsulating magnet 25; the encapsulating magnet 25 is composed of 90wt%-98wt% FeSiCr alloy material and 2wt%-10wt% second resin; the FeSiCr alloy material contains more than 8wt% Si, and is a graded material with large and small particles, wherein the large particles have a particle size of 10-15µm and account for 58wt%-78wt% of the weight of the graded material powder, and the small particles have a particle size of 2-4µm and account for 22wt%-42wt% of the weight of the graded material powder, wherein the coarse powder surface contains a composite oxide layer with a thickness of more than 50nm, and the fine powder surface contains a composite oxide layer with a thickness of more than 20nm, wherein the oxide layer structure on the particle surface is a composite mosaic structure, not a single-layer structure. The Fe oxide in the oxide layer is less than 20wt% of the overall oxide content.

[0021] In this invention, the second resin is one or a combination of at least two of epoxy resin, phenolic resin, and silicone resin, wherein the softening temperature of the second resin is less than 70°C.

[0022] In this invention, the encapsulated magnet 25 encapsulates the winding magnet, the first winding 21, and the second winding 22 into a semi-encapsulated structure. The surface of the first winding 21 that is in the same direction as the first electrode 23 is not encapsulated by the encapsulated magnet 25, and the surface of the second winding 22 that is in the same direction as the second electrode 24 is not encapsulated by the encapsulated magnet 25.

[0023] In this invention, the wound magnet includes: a first limiting plate 26, a first winding center post 27 connected to the first limiting plate 26, a second limiting plate 28 connected to the first winding center post 27, a second winding center post 29 connected to the second limiting plate 28, and a third limiting plate 30 connected to the second winding center post 29; a first winding 21 is wound on the first winding center post 27, and a second winding 22 is wound on the second winding center post 29; a first electrode 23 is disposed on the first limiting plate 26 and / or the second limiting plate 28, and a second electrode 24 is disposed on the second limiting plate 28 and / or the third limiting plate 30.

[0024] In this invention, the high power density transformer further includes: an insulating layer 31 embedded in the second limiting plate 28; the insulating layer 31 is disposed between the first electrode 23 and the second electrode 24; the width of the insulating layer is not less than one-third of the width of the second limiting plate 28.

[0025] In this invention, the wound magnet and the insulating layer are integrally formed; the insulating layer is made of oxide ceramic or nitride ceramic.

[0026] In this invention, the encapsulated magnet 25 covers at least half of the side surface of the wound magnet.

[0027] Example 1

[0028] This embodiment provides a high power density transformer, including: a wound magnet, a first winding, a second winding, an insulating layer, and an encapsulated magnet.

[0029] The wound magnet is composed of: 70 wt% Fe-based nanocrystals, 29 wt% carbonyl Fe powder, and 1 wt% first resin; the Fe-based nanocrystals have the following composition: 43.0 wt% Fe, 35 wt% Ni, 10 wt% Si, 4.5 wt% Al, 6 wt% Mn, and 1.5 wt% Cu, with a particle size of 15-75 μm. The Fe-based nanocrystal powder has an oxide layer of 5-15 nm on its surface, and the grain size of the Fe-based nanocrystals is 30-60 nm; the carbonyl Fe powder has a composite coating layer of phosphating and oxide layers on its surface, with a thickness greater than 80 nm; and the carbonyl Fe powder has a particle size of 5-50 μm.

[0030] The first resin is one or a combination of at least two of epoxy resin, phenolic resin, and silicone resin, wherein the softening temperature of the first resin is less than 70°C.

[0031] The high power density transformer further includes: an encapsulated magnet; the encapsulated magnet is composed of 95wt% FeSiCr alloy material and 5wt% secondary resin; the FeSiCr alloy material contains more than 8.5wt% Si, and is a graded material with large and small particles, wherein the large particles have a particle size of 10-15µm, accounting for 58wt% of the weight of the graded material powder, and the small particles have a particle size of 2-4µm, accounting for 42wt% of the weight of the graded material powder. The coarse powder surface contains a composite oxide layer with a Cr and Si thickness greater than 55nm, and the fine powder surface contains a composite oxide layer with a Cr and Si thickness greater than 23nm. The oxide layer structure on the particle surface is a composite mosaic structure, not a single-layer structure. The Fe oxide in the oxide layer accounts for 7wt% of the total oxide ratio.

[0032] The second resin is one or a combination of at least two of epoxy resin, phenolic resin, and silicone resin, wherein the softening temperature of the second resin is less than 70°C.

[0033] Example 2

[0034] This embodiment provides a high power density transformer, including: a wound magnet, a first winding, a second winding, an insulating layer, and an encapsulated magnet.

[0035] The wound magnet is composed of: 78 wt% Fe-based nanocrystals, 20 wt% carbonyl Fe powder, and 2 wt% first resin; the Fe-based nanocrystals have the following composition: 53.1 wt% Fe, 30 wt% Ni, 8 wt% Si, 3.2 wt% Al, 4.6 wt% Mn, and 1.1 wt% Cu, with a particle size of 15-75 μm. The Fe-based nanocrystal powder has an oxide layer of 5-15 nm on its surface, and the grain size of the Fe-based nanocrystals is 30-60 nm. The carbonyl Fe powder has a composite coating layer of phosphating and oxide layers on its surface, with a thickness greater than 80 nm. The carbonyl Fe powder has a particle size of 5-50 μm.

[0036] The first resin is one or a combination of at least two of epoxy resin, phenolic resin, and silicone resin, wherein the softening temperature of the first resin is less than 70°C.

[0037] The high power density transformer further includes: an encapsulated magnet; the encapsulated magnet is composed of 94wt% FeSiCr alloy material and 6wt% second resin; the FeSiCr alloy material contains more than 9.0wt% Si, and is a graded material with large and small particles, wherein the large particles have a particle size of 10~15µm and account for 65wt% of the weight of the graded material powder, and the small particles have a particle size of 2~4µm and account for 35wt% of the weight of the graded material powder. The coarse powder surface contains a composite oxide layer with a Cr and Si thickness greater than 57nm, and the fine powder surface contains a composite oxide layer with a Cr and Si thickness greater than 31nm. The oxide layer structure on the particle surface is a composite mosaic structure, not a single-layer structure. The Fe oxide in the oxide layer accounts for 10wt% of the total oxide ratio.

[0038] The second resin is one or a combination of at least two of epoxy resin, phenolic resin, and silicone resin, wherein the softening temperature of the second resin is less than 70°C.

[0039] Example 3

[0040] This embodiment provides a high power density transformer, including: a wound magnet, a first winding, a second winding, an insulating layer, and an encapsulated magnet.

[0041] The wound magnet is composed of 85 wt% Fe-based nanocrystals, 13 wt% carbonyl Fe powder, and 2 wt% first resin. The Fe-based nanocrystals have the following composition: 69 wt% Fe, 20 wt% Ni, 6 wt% Si, 1.5 wt% Al, 3 wt% Mn, and 0.5 wt% Cu. The particle size of the Fe-based nanocrystals is 15-75 μm, and the surface of the Fe-based nanocrystal powder has an oxide layer of 5-15 nm. The grain size of the Fe-based nanocrystals is 30-60 nm. The surface of the carbonyl Fe powder contains a composite coating layer of phosphating and oxide layers, wherein the thickness of the composite coating layer is greater than 95 nm. The particle size of the carbonyl Fe powder is 5-50 μm.

[0042] The first resin is one or a combination of at least two of epoxy resin, phenolic resin, and silicone resin, wherein the softening temperature of the first resin is less than 70°C.

[0043] The high power density transformer further includes: an encapsulated magnet; the encapsulated magnet is composed of 92wt% FeSiCr alloy material and 8wt% second resin; the FeSiCr alloy material contains more than 9.5wt% Si, and is a graded material with large and small particles, wherein the large particles have a particle size of 10~15µm, accounting for 58wt% of the weight of the graded material powder, and the small particles have a particle size of 2~4µm, accounting for 42wt% of the weight of the graded material powder. The coarse powder surface contains a composite oxide layer with a Cr and Si thickness greater than 63nm, and the fine powder surface contains a composite oxide layer with a Cr and Si thickness greater than 21nm. The oxide layer structure on the particle surface is a composite mosaic structure, not a single-layer structure. The Fe oxide in the oxide layer accounts for 10wt% of the total oxide ratio.

[0044] The second resin is one or a combination of at least two of epoxy resin, phenolic resin, and silicone resin, wherein the softening temperature of the second resin is less than 70°C.

[0045] Example 4

[0046] This embodiment provides a high power density transformer, including: a wound magnet, a first winding, a second winding, and an insulating layer.

[0047] The wound magnet is composed of: 78 wt% Fe-based nanocrystals, 20 wt% carbonyl Fe powder, and 2 wt% first resin; the Fe-based nanocrystals have the following composition: 53.1 wt% Fe, 30 wt% Ni, 8 wt% Si, 3.2 wt% Al, 4.6 wt% Mn, and 1.1 wt% Cu, with a particle size of 15-75 μm. The Fe-based nanocrystal powder has an oxide layer of 5-15 nm on its surface, and the grain size of the Fe-based nanocrystals is 30-60 nm; the carbonyl Fe powder has a composite coating layer of phosphating and oxide layers on its surface, with a thickness greater than 89 nm; and the carbonyl Fe powder has a particle size of 5-50 μm.

[0048] The first resin is one or a combination of at least two of epoxy resin, phenolic resin, and silicone resin, wherein the softening temperature of the first resin is less than 70°C.

[0049] Comparative Example 1

[0050] This embodiment provides a high power density transformer, including: a wound magnet, a first winding, a second winding, an insulating layer, and an encapsulated magnet.

[0051] The wound magnet is composed of 93wt% FeSiCr, 6wt% carbonyl Fe powder, and 1wt% first resin; the FeSi alloy has a particle size of 15~75um, wherein the FeSi alloy powder has a 10nm oxide layer on its surface, and the carbonyl Fe powder has a composite coating layer of phosphating layer and oxide layer on its surface, wherein the coating layer is 89nm thick; the carbonyl Fe powder has a particle size of 5~50um.

[0052] The first resin is one or a combination of at least two of epoxy resin, phenolic resin, and silicone resin, wherein the softening temperature of the first resin is less than 70°C.

[0053] The high power density transformer further includes: an encapsulated magnet; the encapsulated magnet is composed of 93.5 wt% FeSiCr alloy material and 7 wt% second resin; wherein the FeSiCr alloy material contains 9.0 wt% Si, and is a graded material with large and small particles, wherein the large particles have a particle size of 10-15 μm, accounting for 65 wt% of the weight of the graded material powder, and the small particles have a particle size of 2-4 μm, accounting for 35 wt% of the weight of the graded material powder. The coarse powder surface contains a composite oxide layer of Cr and Si with a thickness of 57 nm, and the fine powder surface contains a composite oxide layer of Cr and Si with a thickness of 31 nm. The oxide layer structure on the particle surface is a composite mosaic structure, not a single-layer structure. The Fe oxide in the oxide layer accounts for 10 wt% of the total oxide content.

[0054] The second resin is one or a combination of at least two of epoxy resin, phenolic resin, and silicone resin, wherein the softening temperature of the second resin is less than 70°C.

[0055] Comparative Example 2

[0056] This embodiment provides a high power density transformer, including: a wound magnet, a first winding, a second winding, an insulating layer, and an encapsulated magnet.

[0057] The wound magnet is composed of 98wt% Fe-based nanocrystals and 2wt% first resin; the Fe-based nanocrystals are composed of 53.1wt% Fe, 30wt% Ni, 8wt% Si, 3.2wt% Al, 4.6wt% Mn, and 1.1wt% Cu, with a particle size of 15~75um and an oxide layer of 5~15nm on the surface of the Fe-based nanocrystal powder, wherein the grain size of the Fe-based nanocrystals is 30~60nm.

[0058] The first resin is one or a combination of at least two of epoxy resin, phenolic resin, and silicone resin, wherein the softening temperature of the first resin is less than 70°C.

[0059] The high power density transformer further includes: an encapsulated magnet; the encapsulated magnet is composed of 93.5 wt% FeSiCr alloy material and 6.5 wt% secondary resin; the FeSiCr alloy material contains more than 9.5 wt% Si, and is a graded material with large and small particles, where the large particles have a particle size of 10-15 μm and account for 65 wt% of the weight of the graded material powder, and the small particles have a particle size of 2-4 μm and account for 35 wt% of the weight of the graded material powder. The coarse powder surface contains a composite oxide layer with a Cr and Si thickness greater than 57 nm, and the fine powder surface contains a composite oxide layer with a Cr and Si thickness greater than 31 nm. The oxide layer structure on the particle surface is a composite mosaic structure, not a single-layer structure. The Fe oxide in the oxide layer accounts for 10 wt% of the total oxide proportion.

[0060] The second resin is one or a combination of at least two of epoxy resin, phenolic resin, and silicone resin, wherein the softening temperature of the second resin is less than 70°C.

[0061] Performance tests were conducted on the products of Examples 1-4 and Comparative Examples 1-2, wherein the product dimensions were: length 30mm * width 25mm * height 12.5mm, the first winding had 20 turns, and the second winding had 100 turns. The inductance value of the magnetic ring sample with a 10% drop in initial permeability μi (1V / 100kHz) was measured using a 3260B LCR meter and a thermistor, and the surface temperature of the transformer at a current of 3A was measured. The test results are shown in Table 1.

[0062] Table 1

[0063]

[0064] As can be seen from the table, the materials obtained in the examples and comparative examples have lower temperatures and larger operating currents under the same preparation conditions and currents at the same inductance values. This indicates that composition control and structural design have a significant impact on the operating current and operating temperature of the devices.

[0065] In summary, this invention provides a high power density transformer. The winding magnet uses a low-loss, high-saturation Fe-based nanocrystalline material to reduce material loss and heat generation. Simultaneously, the high saturation characteristics of the Fe-based nanocrystalline material, combined with carbonyl Fe powder, create a gapless transformer structure, reducing localized heat generation caused by leakage flux loss. Furthermore, the semi-enclosed structure of the encapsulated magnet also reduces leakage flux, thus decreasing product size. Additionally, the semi-enclosed structure provides space near the circuit board solder joints, facilitating heat dissipation for the first and second windings. The insulating layer embedded in the first and second limiting plates prevents short circuits between the first and second electrodes and also dissipates heat, thereby meeting the high power density requirements of transformers in automotive on-board charger (OBC) applications.

[0066] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high power density transformer, characterized in that, include: A wire-wound magnet, comprising a first winding and a second winding wound on the wire-wound magnet, and a first electrode and a second electrode attached to the wire-wound magnet; the lead wire of the first winding extends to the first electrode, and the lead wire of the second winding extends to the second electrode; the wire-wound magnet is composed of: 70wt%~85wt% Fe-based nanocrystals, 15wt%-29wt% carbonyl Fe powder, and 1wt%-5 The composition of the first resin is as follows: The Fe-based nanocrystals consist of 43.0wt%~69wt% Fe, 20wt%~35wt% Ni, 6wt%~10wt% Si, 1.5wt%~4.5wt% Al, 3wt%~6wt% Mn, and 0.5wt%~1.5wt% Cu. The particle size of the Fe-based nanocrystals is 15~75µm, and the surface of the Fe-based nanocrystal powder has an oxide layer of 5~15nm. The grain size of the Fe-based nanocrystals is 30~60nm. The carbonyl Fe powder has a composite coating layer of phosphating and oxide layers on its surface, wherein the thickness of the composite coating layer is greater than 80nm. The particle size of the carbonyl Fe powder is 5~50µm. The first resin is one or a combination of at least two of epoxy resin, phenolic resin, and silicone resin, wherein the softening temperature of the first resin is less than 70°C. It also includes: an encapsulated magnet; the encapsulated magnet is composed of 90wt%-98wt% FeSiCr alloy material and 2wt%-10wt% second resin; the FeSiCr alloy material contains more than 8wt% Si, and is a graded material with large and small particles, wherein the large particles are 10-15µm in diameter and account for 58wt%-78wt% of the weight of the graded material powder, and the small particles are 2-4µm in diameter and account for 22wt%-42wt% of the weight of the graded material powder; wherein the coarse powder has a composite oxide layer with Cr and Si on its surface with a thickness greater than 50nm, and the fine powder has a composite oxide layer with Cr and Si on its surface with a thickness greater than 20nm; wherein the oxide layer structure on the particle surface is a non-single-layer structure; wherein the Fe oxide in the oxide layer is less than 20wt% of the overall oxide ratio. The second resin is one or a combination of at least two of epoxy resin, phenolic resin, and silicone resin, wherein the softening temperature of the second resin is less than 70°C. The encapsulated magnet encapsulates the winding magnet, the first winding, and the second winding into a semi-encapsulated structure. The surface of the first winding that is in the same direction as the first electrode is not encapsulated by the encapsulated magnet, and the surface of the second winding that is in the same direction as the second electrode is not encapsulated by the encapsulated magnet.

2. A high power density transformer according to claim 1, characterized in that, The wound magnet includes: a first limiting plate, a first winding center column connected to the first limiting plate, a second limiting plate connected to the first winding center column, a second winding center column connected to the second limiting plate, and a third limiting plate connected to the second winding center column; the first winding is wound on the first winding center column, and the second winding is wound on the second winding center column; the first electrode is disposed on the first limiting plate and / or the second limiting plate, and the second electrode is disposed on the second limiting plate and / or the third limiting plate.

3. A high power density transformer according to claim 2, characterized in that, Also includes: An insulating layer is embedded in the second limiting plate; the insulating layer is disposed between the first electrode and the second electrode; the width of the insulating layer is not less than one-third of the width of the second limiting plate.

4. A high power density transformer according to claim 3, characterized in that, The wound magnet and the insulating layer are integrally formed; the insulating layer is made of oxide ceramic or nitride ceramic.

5. A high power density transformer according to claim 2, characterized in that, The encapsulated magnet covers at least half of the side surface of the wound magnet.

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