Transformer and power converter

Abstract

The application relates to a transformer and a power converter, the transformer comprising a first winding, a first auxiliary winding, a first shielding layer, an insulation layer, a second shielding layer, a magnetic core and a second winding; the first shielding layer is wrapped around to form a containing space, the first winding and the first auxiliary winding are arranged in the containing space; the first winding and the first auxiliary winding are wound in parallel, and the first winding and the first auxiliary winding have a mirror image potential state; the insulation layer is wrapped on the first shielding layer, the second shielding layer is wrapped on the insulation layer, and the first winding and the second winding realize isolated transmission of electric energy through the magnetic core; at least one end of the first auxiliary winding is arranged in an open state, at least one wiring terminal is arranged on the first auxiliary winding, and the wiring terminal is electrically connected to a side surface of the first shielding layer adjacent to the first auxiliary winding; the transformer can provide a stable equipotential point for the first shielding layer in the insulation layer without relying on external leads, and realizes precise potential clamping of the first shielding layer.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a transformer and a power converter. Background Technology

[0002] In the research and engineering application of solid-state transformers, insulation design is the core foundation for ensuring system reliability and a major technical bottleneck restricting their development towards high power density and high voltage levels. Unlike traditional power frequency transformers, the high-frequency transformers inside solid-state transformers face a strong coupling environment of "electric-thermal-magnetic" multi-physics fields caused by high-frequency excitation and compact structure, posing greater challenges to their insulation design. The high-frequency operation of power switching devices generates voltage excitation with extremely high voltage change rates (dV / dt, typically reaching tens of kV / µs), significantly increasing the polarization loss of the insulating medium and noticeably reducing the partial discharge initiation voltage, which easily accelerates the aging and electrical breakdown process of solid insulation materials. In addition, high power density leads to the compression of physical insulation spacing, a sharp increase in the internal spatial electric field strength, and highly concentrated heat generated by high-frequency losses. The continuous high temperature rise reduces the electrical breakdown strength of the insulating material, forming an electrothermal coupling decay cycle in the insulating medium.

[0003] In existing solutions, additional potential connection wires for the inner shield are typically required to provide potential connection points for the inner shield. For example, a separate solid wire can be led from the inner shield through the main insulation layer to the outside of the transformer. However, this compromises the physical integrity of the main insulation layer and can easily induce partial discharge and surface flashover at the wire exit interface. Alternatively, the inner shield can be directly connected via a tap at the midpoint of the high-voltage main winding. However, this requires damaging the insulation layer of the high-voltage main winding, which, for high-frequency transformers using multi-strand strands, can easily introduce manufacturing defects and cause insulation degradation.

[0004] Therefore, there is an urgent need for a transformer that can achieve the potential connection of the inner shield layer without damaging the insulation structure of the main winding and without external leads, while avoiding additional losses in the auxiliary winding, in order to solve the above-mentioned technical problems. Summary of the Invention

[0005] Therefore, it is necessary to provide a transformer and power converter that can achieve the potential connection of the inner shield layer without damaging the insulation structure of the main winding and without external leads, while avoiding additional losses in the auxiliary winding, in order to address the above-mentioned technical problems.

[0006] In a first aspect, this application provides a transformer, the transformer including a first winding, a first auxiliary winding, a first shielding layer, an insulating layer, a second shielding layer, a magnetic core, and a second winding;

[0007] The first shielding layer surrounds and forms a receiving space, and the first winding and the first auxiliary winding are disposed in the receiving space; the first winding and the first auxiliary winding are wound in parallel, and the first winding and the first auxiliary winding have mirror potential states; the insulating layer covers the first shielding layer, the second shielding layer covers the insulating layer, and the first winding and the second winding achieve isolated transmission of electrical energy through the magnetic core;

[0008] At least one end of the first auxiliary winding is open and suspended. The first auxiliary winding is provided with at least one terminal, which is electrically connected to the side surface of the first shielding layer adjacent to the first auxiliary winding.

[0009] By setting a first auxiliary winding that is wound in parallel with the first winding and has a mirror potential, and leaving at least one end of the first auxiliary winding open and suspended, with the terminal block on it electrically connected to the first shielding layer, a stable equipotential point can be provided for the first shielding layer nearby within the insulation layer without relying on external leads. This achieves precise potential clamping of the first shielding layer without damaging the insulation structure of the first winding for tapping, ensuring the integrity of the main insulation structure. At the same time, since the first auxiliary winding is open-circuited, no current loop is formed inside it, eliminating the risk of additional winding losses and heat generation caused by current shunting or circulating current. Furthermore, all electrical connection structures are enclosed inside the insulation layer, eliminating the need for external wiring and simplifying the transformer output encapsulation process.

[0010] Furthermore, at least one of the terminals is disposed on the first auxiliary winding at the midpoint of the potential corresponding to the first winding.

[0011] Furthermore, one end of the first auxiliary winding is electrically connected to one end of the first winding.

[0012] Furthermore, the transformer also includes a second auxiliary winding, which is disposed within the receiving space. The second auxiliary winding is wound in parallel with the first winding, and one end of the second auxiliary winding is electrically connected to the other end of the first winding. The other end of the second auxiliary winding is open-circuited and suspended. A terminal is provided on the second auxiliary winding, and the terminal is electrically connected to the side surface of the first shielding layer adjacent to the second auxiliary winding.

[0013] Furthermore, the transformer also includes a dielectric layer and a coupling electrode. The dielectric layer at least partially covers the first winding. The coupling electrode is capacitively connected to the first winding through the dielectric layer and electrically connected to the first auxiliary winding. Both ends of the first auxiliary winding are open-circuited and suspended.

[0014] Furthermore, the first shielding layer includes a plurality of spaced conductive portions, which are disposed on one side surface of the first shielding layer adjacent to the first auxiliary winding. The orthographic projection of the terminal on the first shielding layer falls within the range of the corresponding conductive portion, and the terminal is electrically connected to the corresponding conductive portion.

[0015] Furthermore, the conductive portion includes conductive branches extending to both sides along the surface of the first shielding layer. The extending direction of the conductive branches is perpendicular to the axial direction of the first auxiliary winding, and the ends of the conductive branches extending from the same conductive portion are spaced apart.

[0016] Furthermore, the first auxiliary winding is provided with a plurality of terminals, which are axially spaced at different turns of the first auxiliary winding and are electrically connected to the first shielding layer respectively.

[0017] Furthermore, the second shielding layer and the magnetic core are used to receive grounding signals.

[0018] Secondly, this application also provides a power converter, the power converter comprising: a first power conversion module, a second power conversion module, and a transformer as described in the first aspect, wherein the first power conversion module is connected to the first winding, and the second power conversion module is connected to the second winding. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the equivalent circuit of a transformer provided in one embodiment of this application;

[0021] Figure 2 A schematic diagram of the equivalent circuit of a power converter provided in one embodiment of this application;

[0022] Figure 3 A schematic diagram of the transformer equivalent circuit provided for yet another embodiment of this application;

[0023] Figure 4 A schematic diagram of the transformer equivalent circuit provided for yet another embodiment of this application;

[0024] Figure 5 A schematic diagram of the transformer equivalent circuit provided for yet another embodiment of this application;

[0025] Figure 6 A schematic diagram of the transformer equivalent circuit provided for yet another embodiment of this application;

[0026] Figure 7 A schematic diagram of the first shielding layer structure provided in one embodiment of this application;

[0027] Figure 8 A schematic diagram of the transformer equivalent circuit provided for yet another embodiment of this application;

[0028] Figure 9 A schematic diagram of the transformer equivalent circuit provided for yet another embodiment of this application;

[0029] Figure 10 A schematic diagram of the transformer equivalent circuit provided for yet another embodiment of this application;

[0030] Figure 11 A schematic diagram of the equivalent circuit of a power converter provided in one embodiment of this application.

[0031] Explanation of icon numbers:

[0032] Transformer-1; First winding-11; First auxiliary winding-12; First shielding layer-13; Reception space-131; Conductive part-132; Conductive branch-1321; Insulation layer-14; Second shielding layer-15; Magnetic core-16; Second winding-17; Terminal block-18; Second auxiliary winding-19; Dielectric layer-110; Coupling electrode-111; Power converter-2; First power conversion module-21; Second power conversion module-22. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0034] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0035] This application provides a transformer 1, please refer to... Figure 1 , Figure 1This is a schematic diagram of the equivalent circuit of a transformer provided in one embodiment of this application. The transformer 1 includes a first winding 11, a first auxiliary winding 12, a first shielding layer 13, an insulating layer 14, a second shielding layer 15, a magnetic core 16, and a second winding 17;

[0036] The first shielding layer 13 surrounds and forms a receiving space 131 (see [reference]). Figure 5 The first winding 11 and the first auxiliary winding 12 are disposed within the receiving space 131; the first winding 11 and the first auxiliary winding 12 are wound in parallel, and the first winding 11 and the first auxiliary winding 12 have mirror potential states; the insulating layer 14 covers the first shielding layer 13, the second shielding layer 15 covers the insulating layer 14, and the first winding 11 and the second winding 17 achieve isolated transmission of electrical energy through the magnetic core 16;

[0037] At least one end of the first auxiliary winding 12 is open and suspended. At least one terminal 18 is provided on the first auxiliary winding 12. The terminal 18 is electrically connected to the side surface of the first shielding layer 13 adjacent to the first auxiliary winding 12.

[0038] It should be noted that "parallel winding" here refers to the first auxiliary winding 12 and the first winding 11 being wound closely side-by-side in physical space, with both wound along the same axial direction and using the same winding path. This parallel winding structure differs from the electrical "parallel connection," where two windings are connected end-to-end in a circuit to form an electrical loop. In this embodiment, the parallel winding of the first auxiliary winding 12 and the first winding 11 describes their physical spatial layout; they do not form a parallel loop electrically. In fact, at least one end of the first auxiliary winding 12 is open-circuited and suspended precisely to avoid forming an electrical parallel loop with the first winding 11.

[0039] In this embodiment, the first shielding layer 13 is made of a semi-conductive material. It should be noted that the first shielding layer 13 is made of a semi-conductive material rather than a good conductor because semi-conductive materials have a certain resistivity, which can both provide electrostatic shielding and electric field homogenization, while avoiding significant eddy current losses in high-frequency alternating magnetic fields that would occur with good conductors. In the high-frequency transformer 1, if the shielding layer uses a good conductor such as copper foil, the high-frequency magnetic field will induce large eddy currents in the shielding layer, leading to additional losses and localized heating, reducing system efficiency and affecting insulation life. Semi-conductive materials, due to their high resistivity, can effectively suppress the generation of eddy currents, significantly reducing the high-frequency losses of the shielding layer itself while achieving potential clamping and electric field shielding functions. Furthermore, the resistivity characteristics of semi-conductive materials also result in minimal leakage current between different potential connection points through the shielding layer body during multi-point clamping, without significantly affecting the potential distribution.

[0040] Specifically, since the first auxiliary winding 12 and the first winding 11 adopt a tightly parallel winding structure, they are in a highly consistent electromagnetic field environment, meaning that the magnetic flux linked to them and their rate of change are basically the same. According to the law of electromagnetic induction, under the action of the same alternating magnetic field, the spatial distribution of the induced voltage generated on each turn of the first auxiliary winding 12 can accurately replicate the potential distribution at corresponding positions of the first winding 11. The so-called "mirror potential state" means that the potential at each point along the axis of the first auxiliary winding 12 is equal in magnitude and phase to the potential at the corresponding position along the same axis of the first winding 11 (or exhibits a definite mirror symmetry relationship). That is, the spatial distribution of the induced voltage generated on the first auxiliary winding 12 by pure electromagnetic induction can accurately replicate the voltage potential distribution of the first winding 11. This mirror relationship can be achieved by connecting the terminal 18 led out at a specific position of the first auxiliary winding 12 to the first shielding layer 13, so that the first shielding layer 13 can obtain the same potential as the corresponding position of the first winding 11 without damaging the insulation structure of the first winding 11.

[0041] The terminal 18 is essentially a potential tap led out from a certain number of turns on the first auxiliary winding 12. Specifically, an electrical lead-out point is set at a selected number of turns on the winding conductor of the first auxiliary winding 12. This lead-out point is electrically connected to the first shielding layer 13 through an internal wire, which is the potential tap. It can be understood that the terminal 18 can be set at different number of turns on the first auxiliary winding 12. For example, it can be set at the potential midpoint corresponding to the first winding 11, or it can be set at different number of turns on the first auxiliary winding 12 along the axial direction to lead out different potential points respectively.

[0042] Furthermore, in this embodiment, the number of turns of the first auxiliary winding 12 can be less than or equal to the number of turns of the first winding 11. When the number of turns of the first auxiliary winding 12 is less than the number of turns of the first winding 11, the first auxiliary winding 12 covers a portion of the number of turns of the first winding 11, and it can still lead out the same potential as the corresponding position of the first winding 11 through the terminal 18 within the corresponding coverage area. When the number of turns of the first auxiliary winding 12 is equal to the number of turns of the first winding 11, the first auxiliary winding 12 completely covers the entire number of turns of the first winding 11, and a potential tap can be led out at any corresponding position in the axial direction of the first winding 11. Therefore, the number of turns of the first auxiliary winding 12 can be flexibly set according to actual needs to provide the required potential lead-out position. It is understood that, regardless of the number of turns, the first auxiliary winding 12 relies on its open-circuit characteristics to ensure that no circulating current loss is generated.

[0043] Since both the first winding 11 and the first auxiliary winding 12 are disposed within the receiving space 131 formed by the first shielding layer 13 surrounding and covering them, the physical distance between the terminal 18 and the surface of the first shielding layer 13 adjacent to the first auxiliary winding 12 is relatively short. Therefore, the electrical connection between the terminal 18 and the first shielding layer 13 can be completed entirely within the receiving space 131, i.e., within the internal cavity covered by the insulating layer 14, without requiring any wires to be led out from the first shielding layer 13 and penetrate the insulating layer 14. It is understood that this ensures the integrity of the physical structure of the first shielding layer 13 and the insulating layer 14, avoiding the risk of small air gaps, partial discharges, and surface flashovers caused by wires penetrating the interface of the insulating layer 14. Meanwhile, since the first shielding layer 13 is electrically connected to the first auxiliary winding 12 through the terminal block 18, and the first auxiliary winding 12 has a mirror potential state with the first winding 11, the first shielding layer 13 can obtain a potential corresponding to the corresponding position of the first winding 11, thereby achieving precise potential clamping of the first shielding layer 13. Furthermore, the internal proximity connection arrangement can eliminate parasitic inductance caused by long external leads, avoiding the weakening of high-frequency shielding effect due to parasitic inductance and capacitance of the shielding layer.

[0044] It should be noted that the term "open-circuit floating configuration" means that at least one end of the first auxiliary winding 12 is electrically and physically disconnected, neither electrically connected to the first winding 11 or any other winding, nor connected to any external electrical load. Understandably, since at least one end of the first auxiliary winding 12 is completely disconnected electrically, it cannot form a closed electrical loop with the first winding 11 or any external circuit. According to basic circuit principles, current formation requires a closed loop. In the open-circuit state, after the potential of the first auxiliary winding 12 stabilizes, no current flows through it, and its circulating current and load current are strictly zero. Therefore, the first auxiliary winding 12 will not incur additional winding losses or heating risks due to shunt current, load current, or circulating current. Furthermore, the open-circuit auxiliary winding of this application is not equivalent to a conventional Faraday shielding winding. The former is used to provide a potential reference point, while the latter is used for electric field shielding; their number of turns, design purpose, and working principle are fundamentally different.

[0045] It is understood that, in this embodiment, by setting a first auxiliary winding 12 that is wound in parallel with the first winding 11 and has a mirror potential, and by leaving at least one end of the first auxiliary winding 12 open and suspended, and by electrically connecting the terminal 18 thereon to the first shielding layer 13, a stable equipotential point can be provided for the first shielding layer 13 within the insulation layer 14 without relying on external leads. This achieves precise potential clamping of the first shielding layer 13 without damaging the insulation structure of the first winding 11 for tapping, thus ensuring the integrity of the main insulation structure. At the same time, since the first auxiliary winding 12 is open, no current loop is formed inside it, eliminating the risk of additional winding losses and heat generation caused by shunting or circulating current. Furthermore, all electrical connection structures are enclosed within the insulation layer 14, eliminating the need for external wiring and simplifying the transformer 1 output packaging process.

[0046] In one possible implementation, please refer to [the relevant documentation / reference]. Figure 1 and Figure 2 , Figure 2 This is a schematic diagram of the equivalent circuit of a power converter provided in one embodiment of this application. At least one of the terminals 18 is disposed on the first auxiliary winding 12 at the midpoint of the potential of the first winding 11.

[0047] Specifically, the power converter 2 is one application scenario of the transformer 1 provided in this application. The power converter 2 can achieve electrical isolation between input and output and has bidirectional power processing capability. For example... Figure 2As shown, the power converter 2 includes a first power conversion module 21 and a second power conversion module 22. The first power conversion module 21 is connected to one side of the first winding 11 of the transformer 1. The first power conversion module 21 is a power conversion circuit composed of switching transistors, with its bridge arms connected in parallel between the DC input buses. The second power conversion module 22 is connected to one side of the second winding 17 of the transformer 1. The second power conversion module 22 is also a power conversion circuit composed of switching transistors, with its bridge arms connected in parallel between the AC input buses. To provide a stable DC bus voltage to the first power conversion module 21 and absorb ripple current on the bus side, two input capacitors are typically connected in series between the positive and negative DC input buses. These two series-connected input capacitors together form a voltage divider capacitor structure for the DC bus, with the intermediate node being the midpoint of the two input capacitors.

[0048] It should be noted that the first shielding layer 13 obtains a potential corresponding to the first winding 11, typically at least the midpoint of the potential of the first winding 11, i.e., the midpoint of the conductor of the first winding 11's turns. In the power converter 2, the bridge arms of the first power conversion module 21 are respectively connected between the DC input positive bus and the negative bus, and the midpoint potential of the two series-connected input capacitors is the midpoint potential of the DC bus voltage. Since the square wave voltage output from the AC port of the full-bridge circuit changes symmetrically with respect to the midpoint of this bus when the circuit is working, this midpoint potential is a high-frequency static potential during circuit operation. By clamping the potential of the first shielding layer 13 to the midpoint of the potential of the first winding 11, the potential of the first shielding layer 13 can be made consistent with the potential at the corresponding midpoint position on the first winding 11, thereby effectively reducing the electric field strength between the first shielding layer 13 and the first winding 11, suppressing the risk of partial discharge, and optimizing the electric field distribution inside the transformer 1.

[0049] In this embodiment, since the first auxiliary winding 12 and the first winding 11 adopt a tightly parallel winding structure, they are in a completely identical electromagnetic field environment. The potential at each point along the axis of the first auxiliary winding 12 can accurately replicate the potential distribution at the corresponding position of the first winding 11. Therefore, when the number of turns of the first auxiliary winding 12 is designed to be at least half of the total number of turns of the first winding 11, such as Figure 2 As shown, the terminal 18, which is led out from the corresponding turn position of the first auxiliary winding 12 (i.e., the physical midpoint position of the first winding 11), has a potential that is the midpoint of the potential of the first winding 11. The first shielding layer 13 is electrically connected to the first auxiliary winding 12 through this terminal 18, so that the midpoint of the potential of the first winding 11 can be accurately obtained without damaging the insulation structure of the first winding 11.

[0050] It is understood that, in this embodiment, by setting the terminal 18 on the first auxiliary winding 12 at the position corresponding to the midpoint of the potential of the first winding 11, the first shielding layer 13 can directly obtain the midpoint of the potential of the first winding 11 without relying on external leads or damaging the insulation structure of the first winding 11. This midpoint corresponds to the midpoint potential of the two input capacitors in the power converter 2, providing a stable high-frequency potential static point for the first shielding layer 13, effectively suppressing common-mode noise, optimizing the electric field distribution inside the transformer 1, and improving the insulation reliability and electromagnetic compatibility performance of the transformer 1 under high-voltage and high-frequency operating conditions.

[0051] It is understood that, in other possible implementations, the terminal 18 may also be electrically connected to any end of the first winding 11, corresponding to the potential of the positive terminal of one input capacitor or the negative terminal of another input capacitor in the power converter 2; or, the terminal 18 may also be electrically connected to other points of the first winding 11, which is not limited in this application. Furthermore, it should be noted that... Figure 2 The power converter 2 shown is a dual active full-bridge converter, which is only one possible example. In other possible implementations, the power converter 2 can also be a series resonant converter, LLC resonant converter, etc., and this application does not limit it.

[0052] In one possible implementation, please refer again. Figure 1 and Figure 2 One end of the first auxiliary winding 12 is electrically connected to one end of the first winding 11.

[0053] Specifically, one end of the first auxiliary winding 12 is electrically connected to one end of the first winding 11. This connection aims to introduce a defined reference potential point to the first auxiliary winding 12. Since the other end of the first auxiliary winding 12 remains open and suspended, it is electrically "floating." Without a clear potential reference, the potential on the first auxiliary winding 12 may drift uncertainly due to electrostatic induction or stray electric fields, making it impossible to accurately replicate the potential distribution of the first winding 11. By fixing one end of the first auxiliary winding 12 to one end of the first winding 11, a reference potential identical to that at the end of the first winding 11 can be introduced to the first auxiliary winding 12. This effectively prevents electrostatic drift in the potential of the first auxiliary winding 12, ensuring that the potential at each point along the axial direction can stably and accurately mirror the potential distribution of the first winding 11.

[0054] It should be noted that the electrical connection between one end of the first auxiliary winding 12 and one end of the first winding 11 does not affect the insulation structure of the first winding 11. The first auxiliary winding 12 and the first winding 11 are wound in parallel, and are physically independent, each having a complete insulation layer 14. The electrical connection between one end of the first auxiliary winding 12 and one end of the first winding 11 is made at the ends of the two windings, rather than tapping at the middle turns of the first winding 11. Therefore, this connection method completely eliminates the need to strip, puncture, or damage the original insulation layer 14 of the first winding 11. Especially for high-frequency transformers 1 that use multi-strand stranded wire as conductors, this avoids manufacturing defects and the risk of local insulation degradation caused by damaging the insulation layer 14.

[0055] In this embodiment, one end of the first auxiliary winding 12 is electrically connected to one end of the first winding 11, while the other end of the first auxiliary winding 12 remains open and suspended. Since one end of the first auxiliary winding 12 is electrically completely disconnected, even if one end of the first auxiliary winding 12 is electrically connected to one end of the first winding 11, the first auxiliary winding 12 will not incur additional winding losses or heat generation risks due to shunt current, load current, or circulating current.

[0056] Understandably, in this embodiment, by electrically connecting one end of the first auxiliary winding 12 to one end of the first winding 11, a stable reference potential is introduced to the first auxiliary winding 12, effectively preventing electrostatic drift and ensuring that it can accurately replicate the potential distribution of the first winding 11. Simultaneously, this electrical connection method does not damage the insulation structure of the first winding 11, ensuring the integrity and reliability of the main winding insulation. Furthermore, since the other end of the first auxiliary winding 12 remains open and suspended, no current loop is formed inside, eliminating additional losses and heat generation risks caused by shunting or circulating currents, thus ensuring both shielding effectiveness and system efficiency and thermal reliability.

[0057] In one possible implementation, please refer to [the relevant documentation / reference]. Figure 3 , Figure 3 This is a schematic diagram of the equivalent circuit of a transformer provided in another embodiment of this application. The transformer 1 further includes a second auxiliary winding 19, which is disposed within the receiving space 131. The second auxiliary winding 19 is wound in parallel with the first winding 11, and one end of the second auxiliary winding 19 is electrically connected to the other end of the first winding 11. The other end of the second auxiliary winding 19 is open-circuited and suspended. A terminal 18 is provided on the second auxiliary winding 19, and the terminal 18 is electrically connected to the side surface of the first shielding layer 13 adjacent to the second auxiliary winding 19.

[0058] Specifically, the second auxiliary winding 19 and the first winding 11 are wound in parallel. Similar to the first auxiliary winding 12, the second auxiliary winding 19 is also in the same electromagnetic field environment as the first winding 11. Therefore, the potential at each point along the axis of the second auxiliary winding 19 can accurately replicate the potential distribution at the corresponding position of the first winding 11, that is, the second auxiliary winding 19 and the first winding 11 have mirror potential states.

[0059] In this embodiment, such as Figure 3 As shown, one end of the first auxiliary winding 12 is electrically connected to one end of the first winding 11, introducing a reference potential at the beginning of the first winding 11; one end of the second auxiliary winding 19 is electrically connected to the other end of the first winding 11, introducing a reference potential at the end of the first winding 11. The two auxiliary windings introduce reference potentials from both ends of the first winding 11, forming a mirror-symmetric potential configuration in physical space, further enhancing the symmetry of the potential distribution inside the transformer 1. It should be noted that the electrical connection between the first auxiliary winding 12 and one end of the first winding 11, and the electrical connection between the second auxiliary winding 19 and the other end of the first winding 11, are both electrical connections made at the winding ends, requiring no stripping, piercing, or damage to the original insulation structure of the first winding 11, and will not affect the insulation structure of the first winding 11. Furthermore, the other end of the second auxiliary winding 19 remains open and suspended, and it cannot form a closed electrical circuit with the first winding 11 or any external circuit. Therefore, no circulating current will be formed inside the second auxiliary winding 19, and no additional winding loss or heat generation risk will be generated due to current shunting or circulating current.

[0060] In this embodiment, the terminal 18 provided on the second auxiliary winding 19 has the same structure as the terminal 18 provided on the first auxiliary winding 12. Both are potential taps led out from a certain number of turns on the second auxiliary winding 19. Their specific structure and connection method can be referred to the aforementioned description of the terminal 18, which will not be repeated here. It should be further noted that the terminal 18 on the second auxiliary winding 19 is also electrically connected to the side surface of the first shielding layer 13 adjacent to the second auxiliary winding 19. By providing the terminal 18 on the first auxiliary winding 12 and the second auxiliary winding 19 respectively, the corresponding potential at different positions of the first winding 11 can be introduced into different areas of the first shielding layer 13. For example, such as... Figure 3As shown, the terminal 18 on the first auxiliary winding 12 corresponds to the area near the midpoint of the potential of the first winding 11, and the terminal 18 on the second auxiliary winding 19 corresponds to the potential point near the other end of the first winding 11. This multi-point cooperative clamping design can overcome the problem of increased potential distribution differences when clamping a single node due to the use of a semi-conductive material (which has high resistivity) in the first shielding layer 13. By achieving multi-node potential clamping at different physical locations on the surface of the first shielding layer 13, the potential at each point of the first shielding layer 13 is spatially highly matched with the potential of the adjacent turns of the first winding 11, which can effectively reduce the electric field strength between the first shielding layer 13 and the first winding 11, and further optimize the electric field distribution inside the transformer 1.

[0061] It is understood that in this embodiment, by adding a second auxiliary winding 19 wound in parallel with the first winding 11, with one end electrically connected to the other end of the first winding 11 and the other end open and suspended, and by setting the terminal 18 on the second auxiliary winding 19 that is electrically connected to the first shielding layer 13, the corresponding potentials at different positions of the first winding 11 are introduced into different areas of the first shielding layer 13. The first auxiliary winding 12 and the second auxiliary winding 19 symmetrically introduce reference potentials from both ends of the first winding 11, so that the transformer 1 exhibits a highly balanced potential distribution symmetry in space, which can effectively improve the shielding effect. At the same time, the multi-point clamping design effectively overcomes the problem of uneven potential distribution caused by the high resistivity when the first shielding layer 13 is made of semi-conductive material, significantly improves the overall potential uniformity of the first shielding layer 13, further reduces the interlayer electric field strength, and improves the insulation reliability and service life of the transformer 1 under high-frequency and high-voltage conditions.

[0062] In one possible implementation, please refer to [the relevant documentation / reference]. Figure 4 , Figure 4 A schematic diagram of the transformer equivalent circuit provided for another embodiment of this application. For example... Figure 4As shown, the terminal 18 on the first auxiliary winding 12 corresponds to the region near the midpoint of the potential of the first winding 11, and the terminal 18 on the second auxiliary winding 19 also corresponds to the region near the midpoint of the potential of the first winding 11. It can be understood that this arrangement allows the first shielding layer 13 to simultaneously obtain the midpoint reference of the potential of the first winding 11 through both the first auxiliary winding 12 and the second auxiliary winding 19 at different physical positions along its axial direction, forming a redundant connection architecture with multiple points cooperating and clamping at the same target potential. Compared to the single-point clamping method, this redundant connection architecture can further reduce the potential gradient difference caused by the use of semiconductive material in the first shielding layer 13, so that the first shielding layer 13 can maintain a stable potential consistent with the midpoint of the potential of the first winding 11 over a wider area. This more effectively homogenizes the electric field distribution between the first shielding layer 13 and the first winding 11 and suppresses the phenomenon of local electric field concentration. On the other hand, even if the connection between the first auxiliary winding 12 or the second auxiliary winding 19 and the first shielding layer 13 deteriorates due to manufacturing tolerances or long-term operation, the other auxiliary winding can still independently maintain the potential clamping function of the first shielding layer 13, thereby improving the reliability and insulation life of the transformer under high-frequency and high-voltage conditions for long-term operation.

[0063] It should be noted that, in other possible implementations, the way the terminals 18 on the first auxiliary winding 12 and the second auxiliary winding 19 are set with potential points can also be changed or combined according to the actual needs of the transformer 1, and this application does not limit this.

[0064] In one possible implementation, please refer to [the relevant documentation / reference]. Figure 5 , Figure 5 This is a schematic diagram of the equivalent circuit of a transformer provided in another embodiment of this application. The transformer 1 further includes a dielectric layer 110 and a coupling electrode 111. The dielectric layer 110 at least partially covers the first winding 11. The coupling electrode 111 is capacitively connected to the first winding 11 through the dielectric layer 110. The coupling electrode 111 is electrically connected to the first auxiliary winding 12. Both ends of the first auxiliary winding 12 are open-circuited and suspended.

[0065] Specifically, the dielectric layer 110 is made of a high dielectric constant material, such as a high dielectric constant ceramic material, polyester film, or other insulating materials with a high relative dielectric constant. The dielectric layer 110 at least partially covers the periphery of the first winding 11. It is configured by additionally wrapping a high dielectric constant material around the outside of the original insulation structure of the first winding 11, without peeling, piercing, or damaging the original insulation structure of the first winding 11. Therefore, the dielectric layer 110 does not affect the insulation structure and insulation performance of the first winding 11 itself. Especially for high-frequency transformers 1 using multi-strand strands as conductors, this avoids manufacturing defects and the risk of localized insulation degradation caused by damaging the insulation structure.

[0066] It is understood that by covering the first winding 11 with a high dielectric constant dielectric layer 110 and placing the coupling electrode 111 (e.g., a metal foil) outside the dielectric layer 110, the coupling electrode 111 and the conductor inside the first winding 11 are separated by the dielectric layer 110, forming a capacitor structure. The term "capacitive connection" means that the coupling electrode 111 and the first winding 11 are not directly electrically connected through a physical wire, but rather the AC signal is coupled and transmitted through the capacitive effect. That is, the high-frequency AC potential signal on the first winding 11 can be transmitted to the coupling electrode 111 through the dielectric layer 110 via electric field coupling, while the DC component is isolated. The coupling electrode 111 is electrically connected to the first auxiliary winding 12 to transmit the high-frequency AC reference potential extracted through capacitive coupling to the first auxiliary winding 12, providing a high-frequency dynamic reference potential for the first auxiliary winding 12 and preventing electrostatic drift.

[0067] Since the first auxiliary winding 12 obtains a high-frequency dynamic reference potential from the first winding 11 via the coupling electrode 111 and the dielectric layer 110 in a capacitive coupling manner, without needing to be directly electrically connected to the end of the first winding 11 through a physical wire, in this embodiment, both ends of the first auxiliary winding 12 can remain physically open and electrically suspended, without needing to fix either end to the first winding 11 electrically. Thus, the first auxiliary winding 12 will not form a closed electrical loop with the first winding 11 or any external circuit, and its internal circulating current and load current are strictly zero throughout, completely eliminating the additional winding losses and heat generation risks caused by current shunting or circulating current. Simultaneously, relying on a parallel electromagnetic field environment completely identical to that of the first winding 11, the first auxiliary winding 12 can still accurately replicate the potential distribution of the first winding 11, and through multiple terminals 18 provided on its winding body, introduce and distribute the potential at each point to the corresponding area of ​​the first shielding layer 13, achieving multi-point clamping of the first shielding layer 13.

[0068] It is understood that in this embodiment, by setting the dielectric layer 110 and the coupling electrode 111, the coupling electrode 111 is capacitively connected to the first winding 11 through the dielectric layer 110, and electrically connected to the first auxiliary winding 12. This allows for a stable high-frequency dynamic reference potential to the first auxiliary winding 12, which is open at both ends and suspended, without requiring direct electrical connection with physical wires or damaging the insulation structure of the first winding 11. This capacitive coupling method is particularly suitable for applications where both ends of the first auxiliary winding 12 need to remain open and no physical electrical connection is desired. While ensuring that the first auxiliary winding 12 can accurately replicate the potential distribution of the first winding 11, it completely eliminates the possibility of circulating current, further improving the insulation reliability and system efficiency of the transformer 1.

[0069] In one possible implementation, please refer to [the relevant documentation / reference]. Figure 6 and Figure 7 , Figure 6 A schematic diagram of the transformer equivalent circuit provided for yet another embodiment of this application; Figure 7 This is a schematic diagram of a first shielding layer structure provided in one embodiment of this application. The first shielding layer 13 includes a plurality of spaced conductive portions 132. The conductive portions 132 are disposed on one side surface of the first shielding layer 13 adjacent to the first auxiliary winding 12. The orthographic projection of the terminal 18 on the first shielding layer 13 falls within the range of the corresponding conductive portion 132, and the terminal 18 is electrically connected to the corresponding conductive portion 132.

[0070] Specifically, the conductive portion 132 is disposed on the surface of the first shielding layer 13 adjacent to the first auxiliary winding 12, for improving the electrical contact performance between the terminal 18 and the first shielding layer 13. In this embodiment, since the first shielding layer 13 is made of a semi-conductive material, if the terminal 18 is made into direct point contact with the surface of the semi-conductive material of the first shielding layer 13, local heating or uneven potential transfer may occur due to high contact resistance.

[0071] In this embodiment, by providing conductive portions 132 with conductivity superior to that of a semiconducting material on the surface of the first shielding layer 13, and electrically connecting the terminals 18 to the corresponding conductive portions 132, the contact resistance can be effectively reduced, ensuring that the potential introduced by the terminals 18 can be reliably and with low impedance transmitted to the first shielding layer 13. Simultaneously, the plurality of conductive portions 132 are spaced apart along the axial direction of the first auxiliary winding 12, each corresponding to a plurality of terminals 18 extending from different turns on the first auxiliary winding 12. This allows the introduction of corresponding potentials at different positions of the first winding 11 at multiple axial positions of the first shielding layer 13. This multi-point, distributed arrangement of the conductive parts 132 can uniformly transmit the potential introduced by each terminal 18 on the first auxiliary winding 12 to different areas of the first shielding layer 13, effectively overcoming the problem of potential conduction attenuation and uneven distribution caused by the high resistivity of the semiconducting material itself when clamped at a single node. This makes the potential at each point of the first shielding layer 13 highly matched with the potential of the adjacent first winding 11 turns in space, thereby further reducing the electric field strength between the first shielding layer 13 and the first winding 11 and optimizing the electric field distribution inside the transformer 1.

[0072] It is understood that in this embodiment, by providing multiple spaced conductive portions 132 on the surface of the first shielding layer 13 adjacent to the first auxiliary winding 12, and electrically connecting each terminal 18 to the corresponding conductive portion 132, the contact resistance between the terminal 18 and the first shielding layer 13 is effectively reduced, ensuring the reliability and uniformity of potential transmission. Simultaneously, the multiple conductive portions 132 are spaced apart along the axial direction, enabling multi-point clamping to be simultaneously achieved in different areas of the first shielding layer 13. This effectively improves the problem of uneven potential distribution caused by the high resistivity of the semiconductive material, further optimizing the electric field distribution inside the transformer 1 and enhancing the insulation reliability and service life of the transformer 1 under high-frequency, high-voltage conditions.

[0073] In one possible implementation, please refer again. Figure 7The conductive portion 132 includes conductive branches 1321 extending to both sides along the surface of the first shielding layer 13. The extending direction of the conductive branches 1321 is perpendicular to the axial direction of the first auxiliary winding 12. The ends of the conductive branches 1321 extending from the same conductive portion 132 are spaced apart.

[0074] Specifically, the conductive portion 132 has a comb-like structure. The conductive portion 132 directly connected to the terminal 18 is the main trunk, and multiple independent conductive branches 1321 branch outward from the conductive portion 132, realizing a multi-line distributed connection with the first shielding layer 13. It can be understood that, compared with a single-point conductive connection, this multi-branch comb-like structure can evenly transmit the reference potential introduced by the terminal 18 to a large area of ​​the first shielding layer 13, significantly improving the overall potential uniformity of the first shielding layer 13.

[0075] It should be noted that the ends of the conductive branches 1321 extending from the same conductive portion 132 are spaced apart, meaning that the conductive branches 1321 are not closed at their ends, and a certain gap is maintained between the ends of each conductive branch 1321. This non-closed comb-like structure design has significant technical implications: In the high-frequency transformer 1, the first shielding layer 13 is in a high-frequency alternating magnetic field environment. If the ends of the conductive branches 1321 are connected to form a closed conductive loop, according to Faraday's law of electromagnetic induction, induced circulating currents (i.e., eddy currents) will be generated in the closed loop, leading to additional eddy current losses and localized heating, reducing system efficiency and affecting insulation life. In this embodiment, the ends of the conductive branches 1321 are spaced apart, so that the conductive branches 1321 extending from the same conductive portion 132 do not form any closed conductive loops. Structurally, this completely avoids the possibility of circulating currents generated inside the conductive branches 1321, effectively eliminating the eddy current loss problem that exists in traditional solid copper foil or closed conductors in high-frequency alternating magnetic fields. Meanwhile, each conductive branch 1321 is an open-circuit branch structure, which is only used to transfer the potential from the main branch to different areas of the first shielding layer 13, and does not carry circulating current. Therefore, it will not generate additional losses and heat due to eddy current effect.

[0076] It is understood that in this embodiment, by configuring the conductive part 132 to include the conductive branches 1321 extending to both sides along the surface of the first shielding layer 13, and making the extension direction of the conductive branches 1321 perpendicular to the axial direction of the first auxiliary winding 12, and the ends of the conductive branches 1321 extending from the same conductive part 132 are spaced apart, the function of uniformly distributing the reference potential introduced by the terminal 18 to a large area of ​​the first shielding layer 13 is realized. At the same time, the non-closed comb structure fundamentally avoids the generation of circulating currents (eddy currents) in the high-frequency alternating magnetic field, eliminates the high-frequency eddy current loss and local heating problems existing in traditional conductor connection points, and takes into account the high-frequency efficiency and thermal reliability of the system while ensuring the shielding effect and potential uniformity.

[0077] In one possible implementation, please refer to [the relevant documentation / reference]. Figures 8 to 10 , Figure 8 A schematic diagram of the transformer equivalent circuit provided for yet another embodiment of this application; Figure 9 A schematic diagram of the transformer equivalent circuit provided for yet another embodiment of this application; Figure 10 This is a schematic diagram of the equivalent circuit of a transformer provided in another embodiment of this application. A plurality of terminals 18 are provided on the first auxiliary winding 12. The plurality of terminals 18 are axially spaced at different turns of the first auxiliary winding 12 and are electrically connected to the first shielding layer 13 respectively.

[0078] Specifically, such as Figure 8 As shown, in an embodiment where one end of the first auxiliary winding 12 is electrically connected to one end of the first winding 11, and the other end is open and suspended, a single terminal 18 can be provided on the first auxiliary winding 12, or multiple terminals 18 spaced apart along the axial direction can be provided; Figure 9 As shown, both the first auxiliary winding 12 and the second auxiliary winding 19 are provided with a plurality of terminals 18 distributed along their respective axial directions. Each terminal 18 is led out from a different number of turns of the corresponding auxiliary winding and is electrically connected to a different physical location on the first shielding layer 13. Figure 10 As shown, in an embodiment where the first auxiliary winding 12 introduces the reference potential of the first winding 11 through the coupling electrode 111, a single terminal 18 may be provided on the first auxiliary winding 12, or multiple terminals 18 may be provided at intervals along the axial direction.

[0079] It is understood that, in this embodiment, by setting multiple terminals 18 to be electrically connected to the points corresponding to the first winding 11, the potential difference between the conductors of the first shielding layer 13 and the first winding 11 can be reduced. That is, the potential distribution on the surface of the first shielding layer 13 can correspond to the potential of the conductor of the first winding 11, thereby effectively reducing the electric field strength between the first shielding layer 13 and the first winding 11, suppressing the risk of partial discharge, optimizing the electric field distribution inside the transformer 1, and improving the insulation reliability and service life of the transformer 1 under high frequency and high voltage conditions.

[0080] It is understood that the various technical features involved in the above embodiments, such as the connection method between the first auxiliary winding 12 and the first winding 11 (single-end connection or capacitive coupling), the number of terminals 18 (single or multiple), the number of auxiliary windings (single or two), and the comb-like structure of the conductive part 132 and the conductive branch 1321, can be arbitrarily combined, provided that they do not contradict each other. For example, the embodiment in which the conductive part 132 is configured as a comb-like structure can be combined with any of the above embodiments. This application will not describe all the possible combinations one by one, but it should be understood that as long as the combination of these technical features does not contradict each other, it should be considered to be within the scope of this application.

[0081] It is understandable that the above implementation methods can be flexibly combined according to actual design requirements to meet application scenarios with different voltage levels, power levels and insulation design requirements, and have wide applicability and good engineering practicality.

[0082] In one possible implementation, the second shielding layer 15 and the magnetic core 16 are used to receive grounding signals.

[0083] Specifically, receiving a grounding signal for the second shielding layer 15 and the magnetic core 16 means electrically connecting the second shielding layer 15 and the magnetic core 16 to the system reference ground (e.g., the negative terminal of the DC bus or the protective grounding terminal). From the perspective of the working principle of the transformer 1, the first winding 11 and the second winding 17 achieve isolated power transmission through the magnetic core 16. The magnetic core 16 carries high-frequency alternating magnetic flux and usually has a certain degree of conductivity (e.g., ferrite material or metal powder core). During the operation of the transformer 1, the high-frequency alternating magnetic field may induce displacement current or common-mode voltage on the magnetic core 16. If the magnetic core 16 is not grounded, its potential may fluctuate with the change of the high-frequency magnetic field, becoming an interference source of spatial stray electric field coupling, which has an adverse effect on the electric field distribution inside the transformer 1. Connecting the magnetic core 16 to the system reference ground can provide a low-impedance discharge path for the induced charge on the magnetic core 16, stabilize the reference potential of the magnetic core 16, and thus suppress common-mode interference.

[0084] Meanwhile, the second shielding layer 15 covers the outside of the insulating layer 14, forming the outermost shielding structure of the transformer 1. The second shielding layer 15 receives the grounding signal, maintaining a constant reference ground potential and forming an electromagnetic shielding barrier outside the transformer 1. On one hand, the second shielding layer 15 isolates the high-frequency electromagnetic field inside the transformer 1 from the external environment, reducing electromagnetic interference from the transformer 1 to external circuits. On the other hand, the second shielding layer 15 also blocks electromagnetic noise from the external space from entering the transformer 1, preventing interference with the normal operation of the first winding 11 and the second winding 17. Furthermore, the second shielding layer 15, in conjunction with the first shielding layer 13, forms a double-layer shielding structure. The first shielding layer 13 is clamped at a specific potential (such as the midpoint of the potential) of the first winding 11 to optimize the internal electric field distribution, while the second shielding layer 15 is connected to the system reference ground to suppress common-mode noise and external electromagnetic radiation. Through the synergistic cooperation of the inner and outer shielding layers, the electromagnetic compatibility performance of the transformer 1 can be effectively improved.

[0085] Understandably, in this embodiment, by electrically connecting the second shielding layer 15 and the magnetic core 16 to the system reference ground, the second shielding layer 15 forms a stable grounded shielding barrier, which suppresses the electromagnetic radiation emitted by the transformer 1 to the outside and blocks the influence of external noise on the inside of the transformer 1. At the same time, grounding the magnetic core 16 provides a discharge path for induced charges, stabilizes the reference potential of the magnetic core 16, and effectively suppresses common-mode interference. The second shielding layer 15 and the first shielding layer 13 form a dual-layer shielding architecture that works synergistically, jointly improving the electromagnetic compatibility performance and operational reliability of the transformer 1 under high-frequency and high-voltage conditions.

[0086] Based on the same inventive concept, this application also provides a power converter 2, which can be referred to in conjunction with the invention. Figure 2 and Figure 11 , Figure 11 This is a schematic diagram of the equivalent circuit of a power converter provided in one embodiment of this application. The power converter 2 includes a first power conversion module 21, a second power conversion module 22, and a transformer 1 as described above. The first power conversion module 21 is connected to the first winding 11, and the second power conversion module 22 is connected to the second winding 17.

[0087] The technical features of the transformer 1 in the power converter 2 are described above and will not be repeated here.

[0088] The first power conversion module 21 may include any one of the following circuits: DC-DC conversion circuit, DC-AC conversion circuit, AC-AC conversion circuit, and AC-DC conversion circuit; the second power conversion module 22 may include any one of the following circuits: DC-DC conversion circuit, DC-AC conversion circuit, AC-AC conversion circuit, and AC-DC conversion circuit; that is, the power converter 2 may be configured as any one of the following: bidirectional DC / DC converter, bidirectional DC / AC converter, bidirectional AC / AC converter, and bidirectional AC / DC converter.

[0089] For example, the power converter 2 can be configured as any one of a dual active full-bridge converter, a series resonant converter, or an LLC resonant converter. The series resonant converter is an isolated DC / DC topology that achieves power conversion through a series resonant circuit formed by an inductor and a capacitor. It has advantages such as simple structure and the ability to achieve soft switching of the primary-side switching transistor across the entire load range. Therefore, it is suitable for the high-frequency and modular development trend of the high-frequency transformer 1, and can achieve high efficiency and power density. In the solid-state transformer 1 system, the series resonant converter operating in DC transformer mode is one of the candidate solutions for an isolated bidirectional DC / DC converter.

[0090] In this embodiment, such as Figure 11 As shown, the power converter 2 is exemplified as an LLC resonant converter. The LLC resonant converter is a three-element resonant converter developed from a series resonant converter, and its resonant network includes a resonant inductor and a resonant capacitor. For example... Figure 11 As shown, the LLC resonant converter converts the input DC voltage into a high-frequency AC square wave voltage through a front-stage full-bridge inverter circuit. After passing through the resonant cavity, the current becomes a sine wave. This voltage is then transmitted to the subsequent stage through a high-frequency transformer 1, and finally converted into a DC output voltage by the subsequent rectifier and filter circuit. The LLC resonant converter can achieve zero-voltage turn-on of the primary-side switch and zero-current turn-off of the secondary-side rectifier across the entire load range, thereby significantly reducing switching losses and improving overall efficiency. Simultaneously, the LLC resonant converter has a wide voltage regulation range, suitable for applications with large input and output voltage ranges, and does not require an output filter inductor, effectively reducing circuit size. Since soft switching is easily achieved on both the primary and secondary sides, the LLC resonant converter is one of the high-efficiency, high-density, and low-cost isolated DC / DC topologies suitable for medium and low power applications.

[0091] The transformer 1 provided in this application can be widely used in various power converters 2, including but not limited to the dual active full-bridge converter, the series resonant converter, and the LLC resonant converter. Because the transformer 1 in this application constructs a potential reference point on the first shielding layer 13 through the first auxiliary winding 12 with one end open, it can achieve precise potential clamping of the first shielding layer 13 without damaging the main insulation structure, while eliminating additional losses in the auxiliary winding. Therefore, it is particularly suitable for high-frequency isolated DC / DC conversion scenarios with high requirements for insulation reliability and efficiency.

[0092] It is understood that in other possible implementations, the power converter 2 may also be a full-bridge inverter, a full-bridge rectifier, a matrix converter, etc., and this application does not limit it in this regard.

[0093] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0094] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A transformer, characterized in that, The transformer includes a first winding, a first auxiliary winding, a first shielding layer, an insulating layer, a second shielding layer, a magnetic core, and a second winding. The first shielding layer surrounds and forms a receiving space, and the first winding and the first auxiliary winding are disposed in the receiving space; the first winding and the first auxiliary winding are wound in parallel, and the first winding and the first auxiliary winding have mirror potential states; the mirror potential state means that the potential of each point of the first auxiliary winding along its axis is equal to the potential of the first winding at the corresponding position along the same axis. The insulating layer covers the first shielding layer, the second shielding layer covers the insulating layer, and the first winding and the second winding achieve isolated transmission of electrical energy through the magnetic core; At least one end of the first auxiliary winding is open and suspended. The first auxiliary winding is provided with at least one terminal, which is electrically connected to the side surface of the first shielding layer adjacent to the first auxiliary winding.

2. The transformer according to claim 1, characterized in that, At least one of the terminals is located on the first auxiliary winding at the midpoint of the potential corresponding to the first winding.

3. The transformer according to claim 1, characterized in that, One end of the first auxiliary winding is electrically connected to one end of the first winding.

4. The transformer according to claim 3, characterized in that, The transformer also includes a second auxiliary winding, which is disposed within the receiving space. The second auxiliary winding is wound in parallel with the first winding, and one end of the second auxiliary winding is electrically connected to the other end of the first winding. The other end of the second auxiliary winding is open-circuited and suspended. A terminal is provided on the second auxiliary winding, and the terminal is electrically connected to the side surface of the first shielding layer adjacent to the second auxiliary winding.

5. The transformer according to claim 1, characterized in that, The transformer further includes a dielectric layer and a coupling electrode. The dielectric layer at least partially covers the first winding. The coupling electrode is capacitively connected to the first winding through the dielectric layer and electrically connected to the first auxiliary winding. Both ends of the first auxiliary winding are open-circuited and suspended.

6. The transformer according to claim 1, characterized in that, The first shielding layer includes a plurality of spaced conductive portions, which are disposed on one side surface of the first shielding layer adjacent to the first auxiliary winding. The orthographic projection of the terminal on the first shielding layer falls within the range of the corresponding conductive portion, and the terminal is electrically connected to the corresponding conductive portion.

7. The transformer according to claim 6, characterized in that, The conductive portion includes conductive branches extending to both sides along the surface of the first shielding layer. The extension direction of the conductive branches is perpendicular to the axial direction of the first auxiliary winding, and the ends of the conductive branches extending from the same conductive portion are spaced apart.

8. The transformer according to any one of claims 1-7, characterized in that, The first auxiliary winding is provided with a plurality of terminals, which are axially spaced at different turns of the first auxiliary winding and are electrically connected to the first shielding layer respectively.

9. The transformer according to claim 1, characterized in that, The second shielding layer and the magnetic core are used to be electrically connected to the system reference ground to receive grounding signals and to provide a low-impedance discharge path for the induced charge of the magnetic core.

10. A power converter, characterized in that, The power converter includes: a first power conversion module, a second power conversion module, and a transformer as described in any one of claims 1-9, wherein the first power conversion module is connected to the first winding, and the second power conversion module is connected to the second winding.

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