CN117831916A - Medium-high voltage magnetic device - Google Patents

Abstract

The present application relates to a medium-high voltage magnetic device comprising: a first magnetic core, a first winding, and a second magnetic core. The first winding is wound around the first magnetic core in an insulating manner, and the first winding is coupled with the first magnetic core; the second magnetic core is wound around the first winding in an insulating manner; the first magnetic core and the first winding are used for being connected with a high-voltage potential, the second magnetic core is used for being connected with a low-voltage potential, and the potential difference between the first magnetic core and the first winding is smaller than that between the first winding and the second magnetic core, so that the first magnetic core and the second magnetic core are magnetically coupled. The adoption of the medium-high voltage magnetic device can improve the power density and reduce the manufacturing cost.

Description

Medium-high voltage magnetic device

Technical Field

The application relates to the technical field of electricity, in particular to a medium-high voltage magnetic device.

Background

In an electrical power system, a medium voltage system is a common voltage class system, wherein system components are divided into a high voltage side and a low voltage side according to the voltage level. On the low voltage side, the insulation distance is relatively small because the voltage is low and the associated components and equipment do not need to be arranged in view of high voltage insulation. However, on the high voltage side, due to the higher voltage, the components and equipment need to reserve enough insulation distances from all ground potential, low voltage potential and other high voltage potential when being arranged, which results in increased insulation size of the high voltage magnetic part, increased insulation material consumption, increased insulation design and increased process implementation difficulty, and finally reduced power density.

Therefore, how to optimize the potential design and insulation process of the high-voltage magnetic component to improve the power density and reduce the manufacturing cost is an important technical challenge facing the current medium-voltage system field.

Disclosure of Invention

Based on this, it is necessary to provide a medium-high voltage magnetic device capable of improving power density and reducing manufacturing cost.

The application provides a medium-high voltage magnetic device, the medium-high voltage magnetic device includes:

a first magnetic core;

the first winding is wound around the first magnetic core in an insulating manner and is coupled with the first magnetic core;

the second magnetic core is wound around the first winding in an insulating manner;

the first magnetic core and the first winding are used for being connected with a high-voltage potential, the second magnetic core is used for being connected with a low-voltage potential, and the potential difference between the first magnetic core and the first winding is smaller than that between the first winding and the second magnetic core, so that the first magnetic core and the second magnetic core are magnetically coupled.

In one embodiment, the medium-high voltage magnetic device further comprises:

the solid insulating component wraps the first magnetic core and the first winding, and the second magnetic core is wound outside the solid insulating component and is arranged close to the solid insulating component.

In one embodiment, the solid insulating member comprises a body for encasing the first core and the first winding, the medium-high voltage magnetic device further comprising:

the first shielding layer is arranged on the outer surface of the body, close to the second magnetic core.

In one embodiment, the solid insulating member further comprises:

the umbrella skirt member is configured at one end of the body and is in transitional connection with the body to form a curvature transitional surface.

In one embodiment, the first shielding layer is a shielding layer formed by one or more of a semiconductive material, a sprayed conductive material and a metal shell.

In one embodiment, the medium-high voltage magnetic device further comprises:

and the second shielding layer is covered on part or all surfaces of the first magnetic core and/or the first winding.

In one embodiment, the difference between the length of the first magnetic core and the width of the first winding is smaller than a preset difference, and the width of the first winding is a winding distance of the first winding in the length direction of the first magnetic core.

In one embodiment, the medium-high voltage magnetic device is a transformer, and the medium-high voltage magnetic device further includes:

the second winding is wound between the second magnetic core and the first winding in an insulating way, the second winding is coupled with the second magnetic core, the second winding is used for accessing low-voltage potential, and the potential difference between the second winding and the second magnetic core is smaller than that between the second winding and the first winding.

In one embodiment, where a solid insulating member is included, the medium-high voltage magnetic device further includes:

the second windings are symmetrically and insulated in pairs and wound between the second magnetic core and the solid insulating component.

In one embodiment, part or all of the second winding and the second magnetic core are disposed inside the solid insulating member.

The medium-high voltage magnetic device has at least the following beneficial effects:

the first magnetic core and the first winding are used as a whole as high-voltage potential, the first magnetic core and the first winding are connected to the high-voltage potential, the second magnetic core is used as low-voltage potential, and the second magnetic core is connected to the low-voltage potential. In this way, when the magnetic circuit is formed by the two magnetic cores, the first winding, which is the high-voltage winding, is insulated by a thick insulation for the second magnetic core, which is the low-voltage magnetic core, because the potential difference between the first winding and the first magnetic core is large, and the insulation for the first magnetic core, which is the high-voltage magnetic core, is insulated by a thin insulation because the potential difference between the first winding and the first magnetic core is small, so that the insulation distance between the first winding and the first magnetic core is reduced, the insulation size and the use amount of the insulating material are reduced, and the cost is reduced while the power density is improved. In addition, since the second magnetic core located outside is a low-voltage magnetic core, high-voltage insulation is not required to be considered when the second magnetic core is arranged in the system, and insulation design between the medium-high-voltage magnetic device and other equipment is easier to realize.

Drawings

In order to more clearly illustrate the technical solutions of embodiments or conventional techniques of the present application, the drawings required for the descriptions of the embodiments or conventional techniques will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person of ordinary skill in the art.

FIG. 1a is a schematic diagram of a medium and high voltage magnetic device according to one embodiment;

FIG. 1b is a cross-sectional view of the medium and high voltage magnetic device shown in FIG. 1 a;

FIG. 1c is a diagram showing the positional relationship between a first core and a first winding of the medium-high voltage magnetic device shown in FIG. 1 a;

FIG. 2a is a schematic diagram illustrating a position of a second shielding layer according to an embodiment;

FIG. 2b is a schematic diagram illustrating a position of a second shielding layer according to another embodiment;

FIG. 2c is a schematic diagram showing the position of a second shielding layer according to another embodiment;

FIG. 3a is a schematic diagram of a medium-high voltage magnetic device according to another embodiment;

FIG. 3b is a cross-sectional view of the medium and high voltage magnetic device shown in FIG. 3 a;

FIG. 4a is a schematic diagram of a medium-high voltage magnetic device according to another embodiment;

fig. 4b is a cross-sectional view of the medium-high voltage magnetic device shown in fig. 4 a.

Detailed Description

In order to facilitate an understanding of the present application, a more complete description of the present application will now be provided with reference to the relevant figures. Examples of the present application are given in the accompanying drawings. This application may, however, be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

It will be understood that the terms "first," "second," and the like, as used herein, may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another element. For example, a first resistance may be referred to as a second resistance, and similarly, a second resistance may be referred to as a first resistance, without departing from the scope of the present application. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

It is to be understood that in the following embodiments, "connected" is understood to mean "electrically connected", "communicatively connected", etc., if the connected circuits, modules, units, etc., have electrical or data transfer between them.

It is understood that "at least one" means one or more and "a plurality" means two or more. "at least part of an element" means part or all of the element.

As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," and/or the like, specify the presence of stated features, integers, steps, operations, elements, components, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof. Also, the term "and/or" as used in this specification includes any and all combinations of the associated listed items.

In medium voltage power systems, components and equipment are divided into a high voltage side and a low voltage side according to their voltage levels, between which electrical isolation is typically achieved by means of a medium voltage transformer. This isolation is critical to ensure safe and stable operation of the system. On the low voltage side, since the voltage is relatively low, components and devices do not need to be arranged in consideration of high voltage insulation problems, and thus the insulation distance between different potentials can be reduced, thereby optimizing the spatial layout. However, on the high voltage side, the components and devices must be arranged with consideration of the insulation distance from all ground, voltage and other high voltage levels to ensure the safety of the system. This insulation requirement results in an increase in the volume of the high-side equipment and a decrease in the power density.

In order to increase the power density, high voltage magnetic components such as isolation transformers, reactors, etc. use solid insulation casting techniques to shorten the required insulation spacing. The core is used as the core part of the high-voltage magnetic parts, and the potential selection of the core has an important influence on the insulation design. To prevent the cores from developing a levitation potential, the cores in the high voltage magnetic component typically need to be connected to the same potential.

For reactors, the core is typically located within the winding and connected to a low voltage potential. The design of the insulation of the windings to the inside and the outside becomes particularly important as the windings are subjected to high voltage potentials. At a position where electric field distortion may occur, it is necessary to design a transition structure to prevent breakdown voltage or partial discharge. If the magnetic core and the winding are connected to high potential, the high-voltage insulation design is not needed between the winding and the magnetic core, but the external insulation size of the non-winding post magnetic core is still needed to be considered.

For transformers, an inner and outer winding structure is generally adopted, the high-voltage winding is located at the outer side, and the low-voltage winding and the magnetic core are located at the inner side. In this case, the core is typically connected to a low voltage potential. Due to the high potential characteristics of the high voltage windings, the insulation thickness to the inside and outside and the electric field design become particularly critical.

Therefore, the potential selection problem of the magnetic core not only increases the insulation size and the insulation material consumption of the high-voltage magnetic part, but also improves the difficulty of insulation design and process realization, and the factors together lead to the problems of reduced power density and more required insulation materials.

For the above reasons, in one exemplary embodiment, as shown in fig. 1, the present application provides a medium-high voltage magnetic device, including: a first magnetic core 2, a first winding 4 and a second magnetic core 6. The first winding 4 is wound around the first magnetic core 2 in an insulating manner, and the first winding 4 is coupled with the first magnetic core 2; the second magnetic core 6 is arranged around the first winding 4 in an insulating manner; wherein the first magnetic core 2 and the first winding 4 are used for connecting high voltage potential, the second magnetic core 6 is used for connecting low voltage potential, and the potential difference between the first magnetic core 2 and the first winding 4 is smaller than the potential difference between the first winding 4 and the second magnetic core 6, so that the first magnetic core 2 and the second magnetic core 6 are magnetically coupled.

As shown in fig. 1a, the medium-high voltage magnetic device may refer to a medium-high voltage reactor, and is mainly used in a medium-high voltage system, where the working environment voltage may be 3.3kv-35kv, which is not limited herein. The first magnetic core 2 can be a strip-shaped magnetic core, and the second magnetic core 6 can be an annular magnetic core, wherein the first magnetic core 2 and the second magnetic core 6 can be formed by splicing a plurality of sub-magnetic cores.

As shown in fig. 1a-1 c, the first winding 4 is wound around the first magnetic core 2 in an insulating manner, wherein the first winding 4 is formed with a first outgoing line 42 for connecting to a high voltage potential, and the first magnetic core 2 may be connected to one end of the first winding 4 in a single-point or multi-point manner to connect to the high voltage potential. Since the first winding 4 and the first magnetic core 2 are connected to high-voltage potential, the potential difference between the first winding 4 and the first magnetic core 2 is small, and the insulation distance between the two is only required to be designed in an insulation way according to the maximum potential difference, and the insulation is thin. It should be noted that, in the case where the first magnetic core 2 is shielded by the first winding 4, in some embodiments, the first magnetic core 2 may be integrated with the first winding 4 and the first magnetic core 2 as a high-voltage potential without performing potential extraction, thereby simplifying the process. Since the second magnetic core 6 is used for switching in the voltage level, after the first winding 4 is electrified, the magnetic circuits of main magnetic flux are formed on the first magnetic core 2 and the second magnetic core 6, so that the electric energy transmission is realized.

In the above embodiment, the first magnetic core 2 and the first winding 4 are taken as a whole as a high-voltage potential, both the first magnetic core 2 and the first winding 4 are connected to the high-voltage potential, the second magnetic core 6 is taken as a low-voltage potential, and the second magnetic core 6 is connected to the low-voltage potential. Thus, when the magnetic circuit is formed by two magnetic cores, the first winding 4 serving as the high-voltage winding is insulated by a thick insulation for the second magnetic core 6 serving as the low-voltage magnetic core because the potential difference between the first winding 4 and the second magnetic core 6 is large, and the first magnetic core 2 serving as the high-voltage magnetic core is insulated by a thin insulation because the potential difference between the first winding 4 and the first magnetic core 2 is small, so that the insulation distance between the first winding 4 and the first magnetic core 2 is reduced, the insulation size and the use amount of insulating materials are reduced, the power density is improved, and the cost is reduced. In addition, since the second magnetic core 6 located outside is a low-voltage magnetic core, it is not necessary to consider high-voltage insulation when it is arranged in the system, so that the insulation design of the medium-high-voltage magnetic device from other equipment is easier to realize.

In an exemplary embodiment, as shown in fig. 1a-1b, the medium-high voltage magnetic device further comprises a solid insulating member 8. The solid insulating member 8 surrounds the first magnetic core 2 and the first winding 4, and the second magnetic core 6 is wound outside the solid insulating member 8 and is disposed close to the solid insulating member 8.

By wrapping the first magnetic core 2 and the first winding 4, the solid insulating member 8 serves as an electrical isolation and protection, effectively preventing current leakage and electrical failure, improving the reliability of the device, and prolonging the service life thereof, as illustrated in fig. 1a-1 b. Secondly, the introduction of the solid insulating member 8 optimizes the structural design of the medium-high voltage magnetic device. By arranging the second magnetic core 6 around the solid insulating member 8 and close to the solid insulating member 8, a compact layout between the magnetic core and the windings is achieved, which not only reduces the overall volume of the device, but also improves its power density, so that the device, while meeting high performance requirements, has a smaller volume and a lighter weight. In addition, the introduction of the solid insulating member 8 also simplifies the manufacturing process of the medium-high voltage magnetic device, the first magnetic core 2 and the first winding 4 can be cast and molded once through the solid insulating member 8 without multiple mold opening, the insulating package of the magnetic core and the winding can be conveniently realized, the complex insulating structure and the complicated insulating treatment process are avoided, the manufacturing cost is reduced, and the production efficiency is also improved.

In an exemplary embodiment, as shown in fig. 1a, the solid insulation member 8 comprises a body 82, the body 82 being arranged to encase the first core 2 and the first winding 4, the medium-high voltage magnetic device further comprising a first shielding layer 10. The first shielding layer 10 is covered on the outer surface of the body 82 near the second magnetic core 6.

Wherein the first shielding layer 10 may refer to a low voltage shielding layer.

By providing the first shielding layer 10 close to the outer surface of the second magnetic core 6, as shown in fig. 1a-1b, the electric field is concentrated inside the solid insulating member 8, thereby reducing the influence of external electromagnetic interference on the inside of the device, and ensuring that the medium-high voltage magnetic device can work stably and reliably even in a high electromagnetic environment. Second, the introduction of the first shielding layer 10 optimizes the electric field distribution of the device, for example, in the absence of a shielding layer, the electric field may create an uneven distribution on the external surface of the solid insulating member 8, resulting in a reduction of the electrical performance; and the electric field is more uniformly distributed in the solid insulation by covering the shielding layer, so that the electrical efficiency and stability of the device are improved.

In one exemplary embodiment, as shown in fig. 1a, the solid insulating member 8 further comprises a shed member 84. The shed member 84 is configured at one end of the body 82, and is in transitional connection with the body 82 to form a curvature transitional surface.

Illustratively, as depicted in fig. 1a, sharp corners or abrupt structures in the electric field distribution tend to cause electric field lines to concentrate, thereby creating electric field distortions that increase the risk of electrical breakdown. By adding the shed member 84 to the solid insulating member 8, the concentration of electric field lines is avoided by providing a smooth curvature transition surface, so that the electric field distribution is more uniform, and the risk of electrical breakdown is reduced.

In an exemplary embodiment, the first shielding layer 10 is a shielding layer formed by one or more of a semiconductive material, a sprayed conductive material, and a metal shell.

For example, for application in low frequency voltage scenarios, the first shielding layer 10 may employ a sprayed conductive substance or a metal housing; in order to avoid the high frequency eddy current caused by magnetic flux, a semiconducting material with high resistivity is used in the high frequency voltage scenario.

In the above embodiment, according to different application scenarios, the most suitable shielding layer material may be selected. For example, in a low-frequency voltage scene, the spraying of conductive substances or the metal shell as a shielding layer can effectively shield external electromagnetic interference and improve the electrical performance of the device. In the high-frequency voltage scene, in order to avoid high-frequency eddy current caused by magnetic flux, a semiconductive material with high resistivity can be selected as a shielding layer, so that a good shielding effect can be maintained, and the influence of the high-frequency eddy current on the performance of a device can be avoided.

In an exemplary embodiment, as shown in fig. 2 a-2 c, the medium and high voltage magnetic device further comprises a second shield layer 12. The second shielding layer 12 covers part or all of the surface of the first magnetic core 2 and/or the first winding 4.

Wherein the second shielding layer 12 may be a high voltage shielding layer.

For example, as shown in fig. 2 a-2 c, in case the first winding 4 and the first magnetic core 2 are connected to a high voltage potential, the risk of electrical breakdown may increase due to non-uniformity of the electric field distribution in a high voltage operating environment. The surface of the first winding 4 can be externally coated with a high-voltage shielding layer, or part or all of the first magnetic core 2 can also be externally coated with a high-voltage shielding layer, or the first winding 4 and the first magnetic core 2 are externally coated with a high-voltage shielding layer together for homogenizing an electric field and shielding defects of the winding, so that the insulation performance is improved, the risk of electric breakdown is reduced, and the electric performance of a device is improved.

In an exemplary embodiment, as shown in fig. 1c, the difference between the length of the first magnetic core 2 and the width of the first winding 4 is smaller than a preset difference, and the width of the first winding 4 is a winding distance of the first winding 4 in the length direction of the first magnetic core 2.

For example, when the core is too short, flux may concentrate at the end edges of the core, resulting in local winding losses that are too high; when the core is too long, electric field concentration may be formed at the end of the core, resulting in distortion of the electric field and increased risk of electrical breakdown. By limiting the difference between the length of the magnetic core and the width of the windings, as shown in fig. 1c, the length of the first magnetic core 2 is close to the width of the first winding 4, and the uniformity of electric field distribution is ensured, so that the risks of local winding loss and electric breakdown are reduced, and the electric efficiency and the reliability of the device are improved.

In one exemplary embodiment, the medium and high voltage magnetic device is a transformer, and the medium and high voltage magnetic device further includes a second winding 14. The second winding 14 is wound between the second magnetic core 6 and the first winding 4 in an insulating way, the second winding 14 is coupled with the second magnetic core 6, the second winding 14 is used for connecting a low-voltage potential, and the potential difference between the second winding 14 and the second magnetic core 6 is smaller than that between the second winding 14 and the first winding 4.

As shown in fig. 3 a-3 b, the medium-high voltage magnetic device comprises, for example, a first core 2, a first winding 4 and a second core 6, and further comprises at least one second winding 14 to form a transformer. The second winding 14 is connected to the low voltage potential through the second outgoing line 142, and the second magnetic core 6 and the second winding 14 are connected to the low voltage potential, so that the potential difference between the two is smaller, so that the second magnetic core 6 and the second winding 14 are integrally used as the low voltage potential for insulation design, which is helpful for reducing the complexity and cost of the integral electrical system.

In one exemplary embodiment, the medium-high voltage magnetic device includes a plurality of second windings 14 in the case of including the solid insulating member 8. The plurality of second windings 14 are wound between the second magnetic core 6 and the solid insulating member 8 in a pairwise symmetrical insulating manner.

As illustrated in fig. 3 a-3 b, the medium-high voltage magnetic device may further comprise a plurality of second windings 14, and the plurality of second windings 14 may be completely independent from each other to form a multi-port coupling transformer; but also can be connected in series-parallel (the direct winding can be connected in series-parallel, and the equivalent is series-parallel through the control of an external power electronic device), and different voltage boosting and reducing requirements are adapted. In addition, as shown in fig. 3 a-3 b, the second windings 14 are wound between the second magnetic core 6 and the solid insulating member 8 in a pair-by-pair symmetrical insulation manner, i.e. a sandwich structure is formed as shown in the drawings, so as to improve the coupling consistency and reduce the winding loss.

In an exemplary embodiment, as shown in fig. 4 a-4 b, part or all of the second winding 14 and the second magnetic core 6 are arranged inside the solid insulating member 8.

For example, as shown in fig. 4a to 4b, in order to further simplify the manufacturing process of the medium-high voltage magnetic device, part or all of the second winding 14 and the second core 6 may be built in the solid insulating member 8, and a one-shot casting process may be adopted, so that the manufacturing process of the medium-high voltage magnetic device may be significantly simplified. Conventional manufacturing methods may require the individual components to be fabricated, assembled, and secured separately in multiple steps, which not only increases manufacturing time, but may also result in loose or defective connections between the components. The one-time casting molding process can complete the manufacture of a plurality of parts in the same process, thereby greatly improving the production efficiency. Second, the built-in design helps to enhance the overall structural strength of the medium and high voltage magnetic device. The solid insulating member 8 serves as a basic structure of the whole device, and by partially or wholly incorporating the second winding 14 and the second magnetic core 6 therein, a stronger overall structure can be formed, improving the shock resistance, impact resistance, and the like of the device.

In the description of the present specification, reference to the term "some embodiments," "other embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the present application. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application shall be subject to the appended claims.

Claims (10)

1. A medium-high voltage magnetic device, characterized in that the medium-high voltage magnetic device comprises:

a first magnetic core;

the first winding is wound around the first magnetic core in an insulating manner, and the first winding is coupled with the first magnetic core;

the second magnetic core is wound around the first winding in an insulating manner;

the first magnetic core and the first winding are used for being connected with a high-voltage electric potential, the second magnetic core is used for being connected with a low-voltage electric potential, and the potential difference between the first magnetic core and the first winding is smaller than that between the first winding and the second magnetic core, so that the first magnetic core and the second magnetic core are magnetically coupled.

2. The medium-high voltage magnetic device of claim 1, further comprising:

the solid insulation component wraps the first magnetic core and the first winding, and the second magnetic core is wound outside the solid insulation component and is arranged close to the solid insulation component.

3. The medium-high voltage magnetic device according to claim 2, wherein the solid insulating member includes a body for encasing the first core and the first winding, the medium-high voltage magnetic device further comprising:

the first shielding layer is arranged on the outer surface of the body, close to the second magnetic core, in a covering mode.

4. A medium and high voltage magnetic device according to claim 3, wherein said solid insulating member further comprises:

the umbrella skirt member is configured at one end of the body and is in transitional connection with the body to form a curvature transitional surface.

5. The medium-high voltage magnetic device according to claim 3, wherein the first shielding layer is a shielding layer formed by one or more of a semiconductive material, a sprayed conductive material, and a metal shell.

6. The medium-high voltage magnetic device of claim 1, further comprising:

and the second shielding layer is covered on part or all surfaces of the first magnetic core and/or the first winding.

7. The medium-high voltage magnetic device according to claim 1, wherein a difference between a length of the first magnetic core and a width of the first winding is smaller than a preset difference, and the width of the first winding is a winding distance of the first winding in a length direction of the first magnetic core.

8. The medium-high voltage magnetic device according to any one of claims 1-7, wherein the medium-high voltage magnetic device is a transformer, the medium-high voltage magnetic device further comprising:

the second winding is wound between the second magnetic core and the first winding in an insulating mode, the second winding is coupled with the second magnetic core, the second winding is used for being connected with the low-voltage potential, and the potential difference between the second winding and the second magnetic core is smaller than that between the second winding and the first winding.

9. The medium-high voltage magnetic device according to claim 8, wherein in the case of including a solid insulating member, the medium-high voltage magnetic device further comprises:

and the second windings are symmetrically and insulated in pairs and wound between the second magnetic core and the solid insulating component.

10. The medium-high voltage magnetic device according to claim 8, wherein part or all of the second winding and the second core are disposed inside the solid insulating member.