WO2023169224A1

WO2023169224A1 - High-voltage assembly of transformer, and transformer and power device

Info

Publication number: WO2023169224A1
Application number: PCT/CN2023/077915
Authority: WO
Inventors: 张泽龙; 黄朱勇; 胡小情
Original assignee: 华为数字能源技术有限公司
Priority date: 2022-03-07
Filing date: 2023-02-23
Publication date: 2023-09-14
Also published as: CN114743778A

Abstract

The present application relates to a high-voltage assembly of a transformer, and a transformer and a power device. The high-voltage assembly (20) comprises a high-voltage coil (21), an insulator (22), a ground structure (23) and a ground layer (24), wherein the ground structure comprises an embedded member (231) and a connector (232), which are connected to each other; the embedded member is located inside the insulator; part of a surface of the embedded member is exposed and is used for fixing a ground connector (90); the connector (232) is located on the outer surface of the insulator and is connected to the ground layer; the ground layer covers the insulator and the outer surface of the connector (232); and the ground layer (24), the connector (232), the embedded member (231) and the ground connector (90) are electrically connected in sequence to form a ground path. The high-voltage assembly provided in the present application has a stable and reliable ground path.

Description

High-voltage components of transformers, transformers and electrical equipment

This application claims priority to the Chinese patent application filed with the China Patent Office on March 7, 2022, with application number 202210227744.1, and the invention name is "High-voltage components of transformers, transformers and power equipment", the entire content of which is incorporated herein by reference. Applying.

Technical field

The present application relates to the technical field of transformer grounding, and in particular to a high-voltage component of a transformer, a transformer and electrical equipment.

Background technique

In the transformer design process, the grounding design of the transformer has always been a critical and difficult issue. For example, the high-voltage coil in a transformer is covered by an insulation layer. If a ground layer is sprayed on the outer surface of the insulation layer and the ground layer is electrically connected to the system ground, the grounding design of the high-voltage coil can be realized. In this design, the ground layer The stability and strength of the connection with the insulation layer determines the reliability of the grounding structure. Since the ground layer sprayed on the outer surface of the insulation layer only contacts the outer surface of the insulation layer, the bonding stability between the ground layer and the insulation layer is poor, which may cause the ground layer to fall off and reduce the reliability of the ground structure.

Contents of the invention

Embodiments of the present application provide a high-voltage component of a transformer, a transformer and power equipment, which have a reliable grounding structure.

In a first aspect, embodiments of the present application provide a high-voltage component of a transformer, including a high-voltage coil, an insulator, a ground structure and a ground layer. The insulator covers the high-voltage coil; the ground structure includes conductive embedded parts and connectors. , the embedded part and the high-voltage coil are isolated by the insulator, at least part of the embedded part is located inside the insulator, part of the surface of the embedded part is exposed and used to fix the ground connection part, the connection The connecting piece is located on the outer surface of the insulator, and the connecting piece is directly or indirectly connected to the embedded piece; part of the ground layer is connected to the surface of the connecting piece facing away from the insulator, and part of the ground layer is connected to the At least part of the outer surface of the insulator; the ground layer, the connecting piece, the embedded piece and the ground connecting piece are electrically connected in sequence to form a grounding path.

The grounding path of high-voltage components provided by this solution forms a reliable ground connection relationship, which can improve the safety of high-voltage components. The specific analysis is as follows: the ground layer is formed on the surface of the connector through electroplating or spraying to achieve electrical connection between the ground layer and the connector. During the assembly and use of high-voltage components, the locations where the ground layer and connectors are connected are static, and no external force will act on this location. For example, there will be no fixed connectors like screws at this location. Therefore, the grounding The electrical connection structure between the layer and the connector is not easily damaged and is not prone to open circuits. The electrical connection between the ground connector and the embedded component is a direct connection and does not depend on the ground layer. Even if the ground layer between the ground connector and the embedded component is damaged and breaks, it will not affect the ground connector and the embedded component. electrical connections between components. Therefore, the ground path of high-voltage components is stable and the risk of ground failure is low.

In a possible implementation, the embedded component includes first end surfaces and side surfaces facing different and adjacent directions. The first end surface is used to fix the grounding connector. The grounding structure further includes an intermediate component. The piece is located inside the insulator and is used to connect the side and the connecting piece. This solution provides a specific grounding structure architecture. The embedded part and the connecting part are connected through the middle part, which can make the position of the connecting part on the outer surface of the insulator more flexible and adapt to high-voltage components in different application scenarios.

In a possible implementation, the insert includes first end surfaces and side surfaces facing different and adjacent sides, and the first The end surface is used to fix the ground connection piece, the side surface includes a first area and a second area, the first area is connected between the second area and the first end surface, and the second area is located at the Inside the insulator, the first area is located outside the insulator and connected to the connector. The connector in the grounding structure provided by this solution is directly connected to the first area on the side of the embedded part. For the grounding structure, its structure is simpler, making the manufacturing process of connecting the grounding structure and the insulator uncomplicated and easy to implement. Lower production costs.

In a possible implementation, a surface of the connecting member facing away from the insulator is flush and coplanar with the first end surface. It can be understood that the outer surface and the first end surface of the connecting member can jointly form a planar structure or an arc-shaped surface, with a smooth transition between the two without any step structure. In this solution, the outer surface of the connector and the first end surface are coplanar, so that the surface of the grounding structure exposed outside the insulator becomes an integrated smooth transition surface structure. Setting the ground layer on such a smooth transition surface can make The connection between the ground plane and the ground structure is more reliable.

In a possible implementation, the embedded component includes a first end surface, the connecting component includes a first connection area and a second connection area, the first connection area is connected to the first end surface, and the second connection area A connection area is connected to the outer surface of the insulator, and the ground connection is connected to the first connection area. This solution provides a specific solution for the positional relationship between the connector and the embedded component. Since the first connection area of the connector is connected to the first end face of the embedded component, the embedded component can be fixed to the insulator first, and then the connection The piece is connected to the insert. After the insert and the insulator are assembled, the first end face is the part of the insert exposed on the surface of the insulator, making it easier to connect the connecting piece to the first end face.

In a possible implementation, the first end surface and the outer surface of the insulator used to connect the connecting piece are flush and coplanar. In this solution, the connection between the first end surface and the outer surface of the insulator is limited, so that the connector can have a flat structure, and the connection between the connector and the insulator has the advantage of being simple and stable.

In a possible implementation, the second connection areas are distributed on both sides of the first connection area; or, the second connection areas are arranged around the first connection area. This solution provides two specific connector layout plans, with a high degree of application freedom. The appropriate connector layout can be selected according to the structural form of the specific high-voltage components.

In a possible implementation, the connection member includes a hollow area, and part of the ground layer is in the hollow area and connected to the insulator. This solution is helpful to improve the stability of the connection between the connector and the ground layer.

In a possible implementation, the connecting member has a mesh structure. The mesh-structured connector is conducive to improving the stability of the connection between the connector and the ground layer.

In a possible implementation, the insulator includes a main insulating part and a protrusion, the main insulating part covers the high-voltage coil, the main insulating part includes a top surface, a bottom surface and a connection between the top surface and the The side between the bottom surfaces, the top surface is used to face the low-voltage coil of the transformer, the protrusion is protrudingly provided on the side, at least part of the embedded part is located inside the protrusion, and the embedded part is The partial surface connected to the ground connection member and the top surface are oriented in the same direction. This solution can realize the miniaturization of the main insulation part of the insulator, and provide a grounding structure on the protrusion. The grounding structure does not affect the safe distance of the isolation of the high-voltage coil, which is conducive to ensuring the safety of the high-voltage components.

In a possible implementation, the connecting member is located on the outer surface and/or the side of the protrusion. This solution provides different layout plans for the connectors of the grounding structure. The appropriate solution can be selected according to specific application requirements and has good flexibility.

In a possible implementation, the insulator includes a top surface, a bottom surface and a side surface connected between the top surface and the bottom surface, and the top surface and/or the bottom surface are used to face the low-voltage coil of the transformer, The connecting piece is located on the side, and a part of the surface of the embedded piece used to connect the ground connecting piece has the same orientation as the side. This solution is conducive to simplifying the manufacturing process of insulating parts. Since the outer surface of the main insulation part of the insulating part has no bump structure, the process of setting the ground layer on the outer surface of the main insulation part is also easy to control, which is beneficial to improving the ground layer and main insulation. The reliability of the connection between parts.

In a possible implementation, the high-voltage coil includes a winding part and a lead-out part, and the lead-out part and the winding part Arranged adjacently in the first direction, the insulator includes a main body insulating part and a lead insulating part, the main insulating part wraps the winding part, the lead insulating part wraps the lead-out part, and the grounding structure is provided on the In the main body insulation part, in the first direction, the grounding structure is located on the side of the winding part away from the lead-out part. For the transformer where the high-voltage assembly is located, the high-voltage component provided by this embodiment is suitable for application environments with sufficient installation space in the first direction.

In a possible implementation, the high-voltage coil includes a winding part and a lead-out part, the lead-out part and the winding part are arranged adjacent to each other in the first direction, and the insulator includes a body insulation part and a lead insulation part, and the The main body insulation part wraps the winding part, the lead insulation part wraps the lead-out part, the grounding structure is provided on the main body insulation part, the grounding structure and the winding part are spaced apart in the second direction, so The second direction and the first direction are arranged at an included angle. For the transformer where the high-voltage component is located, the high-voltage component provided by this solution is suitable for application environments with sufficient installation space in the second direction. It can control the size of the high-voltage component in the first direction, so that the size of the transformer in the first direction can be controlled. Easy to achieve miniaturization.

In one possible implementation, a hollow portion is provided at a portion where the ground layer and the insulator are connected, and the hollow portion is provided to increase the resistance of the ground layer. In other embodiments, the ground layer is made of conductive material or semiconductor material, and the high-voltage coil is within the radiation range of the leakage magnetic flux of the transformer. In this way, during the operation of the high-voltage component, the ground layer will form a closed ground loop. The existence of the ground layer causes additional losses due to induced electromotive force during the operation of the transformer. The higher the resistivity of the material used in the ground layer, the worse its potential limiting effect, but the smaller the loss caused by electromagnetic induction; vice versa. , the lower the resistivity of the material used in the ground layer, the better its potential limiting effect, but the higher the loss caused by electromagnetic induction, so this application limits the ground layer to semi-conductive materials to balance the loss and potential limiting effect.

In one possible implementation, the ground layer is formed on the surface of the insulator and the connector by spraying or electroplating; or, the ground layer is a flexible strip with semi-conductive properties. This solution provides a variety of ground layer production solutions, with high flexibility in use. You can choose the appropriate solution according to specific needs.

In a possible implementation, the resistivity of the ground structure is lower than the resistivity of the ground layer. This solution is helpful to ensure the stability of grounding.

In a second aspect, embodiments of the present application provide a transformer, including a magnetic core and the high-voltage component described in any possible implementation manner of the first aspect, and the high-voltage component is placed on part of the magnetic core. The transformer provided by this solution has the high-voltage components provided by the first aspect and has a reliable high-voltage grounding path, which can ensure the safety and service life of the transformer.

In a possible implementation, the transformer includes a low-voltage coil, a shield and a conductive cover plate. The low-voltage coil includes a first low-voltage coil and a second low-voltage coil. The shield includes a first shield and a second shield. The conductive cover plate includes a first conductive cover plate and a second conductive cover plate, and the magnetic core includes a first magnetic cover and a second magnetic cover arranged oppositely and connected to the first magnetic cover and the third magnetic cover. The magnetic column between the two magnetic covers, the first conductive cover plate, part of the first shielding member, the first magnetic cover, the first low-voltage coil, the high-voltage component, and the second low-voltage coil , the second magnetic cover, part of the second shielding part and the second conductive cover plate are stacked in sequence, the low voltage coil and the high voltage component surround the magnetic column, part of the first shielding part is located The first magnetic cover and the periphery of the first low-voltage coil, part of the second shielding member is located on the periphery of the second magnetic cover and the second low-voltage coil, and the conductive cover is used for grounding. The resistivity of the shielding member is higher than the resistivity of the conductive cover plate.

The transformer provided by the embodiment of the present application provides an insulator in the high-voltage component and uses the insulator to wrap the high-voltage coil to achieve isolation of the high-voltage coil and the low-voltage coil, which is conducive to the miniaturization design of the transformer. The high-voltage coil grounding layer and grounding structure are used to realize that the potential of the outer surface of the high-voltage component is ground potential. Shields and conductive covers are used to isolate and ground the low-voltage coil, thereby achieving reliable grounding of the transformer. By controlling the resistivity of the ground layer and the shield (specifically, the ground layer is made of semiconductive material and the shield is a mesh structure), the eddy current loss caused by the high-frequency magnetic field of the transformer can be reduced and the working efficiency of the transformer can be improved. Specifically, during the operation of the transformer, changing magnetic flux will be generated, and the magnetic flux is divided into main Magnetic flux and magnetic leakage flux. The main magnetic flux is constrained in the magnetic core for electromagnetic energy conversion, but the leakage magnetic flux is scattered in the transformer system. The structure of the ground layer and shielding on the surface of the high-voltage component will cause magnetic changes in the magnetic flux leakage. Under the influence of the current, an induced voltage is generated, which in turn generates losses. If the resistance value of the ground layer and shield becomes higher, the eddy current loss will become smaller accordingly. Therefore, the eddy current loss can be reduced by controlling the resistivity of the ground layer and shield.

In a possible implementation, the transformer further includes a fixing part, the fixing part is conductive, the fixing part fixedly connects the first conductive cover plate and the second conductive cover plate, and connects the The high-voltage component, the low-voltage coil and the shield are fixed between the first conductive cover plate and the second conductive cover plate. Through the setting of fixing parts, this solution can realize the fixed connection of each component of the transformer on the one hand. On the other hand, the fixing parts are also used to realize the grounding of the low-voltage coil, so that the overall structure of the transformer has the advantage of compactness and simplicity, which is beneficial to the transformer. The design is miniaturized in size.

In a possible implementation, the first shielding member includes a first part and a second part, the first part is stacked between the first magnetic cover and the first conductive cover, and the second The second part is connected to the edge of the first part and extends from the edge of the first part toward the direction of the high-voltage component. The second part is arranged around the periphery of the first magnetic cover and the first low-voltage coil. . This solution allows the second shielding member to cover more area of the second low-voltage coil through the specific structural design of the second part and the first part of the second shielding member, thereby improving the protection and isolation effect of the low-voltage coil.

In a possible implementation, the second part includes a top edge, a bottom edge, a first side and a second side, the top edge is connected to the first part, and the bottom edge contacts the high voltage component. Or a gap is formed with the high-voltage component, and an opening is formed between the first side and the second side, and the opening is at least used to accommodate the lead-out piece of the first low-voltage coil. This solution has the advantage of flexible assembly by setting the second part as an open-loop structure, and through the setting of the opening, it is convenient to install the lead-out parts of the low-voltage coil.

In a possible implementation, the first shielding member includes a sheet-shaped main body and a plurality of through holes provided on the main body. This solution can improve the resistance of the shield by arranging through holes on the sheet-shaped body, which is beneficial to improving the eddy current loss of the transformer.

In a possible implementation, the transformer includes a low-voltage coil, a shield and a conductive cover plate, and the magnetic core includes a first magnetic cover and a second magnetic cover that are oppositely arranged and connected to the first magnetic cover and the conductive cover. The magnetic column between the second magnetic cover, the high-voltage component and the low-voltage coil surround the magnetic column, the high-voltage component, the low-voltage coil, the first magnetic cover, part of the shield and all The conductive cover plates are stacked in sequence, and part of the shielding member is located on the periphery of the first magnetic cover and the low-voltage coil. The conductive cover plate is used for grounding, and the resistivity of the shielding member is higher than that of the conductive cover. The resistivity of the plate. This solution provides a specific transformer architecture. By setting insulators in high-voltage components, using the insulator to wrap the high-voltage coils, the high-voltage coils and low-voltage coils are isolated. The high-voltage coil ground layer and grounding structure are used to achieve the potential of the outer surface of the high-voltage components. Ground potential, use shields and conductive covers to isolate and ground low-voltage coils, achieving reliable grounding of the transformer.

In a possible implementation, the ground connection member is connected between the embedded member and the conductive cover plate. This solution collects the grounding of high-voltage components and the grounding of low-voltage coils through conductive cover plates. For transformers, the design of the grounding structure can save the space of the transformer and is conducive to the design of miniaturized transformer size.

In a possible implementation, the shielding member contacts the high-voltage component. The design of the shield contacting the high-voltage components allows the shield to be connected to the ground layer of the high-voltage components, thus forming a full range of isolation protection for the low-voltage coil, which is beneficial to improving the performance of the transformer.

In a third aspect, embodiment examples of the present application provide a power equipment, including a high-voltage circuit, a low-voltage circuit, and a transformer connected between the high-voltage circuit and the low-voltage circuit. The transformer is any possible implementation manner of the second aspect. transformer described above. The power equipment provided by this solution has the aforementioned transformer structure, which makes the voltage conversion of the power equipment more stable. The performance and life of electrical equipment can be guaranteed.

In a fourth aspect, an embodiment of the present application provides a transformer, including a magnetic core, a high-voltage component, a low-voltage coil, a shield, and a conductive cover plate. The magnetic core includes a first magnetic cover, a second magnetic cover and a magnetic column connected between the first magnetic cover and the second magnetic cover; the high-voltage component includes a high-voltage coil, an insulator and a ground layer. The insulator covers the high-voltage coil, and the ground layer covers at least part of the outer surface of the insulator; the low-voltage coil and the high-voltage component are stacked, and the low-voltage coil and the high-voltage component surround the magnetic column; the high-voltage coil The assembly, the low-voltage coil, the first magnetic cover, part of the shielding member and the conductive cover plate are stacked in sequence, and part of the shielding member is located on the periphery of the first magnetic cover and the low-voltage coil, so The conductive cover plate is used for grounding, and the resistivity of the shielding member is higher than that of the conductive cover plate; the ground layer of the high-voltage component is electrically connected to the conductive cover plate.

The transformer provided by this solution sets an insulator in the high-voltage component and uses the insulator to wrap the high-voltage coil to achieve isolation of the high-voltage coil and the low-voltage coil, which is conducive to the miniaturization design of the transformer. The high-voltage coil grounding layer and grounding structure are used to realize that the potential of the outer surface of the high-voltage component is ground potential. Shields and conductive covers are used to isolate and ground the low-voltage coil, thereby achieving reliable grounding of the transformer.

Description of the drawings

Figure 1A is a schematic diagram of power equipment provided by an embodiment of the present application;

Figure 1B is a schematic diagram of a transformer provided by a possible implementation of the power equipment shown in Figure 1A;

Figure 2A is a three-dimensional schematic view of a high-voltage component provided by an embodiment of the present application;

Figure 2B is a three-dimensional exploded schematic view of a high-voltage component provided by an embodiment of the present application;

Figure 3 is a partial cross-sectional view of a high-voltage component provided by an embodiment of the present application;

Figure 4 is a three-dimensional schematic view of the grounding structure of a high-voltage component provided by an embodiment of the present application;

Figure 5 is a grounding structure of a high-voltage component in the prior art;

Figure 6A is a schematic diagram of an embedded component of a grounding structure of a high-voltage component provided by an embodiment of the present application;

Figure 6B is a schematic diagram of the assembly relationship between the insert and the insulator shown in Figure 6A;

Figure 7A is a schematic diagram of an embedded component of a grounding structure of a high-voltage component provided by an embodiment of the present application;

Figure 7B is a schematic diagram of the assembly relationship between the insert and the insulator shown in Figure 7A;

Figure 8A is a schematic diagram of an embedded component of a grounding structure of a high-voltage component provided by an embodiment of the present application;

Figure 8B is a schematic diagram of an assembly relationship between the insert and the insulator shown in Figure 8A;

Figure 8C is a schematic diagram of another assembly relationship between the insert and the insulator shown in Figure 8A;

Figure 9A is a schematic diagram of a connector of a grounding structure of a high-voltage component provided by an embodiment of the present application;

Figure 9B is a schematic diagram of the connector of the grounding structure of the high-voltage component provided by an embodiment of the present application;

Figure 9C is a schematic diagram of the connector of the grounding structure of the high-voltage component provided by an embodiment of the present application;

Figure 10 is a partial cross-sectional view of a high-voltage component provided by an embodiment of the present application;

Figure 11 is a three-dimensional exploded schematic view of a high-voltage component provided by an embodiment of the present application;

Figure 12 is a schematic diagram of a high-voltage component provided by an embodiment of the present application;

Figure 13 is a three-dimensional schematic diagram of the grounding structure of a high-voltage component provided by an embodiment of the present application;

Figure 14 is a partial cross-sectional view of a high-voltage component provided by an embodiment of the present application;

Figure 15 is a partial cross-sectional view of a high-voltage component provided by an embodiment of the present application;

Figure 16 is a partial cross-sectional view of a high-voltage component provided by an embodiment of the present application;

Figure 17 is a schematic diagram of the ground layer of a high-voltage component provided by an embodiment of the present application;

Figure 18 is a perspective view of a transformer provided by an embodiment of the present application;

Figure 19 is a side view of a transformer provided by an embodiment of the present application;

Figure 20 is an exploded perspective view of a transformer provided by an embodiment of the present application;

Figure 21 is a schematic diagram of the second shield of the transformer provided by an embodiment of the present application.

Detailed ways

The embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.

FIG. 1A is a schematic diagram of electric equipment provided by an embodiment of the present application. Power equipment can be: power electronic transformers, DC microgrids, DC microgrid equipment or flexible power supply equipment, and converter equipment. The power equipment includes a high-voltage circuit, a low-voltage circuit and a transformer. The transformer is connected between the high-voltage circuit and the low-voltage circuit and is used to achieve functions such as raising and lowering voltage, matching impedance, and safe isolation. In one implementation, the transformer provided in the embodiment of the present application is It plays the role of high and low voltage isolation and insulation in power equipment. Specifically, the transformer includes a low-voltage coil, a high-voltage coil and a magnetic core. The low-voltage coil is electrically connected to the low-voltage circuit, and the high-voltage coil is electrically connected to the high-voltage circuit. Through the interaction of the low-voltage coil, the high-voltage coil and the magnetic core, the principle of electromagnetic induction is used to achieve low voltage. Conversion of energy between electrical circuits and high-voltage circuits. The high-voltage circuit and the low-voltage circuit described in this embodiment can be understood as two circuits with different voltages. The voltage of the high-voltage circuit is not limited to a specific high-voltage range value, nor is the voltage of the low-voltage circuit a specific low-voltage range value. As long as The voltage to ground of the high-voltage circuit only needs to be higher than the voltage to ground of the low-voltage circuit.

The power equipment provided by the embodiments of the present application may be a power converter, and may be applicable to the field of new energy smart microgrid, power transmission and distribution field or new energy field (such as photovoltaic grid-connected field or wind power grid-connected field), photovoltaic power generation field (such as For various application fields such as household equipment (such as refrigerators, air conditioners) or grid power supply), or the field of wind power generation, or the field of high-power converters (such as converting direct current into high-power high-voltage alternating current), the specifics can be determined according to the actual application scenario. , there is no restriction here.

FIG. 1B is a schematic diagram of a transformer provided by a possible implementation of the power equipment shown in FIG. 1A . The transformer includes a magnetic core 10 , a high-voltage component 20 and a low-voltage component 30 . The low-voltage component 30 is distributed on two opposite sides of the high-voltage component 20 . On the other side, the low-voltage component 30 and the high-voltage component 20 are stacked. The coil lead-out structure WH of the high-voltage component 20 is used for electrical connection to the high-voltage circuit in FIG. 1A , and the coil lead-out structure WL of the low-voltage component 30 is used for electrical connection to the low-voltage circuit in FIG. 1A .

FIG. 2A is a schematic three-dimensional assembly diagram of the high-voltage component 20 of the transformer provided in an embodiment of the present application. FIG. 2B is a three-dimensional exploded schematic diagram of the high-voltage component 20 of the transformer shown in FIG. 2A . Referring to FIG. 2B , the high-voltage component 20 of the transformer includes a high-voltage coil 21 , an insulator 22 , a ground structure 23 and a ground layer 24 .

In the specific implementation, the high-voltage coil 21 is electrically connected to the high-voltage circuit, and the high-voltage coil 21 is composed of a multi-turn conductor coil. The high-voltage coil 21 includes a winding part 211 , a lead-out part 212 , a first terminal 213 and a second terminal 214 . In one embodiment, the lead-out part 212 includes a first lead segment 2121 and a second lead segment 2122. The first lead segment 2121 and the second lead segment 2122 are relatively spaced apart on the same side of the winding part 211. The winding part 211 is connected in series. Between the first lead segment 2121 and the second lead segment 2122, one end of the first lead segment 2121 away from the winding part 211 is connected to the second terminal 214, and one end of the second lead segment 2122 away from the winding part 211 is connected to the first terminal 213. Two through holes H1 are formed surrounding the winding portion 211, and the two through holes H1 are used to accommodate part of the magnetic core. In one embodiment, the winding part 211 is in a figure-8 shape, or the winding part 211 includes two adjacent annular structures arranged side by side.

The insulator 22 covers the high-voltage coil 21. Specifically, the winding portion 211 and the lead-out portion 212 of the high-voltage coil 21 are completely wrapped by the insulator 22. Part of the second terminal 214 and part of the first terminal 213 are located in the insulator 22, and part of the second terminal 214 And part of the first terminal 213 extends out of the insulator 22 and is exposed, and the exposed parts of the second terminal 214 and the first terminal 213 are used for electrical connection with the high-voltage circuit. In one embodiment, at the position of the through hole H1 of the winding portion 211, the insulator 22 forms a mounting hole H2, and the mounting hole H2 is used to accommodate part of the magnetic core.

By casting the insulator 22 around the high-voltage coil 21, the stability of the connection between the high-voltage coil 21 and the insulator 22 can be increased, and the risk of the high-voltage coil 21 moving relative to the insulator 22 can be reduced, thereby increasing the stability of the transformer and the safety of use. The insulator 22 obtained through the casting or die-casting manufacturing process has less risk of air cavity inside the insulator 22 and can ensure the isolation effect of the insulator 22 . The material of the insulator 22 may be epoxy resin, insulating rubber, etc., and the embodiment of the present application does not impose any special restrictions on the material of the insulator 22 .

The ground layer 24 is located on the outer surface of the insulator 22 to ground the high-voltage component 20 and limits the potential on the outer surface of the insulator 22 to a low potential, for example, the same potential as the system ground. The potential of the ground layer 24 is the potential of the system ground, specifically a low potential. For example, the potential of the ground layer 24 is zero. By providing the ground layer 24 on the outer surface of the insulator 22, the risk of breakdown of the air layer around the high-voltage component can be reduced and the usability of the transformer can be improved. In one implementation, the ground layer 24 is a semiconductive layer.

The thickness of the insulator 22 can be defined as the minimum distance between the outer surface of the high-voltage coil 21 and the outer surface of the insulator 22 . For high-voltage components, the voltage of the high-voltage circuit connected to the high-voltage coil 21 is high voltage, and the voltage difference between the high voltage and the ground is M kilovolts (KV). When M≥1, the minimum thickness T of the insulator 22 needs to satisfy: T ≥0.3mm/KV.

In order to improve the grounding stability of high-voltage components, this application provides a grounding structure 23, which is made of conductive material or semi-conductive material. The partial ground structure 23 is implanted inside the insulator 22, and the partial ground structure 23 is arranged on the outer surface of the insulator 22. The ground layer 24 is connected to the partial ground structure 23 located on the outer surface of the insulator 22. The partial ground structure 23 implanted inside the insulator 22 passes through The ground connection is electrically connected to the system ground. In this way, the ground layer 24, the partial ground structure 23 located on the outer surface of the insulator 22, the partial ground structure 23 implanted inside the insulator 22, and the ground connector are electrically connected in sequence to form a ground path of the high-voltage component 20. The high-voltage component 20 is assembled or used during assembly or use. During the process, this ground path will not suffer any loss, so the high-voltage component 20 provided by the specific embodiment of the present application has a reliable ground path. In summary, this application can improve the grounding stability of the high-voltage component 20 through the provision of the grounding structure 23 . The specific structure of the ground structure 23 is described as follows.

FIG. 3 is a partial cross-sectional view of a high-voltage component provided by an embodiment of the present application, and FIG. 4 is a three-dimensional schematic view of the grounding structure of the high-voltage component provided by an embodiment of the present application. Referring to Figure 2A, Figure 2B, Figure 3 and Figure 4, the grounding structure 23 includes an embedded component 231 and a connecting component 232, both of which are conductive. The embedded component 231 and the high-voltage coil 21 are isolated by the insulator 22. At least part of the embedded part 231 is located inside the insulator 22 , part of the surface of the embedded part 231 is exposed and used to fix the ground connection part 90 , and the connecting part 232 is located on the outer surface of the insulator 22 . The component 232 is directly or indirectly connected to the embedded component 231 . Direct connection means that there is no other connection medium between the connecting piece 232 and the embedded piece 231, and they are in contact with each other and connected to each other. Indirect connection means that there is a gap between the connecting piece 232 and the embedded piece 231, and other connecting structures are used to connect the two. In the embodiment shown in Figures 3 and 4, the connecting piece 232 and the embedded piece 231 are indirectly connected. The grounding structure 23 also includes an intermediate piece 233. The middle piece 233 is located inside the insulator 22 and connected between the connecting piece 232 and the embedded piece. between 231. Part of the ground layer 24 is connected to the surface of the connecting member 232 facing away from the insulator 22 , and part of the ground layer 24 is connected to at least part of the outer surface of the insulator 22 . Through the connection between the ground layer 24 and the connecting member 232 , The connection between the connecting piece 232 and the embedded piece 231 , as well as the connection between the embedded piece 231 and the ground connecting piece 90 , realize the ground path of the high-voltage component 20 . Since the embedded part 231 of the grounding structure 23 is located inside the insulator 22 , a reliable ground connection relationship is formed between the connecting part 232 and the embedded part 231 , and between the ground layer 24 and the connecting part 232 , which can improve the safety of the high-voltage component 20 .

For the high-voltage component 20, a ground path is formed from the ground layer 24 to the ground connector 90. The high-voltage component 20 provided by this application includes two ground paths. The first ground path is: the ground layer 24 (covering the surface of the connector 232 The ground path formed by the partial ground layer 24), the connector 232, the embedded component 231, and the ground connector 90 are electrically connected in sequence; the second ground path is: the ground layer 24 (covering the portion of the embedded component 231 exposed on the surface of the insulator 22 The ground layer 24) is electrically connected to the ground path formed between the ground connection member 90 and the embedded member 231. For the second ground path, the fixed ground During the process of connecting the grounding member 90, external force acts on the grounding layer 24, which may damage the grounding layer 24 covering the portion of the embedded member 231 exposed on the surface of the insulator 22, causing the second grounding path to be disconnected. In the event of damage, the high-voltage component 20 provided by the present application also has a first ground path, and the first ground path will not be affected by external forces during the process of assembling the high-voltage component and the transformer, and will not be easily damaged or destroyed. Easy to fail.

Figure 5 shows a grounding structure of a high-voltage component in the prior art. The outer surface of the insulator 22' is provided with a grounding layer 24'. The insulator 22' is provided with a protruding structure 221'. This protruding structure 221' is used for grounding. The protruding structure 221' The outer surface is also covered with a ground layer 24'. The protruding structure 221' is provided with a grounding hole 222', the grounding hole 222' is used to cooperate with the fastener 25', and the fastener 25' is used to connect the grounding connector. For example, the fastener 25' includes a bolt 251' and a nut 252'. During the process of assembling the ground connection, the bolts and nuts need to be tightened with the help of tools. After assembly, the ground layer 24' between the bolt 251' and the insulator 22', the bolt 251', and the ground connector are electrically connected in sequence to form a ground path. During the assembly process, the ground layer 24' on the outer surface of the ground hole 222' is easily broken under the action of tightening force. The break of the ground layer 24' will inevitably lead to the disconnection of the ground path, causing the grounding of the high-voltage component to fail.

Compared with the grounding structure of the high-voltage component shown in FIG. 5 , the ground path failure risk of the high-voltage component provided by the embodiment of the present application is significantly lower. Specifically, referring to FIG. 2B and FIG. 3 , the ground layer 24 is formed on the surface of the connector 232 by electroplating or spraying to achieve electrical connection between the ground layer 24 and the connector 232 . During the assembly and use of the high-voltage component 20, the connection positions between the ground layer 24 and the connector 232 are static, and no external force will act on this position. For example, no fixed connectors like screws will be provided at this position. Therefore, the electrical connection structure between the ground layer 24 and the connector 232 is not easily damaged, and it is not easy to cause an open circuit. The electrical connection between the ground connector 90 and the embedded member 231 is a direct connection and does not depend on the ground layer 24. Even if the ground layer 24 between the ground connector 90 and the embedded member 231 is damaged and breaks, it will not The electrical connection relationship between the ground connection part 90 and the embedded part 231 is affected. Therefore, the ground path of the high-voltage component 20 is stable and the risk of ground failure is low.

FIG. 6A is a structure of the insert 231 in an embodiment, and FIG. 6B is a schematic diagram of the assembly relationship between the insert 231 and the insulator 22 shown in FIG. 6A . Referring to Figures 6A and 6B, in this embodiment, the insert 231 has a three-section structure, including a first section 231A, a second section 231B, and a third section 231C. The second section 231B is connected to the first section 231A and the third section 231C. Between the sections 231C, the diameters of the first section 231A and the third section 231C are larger than the diameter of the second section 231B. The second section 231B is generally cylindrical. The insert 231 includes a first end surface S1, a second end surface S2 and a side surface S3. The first end surface S1 is the surface of the first section 231A facing away from the second section 231B. The second end face S2 is the surface of the third section 231C facing away from the second section 231B. The first end surface S1 and the second end surface S2 can be parallel to each other. The other surfaces on 231A except the first end surface S1, the outer surface of the second section 231B, and the other surfaces on the third section 231C except the second end surface S2 together form the side surface S3. As shown in FIG. 6B , the side surface S3 and the second end surface S2 are located inside the insulator 22 , and the first end surface S1 is located on the outer surface of the insulator 22 . In this embodiment, the insert 231 is designed as a three-section structure, so that the side S3 forms a concave structure, so that the joint surface between the insulator 22 and the insert 231 forms a bent and extended state, which can lift the insert 231 and the insulator. The bonding force between 22.

In this embodiment, the embedded part 231 is provided with a mounting hole 2311. The opening position of the mounting hole 2311 is on the first end face S1, that is, the mounting hole 2311 extends from the first end face S1 into the embedded part 231. The mounting hole 2311 is used for Secure ground connection 90. Specifically, the mounting hole 2311 may be a threaded hole, and the ground connector 90 may be fixed through the cooperation of the screw and the mounting hole 2311 (see FIG. 2A ). In other embodiments, the ground connector 90 can also have a threaded structure and directly match the threaded hole. In other embodiments, the ground connector 90 can also be fixed to the insert 231 by welding, or connected to the insert 231 by snapping. For example, a snap slot is provided on the embedded component 231, and the ground connection member 90 has a buckle structure that matches the snap slot.

The insert 231 includes a first end surface S1 and a side surface S3 facing different and adjacent sides. The first end surface S1 is used for fixing. Defining the ground connecting piece 90, the grounding structure 23 also includes an intermediate piece 233, and the middle piece 233 is connected between the side S3 and the connecting piece 232. This solution provides a specific architecture of the grounding structure 23. The embedded part 231 and the connecting part 232 are connected through the middle part 233, which can make the position of the connecting part 232 on the outer surface of the insulator 22 more flexible and adapt to different application scenarios. high voltage components 20.

FIG. 7A is a structure of the insert 231 in an embodiment, and FIG. 7B is a schematic diagram of the assembly relationship between the insert 231 and the insulator 22 shown in FIG. 7A . Referring to Figures 7A and 7B, the insert 231 includes a first end surface S1, a second end surface S2 and a side surface S3. The first end surface S1 and the second end surface S2 have equal areas. The first end surface S1 is located on the outer surface of the insulator 22, and the second end surface S2 and side S3 are located inside the insulator 22 . The insert 231 is provided with a mounting hole 2311, and the opening of the mounting hole 2311 is located on the first end surface S1. In this embodiment, the insert 231 is cylindrical, and the side S3 is a cylindrical structure. The insert 231 of this structure can also be firmly combined with the insulator 22 and has the advantages of simple structure and low manufacturing cost.

Figure 8A is a structure of the insert 231 in an embodiment. Figure 8B is a schematic diagram of the assembly relationship between the insert 231 and the insulator 22 shown in Figure 8A. Figure 8C is a diagram of the insert 231 and the insulator shown in Figure 8A. Schematic diagram of another assembly relationship between 22. The embedded part 231 is in the shape of a truncated cone. The embedded part 231 includes a first end surface S1, a second end surface S2 and a side surface S3. The area of the first end surface S1 is larger than the area of the second end surface S2. The embedded part 231 is provided with a mounting hole, and the mounting hole is It is in the shape of a through hole, and the mounting hole extends from the first end surface S1 to the second end surface S2. Referring to Figures 8A and 8B, in one assembly method, the first end surface S1 is located on the outer surface of the insulator 22, and the second end surface S2 and side surface S3 are located inside the insulator 22. In this assembly method, the insulator can be poured on the surface of the high-voltage coil 21. 22, the insert 231 is installed inside the insulator 22, and the second end surface S2 is placed inside the insulator 22, which has the advantage of convenient assembly. Referring to Figures 8A and 8C, in another assembly method, the second end surface S2 is located on the outer surface of the insulation, and the first end surface S1 and side surface S3 are located inside the insulator 22. This assembly method can embed the insulation during the process of pouring the insulation. The component 231 is cast inside the insulator 22, and the second end surface S2 is exposed through mechanical processing. Since the area of the first end surface S1 is larger than the second end surface S2, and the force of the insulator 22 on the side S3 helps to push the embedded part 231 is fixed in the insulator 22, and the embedded component 231 is not easily detached from the insulator 22. Therefore, this embodiment has the advantage of stable and firm combination.

In the embodiment shown in FIG. 4 , the connecting member 232 has a sheet-like structure, and no holes or hollow structures are provided on the connecting member 232 . In other embodiments, a hollow area may be provided on the connector 232. When the connector 232 is installed on the surface of the insulator 22, part of the ground layer 24 may be located in the hollow area and connected to the insulator 22, or part of the insulator 22 may be located on the surface of the insulator 22. The hollow area is connected to the connector 232 . Therefore, this solution can increase the reliability of the connection between the connecting member 232 and the insulator 22 , and between the ground layer 24 and the connecting member 232 and the insulator 22 .

Referring to FIG. 9A , the connector 232 may have a mesh structure. It can be understood that the connector 232 can be obtained by weaving metal wires or metal strips into a mesh shape, and the through holes formed between the metal wires or metal strips are hollow areas.

Referring to FIG. 9B , the connecting member 232 may have a sheet-like structure. The sheet-like structure is provided with a plurality of through holes, and the plurality of through holes constitute the hollow area of the connecting member 232 . In this embodiment, the hollow area has a circular through-hole structure. In other embodiments, the shape of the through-hole is not limited to circular, and can also be other shapes, such as rectangle, triangle, etc. As shown in FIG. 9C , the connecting member 232 is provided with through holes of different shapes.

In a specific implementation, the connecting piece 232 is a flexible structure, and the flexible structural connecting piece 232 can form a gap-free fit with the surface of the insulator 22 to improve the structural strength and stability.

Referring to FIG. 10 , in one embodiment, the outer surface of the insulator 22 includes a first surface S5 and a second surface S6 . The first surface S5 and the second surface S6 are oriented in different directions (it can be understood that they are not coplanar). Surface S6 and second surface S6 may be adjacent. The embedded part 231 includes a first end surface S1 and a side surface S3. The first end surface S1 and the side surface S3 are adjacent and have different orientations. The first end surface S1 is located on the first surface S5 of the insulator 22. The side surface S3 is located inside the insulator 22. The connecting member 232 is connected to Between the side S3 of the embedded part 231 and the connecting part 232 , the connecting part 232 is located on the second surface S6 of the insulator 22 .

In the embodiment shown in FIG. 2B , the insulator 22 includes a main insulating part 221 , a lead insulating part 222 and a protrusion 223 . The main insulating part 221 covers the winding part 211 of the high-voltage coil 21 . The main insulating part 221 It includes a top surface S7, a bottom surface S8 and an insulating side S9 connected between the top surface S7 and the bottom surface S8. The top surface S7 is used to face the low-voltage coil of the transformer, and the protrusion 223 is protrudingly provided on the Insulating side S9, at least part of the embedded part 231 is located inside the protrusion 223, and part of the surface of the embedded part 231 (the first end surface S1) of the ground connection part 90 is connected to the top surface S7 have the same orientation. This solution can realize the miniaturization of the main insulation part of the insulator, and provide a grounding structure on the protrusion. The grounding structure does not affect the safe distance of the isolation of the high-voltage coil, which is conducive to ensuring the safety of the high-voltage components.

The connecting piece 232 can be located on the outer surface of the protrusion 223, and the connecting piece 232 can also be located on the insulating side S9 of the main insulating portion 221. The connecting piece 232 can also be arranged on the outer surface of the protruding piece 223 and the insulating side of the main insulating portion 221. S9, this solution provides different layout plans for the connectors of the grounding structure. The appropriate solution can be selected according to the specific application requirements, and the flexibility is good. The lead insulation part 222 wraps the lead-out part 212 of the high-voltage coil 21 . The main body insulating part 221 and the lead insulating part 222 are arranged adjacently in the first direction A1. The protrusion 223 and the main insulating part 221 are arranged adjacently in the second direction A2. The second direction A2 and the first direction A1 form an included angle. In this embodiment, the lead-out portion 212 and the winding portion 211 of the high-voltage coil 21 are adjacently arranged in the first direction A1, and the ground structure 23 and the winding portion 211 of the high-voltage coil 21 are spaced apart in the second direction A2. For the transformer where the high-voltage component 20 is located, the high-voltage component 20 provided by this solution is suitable for application environments with sufficient installation space in the second direction A2. The size of the high-voltage component 20 in the first direction A1 can be controlled so that the transformer can be installed in the second direction A2. The size in one direction is easy to achieve miniaturization.

Referring to Figure 11, in the embodiment shown in Figure 11, the grounding structure 23 is provided on the protrusion 223, and the partial surface of the embedded part 231 for connecting the grounding connector 90 and the top surface of the main insulating part 221 are in the same direction. . Compared with the embodiment shown in FIG. 2B , the specific position of the protrusion 223 is adjusted in this embodiment. In this embodiment, the lead insulation part 222 , the body insulation part 221 and the protrusion 223 are arranged in sequence along the first direction. The lead-out part 212 and the winding part 211 of the high-voltage coil 21 are arranged adjacent to each other in the first direction, and in the first direction, the grounding structure 23 is located on the side of the winding part 211 away from the lead-out part 212. It is understood that the lead-out part 212, the winding part 211 and the grounding structure 23 are arranged in sequence in the first direction. For the transformer where the high-voltage assembly is located, the high-voltage component provided by this embodiment is suitable for application environments with sufficient installation space in the first direction.

In one embodiment of the present application, a protrusion 223 is provided on the insulating side S9 of the main body insulating portion 221 of the insulator 22 and the grounding structure 23 is arranged at the position of the protrusion 223, thereby ensuring that the overall size of the insulator 22 is miniaturized. The position of 223 on the side S3 can be set according to the specific use environment and assembly requirements, and is not limited in this application.

Referring to FIG. 12 , in the embodiment shown in FIG. 12 , the insulator 22 only includes a main body insulating part 221 and a lead insulating part 222 , and the insulating side surface S9 of the main body insulating part 221 is not provided with any protrusions 223 . In this embodiment, the main body insulating part 221 includes a top surface S7, a bottom surface (on the opposite side of the top surface S7, which cannot be shown in the figure) and an insulating side surface S9 connected between the top surface S7 and the bottom surface. The grounding structure 23 is provided on the main body. on the insulating part 221. In a specific implementation, the embedded component 231 of the grounding structure 23 includes a first end surface S1 , which is exposed on the insulating side surface S9 of the main insulation part 221 . The first end surface S1 is used to fix the grounding connector 90 . The connecting piece 232 of the ground structure 23 is directly connected to the embedded piece 231 , and the connecting piece 232 is located on the insulating side S9 of the main body insulating part 221 . The first end surface S1 is oriented in the same direction as the insulating side surface S9 of the main body insulating portion 221 . This solution is conducive to simplifying the manufacturing process of the insulator. Since the outer surface of the main insulating part 221 of the insulating part has no protrusion 223 structure, the process of setting the ground layer 24 on the outer surface of the main insulating part 221 is also easy to control, which is beneficial to improving grounding. Reliability of the connection between layer 24 and body insulation 221.

Referring to FIG. 13 , in one embodiment, the embedded component 231 includes a first end surface S1 and a side surface S3 facing different and adjacent sides. The first end surface S1 is used to fix the grounding connector 90 . Specifically, the first end surface S1 is used to fix the grounding connector 90 . Specifically, One end surface S1 is provided with a mounting hole 2311 , and the mounting hole 2311 is used to connect the ground connector 90 . The side S3 includes a first area S31 and a second area S32. The first area S31 is connected between the second area S32 and the first end surface S1. The connecting piece 232 is connected to the first area S31. The positional relationship between the ground structure 23 and the insulator 22 is: the second area S32 is located inside the insulator 22, and the first area S31 is located outside the insulator 22. In one embodiment, the connecting member 232 is away from the insulator. The surface of 22 may be flush and coplanar with the first end surface S1. It can be understood that the outer surface of the connecting member 232 and the first end surface S1 can jointly form a planar structure or an arc-shaped surface, with a smooth transition between the two without any step structure. In this solution, the outer surface of the connector 232 and the first end surface S1 are coplanar, so that the surface of the ground structure exposed outside the insulator is an integrated smooth transition surface structure, and a ground layer is provided on such a smooth transition surface. The connection between the ground layer 24 and the ground structure 23 can be made more reliable.

Referring to Figure 14, in one embodiment, the connecting piece 232 and the embedded piece 231 are directly connected. The embedded piece 231 is columnar. The embedded piece 231 includes a first end surface S1 and a side surface S3. The side surface S3 includes a first area S31 and a second area S32. , the first area S31 is located between the second area S32 and the first end surface S1, the second area S32 is located inside the insulator 22, the first area S31 extends out of the insulator 22, the first end surface S1 is located outside the insulator 22, and the connector 232 connects To the first area S31, the connecting member 232 includes an outer surface 2321. The outer surface 2321 of the connecting member 232 is located on the outer surface of the insulator 22 and is not covered by the insulator 22. The other surfaces of the connecting member 232 except its outer surface 2321 are in contact with the insulator. 22 connections. The outer surface 2321 of the connecting member 232 is used to connect the ground layer 24 . In this embodiment, the first end surface S1 and the outer surface 2321 of the connecting member 232 are not coplanar, that is, the first end surface S1 and the outer surface 2321 of the connecting member 232 are connected through part of the side surface S3. The connecting piece 232 in the grounding structure 23 provided by this solution is directly connected to the first area S31 of the side S3 of the embedded piece 231. For the grounding structure 23, its structure is simpler, making the process of connecting the grounding structure 23 and the insulator 22 The production process is not complicated and it is easy to achieve lower production costs.

Referring to Figure 15, in one embodiment, the connecting piece 232 is connected to the first end surface S1 of the embedded piece 231. Specifically, the connecting piece 232 includes a first connecting area 2322 and a second connecting area 2323. The first connecting area 2322 is connected to the first end surface S1, the second connection area 2323 is connected to the outer surface of the insulator 22, and the ground connection member 90 is connected to the first connection area. The first end surface S1 and the outer surface of the insulator 22 used to connect the connector 232 are flush and coplanar. In this solution, the positions of the first end surface S1 and the outer surface of the insulator 22 are related to each other, so that the connector 232 It can be a flat structure, and the connection between the connecting piece 232 and the insulator 22 has the advantage of being simple and stable. In the embodiment shown in FIG. 15 , the second connection area 2323 is distributed on one side of the first connection area 2322 . In other embodiments, as shown in Figure 16, the second connection area 2323 can also be distributed on both sides of the first connection area 2322, or the second connection area 2323 can be arranged around the first connection area 2322. This solution provides two A specific arrangement of connectors has a high degree of application freedom. The appropriate arrangement of connectors can be selected according to the structural form of the specific high-voltage components. This solution provides a specific positional relationship between the connecting piece 232 and the embedded piece 231. Since the first connection area 2322 of the connecting piece 232 is connected to the first end surface S1 of the embedded piece 231, the embedded piece 231 can be connected first. It is fixed on the insulator 22, and then the connecting piece 232 is connected to the first end surface S1. After the embedded component 231 and the insulator 22 are assembled, the first end surface S1 is exposed on the surface of the insulator 22. In this case, it is easier to connect the connecting component 232 to the first end surface S1. For example, the connection and fixation can be achieved by welding. The insert 231 may be an integral structure with the insulator 22 , that is, during the process of pouring the insulator 22 , the insert 231 is disposed therein.

In the embodiment shown in FIGS. 14 , 15 and 16 , the part of the insulator between the surface of the insert 231 away from the first end surface S1 and the high-voltage coil 21 is the thinnest part of the insulator 22 , and it is necessary to ensure that this part of the insulator 22 The thickness is within the safe distance range (for example, greater than or equal to 0.3mm/KV).

In the embodiment shown in Figures 14, 15 and 16, the connecting piece 232 can be an integrated structure and can be distributed on one side of the first end face S1 or arranged around the first end face S1; the connecting piece 232 can also be split. Structure, the connecting piece 232 includes multiple independent components, and the multiple independent components are directly connected to the insert 231 and distributed around the periphery of the first end surface S1.

In the embodiment shown in FIG. 2B , the ground layer 24 covers the entire area of the main insulation portion 221 of the insulator 22 , and no hole structure is provided on the ground layer 24 .

Referring to Figure 17, in one embodiment, the ground layer 24 is provided with a hollow portion 242. The hollow portion 242 is provided to increase the resistance of the ground layer 24. In this embodiment, the ground layer 24 forms a closed structure around the insulator 22. The ground loop makes the potential of the outer surface of the insulator 22 equal to the ground potential, thereby achieving the reliability of the grounding of the high-voltage component 20 and effectively reducing the partial discharge on the surface of the high-voltage component 20 .

The main function of the ground layer 24 is to surround the surface of the insulator 22 so that the potential on the surface of the insulator 22 is limited to a low potential. The ground layer 24 is made of conductor material or semiconductor material, and the high-voltage coil 21 is within the radiation range of the leakage magnetic flux of the transformer. In this way, during the operation of the high-voltage component, the ground layer 24 will form a closed ground loop. The existence of the ground layer 24 causes additional losses due to induced electromotive force during operation of the transformer. The higher the resistivity of the material used in the ground layer 24, the worse its potential limiting effect, but the smaller the loss caused by electromagnetic induction. On the contrary, the lower the resistivity of the material used in the ground layer 24, the better the potential limitation effect, but the higher the loss caused by electromagnetic induction. Therefore, this application limits the ground layer 24 to a semi-conductive material to balance the loss and potential limitation. Effect.

Specifically, the ground layer 24 is formed on the surface of the insulator 22 and the connector 232 by spraying or electroplating. In other embodiments, the ground layer 24 can also be a flexible tape with semi-conductive properties. By winding the flexible tape around the outer surface of the insulator 22 , the flexible tape can also be fixed to the outer surface of the insulator 22 through adhesive or other means. .

In one implementation, the resistivity of the ground structure 23 is lower than the resistivity of the ground layer 24 . The ground layer 24 is a semiconductive material, and the resistivity of the ground layer 24 can be in the range of 0.01Ω·cm to 100000Ω·cm, for example: 1000Ω·cm. For the grounding structure 23, its resistance value satisfies <1 ohm/unit cm length. The resistivity of the grounding structure 23 is low, which can ensure that the grounding resistance is as small as possible, can ensure good grounding protection, and can reliably connect the semi-conductive layer The potential is pulled down to the PE(0) potential. On the contrary, if the resistance of the ground structure 23 is too large, the grounding effect may be poor, causing the potential of the ground layer 24 on the surface of the high-voltage component to be unstable and the insulation effect to be poor. In a specific application scenario, safety standards have requirements for ground resistance, for example: <1 ohm/unit cm length.

This application not only improves the structural stability of the ground layer 24 through the combination of the embedded part 231 of the ground structure 23 and the insulator 22 and the connection between the connecting part 232 and the ground layer 24, but also achieves the reliability of the grounding of high-voltage components, which can effectively Reduce partial discharge on the surface of high-voltage components. The outer surface of the insulator 22 is provided with the ground layer 24 so that the potential of the outer surface of the high-voltage component in contact with the air is zero, reducing the electric field intensity between the high-voltage component and the low-voltage coil, and also reducing the electric field intensity between the high-voltage component and the magnetic core. The voltage difference and the electric field strength in the air reduce the risk of breakdown of the air between the high-voltage component and the low-voltage coil, and between the high-voltage component and the magnetic core, which can improve the safety of the transformer.

FIG. 18 is a perspective view of the transformer 100 provided by an embodiment of the present application. FIG. 19 is a side view of the transformer 100 provided by an embodiment of the present application. FIG. 20 is a perspective exploded view of the transformer 100 provided by an embodiment of the present application. .

Referring to FIGS. 18 , 19 and 20 , the transformer 100 includes a magnetic core 10 , a high-voltage component 20 , a low-voltage coil 31 , a shield 32 , a conductive cover 40 and a fixing 50 .

In one embodiment, the high-voltage component 20 may be the high-voltage component described in the previous embodiment.

In another embodiment, the high-voltage assembly 20 can also be distinguished from the high-voltage assembly described in the previous embodiments. The high-voltage assembly includes a high-voltage coil, an insulator and a ground layer. The insulator covers the high-voltage coil, and the ground layer covers at least part of the high-voltage coil. The outer surface of the insulator, so that the potential on the outer surface of the insulator is the potential of ground.

Both of these two specific high-voltage components can be applied in the transformer provided in the embodiment of the present application, and both can be used with the transformer. used in conjunction with other components.

The specific form of the low-voltage coil 31 may be the same as the form of the high-voltage coil 21 of the high-voltage assembly 20 in the embodiment shown in FIG. Hole H1, these two through holes H1 are used to assemble the magnetic core 10, and the lead-out member 312 extends from the coil body 311 for connecting the low-voltage circuit. Specifically, the coil body 311 of the low-voltage coil 31 may be composed of a multi-turn conductor coil wound around a low-voltage bobbin. In one embodiment, the number of low-voltage coils 31 is two, namely: a first low-voltage coil 31A and a second low-voltage coil 31B. The first low-voltage coil 31A is located on one side of the top of the high-voltage component 20 , and the second low-voltage coil 31B is located on One side of the bottom of the high-voltage assembly 20 , that is, the high-voltage assembly 20 is located between the first low-voltage coil 31A and the second low-voltage coil 31B. The first low-voltage coil 31A and the second low-voltage coil 31B may be connected in series or in parallel.

The magnetic core 10 includes a first magnetic cover 11 , a second magnetic cover 12 that are oppositely arranged, and a magnetic column 13 connected between the first magnetic cover 11 and the second magnetic cover 12 . The low-voltage coil 31 and the The high voltage component 20 is used to surround the magnetic column 13 . In one embodiment, the magnetic core 10 has a two-piece structure. The magnetic column 13 includes a first column 131 and a second column 132. The first column 131 is connected to the first magnetic cover 11 to form the first magnetic component 10A. 132 is connected to the second magnetic cover 12 to form the second magnetic component 10B, and the first magnetic component 10A and the second magnetic component 10B are butted to form the magnetic core 10 . Specifically, the number of magnetic posts 13 is two, that is to say, two first posts 131 are connected to the first magnetic cover 11, two second posts 132 are connected to the second magnetic cover 12, and the first magnetic part The structural shape and size of the second magnetic component 10A and the second magnetic component 10B are the same.

During assembly, the winding portion 211 of the high-voltage coil 21 of the high-voltage assembly 20 and the coil body 311 of the low-voltage coil 31 are stacked to form the coil assembly D. Specifically, the high-voltage assembly 20 is stacked on the first low-voltage coil 31A and the second low-voltage coil. 31B, the mounting hole H2 on the insulator 22 of the high-voltage component 20 is connected with the through hole H1 formed by the coil body 311 of the low-voltage coil 31, and constitutes an assembly through hole H12. The lead-out portion 212 of the high-voltage coil 21 of the high-voltage component 20 and The lead-out parts 312 of the low-voltage coil 31 are respectively located on opposite sides of the coil assembly D to facilitate the wiring of the transformer to the high-voltage circuit and the low-voltage circuit, and the isolation between the high-voltage and low-voltage circuits. The first post 131 of the first magnetic component 10A extends into the assembly through hole H12 from one side of the coil assembly D, and the second post 132 of the second magnetic component 10B extends into the assembly through hole H12 from the other side of the coil assembly D. The first column 131 and the second column 132 can be connected and fixed, and a gap can also be left between the first column 131 and the second column 132 . The first magnetic cover 11 is stacked on the side of the first low-voltage coil 31A facing away from the high-voltage component 20 , and the second magnetic cover 12 is stacked on the side of the second low-voltage coil 31B facing away from the high-voltage component 20 .

The shield 32 includes a first shield 32A and a second shield 32B, and the conductive cover 40 includes a first conductive cover 40A and a second conductive cover 40B.

The first shield 32A is assembled on the side of the first magnetic cover 11 away from the first low-voltage coil 31A. The first shield 32A covers part of the first magnetic cover 11 and the first low-voltage coil 31A. The first shield 32A and the second The shielding member 32B has the same structure. For convenience of description, the structure of the second shielding member 32B is described in detail by taking the second shielding member 32B as an example. The second shield 32B includes a first part 321 and a second part 322. The first part 321 is stacked between the second magnetic cover 12 and the second conductive cover 40B. The second part 322 Connected to the edge of the first part 321 and extending from the edge of the first part 321 toward the direction of the high-voltage assembly 20 , the second part 322 is arranged around the second magnetic cover 12 and the second The periphery of the low voltage coil 31B. In this solution, through the specific structural design of the second part and the first part of the second shield 32B, the second shield can cover more area of the second low-voltage coil 31B, which can improve the protection and isolation effect of the low-voltage coil.

In one embodiment, the second part 322 surrounds part of the second magnetic cover 12 and the second low-voltage coil 31B to form an open-loop structure. Specifically, the second part 322 includes a top edge 3221, a bottom edge 3222, a first side The side 3223 and the second side 3224, the top side 3221 is connected to the first part 321, the bottom side 3222 contacts the high-voltage component 20 or forms a gap with the high-voltage component 20, the first side An opening 323 is formed between the side 3223 and the second side 3224, and the opening 323 The port 323 is at least used to accommodate the lead-out piece of the second low-voltage coil 31B. In this solution, the second part 322 is configured as an open-loop structure, and the opening 323 is provided to facilitate the installation of the lead-out parts of the low-voltage coil, which has the advantage of flexible assembly.

The design of the shield contacting the high-voltage components allows the shield to be connected to the ground layer of the high-voltage components, thus forming a full range of isolation protection for the low-voltage coil, which is beneficial to improving the performance of the transformer.

The top edge 3221 and the bottom edge 3222 are U-shaped or C-shaped, and part of the second magnetic cover 12 and part of the second low-voltage coil 31B are located in the opening 323 . In one embodiment, the second part 322 forms a closed-loop structure around the periphery of the second magnetic cover 12 and the second low-voltage coil 31B. As shown in FIG. 21 , the top edge 3221 and the bottom edge of the second part 322 3222 are all in the shape of a closed ring (circular, oval, oblong or rectangular), and a lead extension hole 3225 is provided on the second part 322 for the lead-out part of the low-voltage coil to extend.

In a specific implementation, the first shield 32A includes a sheet-shaped main body 325 and a plurality of through holes 326 provided on the main body. The shape of the through hole 326 may be circular, square, diamond, etc., and the maximum lateral or vertical dimension of the shape of the through hole 326 does not exceed 10 mm. The second shield 32B may have the same structure as the first shield 32A. This solution can improve the resistance of the shield by arranging through holes on the sheet-shaped body, which is beneficial to improving the eddy current loss of the transformer.

The first conductive cover 40A is located on the side of the first shield 32A facing away from the first magnetic cover 11, and the second conductive cover 40B is located on the side of the second shield 32B facing away from the second magnetic cover 12. The conductive cover 40 is used for Ground.

The resistivity of shield 32 is higher than the resistivity of conductive cover 40 . In one embodiment, the area of the first conductive cover 40A is smaller than the area of the second conductive cover 40B. The second conductive cover 40B is used to install the transformer 100 into the power equipment, and the grounding structure 23 of the high-voltage component 20 passes through it. The ground connection member 90 is connected to the second conductive cover 40B. Specifically, the ground connection member 90 may be a metal wire structure, one end of which is fixed to the embedded part 231 of the ground structure 23 of the high-voltage component through screws, and the other end is fixed to the second conductive cover 40B through screws. The second conductive cover 40B is a component connected between the high voltage component 20 and the system ground. This solution collects the grounding of high-voltage components and the grounding of low-voltage coils through the second conductive cover plate. For the transformer, the design of the grounding structure can save the space of the transformer and is conducive to the design of miniaturized transformer size.

In summary, the first conductive cover 40A, part of the first shield 32A, the first magnetic cover 11, the first low-voltage coil 31A, the high-voltage component 20, and the second low-voltage coil 31B, the second magnetic cover 12, part of the second shield 32B and the second conductive cover 40B are stacked in sequence.

The fixing piece 50 is conductive and can be made of metal. The fixing piece 50 is used to fixedly connect the first conductive cover 40A and the second conductive cover 40B, and connect the high-voltage component 20 and the second conductive cover 40B. The low-voltage coil 31 and the shield 32 are fixed between the first conductive cover plate 40A and the second conductive cover plate 40B. Through the setting of fixing parts, this solution can realize the fixed connection of each component of the transformer on the one hand. On the other hand, the fixing parts are also used to realize the grounding of the low-voltage coil, so that the overall structure of the transformer has the advantage of compactness and simplicity, which is beneficial to the transformer. The design is miniaturized in size. In one embodiment, the fixing member 50 is in the shape of a belt or a ring. The high-voltage component 20 , the low-voltage coil 31 , the shield 32 and the conductive cover 40 are assembled to form a transformer module. The fixing member 50 is wrapped around the periphery of the transformer module. In other embodiments, the fixing member 50 may also be a bolt structure. The bolts pass through the first conductive cover plate 40A and the second conductive cover plate 40B and cooperate with nuts to connect the high-voltage component 20 and the low-voltage coil 31 The shielding member 32 is fixed between the first conductive cover plate 40A and the second conductive cover plate 40B.

In other embodiments, the number of low-voltage coils 31 can also be one, so that the number of shielding members 32 is also one, the number of conductive cover plates 40 is two, and the high-voltage component 20, the low-voltage coil 31 and the shielding members 32 are stacked in sequence. between two conductive cover plates 40 .

The transformer 100 provided in the embodiment of the present application realizes the isolation of the high-voltage coil 21 and the low-voltage coil 31 by arranging an insulator 22 in the high-voltage component, using the insulator 22 to wrap the high-voltage coil 21, and using the ground layer 24 and the grounding structure 23 of the high-voltage coil 21 to realize the high-voltage component. The potential of the outer surface of 20 is ground potential, and the shield 32 and the conductive cover 40 are used to realize the low-voltage line. The isolation and grounding of the ring 31 realizes the reliable grounding of the transformer 100. By controlling the resistivity of the ground layer 24 and the shield 32 (specifically, the ground layer 24 is a semiconductive material and the shield is a mesh structure), the eddy current loss caused by the high-frequency magnetic field of the transformer 100 can be reduced, and the transformer 100 can be improved. work efficiency. Specifically, during the operation of the transformer 100, a changing magnetic flux will be generated. The magnetic flux is divided into a main magnetic flux and a leakage magnetic flux. The main magnetic flux is constrained in the magnetic core for electromagnetic energy conversion, but the leakage magnetic flux is scattered in the magnetic core. In the transformer system, the structure of the ground layer 24 and the shield 32 on the surface of the high-voltage component 20 will generate an induced voltage under the influence of magnetic leakage flux, thereby causing losses. If the resistance values of the ground layer 24 and the shield 32 become higher, the eddy current loss will be correspondingly smaller. Therefore, the eddy current loss can be reduced by controlling the resistivity of the ground layer 24 and the shield 32 .

The first, second, third, fourth and various numerical numbers involved in this article are only for convenience of description and are not used to limit the scope of this application.

It should be understood that in the various embodiments of the present application, the size of the sequence numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its functions and internal logic, and should not be used in the embodiments of the present application. The implementation process constitutes any limitation.

The above embodiments are only used to illustrate the technical solutions of the present application, but are not intended to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments. Modifications may be made to the recorded technical solutions, or equivalent substitutions may be made to some of the technical features; however, these modifications or substitutions do not cause the essence of the corresponding technical solutions to depart from the scope of the technical solutions of the embodiments of the present application.

Claims

A high-voltage component of a transformer, which is characterized by including:

high voltage coil;

Insulator, covering the high-voltage coil;

The grounding structure includes an embedded part and a connecting part that are conductive. The embedded part and the high-voltage coil are isolated by the insulator. At least part of the embedded part is located inside the insulator. The embedded part is Part of the surface is exposed and used to fix a grounding connector, the connector is located on the outer surface of the insulator, and the connector is directly or indirectly connected to the embedded component; and

A ground layer, part of the ground layer is connected to the surface of the connecting member facing away from the insulator, part of the ground layer is connected to at least part of the outer surface of the insulator;

The ground layer, the connecting piece, the embedded piece and the ground connecting piece are electrically connected in sequence to form a ground path.
The high-voltage component of the transformer according to claim 1, wherein the embedded part includes first end faces and side faces facing different and adjacent sides, the first end face being used to fix the ground connection piece, and the ground structure It also includes an intermediate piece located inside the insulator and used to connect the side and the connecting piece.
The high-voltage component of the transformer according to claim 1, wherein the embedded component includes a first end surface and a side surface facing different and adjacent sides, the first end surface is used to fix the ground connection component, and the side surface includes A first region and a second region, the first region is connected between the second region and the first end surface, the second region is located inside the insulator, and the first region is located between the insulator. outside and connected to the connector.
The high-voltage component of the transformer according to claim 3, wherein a surface of the connecting member facing away from the insulator is flush and coplanar with the first end surface.
The high-voltage component of the transformer according to claim 1, wherein the embedded part includes a first end surface, the connecting part includes a first connection area and a second connection area, the first connection area is connected to the On the first end surface, the second connection area is connected to the outer surface of the insulator, and the ground connection member is connected to the first connection area.
The high-voltage component of the transformer according to claim 5, wherein the first end surface is flush and coplanar with an outer surface of the insulator used to connect the connecting piece.
The high-voltage component of the transformer according to claim 5, wherein the second connection areas are distributed on both sides of the first connection area; or, the second connection areas are arranged around the first connection area. .
The high-voltage component of the transformer according to any one of claims 1 to 7, wherein the connecting member includes a hollow area, and part of the ground layer is in the hollow area and connected to the insulator.
The high-voltage component of the transformer according to claim 8, wherein the connecting member has a mesh structure.
The high-voltage component of the transformer according to any one of claims 1 to 9, wherein the insulator includes a main insulation part and a protrusion, the main insulation part covers the high-voltage coil, and the main insulation part includes The top surface, the bottom surface and the side surface connected between the top surface and the bottom surface, the top surface is used to face the low-voltage coil of the transformer, the protrusion is protrudingly provided on the side surface, and at least part of the insert is located Inside the protrusion, part of the surface of the insert used to connect the ground connector and the top surface are oriented in the same direction.
The high-voltage component of the transformer according to claim 10, wherein the connecting piece is located on the outer surface and/or the side of the protrusion.
The high-voltage component of the transformer according to any one of claims 1 to 9, wherein the insulator includes a top surface, a bottom surface and a side surface connected between the top surface and the bottom surface, and the top surface and \Or the bottom surface is used to face the low-voltage coil of the transformer, the connector is located on the side, and the embedded component is used to connect part of the surface of the ground connector and all The sides are oriented in the same direction.
The high-voltage component of the transformer according to any one of claims 10 to 12, wherein the high-voltage coil includes a winding part and a lead-out part, and the lead-out part and the winding part are arranged adjacently in the first direction, so The insulator includes a main body insulating part and a lead insulating part, the main insulating part wraps the winding part, the lead insulating part wraps the lead-out part, the grounding structure is provided in the main insulating part, and in the first direction, the grounding structure is located on a side of the winding part away from the lead-out part.
The high-voltage component of the transformer according to any one of claims 10 to 12, wherein the high-voltage coil includes a winding part and a lead-out part, and the lead-out part and the winding part are arranged adjacently in the first direction, so The insulator includes a main body insulating part and a lead insulating part, the main insulating part wraps the winding part, the lead insulating part wraps the lead-out part, the grounding structure is provided on the main insulating part, the grounding structure and The winding portions are spaced apart in a second direction, and the second direction and the first direction are arranged at an included angle.
The high-voltage component of the transformer according to any one of claims 1 to 14, characterized in that the part where the ground layer and the insulator are connected is provided with a hollow part, and the hollow part is provided to increase the number of the ground layer. The resistance.
The high-voltage component of the transformer according to any one of claims 1 to 15, wherein the ground layer is formed on the surface of the insulator and the connector by spraying or electroplating; or, the ground layer It is a flexible tape with semi-conductive properties.
The high-voltage component of the transformer according to any one of claims 1 to 16, wherein the resistivity of the ground structure is lower than the resistivity of the ground layer.
A transformer, characterized in that it includes a magnetic core and the high-voltage component according to any one of claims 1 to 17, and the high-voltage component is placed on part of the magnetic core.
The transformer of claim 18, wherein the transformer includes a low-voltage coil, a shield and a conductive cover, the low-voltage coil includes a first low-voltage coil and a second low-voltage coil, and the shield includes a first shield. and a second shielding member, the conductive cover plate includes a first conductive cover plate and a second conductive cover plate, the magnetic core includes a first magnetic cover, a second magnetic cover and a first magnetic cover that are oppositely arranged and connected to the first magnetic cover. The magnetic column between the cover and the second magnetic cover, the first conductive cover, part of the first shield, the first magnetic cover, the first low-voltage coil, the high-voltage component, all The second low-voltage coil, the second magnetic cover, part of the second shield and the second conductive cover are stacked in sequence, and the low-voltage coil and the high-voltage component surround the magnetic column, and part of the The first shielding member is located on the periphery of the first magnetic cover and the first low-voltage coil, and part of the second shielding member is located on the periphery of the second magnetic cover and the second low-voltage coil. The conductive cover plate For grounding, the resistivity of the shield is higher than the resistivity of the conductive cover.
The transformer according to claim 19, characterized in that the transformer further includes a fixing member, the fixing member is conductive, and the fixing member is fixedly connected to the first conductive cover plate and the second conductive cover plate. , and fix the high-voltage component, the low-voltage coil and the shield between the first conductive cover plate and the second conductive cover plate.
The transformer of claim 19 or 20, wherein the first shielding member includes a first part and a second part, and the first part is stacked between the first magnetic cover and the first conductive cover plate. The second part is connected to the edge of the first part and extends from the edge of the first part toward the direction of the high-voltage assembly. The second part is arranged around the first magnetic cover and the the periphery of the first low-voltage coil.
The transformer of claim 21, wherein the second portion includes a top edge, a bottom edge, a first side, and a second side, the top edge being connected to the first portion, and the bottom edge Contacting or forming a gap with the high-voltage component, an opening is formed between the first side and the second side, and the opening is at least used to accommodate the lead-out member of the first low-voltage coil. .
The transformer according to any one of claims 19 to 22, wherein the first shielding member includes a sheet-shaped body and a plurality of through holes provided on the main body.
The transformer according to claim 18, characterized in that the transformer includes a low-voltage coil, a shield and a conductive cover plate, and the magnetic core includes a first magnetic cover, a second magnetic cover and a second magnetic cover that are oppositely arranged and connected to the first magnetic cover. A magnetic column is between a magnetic cover and the second magnetic cover. The high-voltage component and the low-voltage coil surround the magnetic column. The high-voltage component, the low-voltage coil, the first magnetic cover, and some of the The shielding member and the conductive cover plate are stacked in sequence, part of the shielding member is located on the periphery of the first magnetic cover and the low-voltage coil, the conductive cover plate is used for grounding, and the resistivity of the shielding member is high to the resistivity of the conductive cover plate.
The transformer according to any one of claims 18 to 24, wherein the ground connection member is connected between the embedded member and the conductive cover plate.
The transformer of any one of claims 18-25, wherein the shield contacts the high voltage component.
An electric power equipment, characterized in that it includes a high-voltage circuit, a low-voltage circuit, and a transformer according to any one of claims 18 to 26 connected between the high-voltage circuit and the low-voltage circuit.
A transformer, characterized by including:

A magnetic core, including a first magnetic cover, a second magnetic cover arranged oppositely, and a magnetic column connected between the first magnetic cover and the second magnetic cover;

A high-voltage component, including a high-voltage coil, an insulator and a ground layer, the insulator covering the high-voltage coil, and the ground layer covering at least part of the outer surface of the insulator;

A low-voltage coil and the high-voltage component are arranged in a stack, and the low-voltage coil and the high-voltage component surround the magnetic column;

Shield and conductive cover plate, the high-voltage component, the low-voltage coil, the first magnetic cover, part of the shield part and the conductive cover plate are stacked in sequence, and part of the shield part is located on the first magnetic cover. Cover and the periphery of the low-voltage coil, the conductive cover plate is used for grounding, and the resistivity of the shield is higher than the resistivity of the conductive cover plate;

The ground layer of the high voltage component is electrically connected to the conductive cover plate.