CN209804426U

CN209804426U - high-voltage transformer and power electronic device

Info

Publication number: CN209804426U
Application number: CN201920768057.4U
Authority: CN
Inventors: 张全良; 郭世忠
Original assignee: Delta Electronics Shanghai Co Ltd
Current assignee: Delta Electronics Shanghai Co Ltd
Priority date: 2019-05-24
Filing date: 2019-05-24
Publication date: 2019-12-17
Anticipated expiration: 2029-05-24

Abstract

the utility model provides a high voltage transformer and power electronic device. The high-voltage transformer comprises a magnetic core, a secondary side coil unit, a primary side coil unit, a second insulating part, a first retaining wall and a second retaining wall. The primary coil unit comprises a primary winding and a first insulating part, wherein a through hole is formed in the first insulating part, and the primary winding surrounds the through hole and is coated and fixed by the first insulating part. The first insulating portion has a shielding layer formed thereon for securing the ground. The second insulating part is formed by extending the first insulating part to a direction far away from the primary coil unit, the primary coil unit is provided with two outgoing lines and connecting terminals, and the outgoing lines and at least part of the connecting terminals are embedded in the second insulating part; the first retaining wall is in a closed ring shape, is arranged on the peripheral side of the end part of the second insulating part and extends towards the direction far away from the primary coil unit; the second retaining wall is arranged in the first retaining wall and extends towards the direction far away from the primary coil unit, and the second retaining wall is higher than the wiring terminals and separates the two wiring terminals.

Description

high-voltage transformer and power electronic device

Technical Field

The utility model relates to a high voltage transformer and power electronic device.

Background

In a conventional distribution network, for example, high voltage power of 6kV (kilovolt) or more is generally supplied to each load after being stepped down by a distribution transformer. Therefore, in such distribution networks, a distribution transformer is a very important component thereof. The traditional distribution transformer has many defects, such as large volume, heavy weight, large no-load loss, failure automatic isolation, easy interference of output by a power grid, and the like.

At present, the industry is seeking to adopt a new technical scheme Power electronic Transformer (Power electronic Transformer) to replace a Power frequency distribution Transformer to make up for various defects thereof and realize high Power density, miniaturization, high efficiency and intellectualization of a distribution system. One of the core components of PET is a high frequency high voltage transformer, which is used for power conversion and isolation on the high and low voltage sides.

generally, there are several ways to make high-frequency high-voltage transformers: first, it can be like a line frequency dry transformer, using air as the primary ground-insulating medium. However, air insulation is weak, and thus a large insulation size is required. The power density of the product is not improved; meanwhile, the outer surface of the high-voltage side presents high-voltage potential, and the safety distance needs to be considered, so that the improvement of the power density is not facilitated. Second, like oil-immersed transformers, insulating oil is used as the medium that insulates primarily against ground. However, the method needs a shell and flammable insulating oil, and has potential safety hazards in indoor use environments. And thirdly, the integrated epoxy cast transformer is manufactured by adopting a vacuum casting process, and the winding and the magnetic core are integrally cast in resin. Under the condition of insulation fault, high voltage and low voltage cannot be effectively isolated safely, and potential safety hazard exists; meanwhile, the outer surface of the high-voltage side presents high-voltage potential, and the safety distance needs to be considered, so that the improvement of the power density is not facilitated.

At present, in the field of medium-high voltage transformers, the following methods are generally adopted for outgoing lines: firstly, the silica gel line is directly led out from the solid insulation, and the silica gel line and the solid insulation have high insulation strength, so that the requirement of the product on the ground insulation strength can be met. However, the combination of the solid insulated silica gel wire on the interface and in the silica gel wire can not avoid the existence of air, so that the product has the hidden trouble of partial discharge, and the long-term aging capability of the product is unqualified; and secondly, the porcelain bottle outlet is a common wire outlet mode of an oil-immersed insulation product, and the voltage-resistant requirement of the product can be met by utilizing the stronger insulation strength of the insulating oil. Because the design needs larger space, namely the length of the outgoing line is more than or equal to the electrical clearance, the integral power density of the product is reduced, and meanwhile, because oil is required to be filled, the application of the product is restricted by the sealing and fire-fighting hidden troubles; and thirdly, the integrated epoxy columnar outgoing line is directly led out from the inside of the coil, and the columnar outgoing line is externally insulated and integrally formed with the body. The product meets the overall insulation requirement of the product by utilizing the high insulation strength of solid insulation, avoids the defects of street corner and different insulation media inside the product, and better meets the requirement of insulation performance. But similar to the porcelain insulator outgoing line, a larger space is needed, namely the outgoing line length is more than or equal to the electric gap, so that the overall power density of the product is reduced.

The above information disclosed in the background section is only for enhancement of understanding of the background of the present invention, and therefore it may include information that does not constitute related art known to those of ordinary skill in the art.

SUMMERY OF THE UTILITY MODEL

the utility model discloses a main aim at overcomes above-mentioned prior art's at least defect, provides a security and is favorable to improving power density's high voltage transformer and power electronic device.

additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

According to an aspect of the present invention, a high voltage transformer includes a magnetic core, a secondary winding unit, a primary winding unit, a second insulating portion, a first retaining wall, and a second retaining wall. The primary coil unit comprises a primary winding and a first insulating part, wherein one or more through holes are formed in the first insulating part, one or more primary windings surround at least one through hole and are coated by the first insulating part and fixed in the first insulating part, the magnetic core penetrates through the at least one through hole, a shielding layer is formed on the surface of the first insulating part, and the shielding layer is used for being connected with a ground safely. The second insulating part is formed by extending the first insulating part to a direction far away from the primary coil unit, the primary coil unit is provided with two outgoing lines, the end parts of the outgoing lines are provided with wiring terminals, and the outgoing lines and at least part of the wiring terminals are embedded in the second insulating part; the first retaining wall is in a closed ring shape, is arranged on the peripheral side of the end part of the second insulating part and extends towards the direction far away from the primary coil unit; the second retaining wall is arranged in the first retaining wall, one end of the second retaining wall is connected to the second insulating part, the other end of the second retaining wall extends towards the direction far away from the primary coil unit, and the second retaining wall is higher than the wiring terminals and separates the wiring terminals.

According to the utility model discloses an embodiment still includes:

The third barricade is closed annular, locates the tip week side of second insulating part to keeping away from primary coil unit direction extends, the third barricade is located in the first barricade, and with an interval has between the first barricade.

according to an embodiment of the present invention, the height of the third retaining wall is higher than, lower than or equal to the height of the first retaining wall.

According to an embodiment of the present invention, the outer surface of the first retaining wall and the outer surface of the second insulating portion are provided with an umbrella skirt.

According to an embodiment of the present invention, the first retaining wall and the second insulating portion are integrally formed; and/or the second retaining wall and the second insulating part are of an integrally formed structure.

According to the utility model discloses an embodiment, the third barricade with the second insulating part is the integrated into one piece structure.

According to an embodiment of the present invention, the shielding layer covers more than 90% of the surface of the first insulating portion.

According to an embodiment of the present invention, the shielding layer is a copper foil, an aluminum foil, a zinc layer, a silver conductive paint layer or a silver-copper alloy conductive paint layer.

According to an embodiment of the present invention, the shielding layer is a conductive layer formed on the surface of the first insulating portion by pasting, electroplating, evaporation, casting or spraying.

According to the utility model discloses an embodiment, be equipped with ground terminal on the shielding layer, be used for connecting the shielding layer with safely.

According to an embodiment of the present invention, the first insulating portion is made of resin.

According to another aspect of the present invention, a high voltage transformer, the high voltage transformer comprises:

A secondary coil unit including one or more secondary windings; and

The primary coil unit comprises one or more primary windings and a first insulating part, wherein one or more through holes are formed in the first insulating part, the one or more primary windings surround at least one through hole, are coated by the first insulating part and are fixed in the first insulating part, the magnetic core penetrates through at least one through hole, a shielding layer is formed on the surface of the first insulating part, and the shielding layer is used for being connected with a ground safely;

the first insulating part extends towards the direction far away from the primary coil unit, the primary coil unit is provided with two outgoing wires, the end parts of the outgoing wires are provided with wiring terminals, and the outgoing wires and at least part of the wiring terminals are embedded in the first insulating part;

The first retaining wall is in a closed ring shape, is arranged on the peripheral side of the end part of the second insulating part and extends towards the direction far away from the primary coil unit;

and the second retaining wall is arranged in the first retaining wall, one end of the second retaining wall is connected with the second insulating part, the other end of the second retaining wall extends towards the direction of the primary coil unit, and the second retaining wall is higher than the wiring terminal and separates the wiring terminal from the wiring terminal.

According to another aspect of the present invention, a power electronic device, comprises a high voltage transformer, wherein the high voltage transformer is the high voltage transformer.

According to the above technical scheme, the utility model discloses possess at least one in following advantage and the positive effect:

In the high-voltage transformer of the utility model, the primary winding of the primary coil unit is coated by the first insulating part and is fixed in the first insulating part, that is, the first insulating part plays a role in fixing and insulating the primary winding at the same time, which is beneficial to improving the safety performance of the high-voltage transformer; furthermore, a shielding layer is formed on the surface of the first insulating part and can be electrically connected with a safety ground, so that the high-voltage potential of the primary coil unit is reduced, the surface of the high-voltage transformer is low-voltage potential or zero potential, and the safety performance of the high-voltage transformer is obviously improved.

On the other hand, because the primary coil unit is at a low voltage potential or a zero potential, other components such as a secondary coil unit or a capacitor can be arranged in a close range around the primary coil unit and even directly contacted with the primary coil unit, so that the power density can be obviously improved.

and simultaneously, the utility model discloses a high voltage transformer first insulation portion, by the second insulation portion that this first insulation portion extends, the play line of primary coil unit is buried underground in the second insulation portion to be equipped with the first barricade that surrounds two leading-out terminals and the second barricade of two leading-out terminals of spaced apart on the second insulation portion, thereby showing electric clearance and the creepage distance that has increased binding post to the shielding layer, the ground dielectric strength of winding has been improved, high voltage transformer's antifouling moisture barrier property has been improved simultaneously.

Drawings

The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

FIG. 1 is a circuit architecture diagram of PET;

FIG. 2 is a schematic block circuit diagram of the circuit architecture diagram of the PET of FIG. 1;

fig. 3 is a schematic perspective view of an embodiment of the high voltage transformer of the present invention;

Fig. 4 is a longitudinal sectional view of the high voltage transformer shown in fig. 3;

FIG. 5 is a top view of the high voltage transformer shown in FIG. 3;

fig. 6 is a longitudinal sectional view of another embodiment of the high voltage transformer of the present invention;

Fig. 7 is a top view of the high voltage transformer shown in fig. 6.

In the figure: 11. a primary side coil unit; 30. a magnetic core; 40. a secondary coil unit; 50. a primary winding; 501. wire outgoing; 502. a wiring terminal; 51. a first insulating portion; 510. a via hole; 52. a shielding layer; 53. a second insulating section; 54. a first retaining wall; 55. a second retaining wall; 56. and a third retaining wall.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted.

see fig. 1 and 2. As shown in fig. 1, fig. 1 is a circuit architecture diagram of a PET, which is a multi-module input serial/output parallel system architecture, and each module may include, for example, an AD/DC unit, a DC bus and a DC/DC unit, which are connected in sequence. As shown in fig. 2, fig. 2 is a schematic circuit diagram of one module in the circuit architecture diagram of the PET shown in fig. 1, which is a cascaded AC/DC and DC/DC unit. The components of the DC/DC unit that comprise a core are high-frequency high-voltage transformers, which are used for power conversion and insulation isolation on the high-voltage side and the low-voltage side.

High-voltage transformer

Referring to fig. 3 to 5, fig. 3 is a schematic perspective view of an embodiment of a high voltage transformer according to the present invention; fig. 4 is a longitudinal sectional view of the high voltage transformer shown in fig. 3; fig. 5 is a top view of the high voltage transformer shown in fig. 3.

The utility model discloses an embodiment of high voltage transformer includes magnetic core 30, secondary winding unit 40, primary winding unit 11, second insulating part 53, first barricade 54 and second barricade 55.

The core 30 may be an E-core, U-core, or the like, having one or more legs.

the secondary coil unit 40 includes one secondary winding, and may include a plurality of secondary windings. The primary coil unit 11 includes a primary winding 50, and may also include a plurality of primary windings 50 and a first insulating portion 51.

The first insulating portion 51 may be made of an insulating material such as resin, and has a via hole 510 (see fig. 6) formed therein for the magnetic pillar of the magnetic core to pass therethrough. In other embodiments, the number of the vias 510 in the first insulating portion 51 is not limited to one, and may be two or more. The primary winding 50 is disposed around the via 510 and is wrapped by the first insulator 51 and secured within the first insulator 51. The first insulating portion 51 has a shielding layer 52 formed on the surface thereof. The maximum voltage to ground of the primary coil unit 11 may be more than 2kV (kilovolts), for example, 3kV, 6kV, 10kV, 20kV, or the like. The first insulating portion 51 facilitates the design of the primary and secondary voltage difference, and the ratio of the maximum voltage to ground of the primary coil unit 11 to the maximum voltage to ground of the secondary coil unit 40 may be not less than 5. The surface of the first insulating portion 51 includes an outer surface of the first insulating portion 51, and further, the surface of the first insulating portion 51 further includes an inner surface, i.e., a surface of the first insulating portion 51 defining the via hole.

as shown in fig. 3, the primary coil unit 11 and the secondary coil unit 40 can be stacked together and disposed on the same stem, in other embodiments, the secondary coil unit 40 can also be disposed in the via hole of the primary coil unit 11, or disposed on different stems with the primary coil unit 11, respectively, the present invention is not limited thereto.

the utility model discloses in, the quantity of primary winding 50 can be a plurality ofly among the primary coil unit 11, and a plurality of primary windings 50 can direct series connection, indirect series connection, direct parallel connection or indirect parallel connection, also can mutually independent and do not have direct electric connection each other, the utility model discloses not so for the limit.

the shielding layer 52 may cover all surfaces of the first insulating portion 51, including an inner surface and an outer surface, etc.; the shielding layer 52 may cover only a part of the surface of the first insulating portion 51, but not other surfaces, and usually, in order to obtain a better shielding effect, the shielding layer 52 may cover more than 90% of the surface of the first insulating portion 51. The shielding layer 52 may be a copper foil, an aluminum foil, a zinc layer, a silver conductive paint layer, or a silver-copper alloy conductive paint layer, etc. attached to the surface of the first insulating portion 51, such as an aluminum foil with a thickness of 0.2mm or a zinc layer with a thickness of 18 um; the shielding layer 52 may be a metal film such as a conductive gold film formed on the surface of the first insulating portion 51 by processes such as pasting, electroplating, evaporation, casting, or spraying, but the present invention is not limited thereto.

The shielding layer 52 can be used to connect a safety ground, which can be formed by a conductor block buried in the ground, for example, so as to reduce the high-voltage potential on the surface of the primary coil unit 11 and improve the safety performance of the high-voltage transformer. In some embodiments, for convenience of safety connection, the shielding layer 52 is provided with a ground terminal, and the ground terminal 20 may be used to connect the shielding layer 52 and the safety ground in a surface-mount manner such as a ground pad, or in a direct-insert manner such as a pin.

in some embodiments, the shielding layer 52 has a spacing portion to prevent the shielding layer 52 from forming a closed conductive loop, for example, a gap is formed on the shielding layer 52, and further, an insulating material may be disposed in the gap.

The secondary coil unit 40 may include one or more secondary windings, and the plurality of secondary windings may be directly connected in series, indirectly connected in series, directly connected in parallel or indirectly connected in parallel, and may be independent of each other without direct electric connection, and the present invention is not limited thereto. In this embodiment, the secondary winding unit 40 may have the same structure as the primary winding unit 11, and includes a secondary winding fixed and covered by an insulating material, the insulating material having a via hole, the secondary winding being disposed around the via hole, and the insulating material being entirely covered or partially covered by a shielding layer. In other embodiments, the secondary coil unit 40 may have a different structure from the primary coil unit 11.

In the assembled high-voltage transformer, the primary coil unit 11, the secondary coil unit 40 and the magnetic core 13 can be exposed in the air, so that the heat dissipation mode is simplified, and the heat dissipation effect is good.

In the first embodiment of the high-voltage transformer, since the shielding layer 52 is connected to the ground safely, the surface of the high-voltage transformer presents zero potential, and other devices can be arranged near the primary coil unit 11 while improving the safety performance, so that the high-voltage transformer has a compact structure, and is beneficial to improving the power density and reducing the volume; the high-voltage transformer can also be arranged near other equipment, and the use is more flexible and convenient.

The second insulating portion 53 is formed by extending the first insulating portion 51 away from the primary coil unit, and the second insulating portion 53 may be made of the same material as the first insulating portion 51 and be integrally formed with the first insulating portion 51.

the primary coil unit 11 includes two outgoing lines 501 (e.g., the head and tail ends of the primary winding 50), and for facilitating electrical connection, a connection terminal 502 is disposed at an end of the outgoing line 501, and the outgoing line 501 and at least a part of the connection terminal 502 are embedded in the second insulating portion 53. The terminal 502 may be a concave metal connector or a convex connector. In other embodiments of the present invention, the primary coil unit 11 may further include three or more outgoing lines 501 according to the number of the primary coils and the connection manner.

The first retaining wall 54 has a closed ring shape and may be made of an insulating material. The first retaining wall 54 is provided on the end periphery side of the second insulating portion 53 and extends in a direction away from the primary coil unit 11. The first dam 54 may be made of the same material as the second insulating portion 53 and be integrally formed with the second insulating portion 53. The terminal 502 is surrounded by the first retaining wall 54. The first wall 54 increases the electrical gap and creepage distance from the terminal 502 to the shield 52, and improves the ground insulation strength of the primary winding 50.

In some embodiments, the outer surface of the first retaining wall 54 and the outer surface of the second insulating portion 53 may be provided with a shed to further increase the creepage distance.

The second retaining wall 55 is disposed in the first retaining wall 54, and may be in a plate shape, the bottom end of the second retaining wall is connected to the second insulating portion 53, and the top end of the second retaining wall extends away from the primary coil unit 11, as shown in fig. 5, and the other two opposite sides may be connected to the first retaining wall 54. The second retaining wall 55 may be made of an insulating material. The second bank 55 may be made of the same material as the second insulating portion 53 and be integrally formed with the second insulating portion 53. The second wall 55 separates the two connection terminals 502, increasing the creepage distance between the two connection terminals 502.

The height H of the second retaining wall 55 is higher than the connecting terminal 502, so that the electrical gap between the two connecting terminals 502 can be increased, the first retaining wall 54 and the second retaining wall 55 play a role in increasing the insulation strength of the high-voltage transformer, and the antifouling and moisture-proof performance of the high-voltage transformer can be improved.

Referring to fig. 6 and 7, fig. 6 is a longitudinal sectional view of another embodiment of the high voltage transformer of the present invention, in which the magnetic core is removed to show the via hole 510 formed in the first insulating portion 51; fig. 7 is a top view of the high voltage transformer shown in fig. 6. The high voltage transformer of this embodiment further includes a third dam wall 56 on the basis of the embodiment shown in fig. 3 to 5.

The third baffle wall 56 has a closed loop shape such as a racetrack shape, an oval shape, a circular shape, etc. The third wall 56 is provided on the end periphery side of the second insulating portion 53 and extends in a direction away from the primary coil unit 11. The third retaining wall 56 may be made of an insulating material. The third wall 56 may be integrally formed with the second insulating portion 53. The third wall 56 is lower than the first wall 54. In other embodiments, the height of the third retaining wall 56 can be higher than or equal to the height of the first retaining wall 54. The two connection terminals 502 may be surrounded by the third partition wall 56. The third wall 56 can further increase the electrical gap and creepage distance from the terminal 502 to the shield 52, thereby further improving the ground insulation strength of the primary winding.

the third retaining wall 56 is located in the first retaining wall 54 and has a distance S with the first retaining wall 54. The spacing S is advantageous for increasing the creepage distance of the terminal 502 to ground.

the utility model provides a high voltage transformer embodiment compares in the embodiment that fig. 3 to 5 show, has saved the magnetic core, and other structures of high voltage transformer embodiment are the same with the embodiment that fig. 3 to 5 show, and no longer describe here.

Power electronic device

The utility model also provides a power electronic device, this power electronic device includes the utility model discloses previously any kind of high voltage transformer. As the shielding layer is safely covered, the potential of the surface of the power electronic device is reduced and even the potential of the surface of the power electronic device is zero, thereby greatly improving the safety performance.

relative terms, such as "upper" or "lower", "front" or "rear", may be used in the above embodiments to describe one component's relative relationship to another component of the icon. It will be understood that if the device illustrated in the drawings is turned over and turned upside down, elements described as "upper" or "lower", "front" or "rear" will be referred to as elements "lower" or "upper", "rear" or "front". The terms "a," "an," "the," and "at least one" are used to indicate the presence of one or more elements/components/etc. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements, and the terms "first," "second," and the like, are used merely as labels, and are not numerical limitations on their objects.

It is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth herein. The present invention is capable of other embodiments and of being practiced and carried out in a variety of ways. The foregoing variations and modifications fall within the scope of the present invention. It will be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention.

Claims

1. A high voltage transformer, characterized in that it comprises:

a magnetic core;

A secondary coil unit including one or more secondary windings; and

2. The high voltage transformer of claim 1, further comprising:

3. The high voltage transformer of claim 2, wherein the height of the third wall is higher than, lower than or equal to the height of the first wall.

4. The high voltage transformer of claim 1, wherein an outer surface of the first dam and an outer surface of the second insulating portion are provided with sheds.

5. the high voltage transformer of claim 1, wherein the first dam and the second insulation portion are integrally formed; and/or the second retaining wall and the second insulating part are of an integrally formed structure.

6. The high voltage transformer according to claim 2, wherein the third wall and the second insulating portion are integrally formed.

7. The high voltage transformer of claim 1, wherein the shield layer covers more than 90% of the first insulating surface.

8. The high voltage transformer of claim 1, wherein the shielding layer is a copper foil, an aluminum foil, a zinc layer, a silver conductive paint layer, or a silver-copper alloy conductive paint layer.

9. The high voltage transformer of claim 1, wherein the shielding layer is a conductive layer formed on the first insulating surface by pasting, plating, evaporation, casting or sputtering.

10. The high voltage transformer of claim 1, wherein said shield has a ground terminal for connecting said shield to said ground.

11. The high voltage transformer of claim 1, wherein the first insulating portion is made of resin.

12. A high voltage transformer, characterized in that it comprises:

A secondary coil unit including one or more secondary windings; and

The primary coil unit comprises one or more primary windings and a first insulating part, wherein one or more through holes are formed in the first insulating part, the one or more primary windings surround at least one through hole, are coated by the first insulating part and are fixed in the first insulating part, and a shielding layer is formed on the surface of the first insulating part and is used for being connected with a ground safely;

13. A power electronic device, characterized in that it comprises a high voltage transformer, wherein the high voltage transformer is a high voltage transformer according to any of claims 1-12.