EP4200884A1

EP4200884A1 - Oil tank for converter transformer and converter transformer including same

Info

Publication number: EP4200884A1
Application number: EP20952714.2A
Authority: EP
Inventors: Ren Wang; Adrian VOLK; Reiner WEISSKOPF
Original assignee: Siemens Energy Global GmbH and Co KG
Current assignee: Siemens Energy Global GmbH and Co KG
Priority date: 2020-09-09
Filing date: 2020-09-09
Publication date: 2023-06-28
Also published as: EP4200884A4; CN116195014A; WO2022051926A1

Abstract

Disclosed are an oil tank for a converter transformer and the converter transformer including the oil tank. The oil tank (10) includes a top (11), a bottom (12), a circumferential wall (13) that connects the top and the bottom, and at least one shielding device (20) mounted on an inner surface of the circumferential wall; the circumferential wall (13) has a first outwardly convex structure in a region facing a winding (30) of the converter transformer, so as to form a corresponding first inner surface concave portion on the inner surface of the circumferential wall; the shielding device has a second outwardly convex structure matching with the first inner surface concave portion of the circumferential wall, so as to form a corresponding second inner surface concave portion on an inner surface of the shielding device; and the second inner surface concave portion keeps a predetermined insulating distance from an outer surface of the winding of the converter transformer. According to the oil tank provided by the present invention, the stray loss of the oil tank is reduced, the transportation size of the transformer with the oil tank can be decreased, and the internal space in the oil tank is optimized.

Description

Oil tank for converter transformer and converter transformer including same

Technical Field

The present invention relates to the field of transformers, and in particular to an oil tank for a converter transformer and the converter transformer including the oil tank.

Background

Windings and iron cores penetrated into the windings are disposed in an oil tank of a converter transformer. During operation of the converter transformer, a leakage flux is generated around the windings. When the leakage flux passes through a wall of the oil tank, stray losses are generated, and sometimes, the oil tank of the transformer is overheated. In order to solve the above problem, a shielding device is designed on the oil tank of the existing converter transformer, such that the leakage flux preferentially passes through the shielding device having better magnetic permeability, thereby reducing the stray losses of the leakage flux on the wall of the oil tank.
Traditionally, for the purpose of reducing the stray losses of the oil tank of the transformer, magnetic shielding formed by magnetic silicon steel sheets, or electric shielding formed by copper plates or electric shielding formed by aluminum plates or other protective measures are used on the oil tank. Concerning the magnetic shielding of the silicon steel sheets, the shielding is typically parallel with the oil tank in installation; and the magnetic shielding is relatively thick and generally keeps a certain space with the oil tank. For the conventional copper shielding or aluminum shielding, shielding materials are of an overall flat plate type and are typically parallel with the oil tank in installation; and the copper shielding or aluminum shielding often keeps a certain space with the oil tank. When a transportation condition of the transformer is limited, due to poor design flexibility of the traditional shielding manners, the internal space in the oil tank is wasted.
Summary
In order to solve the above problem, an objective of the present invention is to provide an oil tank for a converter transformer and the converter transformer including the oil tank. With the oil tank, the stray loss of the oil tank can be reduced, the transportation size of the transformer with the oil tank can be decreased, and the internal space in the oil tank is optimized.
According to one aspect of the present invention, an oil tank for a converter transformer is provided. The oil tank comprises a top, a bottom, a circumferential wall that connects the top and the bottom, and at least one shielding device mounted on an inner surface of the circumferential wall; particularly, the circumferential wall has a first outwardly convex structure in a region facing a winding of the converter transformer, so as to form a corresponding first inner surface concave portion on the inner surface of the circumferential wall; the shielding device has a second outwardly convex structure matching with the first inner surface concave portion of the circumferential wall, so as to form a corresponding second inner surface concave portion on an inner surface of the shielding device; and the second inner surface concave portion keeps a predetermined insulating distance from an outer surface of the winding of the converter transformer.
By providing the first outwardly convex structure on the circumferential wall and the second outwardly convex structure on the shielding device, while the insulating distance from the winding is ensured, the size of the oil tank in the width direction can be reduced, thereby reducing the overall size of the oil tank.
In an exemplary implementation, each of the first outwardly convex structure and the second outwardly convex structure is of an arc convex structure in a plane perpendicular to a vertical central axis of the winding of the converter transformer.
In this way, the first outwardly convex structure and the second outwardly convex structure are better adapted to the shape of the winding of the converter transformer, such that the overall size of the oil tank is sufficiently reduced.
In an exemplary implementation, the shielding device is formed by combining a plurality of copper plates.
The shielding device is of the combined structure with a plurality of small copper plates, so a coverage structure of any appropriate shape for the shielding device may be implemented, and thus it will be better for the magnetic protection on the tank wall.
In an exemplary implementation, each copper plate in the plurality of copper plates is of a quadrilateral shape, the plurality of copper plates include a first group of copper plates in a flat shape and a second group of copper plates in a curved shape, the first group of copper plates are combined into a flat structure of the shielding device, and the second group of copper plates are combined into the second outwardly convex structure of the shielding device.
With the reasonable arrangement of the first group of copper plates and the second group of copper plates, the reasonable and optimized coverage structure for the shielding device is better implemented, and it will be better for the magnetic protection on the tank wall.
In an exemplary implementation, the shielding device is formed by a single copper plate, and the single copper plate has a flat structure and the second outwardly convex structure.
By making the shielding device with the single copper plate, the shielding device is simplified in structure and can be easily mounted on the inner wall of the oil tank.
In an exemplary implementation, the shielding device and the circumferential wall of the oil tank are directly welded or directly connected by bolts.
The shielding device and the circumferential wall of the oil tank are directly welded for fixation or directly connected by the bolt, which reduces the spatial distance between the shielding device and the circumferential wall of the oil tank.
In an exemplary implementation, the shielding device has a thickness of 4 mm to 6 mm, and/or a radian of each of the first outwardly convex structure of the circumferential wall and the second outwardly convex structure of the shielding device ranges from 40° to 60°.
By reasonably designing the thickness of the shielding device and the radians of the first outwardly convex structure and the second outwardly convex structure, the overall size of the oil tank is reduced while the effective shielding is ensured.
In an exemplary implementation, the circumferential wall of the oil tank includes two primary sidewalls opposite to each other and two secondary sidewalls opposite to each other, two shielding devices are provided, the two shielding devices are oppositely and correspondingly mounted on the two primary sidewalls, and a lower portion of either or both of the two shielding device is formed as a tilt portion that is tilted inward along a downward direction.
In this way, the arrangement of the shielding device is very suitable for the inner surface of the oil tank; and it is a reasonable arrangement, while the effective shielding is ensured, the overall size of the oil tank is reduced.
In an exemplary implementation, the shielding device includes a plurality of flat structures and a plurality of the second outwardly convex structures, and the plurality of flat structures and the plurality of the second outwardly convex structures of the shielding device are arranged alternately.
In this way, the shape of the shielding device can be properly matched with the shapes of other relevant components in the oil tank, such that while the effective shielding is ensured, the overall size of the oil tank is reduced.
According to another aspect of the present invention, a converter transformer is provided, which comprises the oil tank having the above features of the present invention. According to the converter transformer provided by the present invention, the stray loss of the oil tank is reduced, the overall transportation size of the converter transformer with the oil tank can be decreased to the greatest extent, and the internal space in the oil tank is optimized.
To sum up, the oil tank for the converter transformer and the converter transformer including the oil tank provided by the present invention can mainly achieve the following beneficial technical effects superior to the conventional art:
Firstly, as the winding in the converter transformer is of an arc shape, by designing an appropriate region of the circumferential wall of the oil tank and an appropriate region of the copper shielding device into the arc convex structures, while the insulating distance from the coil winding is ensured, the size of the oil tank in the width direction can be reduced. Particularly, when the transportation condition of the converter transformer is limited, the present invention is obviously advantageous.
Secondly, the shielding device and the circumferential wall of the oil tank are directly welded for fixation, thereby reducing the spatial distance between the shielding device and the circumferential wall.
Thirdly, the shielding device is of the combined structure with a plurality of small copper plates, so various appropriate coverage structures for the shielding device can be implemented, and it will be better for the magnetic protection on the tank wall.

Brief Description of the Drawings

The accompanying drawings are described here to provide a further understanding of the disclosure, and form a part of the disclosure. The schematic embodiments and description of the disclosure are adopted to explain the disclosure, and do not form improper limits to the disclosure. In the drawings:
Fig. 1 is a perspective schematic diagram of an oil tank for a converter transformer according to a preferred embodiment of the present invention, in which some components are omitted for the sake of clarity.
Fig. 2 is another perspective schematic diagram of the oil tank for a converter transformer according to the preferred embodiment of the present invention, in which some components are omitted for the sake of clarity.
Fig. 3 is a perspective schematic diagram of a shielding device of the oil tank for a converter transformer according to the preferred embodiment of the present invention.
Fig. 4 is a perspective schematic diagram of a converter transformer according to a preferred embodiment of the present invention, in which some components are omitted for the sake of clarity.
10. Oil tank;
11. Top;
12. Bottom;
13. Circumferential wall;
20. Shielding device;
21. First group of copper plates;
22. Second group of copper plates;
30. Winding;
40. Iron core; and
100. Converter transformer.
Detailed Description of the Embodiments
The technical solutions in the embodiments of the present invention will be clearly and completely described hereinafter with the accompanying drawings in the embodiments of the present invention. It is apparent that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall pertain to the protection scope of the present invention.
In order to make those of ordinary skill in the art understand the solutions of the present invention more clearly, the principles of the shielding device in the disclosure are briefly described first. The shielding device formed by copper plates is mainly described in the disclosure. Certainly, it may be understood that other appropriate materials, such as aluminum plates, may also be used to form the shielding device. The principles of the shielding device of the present invention are to utilize high conductivities of the copper plates. When the spatial leakage flux of the transformer leaks to the copper plates, induced eddy currents are generated on the surfaces of the copper plates and the reverse magnetic flux is generated, thereby reversely blocking the original leakage flux and preventing the entry of the leakage flux into the oil tank. Such a shielding manner of the shielding device in the present invention may also be referred to electric shielding.
Hereinafter, the converter transformer and the oil tank thereof in the preferred embodiments are specially described.
Referring to Fig. 1, Fig. 2 and Fig. 4, Fig. 1 is a perspective schematic diagram of an oil tank 10 for a converter transformer according to a preferred embodiment of the present invention, Fig. 2 is another perspective schematic diagram of the oil tank 10, and Fig. 4 is a perspective schematic diagram of the converter transformer 100. For the sake of clarity, some components are omitted in Fig. 1, Fig. 2 and Fig. 4.
The oil tank 10 of the present invention may be called a special-shaped oil tank, and the shielding device 20 of the present invention may also be called a special-shaped shielding device.
Specially, the oil tank 10 includes a top 11, a bottom 12, a circumferential wall 13 that connects the top 11 and the bottom 12, and at least one shielding device 20 mounted on an inner surface of the circumferential wall 13. Referring to Fig. 1 and Fig. 2, the circumferential wall 13 includes two primary sidewalls opposite to each other and two secondary sidewalls opposite to each other. Two shielding devices 20 may be provided (one shielding device having arc convex structures is mainly illustrated in the figures) , the two shielding devices are oppositely and correspondingly mounted on the two primary sidewalls, and a lower portion of either or both of the two shielding device is formed as a tilt portion that is tilted inward along a downward direction.
The circumferential wall 13 of the oil tank 10 has a first outwardly convex structure in a region facing a winding 30 of the converter transformer, so as to form a corresponding first inner surface concave portion on the inner surface of the circumferential wall 13; the shielding device 20 has a second outwardly convex structure matching with the first inner surface concave portion , so as to form a corresponding second inner surface concave portion on an inner surface of the shielding device 20; and the second inner surface concave portion keeps a predetermined insulating distance from an outer surface of the winding 30. Specifically, each of the first outwardly convex structure and the second outwardly convex structure is of an arc convex structure in a plane (the plane may also be called a horizontal plane) perpendicular to a vertical central axis of the winding 30.
Referring to Fig. 3, the specific structure of the shielding device 20 is illustrated below. The shielding device 20 is formed by combining a plurality of copper plates. Each copper plate in the plurality of copper plates is of a quadrilateral shape, the plurality of copper plates include a first group of copper plates 21 in a flat shape and a second group of copper plates 22 in a curved shape, the first group of copper plates 21 are combined into a plurality of flat structures of the shielding device 20, and the second group of copper plates 22 are combined into a plurality of second outwardly convex structures of the shielding device 20. The plurality of flat structures and the plurality of second outwardly convex structures of the shielding device 20 are arranged alternately.
In addition, the shielding device 20 and the circumferential wall 13 are directly welded or directly connected by bolts. The shielding device 20 has a thickness of 5 mm, and a radian of each of the first outwardly convex structure of the circumferential wall 13 and the second outwardly convex structure of the shielding device 20 is 46.6°.
Referring to Fig. 4 again, the description is made to main components of the converter transformer 100. The front primary sidewall and shielding device of the oil tank 10 are omitted in Fig. 4. The converter transformer 100 mainly includes the oil tank 10, two windings 30 disposed inside the oil tank 10 and two iron cores 40 passing through the two windings. Certainly, the converter transformer 100 should further include some other components known to those skilled in the art. For components that are not closely related to the inventive concept of the present invention, relevant descriptions are omitted. It is to be understood that although not shown in Fig. 4, the second group of copper plates 22 in arc-shape of the shielding device 20 in Fig. 3 are arranged opposite to outer circumferential arcs of the two windings 30.
The preferred implementation of the present invention has been described above, but it is to be understood that some features in the solutions of the present invention may further be implemented in other manners to achieve the objective of the present invention.
In the first aspect, both the oil tank and the shielding device in the present invention are provided with the arc convex structure, and the arc convex structure may have any appropriate radian, for example, the radian ranges from 40° to 60°.
In the second aspect, the shielding device of the present invention may have any appropriate thickness, such as 4-6 mm.
In the third aspect, the shielding device of the present invention is formed by combining a plurality of small copper plates, and the number of the copper plates may be any appropriate value. Certainly, the copper shielding device may also be made of a single copper plate, and the single copper plate has a flat structure and a second outwardly convex structure.
In the fourth aspect, the oil tank illustrated in the implementation of the present invention includes two shielding devices disposed on the circumferential wall of the oil tank. However, in actual applications, the manner for arranging the shielding devices may be modified properly based on the structure of the oil tank of the converter transformer; for example, three or four shielding devices are included; and also for example, the shielding devices may be arranged on other inner walls of the oil tank except for the circumferential wall, and matched with the special shapes of the relevant inner walls.
In the fifth aspect, as the converter transformer of the present invention includes two windings, there are two outwardly convex structures of the oil tank and two outwardly convex structures of the shielding device. However, it is to be understood that the converter transformer may include other numbers of windings, such as one winding or three windings, and the number of the outwardly convex structures of the oil tank and the number of the outwardly convex structures of the shielding device may also change accordingly.
To sum up, in the present invention, the oil tank is locally designed into the special outwardly convex shape and the copper shielding device is also designed into the corresponding convex shape, and the copper shielding device is embedded into the circumferential wall of the oil tank. By means of that the copper shielding device of the special shape is matched with the oil tank of the special shape, the stray loss of the oil tank can be reduced, the transportation size of the transformer with the oil tank can be decreased to the greatest extent, and the internal space in the oil tank is optimized.
It is to be noted that terms used herein only aim to describe specific implementations, and are not intended to limit exemplar implementations of this application. Unless otherwise explicitly directed by the context, singular forms of terms used herein are intended to include plural forms.
The above are only preferred embodiments of the disclosure. It should be pointed out that those of ordinary skill in the art may further make multiple modifications and changes without departing from the principle of the disclosure, and those improvements and changes are also should be considered as the protection scope of the disclosure.

Claims

An oil tank for a converter transformer, the oil tank (10) comprising a top (11) , a bottom (12) , a circumferential wall (13) that connects the top (11) and the bottom (12) , and at least one shielding device (20) mounted on an inner surface of the circumferential wall (13) , characterized in that

the circumferential wall (13) has a first outwardly convex structure in a region facing a winding (30) of the converter transformer, so as to form a corresponding first inner surface concave portion on the inner surface of the circumferential wall (13) ; the shielding device (20) has a second outwardly convex structure matching with the first inner surface concave portion of the circumferential wall (13) , so as to form a corresponding second inner surface concave portion on an inner surface of the shielding device (20) ; and the second inner surface concave portion keeps a predetermined insulating distance from an outer surface of the winding of the converter transformer.
The oil tank for the converter transformer as claimed in claim 1, characterized in that each of the first outwardly convex structure and the second outwardly convex structure is of an arc convex structure in a plane perpendicular to a vertical central axis of the winding of the converter transformer.
The oil tank for the converter transformer as claimed in claim 1, characterized in that the shielding device (20) is formed by combining a plurality of copper plates.
The oil tank for the converter transformer as claimed in claim 3, characterized in that each copper plate in the plurality of copper plates is of a quadrilateral shape, the plurality of copper plates comprise a first group of copper plates (21) in a flat shape and a second group of copper plates (22) in a curved shape, the first group of copper plates are combined into a flat structure of the shielding device (20) , and the second group of copper plates are combined into the second outwardly convex structure of the shielding device (20) .
The oil tank for the converter transformer as claimed in claim 1, characterized in that the shielding device (20) is formed by a single copper plate, and the single copper plate has a flat structure and the second outwardly convex structure.
The oil tank for the converter transformer as claimed in claim 1, characterized in that the shielding device (20) and the circumferential wall (13) of the oil tank (10) are directly welded or directly connected by bolts.
The oil tank for the converter transformer as claimed in claim 2, characterized in that the shielding device (20) has a thickness of 4 mm to 6 mm, and/or a radian of each of the first outwardly convex structure of the circumferential wall (13) and the second outwardly convex structure of the shielding device (20) ranges from 40° to 60°.
The oil tank for the converter transformer as claimed in claim 1, characterized in that the circumferential wall (13) of the oil tank (10) comprises two primary sidewalls opposite to each other and two secondary sidewalls opposite to each other, two shielding devices (20) are provided, the two shielding devices are oppositely and correspondingly mounted on the two primary sidewalls, and a lower portion of either or both of the two shielding devices is formed as a tilt portion that is tilted inward along a downward direction.
The oil tank for the converter transformer as claimed in claim 1, characterized in that the shielding device (20) comprises a plurality of flat structures and a plurality of the second outwardly convex structures, and the plurality of flat structures and the plurality of the second outwardly convex structures of the shielding device (20) are arranged alternately.
A converter transformer, characterized by comprising the oil tank for the converter transformer as claimed in any one of claims 1 to 9.