EP4150652A1

EP4150652A1 - Electrical appliance comprising a boiler having a shape complementary to the active part

Info

Publication number: EP4150652A1
Application number: EP20735100.8A
Authority: EP
Inventors: Tobias ENGLMANN; David Weber; Viktor WINS; Oliver Meckel; Aime Mbuy
Original assignee: Siemens Energy Global GmbH and Co KG
Current assignee: Siemens Energy Global GmbH and Co KG
Priority date: 2020-06-19
Filing date: 2020-06-19
Publication date: 2023-03-22
Also published as: CN115917678A; WO2021254641A1; US20230230745A1

Abstract

In order to create an electrical appliance (1) for connecting to a high voltage and comprising an active part (18), which is provided with a magnetisable core (25) and at least two winding assemblies (19, 20), each surrounding a core section (23, 24) of the core (25) and having windings (21, 22) that are inductively coupled to one another, and comprising a boiler (2) which can be filled with an insulating fluid and in which the active part (18) is entirely arranged, wherein the boiler (2) has two end casings (4, 5) and a central part (3) arranged between the end casings, wherein said electrical appliance is designed to be compact and has a low tare weight, according to the invention, the central part (3) forms a hollow body (6, 7) for each winding assembly (19, 20), through which a respective one of the core sections (23, 24) extends, which is surrounded by an associated winding assembly (6, 7), wherein the hollow bodies (6, 7) are connected to one another on the inside and only via the internal volume of the end casings (4, 5).

Description

description

Electrical device with a boiler designed to complement the shape of the active part

The invention relates to an electrical device for connection to a high voltage with an active part, which has a magnetizable core and at least two winding arrangements, which each enclose a core section of the core and have inductively coupled windings, and a tank that can be filled with an insulating fluid, in in which the active part is completely arranged, the boiler having two end hoods and a central part arranged between the end hoods.

Such an electrical device is already known from WO 2008/184775 A1. A railway transformer is shown there, which has an active part and a housing or tank in which the active part is arranged. The active part is formed from a core with two core legs, each of which is enclosed by two concentrically arranged windings. The boiler has a central part that surrounds the outer contour of the windings in a complementary manner. In other words, the middle part forms two hollow cylinders, the inner volumes of which partially overlap. Due to the partially shape-complementary design, the internal volume of the housing and thus the oil volume of the railway transformer can be reduced.

WO 2016 / 038222A1 discloses a railway transformer with an active part and a tank, the core of the active part being arranged completely outside the housing. The rail transformer is attached to the rail vehicle via the core so that no forces are introduced into the boiler while it is in motion. The boiler can therefore be made of a lightweight material such as plastic. Railway transformers are intended for mounting on a rail vehicle, such as a locomotive or a railcar. They are used to provide a desired traction voltage for the drive of the locomotive or railcar depending on various input voltages. Known railway transformers have a metallic tank which is at ground potential and which is filled with an insulating fluid, for example an ester liquid. The so-called active part of the transformer is arranged in the tank and comprises a core consisting of magnetizable sheet metal and at least two windings concentrically surrounding a section of the core. The boiler is equipped with bushings to connect the transformer to a high voltage.

The previously known electrical device has the disadvantage that the boiler is designed to occupy space and the electrical device has a high dead weight. However, a compact, lightweight structure is desirable, particularly in railway applications.

The object of the invention is therefore to provide an electrical device of the type mentioned at the beginning, which is designed to be compact and has a low intrinsic weight.

The invention solves this problem in that the middle part forms a hollow body for each winding arrangement, through which one of the core sections extends, which is enclosed by its assigned winding arrangement, the hollow bodies being connected to one another on the inside and only via the inner volume of the end hoods.

In the context of the invention, the tank is not box-shaped but is adapted to the outer contour of at least two winding arrangements. Although this has already been proposed in the prior art mentioned at the outset, the invention continues with regard to the design of the boiler which is complementary in shape to the winding arrangements. So within the scope of the invention, each winding arrangement is completely enclosed by a hollow body of the boiler. The insulating fluid can no longer pass from one hollow body to the next, as in the prior art mentioned above. Rather, the insulating fluid must flow out of one hollow body into the interior of one of the end hoods and can only enter the other hollow body from there. The tank maintains a distance from the outer winding of the respective winding arrangement which is sufficient to ensure the desired dielectric strength of the electrical device. Due to the shape-complementary design of the boiler over the entire circumference of the boiler, at least in the area of the windings, it has a small internal volume, so that the boiler has to be filled with less insulating fluid. Because of the smaller volume of the insulating fluid, the electrical device is lighter and more compact than an electrical device according to the prior art. With regard to the smaller amount of insulating fluid, there are also cost advantages. The shape-complementary design of the boiler is fully within the scope of the invention and not limited to adaptations in certain surface areas of the winding arrangements.

A magnetizable material is understood here to be a ferromagnetic material such as iron.

In the context of the invention, windings of a winding arrangement are arranged concentrically to one another. An outer winding is designed, for example, as a primary winding for higher voltages than a secondary winding arranged further inside. In addition to a primary and secondary winding, each winding arrangement can also have further windings, such as an auxiliary operating winding, a step winding or the like.

In a variant, the active part has two winding arrangements with, for example, four windings, wherein two windings are arranged concentrically to one another and enclose a common leg of the core as a Kernab section. This is, for example, an inner low-voltage winding and a high-voltage winding surrounding the low-voltage winding. The core expediently has a further leg, which is also enclosed by a low-voltage or high-voltage winding. The two low-voltage and high-voltage windings are connected in series, for example. In this embodiment of the electrical device according to the invention, only the high-voltage windings define the outer contour of the active part. Each of the two hollow bodies encloses one of the two winding arrangements. Each hollow body is advantageously designed with a complementary shape to the outer contour of the two high-voltage windings. The winding arrangements are advantageously arranged next to one another, each extending in an axial or longitudinal direction. The core legs, which each extend through one of the two winding arrangements, are therefore also aligned parallel to one another. In other words, the inner wall of the middle part advantageously follows the outer contour of the outer windings of the respective winding arrangement over the entire circumference.

In the context of the invention, the hollow bodies are preferably dimensioned and configured identically to one another.

Of course, three or more legs can also be provided within the scope of the invention, each leg being equipped with a winding arrangement.

Advantageously, the end hoods are also adapted to the active part sections which are arranged in their inner volume. According to this further development of the invention, the boiler not only clings to the outer contour of the outer windings outside of its central part, at least in its inner configuration. Rather, the boiler is also complementary in shape to other sections of the active part designed, which also define the outer contour of the active part. As a rule, the core has a lower and an upper yoke which extend above and below the end faces of the respective windings. On the upper and lower yoke, a press frame is usually provided, with which magnetized metal sheets of the core that lie flat against one another are pressed against one another. The upper and lower yoke, together with the respective press frame, then define the outer contour of the active part, which is not defined by the windings. However, while the windings define a generally cylindrical outer contour, the remaining outer contour of the active part deviates considerably from this. The shape-complementary adaptation of the boiler to this somewhat more complex outer contour is therefore limited to forming a box-shaped envelope. This means that the design of the boiler does not imitate every screw or every bolt, but rather imitates the entire section with a box-shaped and partially bevelled contour. This box-shaped contour then delimits an interior space which enables the said active part sections to be accommodated in a stress-proof manner, but at the same time limits the interior volume of the boiler to a minimum.

Advantageously, each hollow body is designed as a circular cylindrical pipe section. Since the outer contour of a winding arrangement is generally circular-cylindrical, the tubular design is the best way of minimizing the internal volume of the boiler. The longitudinal axis of the pipe section and the longitudinal axis of the winding arrangement coincide. In other words, each pipe section is concentric with the winding arrangement that extends therethrough.

In a further development of this, the middle part forms a plurality of pipe sections, each of which is provided for receiving a winding arrangement, but the inner volume of the pipe sections does not overlap. at In this variant of the invention, an active part is used which has three or four winding arrangements aligned in parallel and located next to and / or one below the other. Here, too, each outer winding can be arranged concentrically to an inner winding. Each of these outer windings is arranged in an associated tube section of the boiler, with each individual tube section completely enclosing the windings stored in it.

Advantageously, the middle part has two flat flange sections, between which each hollow body extends, and each flange section is mechanically detachably connected to a flange section of one of the end hoods, sealing means being arranged between flange sections. The middle part and the end hoods must be tightly connected to one another in order to reliably prevent an undesired escape of insulating fluid from the boiler. A flange connection is particularly suitable for this. It is therefore advantageous if the central part forms a flange section extending outwardly from the outer contour in a right-hand winding in the radial direction on its two end faces. As part of this further development, the end hoods form a corresponding flange section which is partly exactly opposite one of the two flange sections of the center. The flange sections can therefore be placed against one another and pressed against one another, the sealing means, for example a circumferentially closed circumferential O-ring, ensuring that no insulating fluid can escape. The pressing can be done, for example, by a screw connection, with a screw of the screw connection extending through through bores in the flange sections of the end caps and engaging with its external thread in an internal thread that engages in bores of the flange section of the central part that are only open on one side.

The middle part expediently consists of a plastic. Any suitable polymer comes in as a plastic Consideration. Plastics are light in comparison to metallic materials, so that there is a further reduction in the weight of the electrical device according to the invention.

In order to increase the mechanical strength, plastics reinforced with fibers, in particular plastics reinforced with glass fibers, are suitable.

The end caps are preferably made of a metal or a metallic alloy. The end caps are advantageously made of steel.

The end hoods are expediently each box-shaped. A box-shaped design can be made as standard. An adaptation to the respective active part is not necessary in this variant of the invention. In this way, costs can be saved.

At least one end cap advantageously has a viewing window and / or a hand opening. According to this further development of the invention, the electrical device can be easily manufactured and maintained.

The electrical device is preferably a railway transformer.

In a preferred variant, the core has two core legs which are connected to one another via an upper and lower yoke, each core leg extending through a cavity and being surrounded by a winding arrangement.

The active part is expediently connected to the boiler only at the end hoods, the hoods being connected to fasteners for mounting on a rail vehicle.

In this way, it is avoided that high forces are introduced into the middle part, which can therefore be made of a light material. A light material within the meaning of the present invention is any material with a density that is two times lower than that of steel. Steel has a density of 7.85-7.87 g / cm ³ . Materials with a density of less than 3.9 g / cm ³ are light materials within the meaning of the invention. Examples of such light materials are aluminum, plastics and plastics reinforced with fibers. The middle part preferably consists essentially of a plastic reinforced with glass fibers with a density of 2.5 g / cm ³ .

The end hoods are preferably each connected to a cross member of a support frame. The construction of the support frame is simple and therefore inexpensive. Each end hood rests with a flat underside on the upper broad side of the cross member, which is also flat. Appropriately, spacers are net angeord between the yoke with clamping frame and the inner wall flat bottom. The cross member is preferably designed as a hollow profile carrier and consists of a mechanically strong material, in particular steel.

The active part expediently extends horizontally in its longitudinal direction in the fastened position of the electrical device. In other words, the electrical device, designed here as a train transformer, is installed horizontally on the rail vehicle.

Further useful refinements and advantages of the invention are the subject matter of the following description of exemplary embodiments of the invention, with reference to the figures of the drawing, the same reference symbols referring to components having the same effect and where

Figure 1 shows an embodiment of the electrical device according to the invention,

FIG. 2 shows the active part of the electrical device according to FIG. 1, FIG. 3 shows a central part of the electrical device according to FIG

1, FIG. 4 shows an interior view of an end hood of the electrical device according to FIG. 1 and FIG

Figure 5 illustrate the electrical device according to Figure 1 on a support frame each in a perspective view.

FIG. 1 shows an exemplary embodiment of the electrical device according to the invention, which is designed as a railway transformer 1. The railway transformer 1 has a housing 1 which is visible from the outside and which comprises a central part 3, a rear end hood 4 and a front end hood 5. The middle part 3 has two pipe sections 6 and 7 as hollow bodies which delimit a circular cylindrical inner cavity. On both end faces of the pipe sections 6 and 7, a flange section 8 and 9 is formed, which extends at right angles to the longitudinal direction of the pipe sections 6 and 7 from the Rohrab section radially outward. Each flange section 8 and 9 is flat. In other words, the outer surface of the flange sections 8 and 9 each lies in one plane. Each end cap 4 and 5 has a corresponding end flange portion 10 and 11, the flange portion 10 of the rear end cap 4 opposite the flange portion 8 and the flange portion 11 of the front end cap 5 opposite the flange portion 9 of the central part 3. In the flange section 11 of the front end hood 5, through-bores can be seen, in which screws can be arranged, the bores of the flange section 9 of the central part 3, which are open on one side, are screwed in. A corresponding fastening is provided for the flange sections 8 and 10, but the through bores are not shown due to the selected view.

A circumferential O-ring is arranged between the flange sections 8, 19 and 9, 11 and is inserted into a groove made in each of the flange sections 8 and 9. By tightening screws (not shown in the figures), the flange sections 9 and 11 or 8 and 10 pressed together, whereby the O-ring inserted into the groove between them ensures a fluid-tight connection of these two components due to its elastic deformation.

The end hoods 4 and 5 are box-shaped and have an end wall 12 facing away from the respective flange section 10 or 11, a side wall 12 extending between the end wall 12 and the flange section 11. The box-shaped structure is beveled at the corners in order to avoid unnecessary internal volume of the end hoods 4 and 5, respectively. Furthermore, hand openings 14 can be seen, which are releasably attached to the side wall 13 of the end hoods 4 and 5, respectively. A high-voltage bushing 15 and cable outlets 16 can also be seen in the front end wall.

For mechanical reinforcement of the bottom area of the end caps 4 and 5, not shown in the figures, L-shaped brackets 17 are used, most of which extend below the end cap 4 and 5 and which are firmly connected to the end cap in each case. The brackets also serve to attach the spacers to the inside of the respective end cap. In addition, the holders and thus the respective end cap can be more firmly connected to a fastening means.

An active part (not visible in FIG. 1) is arranged in the boiler or, in other words, in the housing 2.

FIG. 2 shows the traction transformer 1 according to FIG. 1 from behind, parts of the housing having been omitted in order to obtain a clear view of the active part 18. The active part 18 comprises two winding arrangements 19 and 20, each winding arrangement 19, 20 having an outer primary or high-voltage winding 21 and an inner low-voltage or secondary winding 22. The high-voltage winding 21 and the low-voltage winding 22 are each arranged concentrically to one another. As already stated, Each winding arrangement can also have further windings such as an auxiliary winding and / or a step winding. In a variant of the invention, the secondary winding and possibly further windings are on the outside, while the primary winding is on the inside.

Through each winding arrangement 19 and 20 extends a core leg 23 and 24 of a core 25, the legs next to the core 23 and 24 an upper yoke 26 and a lower yoke 27 with which the core legs 23 and 24 are connected at both ends. In this way, the core 25 forms a closed iron circle. It can also be seen that the winding arrangements 19 and 20 of the active part 18 are each arranged in one of the tube sections 6 and 7 of the middle part 3. The tube sections completely enclose the respective winding arrangement. When the railway transformer is in operation, the boiler 2 is filled with an insulating fluid, for example an ester oil, a mineral oil, a silicone oil or the like. Since the pipe sections completely enclose their assigned winding arrangement, insulating fluid can only get into the pipe section 7 from the pipe section 6 via the inner volume of one of the end hoods 4 or 5.

In the axial direction, the winding arrangements 19 or

20 surmounted by the core leg. The ends of the core legs 24 and the yokes 26, 27 are therefore not arranged in the central part 3 but in the respective end hoods 4 and 5 of the boiler 2. More precisely, the upper yoke 26 is arranged within the end hood 4 and the lower yoke 27 is arranged within the end hood 5. In any case, the active part with its core 25 is arranged completely within the boiler 2.

FIG. 3 shows the structure of the means 3 of the housing 2 of the railway transformer according to FIG. 1 in more detail. In particular, the pipe sections 6 and 7 can be seen in this perspective illustration, as well as the respective delimited by them Cavities 28 and 29, which are designed circular cylindrical. These circular hollow cylinders have a slightly larger radius than the respective winding arrangement, so that in the radial direction there is a uniform spacing of 3-5 mm between the winding arrangement and the inside of the pipe sections. This enables the form-complementary inclusion of the winding arrangements of the active part made of a non-conductive material.

In addition, the front flange section 9 is shown in greater detail in FIG. In particular, it can be seen that it has bores provided with an internal thread and open on one side, into which suitable screws can be screwed. Furthermore, the circumferential O-ring 31 can be seen, which serves for the fluid-tight connection of the middle part 3 to the respective end hood 4 or 5.

FIG. 4 shows the end hood 5 of the railway transformer 1 according to FIG. 1 in a perspective view from the inside. The hand holes 14 are shown in Figure 4 without the cover required during operation. A simple plate is used as a cover, which is placed on the side wall and, for example, is firmly connected to the corresponding side wall of the end cap 5 by screwing. Again, a circumferential O-ring 31 serves to close the hand hole 14 in a fluid-tight manner. In addition, the longitudinal sections of the L-shaped holding parts 17 can be seen, which ensure that the end cap can be installed on the floor area. Furthermore, through-holes 32 can be seen which enable the introduction of bushings and / or other connections into the interior of the end cap 5.

FIG. 5 shows the railway transformer 1 according to FIG. 1 together with the fastening means 33, which are designed as support frames 33. The support frame 33 has two longitudinal beams 34 opposite one another and aligned parallel to one another, between which a front and rear cross member 35 extend. The railway transformer 1 is located here only with its end hoods 4 and 5, specifically with the holding part 17 mounted firmly on the end hoods on the respective cross member 35 and can be mechanically fastened there. In this way, the introduction of high forces into the middle part 3 is avoided. According to the present invention, the middle part 3 can therefore be made of a lightweight material and, in the exemplary embodiment shown, consists of a glass fiber reinforced base material (GRP). On the side members 34 protrude laterally fastening bolts 36, which are used to mount the railway transformer 1 on a rail vehicle in a horizontal position.

Claims

1. Electrical device (1) for connection to a high voltage with

- An active part (18) which has a magnetizable core (25) and at least two winding arrangements (19, 20) which each enclose a core section (23, 24) of the core (25) and windings (21, 22) that are inductively coupled to one another ), and

- A tank (2) which can be filled with an insulating fluid and in which the active part (18) is completely arranged, wherein

- The boiler (2) has two end hoods (4, 5) and a central part (3) arranged between the end hoods, characterized in that the central part (3) forms a hollow body (6, 7) for each winding arrangement (19, 20), through which one of the core sections (23, 24) extends, which is enclosed by an associated winding arrangement (6, 7), the hollow bodies (6, 7) being connected to one another inside and only over the inner volume of the end hoods (4, 5) are.

2. Electrical device (1) according to claim 1, d a d u r c h g e k e n n z e i c h n e t that each hollow body is a circular cylindrical pipe section (6, 7).

3. Electrical device (1) according to one of the preceding claims, characterized in that the central part (3) has two flat flange sections (8, 9), between which each hollow body (6, 7) extends, and that each flange section (8 , 9) is mechanically releasably connected to a flange section (10, 11) of one of the end hoods (4, 5), with sealing means (31) being arranged between the flange sections (8, 9, 10, 11).

4. Electrical device (1) according to one of the preceding claims, characterized in that the middle part (3) consists of a plastic.

5. Electrical device (1) according to one of the preceding claims, d a d u c h g e k e n n z e i c h n e t that the central part (3) is made of a fiber-reinforced plastic.

6. Electrical device (1) according to one of the preceding claims, d a d u c h g e k e n n z e i c h n e t that the end hoods (4, 5) made of a metal or a metallic one

Alloy are made.

7. Electrical device (1) according to one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that the end hoods (4, 5) are each box-shaped.

8. Electrical device (1) according to one of the preceding

Claims 1 to 6, d u r c h g e k e n n n z e i c h n e t that the end hoods (4, 5) complementary in shape to the section of the

Active part (18) are formed, which they are opposite.

9. Electrical device (1) according to one of the preceding claims, d a d u c h g e k e n n z e i c h n e t that at least one end hood (4, 5) has a viewing window and / or a hand opening (14).

10. Electrical device (1) according to one of the preceding claims, characterized in that the core (25) has two core legs (34, 24) which are connected to one another via an upper (26) and lower (27) yoke, each core leg (23, 24) through one of the Hollow body (6, 7) extends and is surrounded by a winding arrangement (19, 20).

11. Electrical device (1) according to one of the preceding claims, characterized in that the active part (18) is mechanically connected to the boiler (2) only at the end hoods (4, 5), the end hoods (4, 5) having fastening means (33) are connected for mounting on a rail vehicle.

12. Electrical device (1) according to claim 11, d a d u r c h g e k e n n z e i c h n e t that the end hoods (4, 5) are each connected to a cross member (35) of a support frame (33).