CN205122332U - Transformer sleeve - Google Patents

Abstract

A transformer bushing is provided. The present disclosure relates to a transformer installation comprising a wall 3 of a hall 2 , a transformer tank 1 arranged outside the wall 2 , and a bushing 7 mounted to the transformer tank 1 and extending through the wall 3 into the hall 2 . The bushing comprises a flange 5 and an insulating shell 6 for fastening the bushing to the transformer tank. The insulating casing 6 extends the wall 3 and enters the hall 2 .

Description

Transformer bushing

technical field

The present disclosure relates to transformer bushings for through-wall mounting in transformer tanks.

Background technique

Transformer boxes, especially high voltage transformers, may have a transformer tower for fitting bushings to the transformer box. Towers are especially useful if the casing is large and can extend a significant distance into the transformer tank. If towers are not used, the tank may therefore have to be made larger to accommodate the large casing.

The tower of the transformer box may extend into a valve hall, building, which for example contains the valves of the inverter of a high voltage direct current power plant (HVDC), whose inverter is connected into the transformer box via conductor flow through bushings mounted on the tower the transformer.

The transformer tank, and thus the tower, is usually filled with transformer oil used to insulate and cool the transformer. This means that since the tower extends into the valve hall, transformer oil may leak into the valve hall.

Contents of the invention

The object of the invention facilitates, for example, oil-free valve halls.

According to one aspect of the present invention, there is provided a transformer arrangement comprising a wall of a hall, a transformer box placed outside the hall, and bushings mounted on the transformer box and extending through the wall into the hall. The bushing contains flanges for fastening the bushing to the transformer tank, and the insulating case. An insulating shell extends through the wall into the hall. The shell extending through the wall means that this flange (usually placed between the box and the shell) does not extend into the hall.

According to another aspect of the present invention, a bushing for a transformer is provided. The bushing comprises an insulating housing configured for through-wall mounting. As already mentioned here, the conventional insulating housing of the bushing is not configured as a wall penetration, since towers or flanges pass through the wall. In contrast, according to the invention, the insulating shell of the bushing is arranged through the wall.

Note that any feature in any aspect can be applied to any other aspect, where appropriate. Likewise, any advantage of any aspect may be applied to any aspect of the other aspects. Other objects, features and advantages of the included embodiments will be apparent from the following detailed disclosure, the appended series claims, and the accompanying drawings.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless otherwise specifically defined herein. Unless otherwise specifically expressly stated, all references to "a/an/element, device, component, means, step, etc." are to be construed openly as at least one instance of the intended element, device, component, means, step, etc.

Description of drawings

Examples will be described by way of example, with reference to the accompanying drawings, in which:

Fig. 1 is a schematic cross-sectional view of an example of an installed transformer according to the invention.

Figure 2 is a schematic cross-sectional view of an example of a bushing according to the invention compared with an embodiment not according to the invention.

detailed description

Embodiments will be described in more detail hereinafter with reference to the accompanying drawings, in which certain embodiments are shown. However, many different forms of embodiment are possible within the scope of the present disclosure. In addition, the embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully cover the scope of the disclosure to those skilled in the art. Like reference numerals refer to like elements throughout the description.

FIG. 1 illustrates an embodiment of a transformer according to the invention with respect to the installation of a valve hall 2 .

The transformer box 1 has a tower 4 for bushings 7 mounted thereon. The tower may be provided on the top or side wall of the transformer box 1 , but is shown in the figure as a side wall facing the valve hall wall 3 adjacent to the valve hall 2 . Note that in some embodiments the transformer tank 1 may be without the tower 4, in which case the bushing 7 may be mounted directly on the wall of the transformer tank. The transformer can, for example, be in a transformer hall separated from the valve hall 2 by the valve hall wall 3 .

The casing 7 mounted on the tower 4 is secured to the tower by means of a flange of the casing, typically of metallic material. The bushing comprises a longitudinal cylindrical (or conical) shell 6 of electrically insulating material such as porcelain or (resin fiber) composite material. The function of the insulating casing 6 is to pass the longitudinal conductor 8 through the hole of the cylindrical insulating casing 6 of the bushing 7 from the transformer box to the converter (not shown) in the valve hall 2 when passing through the hole of the valve hall wall 3 A transformer (not shown) in 1 is insulated and also provides a suitable discharge distance between the uninsulated part of the conductor 8 and the valve hall wall 3 or any other grounded structure in the valve hall 2 . The discharge distance is the distance the arc of discharge needs to travel (from air or other surrounding medium) in order to short circuit in the electrical device. For higher voltages, it is necessary to provide a longer discharge distance by means of the bushing 7 . According to the invention, the insulating casing 6 is the part of the bushing through the valve hall wall 3, i.e. the flange 5 and the tower 4 of the transformer box 1, which extends outside the valve hall wall 3 and does not extend into the valve hall 2, and can Usually it may not extend into the valve hall wall 3 .

An insulating casing 6 (also referred to herein as an insulator) typically surrounds a condenser core (not shown), which is concentrically arranged longitudinally along the bushing 7 between the conductor 8 and the insulating casing 6 . The condenser core may be of any type, eg resin impregnated paper (RIP), oil impregnated paper (OIP), but RIP may be more preferred as OIP type bushings will still introduce oil into the valve hall 2 . This would be an object that the present invention needs to avoid.

An advantage of the present invention is that the column 4 does not extend into the valve hall 2, as it would thus avoid introducing transformer oil or any other insulating liquid (such as a grease liquid) used in the transformer tank into the valve hall. It may be desirable to keep the valve hall 2 free from any transformer fluid.

Figure 2 compares a bushing installation according to the invention (bottom) with other installations (middle) and with an existing conventional installation (top). Also shown is the discharge distance provided by the bushing 7 to the valve hall wall 3 .

In a conventional installation, the column 4 extends through the valve hall wall 3 and into the valve hall 2 . This installation risks introducing transformer liquid into the valve hall, since the tower is filled with undesired transformer liquid.

An alternative installation that does not introduce transformer fluid into the valve hall extends the main flange of the bushing through the valve hall wall 3 and into the valve hall. Extending the flange straight ahead in this way, since it has less influence on the dielectric properties, is however not according to the invention.

Alternatively, the invention provides the insulator 6 to extend through the valve hall wall 3 so that the flange 5 does not extend into the valve hall. It may be acceptable according to the invention that the flange 5 (and possibly the tower 4) extend into the valve hall wall 3 but not into the valve hall, i.e. the flange or the tower does not extend to the inner surface of the valve hall wall, usually The flanges or towers do not extend to or through the outer surface of the valve hall wall, ie the towers and flanges are entirely outside the valve hall wall and do not extend into it. The air-side insulator (shell) 6 is extended according to the invention through the valve hall wall 3, which enables this installation to be possible with the same or improved mechanical properties compared to an alternative liquid-free installation in which the flange 5 extends into the valve hall 2 cheaper to manufacture.

According to one aspect of the present invention, a transformer device is provided, which includes a wall 3 of the hall 2, a transformer box 1 arranged outside the hall 2, and a transformer box 1 installed to the transformer box 1 and extending into the hall 2 through the wall 3. Casing 7. The bushing comprises a flange 5 for fastening the bushing to the transformer tank, and a cylindrical insulating shell 6 . A cylindrical insulating shell 6 extends through the wall 3 and into the hall 2 . Shell 6 extending through wall 3 means that flange 5 (placed between tank 1 and shell 6 ) does not extend into hall 2 .

In some embodiments the flange 5 is completely outside the wall 3 , ie the flange does not extend into the wall 3 .

In some embodiments, the sleeve includes a RIP core. The cylindrical core in the shell 6 therefore does not contain liquid, such as transformer oil, and does not introduce any liquid into the hall 2 .

In some embodiments, the transformer tank includes a tower 4, and bushings are mounted to said tower. As explained above, towers are particularly advantageous for large casings (eg high pressure applications).

In some embodiments, the transformer tank 1 is filled with an electrically insulating liquid, such as oil, which, by virtue of the invention, is not introduced into the hall 2 .

In some embodiments, hall 2 is a valve hall and wall 3 is a valve hall wall. The above examples relate to valve halls, but the invention can be used with any hall 2 and wall 3, especially when it is not desired to introduce transformer liquid into the hall.

According to another aspect of the invention there is provided a bushing 7 for a transformer. The bushing comprises an electrically insulating casing 6 configured to fit through the wall 3 . As discussed herein, the conventional cylindrical insulating shell of the bushing is not configured to pass through the wall, since the towers or flanges pass through the wall, instead according to the present invention, the cylindrical insulating shell 6 of the bushing 7 is Configured to pass through a wall.

In some embodiments, the shell 6 is configured to pass through the wall 3 by providing means for engaging with the wall 3 . Such means may eg comprise flanges or similar means for engaging or fastening to the inner or outer surface of the wall 3 .

The disclosure has been described above primarily with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are possible within the scope of the present disclosure, as defined by the appended claims.

Claims (8)

1. A transformer device comprising: the wall (3) of the hall (2); a transformer box (1) positioned outside said hall (2); and bushing (7) mounted to the transformer tank (1) and extending through the wall (3) into the hall (2), the bushing comprising a The bushing is fastened to the flange (5) of the transformer box and the insulating case (6); Wherein said insulating shell (6) extends through said wall (3) and into said hall (2). 2. Transformer arrangement according to claim 1, wherein said flange (5) is completely outside said wall (3). 3. The transformer arrangement of claim 1, wherein the bushing comprises resin impregnated paper, RIP, core. 4. Transformer arrangement according to claim 1, wherein said transformer tank comprises a tower (4), and wherein said bushing (7) is mounted to said tower. 5. Transformer arrangement according to claim 1, wherein the transformer tank (1) is filled with an electrically insulating liquid, such as oil. 6. Transformer arrangement according to claim 1, wherein said hall (2) is a valve hall and said wall (3) is a valve hall wall. 7. A bushing (7) for a transformer, said bushing comprising an electrically insulating shell (6) configured for mounting through a wall (3). 8. Bushing according to claim 7, wherein said electrically insulating shell (6) has means for engaging said wall (3).