Socket sleeve for transformer

Abstract

The invention discloses a socket sleeve for a transformer. The socket sleeve comprises a metal shell, wherein a solid insulating layer is filled in the metal shell; four independent cable terminal socket holes which are distributed at an X-shaped end point are formed on one side of the solid insulating layer facing an opening of the metal shell; the four cable terminal socket holes are symmetrical about a centre line of the metal shell; conductor layers which are matched with the socket holes in an X shape and are mutually and electrically connected are arranged at the bottoms of the four cable terminal socket holes; arc-shaped chamfers are formed on edges of the conductor layers; a metal cover plate which is matched with the metal shell is arranged at one end of the opening of the metal shell; four through holes corresponding to the cable terminal socket holes are formed on the metal cover plate; a plug connected with the transformer is arranged on a side surface of the metal shell; and the plug is electrically connected with the conductor layers. The socket sleeve has a dry structure, and is compact and reasonable in structure, easy and convenient to mount and small in occupied space. Therefore, the arrangement of outgoing cables is particularly simple and attractive.

Description

technical field [0001] The invention relates to a cable accessory, in particular to a socket bushing for a transformer. Background technique [0002] In the power supply system or traction power supply system, the cable line is drawn from the medium voltage end or 27.5kV end of the power transformer to supply power for end users or electric locomotives. At present, there are two structures: one is to use insulating bushings (such as porcelain bushings) Pipe) as the outlet end, the outlet cable is connected to its terminal through the outdoor cable terminal; the second is to use the inner cone insulator, and the outlet cable is inserted into the insulator through the inner cone plug-in cable terminal. Most domestic manufacturers adopt the structure of insulating bushing, which has the following disadvantages: ①The protection performance is poor, and the high-voltage conductive part is directly exposed in the air. ②The stability of the product is unreliable, and the porcelain...

AI Technical Summary

Problems solved by technology

Most domestic manufacturers adopt the structure of insulating bushing, which has the following disadvantages: ①The protection performance is poor, and the high-voltage conductive part is directly exposed in the air

② The stability of the product is unreliable, and the porcelain casing needs maintenance, and the dust on the surface should be cleaned regularly

③ It takes up a lot of space, and it needs supporting parts such as transitional copper busbars and supporting insulators

④ The structure is not compact, not beautiful, and the layout of outgoing cables is complicated

Domestic manufacturers also use the structure of inner cone insulators. Although this structure can basically meet the requirements of this type of product in terms of product protection and operation stability, it takes up a lot of space, the structure is not compact, and the appearance is not beautiful. It is necessary to lead out multiple insulators at the same time. In the case of cables, the problem of complicated layout of outgoing cables also exists, and because the inner cone insulator is installed inside the transformer box, in order to meet the requirements of multiple outgoing cables, the internal structure of the transformer becomes complicated, the size increases, and the cost increases. also extremely inconvenient

[0003] In order to solve a series of installation and maintenance problems caused by multiple outgoing cables requiring multiple cable inserts, and to simplify the structure as much as possible, various manufacturers have made various beneficial attempts, such as concentrating three-phase phase wires and grounding wires in one bushing to Reduce the occupied volume, etc., but the above-mentioned improvements, in the transformer bushing, still use insulating oil as the insulating material (that is, oil-filled type)

For products that use insulating oil as the insulating medium, as long as sufficient insulation distances are maintained between the opposite grounds and phases, there is no need to consider the expansion coefficient between the insulating oil and the conductor, and there is no interaction between them. Therefore, the product with oil-filled structure is the easiest to realize, but this kind of product needs to be monitored in order to prevent failure caused by the leakage of insulating oil, and at the same time, the leaked insulating oil will pollute the environment

Although most manufacturers have realized that the use of solid insulating materials (that is, dry type) will have outstanding advantages in terms of installation, maintenance, and volume reduction, but due to the large difference in expansion coefficient between insulating materials and metal conductors, it is impossible to solve the problem. , when a large current or conductor dissipates heat, it will lead to a technical bottleneck of cracking of the solid insulating material, resulting in a blank application of dry-type transformer socket bushings

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