JPH0135458Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in the interphase connection structure of a molded transformer. In recent years, compact substations that use solid insulation, so-called mini-clad substations, have become popular in order to save space and improve reliability.
The interphase connections of molded three-phase station transformers, three-phase grounded instrument transformers, etc. used in such locations require high insulation reliability (semi-outdoor specifications), non-exposed live parts, and limited space. Savings, etc. are required. For example, in the neutral point connection of a three-phase station transformer, a structure as shown in FIG. 1 has conventionally been adopted. That is, in FIG. 1, 1 is a molded coil,
2 is an iron core, 3 is a bushing for interphase connection, 4 is a lead assembly for connection, 5 is a connector part of the lead assembly 4 , and 6 is a branch point of the lead assembly 4. The bushing 3 and the connector part 5 have a structure in which they are fastened together by packing or the like to provide a sufficient insulation distance between the live part and the ground part and to prevent moisture from entering. Further, in many cases , a high-voltage cable is used as the grounding lead assembly 4, and the surface of the cable is shielded and grounded, and the surface of the molded coil is also grounded with a conductive film applied thereto. In such a conventional connection lead assembly 4 , not only the cable material cost but also the connector part 5
In addition, there are factors such as an increase in the cost of processing the branch point 6 and a decrease in the reliability of the processed part.Furthermore, since the lead assembly 4 itself for connection occupies a large space, the volume of the entire device becomes large. It has the following disadvantages. The present invention provides an interphase connection structure for molded coils in which the lead assembly 4 for connection can be omitted in order to eliminate such difficulties. Next, the present invention will be explained based on FIGS. 2 to 5. For convenience of explanation, the same parts as in FIG. 1 are given the same numbers. FIG. 2 is a plan view showing an embodiment of a three-phase transformer having a molded coil connection structure according to the present invention, and FIG. 3 is a side view. First, there are three molded coils 1a, 1b, and 1c supported by an iron core 2, and a bushing 9 for electrical connection and a dummy bushing 10 are connected to the contact surfaces of 1a, 1b, 1b, and 1c via appropriate packing 8. They are in contact with each other and are tightened from both sides by two frames 12 and four studs 13. Further, the opposing bushings 9 are connected by a connecting fitting 11 that electrically connects the molded coils 1a, 1b, and 1c, and are pressed together by an insulating packing surface. FIG. 4 is a perspective view showing the contact surface of the molded coil 1c, in which one bushing 9 and two dummy bushings 10 are used to connect the molded coils 1b and 1c.
This shows that they are pressed together, and that the insulating packing 8 insulates and seals the connection part. The reason why there are three bushings and three dummy bushings is because it is most convenient to form one plane at three points, and the dummy bushings are not essential. Moreover, this dummy bushing has a structure that can be changed into a bushing by passing a connecting fitting through it as necessary. FIG. 5 is an enlarged partial sectional view showing the contact surfaces of the two bushings 9, in which the connecting fitting 11 is connected to the male fitting 11.
The figure shows a state in which the two parts are fitted together and electrically connected by pressure applied from both sides. This completes the electrical connection, insulation, and airtightness of the connection between the molded coils of each phase, and maintains appropriate spacing and parallelism between each coil, making it superior in terms of structure and assembly work. . Note that since the wiring can be appropriately performed within the molded resin, it can be applied not only to the above-mentioned neutral point connection but also to phase-to-phase connection of three-phase delta connection, connection between single-phase coils, etc. As explained above, by using the molded coil connection structure according to the present invention, it is possible to omit the assembly of connection leads, which has the effect of reducing manufacturing costs, improving reliability, and saving space. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a conventional molded coil connection structure. 2 to 5 show an embodiment of the present invention, and FIG. 2 is a plan view;
3 is a side view, FIG. 4 is a perspective view showing the contact surface of the molded coil, and FIG. 5 is an enlarged longitudinal sectional view of a bushing for electrical connection. In the figure, 1 is a molded coil, 9 is a bushing, and 11 is a connecting fitting.

Claims (1)

[Scope of utility model registration request] Bushings are provided on the adjacent surfaces of a plurality of molded coils arranged in parallel, and the bushings are directly sealed and connected via packing, and the molded coils are connected to each other by connecting fittings provided inside the bushings. An interphase connection structure of molded coils characterized by an electrical connection between them.