JPH0334901Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a current transformer having a plurality of turns of the primary coil.

Figures 1 to 8 show a conventional current transformer of this type, with Figure 1 being a longitudinal sectional view and Figure 2 being the same as in Figure 1.
An enlarged cross-sectional view along the line, FIG. 3 is the − of FIG.
In the enlarged cross-sectional view taken along the line, 1 is a primary coil made of a rectangular conductor and consists of a straight part 1a and a circular part 1b, and 4 is an internal shield formed entirely on the inner wall of a hollow main insulator 8. An oil reservoir 5 is provided between the primary coil 1 and the primary coil 1 by a plurality of insulating spacers 6 and 7.

Since the conventional current transformer is constructed as described above, the heat generated in the primary coil 1 due to the current flowing through the primary coil 1 is transferred to the primary coil 1.
Heat is dissipated to the outside through an oil sump 5 formed between the inner shield 4 and the inner shield 4 and the surface of the main insulator 8, and the main insulation molding of the primary coil 1 is The purpose of mitigating the electric field is to use an internal shield 4. However, according to such conventional means, the internal shield 4 becomes an essential part of the structure, which is extremely uneconomical and heavy. The workability was extremely poor, and since the oil in the oil sump 5 came into contact only with the outer surface of the primary coil, and the oil did not come into contact with the inside of the primary coil (the stacked surface), the cooling effect was poor. .

This idea was made with attention to this point, and a pipe conductor is used as the straight part of the primary coil to form an oil passage, and a spiral conductor is used as the circular part of the primary coil to form an oil passage. In addition, we have created an economical current transformer that eliminates the internal shield formed on the inner wall of the hollow main insulator, reducing weight and improving workability. This is what we are trying to provide.

That is, FIGS. 4 to 6 all show one embodiment of this invention, and FIG. 4 is a longitudinal cross-sectional view, and FIG.
The figure is an enlarged sectional view taken along the - line in Figure 4.
The figure is an enlarged sectional view taken along the - line in FIG. 4.

Reference numeral 10 denotes a linear central pipe conductor 10a forming a first oil pipe 14, a linear outer pipe conductor 10b forming a second oil pipe 15 outside this central pipe conductor 10a,
The primary coil is constituted by a spiral conductor 10c, the inner end of which is electrically connected to the inner end of the central pipe conductor 10a, and which is made of a flat metal band forming the third oil passage 18. The coil 10 is embedded within the main insulator 8 as shown in FIG. 16 is inserted between the central pipe conductor 10a and the outer pipe conductor 10b, and a plurality of spacers for forming the second oil passage 15; 19 is inserted between each of the spiral conductors 10c, A plurality of spacers 20 for forming the third oil passage 18 are forming spacers that are inserted between each side edge of the spiral conductor 10c and the main insulator 8, and have the effect of relaxing an electric field.

As described above, the current transformer of this invention includes a central pipe conductor 10a forming the first oil pipe 14, an outer pipe conductor 10b forming the second oil pipe 15 outside the central pipe conductor 10a, and an inner end. is electrically connected to the inner end of the central pipe conductor 10a and forms a primary coil 10 embedded in the main insulator 8 with a spiral conductor 10c forming a third oil passage 18. Therefore, in this primary coil 10, there are a first oil pipe 14, a second oil pipe 15, and a third oil pipe that communicate with each other.
Oil road 18 will exist. Therefore, the primary coil 10 generated by the flow of current
The heat generated in the oil pipes 18, 15, and 14 is led to an external expansion chamber (not shown) through the insulating oil, and is dissipated. This has an excellent practical effect of significantly improving the cooling effect of the conductor 10a, the outer tube conductor 10b, and the spiral conductor 10c. Further, forming spacers 20 are provided between each side edge of the spiral conductor 10c of the primary coil 10 and the main insulator 8.
By inserting the insulator, it acts to alleviate the electric field, so there is no need to form an internal shield over the entire inner wall of the hollow main insulator 8 as in the conventional case, resulting in weight reduction and workability. This has an excellent practical effect of providing an improved and economical current transformer.

[Brief explanation of the drawing]

Figures 1 to 3 show conventional current transformers.
1 is a longitudinal sectional view, FIG. 2 is an enlarged sectional view taken along the - line in FIG. 1, and FIG. 3 is an enlarged sectional view taken along the - line in FIG. 1. Moreover, FIGS. 4 to 6 all show one embodiment of this invention.
5 is an enlarged sectional view taken along the - line in FIG. 4, and FIG. 6 is an enlarged sectional view taken along the - line in FIG. 4. In the drawing, 8 is the main insulator, 10 is the primary coil, 1
0a is the center pipe conductor, 10b is the outer pipe conductor, 10c is the spiral conductor, 14 is the first oil pipe, 15 is the second oil pipe, 1
6 and 19 are spacers, 18 is a third oil pipe, and 20 is a molding spacer. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims for Utility Model Registration] (1) A central pipe conductor forming a first oil passage, an outer pipe conductor forming a second oil passage on the outside of this central pipe conductor, and an inner end of the central pipe conductor forming a second oil passage. A conductor consisting of a plurality of spiral turns, which is electrically connected to the inner end of the pipe and forms a third oil passage, constitutes a primary coil buried in the main insulator, and the central pipe conductor and the outer between pipe conductors and between multi-turn spiral conductors,
A current transformer characterized in that a plurality of spacers are interposed to form each oil passage, and a forming spacer is interposed between each side edge of the spiral conductor and the main insulator. (2) Utility model registration claim 1, characterized in that the first to third oil passages are communicated with each other and the insulating oil in each oil passage is guided to an expansion chamber provided outside the main insulator. Current transformer as described.