JPH0467765B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an insulator type current transformer in which the current transformation ratio is changed by switching the connection of the primary coil, and particularly to improvements in the switching section.

[Conventional technology]

Figure 3 shows, for example, Utility Model Application No. 59-161622
Fig. 4 is a sectional view along the line - of Fig. 3, Fig. 5 is a circuit diagram in the connected state of Fig. 4, 6 is a sectional view similar to FIG. 4 showing a connection state different from that in FIG. 4, and FIG. 7 is a circuit diagram in the connection state of FIG. 6. In the figure, 1 is a primary coil consisting of two primary windings 1a and 1b, 1K,
1L, 2K, and 2L are primary windings 1a and 1b, respectively.
2 is the secondary coil, 3 is the lead connected to the end of the
4 is a lower tank accommodating the primary coil 1 and the secondary coil 2; 4 is an insulator erected above the lower tank 3 and through which the leads 1K, 1L, 2K, and 2L are inserted;
Reference numeral 5 is a head tank shown at the upper end of the insulator 4 and containing an insulating medium 6 such as oil, 51 is a side wall of the head tank 5, and 52 is a flat top cover. 7, 8, 9, 10 are the leads 1K, 1L,
These terminals are individually connected to 2K and 2L, and these terminals are attached to the side wall 51 of the head tank 5. 11, 12 are line connection conductors, 13, 1
Reference numeral 4 denotes a connecting piece for switching the connection between the terminals 7, 8, 9, and 10 to switch the connection of the primary windings 1a and 1b to series or parallel;
1 and the arrangement of the terminals 7 to 10.

Next, the operation will be explained. When the line current is relatively large, connecting piece 1 is connected as shown in Figure 4.
3 connects the terminals 7 and 8 to each other, and the connecting piece 14
Terminals 9 and 10 are connected to each other by , and primary windings 1a and 1b are connected in parallel as shown in FIG. When the line current is relatively small, the terminals 8 and 9 are connected to each other by the connection piece 13 as shown in FIG. 6, and the primary windings 1a and 1 are connected as shown in FIG.
Connect b in series.

[Problem that the invention seeks to solve]

A conventional insulator type current transformer is configured as described above.
The terminals 7, 8, 9, 10 are connected to the side wall 51 of the head tank 5.
Since it is installed in Although it is made of a non-magnetic material such as steel, it requires a large amount of non-magnetic material and is expensive. Furthermore, since the connecting pieces 13 and 14 must be bent according to the shape of the side wall 51 of the head tank 5 and the arrangement of the terminals 7 to 10, manufacturing the connecting pieces 13 and 14 is troublesome and expensive. There were also some problems.

This invention was made to solve the problems of the conventional ones, and it is possible to reduce the amount of non-magnetic material used, and the connecting pieces can be easily manufactured with good workability, so that an inexpensive insulator type current transformer can be manufactured. The purpose is to provide.

[Means for solving problems]

In the insulator type current transformer according to the present invention, the terminals of the primary winding are provided on the top cover of the head tank, and the connection piece is configured to switch the connection between the terminals on the top cover, and is arranged in a flat plate shape. It was formed.

[Effect]

In this invention, the primary current passes through the top cover, which has a smaller area than the side wall of the head tank, and the connection between the terminals is switched on the top cover by a flat connecting piece.

[Embodiments of the invention]

One embodiment of the invention is shown in FIGS. 1 and 2. FIG. 1 is a longitudinal cross-sectional view, and FIG. 2 is a plan view of the head tank. The same parts as those of the prior art are given the same reference numerals and their explanations will be omitted. The terminals 7, 8, 9, 10 of the primary windings 1a, 1b are attached to the top cover 52 of the head tank 5. 1
5 and 16 are connection pieces each having a flat plate shape. The operation is the same as the conventional one.

By attaching the terminals 7 to 10 to the top cover 52 of the head tank 5 in this way, the primary current passes through the top cover 52 and eddy current tends to occur inside the top cover 52. Since the cover 52 has a smaller area than the side wall 51, even if the top cover 52 is made of a non-magnetic material, the amount thereof is smaller than the conventional case where the side wall 51 is made of a non-magnetic material, thereby reducing the cost. In addition, since the connection pieces 15 and 16 perform connection switching between the terminals 7 to 10 on the flat top cover 52, this can be done by changing the shape of the side wall 51 or the terminals 7 to 10, as in the conventional case.
There is no need to bend it according to the arrangement of the parts 10, and since it is formed into a simple flat plate shape, it can be manufactured with good workability and at low cost.

In the above embodiment, the cross-sectional shape of the head tank 5 is rectangular, but it may be other shapes such as circular or elliptical. Furthermore, the number of primary windings is not limited to two, but may be three or more.

〔Effect of the invention〕

As described above, according to the present invention, since the terminals of the primary winding are attached to the top cover of the head tank, in order to reduce eddy current loss, it is sufficient to form the top cover with a small area from a non-magnetic material. The amount used is saved, and since the connecting piece is formed into a flat plate shape, it can be manufactured easily with good workability, so that an inexpensive insulator type current transformer can be obtained.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of one embodiment of the present invention;
The figure is a plan view of the top tank in Figure 1, Figure 3 is a longitudinal sectional view of a conventional insulator type current transformer, Figure 4 is a sectional view taken along the line - in Figure 3, and Figure 5 is a FIG. 6 is a sectional view similar to FIG. 4 showing a connection state different from that shown in FIG. 4, and FIG. 7 is a circuit diagram in the connection state shown in FIG. 6. In the figure, 1 is a primary coil, 1a, 1b are primary windings, 1K, 1L, 2K, 2L are leads, 2 is a secondary coil, 3 is a lower coil, 4 is an insulator, 5 is a top tank, 52 is a top cover , 6 is an insulating medium, 7
10 are terminals of the primary winding, and 15 and 16 are connection pieces. Note that the same reference numerals in each figure indicate the same or the responsible department.

Claims (1)

[Claims] 1. A lower tank that houses a primary coil and a secondary coil consisting of a plurality of primary windings, an insulator that is erected above the lower tank, and through which the leads connected to each end of the primary winding are inserted, and a flat plate-shaped insulator. A head tank having a top cover and placed on the upper end of the insulator and containing an insulating medium, a terminal provided on the head tank and connected to the lead, and a connection between the terminals is switched. In an insulator type current transformer equipped with a connecting piece for switching connections between a plurality of primary windings, the terminal is attached to the top cover of the head tank, and the connecting piece connects the terminals to each other on the top cover. An insulator type current transformer characterized in that it is configured to switch between the two sides and is formed in a flat plate shape.