JPH037934Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a current transformation device, for example, a current transformation device that is an improved primary side switching device that changes the current transformation ratio by switching the primary side.

Fig. 1 is a partial side sectional view showing the head of a conventional current transformer, Fig. 2 is a plane sectional view taken along the line - in Fig. 1 when wires are connected in parallel, and Fig. 3 shows the wiring state in Fig. 2. It is a wiring diagram. In Figures 1 to 3,
The primary coil 1 is connected to, for example, a line on which current is measured, and includes a first primary coil 1a having connection terminals 1K and 1L, and a second primary coil 1b having connection terminals 2K and 2L. There is. The secondary coil 2 is inductively coupled to the primary coil 1, induces a current flowing through the primary coil 1 at a predetermined current transformation ratio, and is provided with connection terminals k and l. The head tank 3 has a connection terminal 1K of the first primary coil 1a,
1L and the connection terminal 2K, 2 of the second primary coil 1b
This is for storing L. The first, second, and third bushings 4, 5, and 6 are attached to the head tank 3, and the connection terminals 1L, 2K, and 2L are led to the outside via leads and wires 7, respectively. .
The same potential terminal 8 is attached to the head tank 3 at the same potential, for example, and leads the connection terminal 1K to the outside via the lead wire 7. The first line connection terminal 9 is attached to the third bushing 6 with a bolt (not shown) and connected to the connection terminal 2L. The second line connection terminal 10 is attached to the same potential terminal 8 with a bolt (not shown),
It is connected to the connection terminal 1K. The first series-parallel switching conductor 11 connects the first and third bushings 4,
6 with bolts (not shown) to short-circuit between the connection terminals 1L and 2L. Second
The series-parallel switching conductor 12 is attached by a bolt (not shown) between the second bushing 5 and the same potential terminal 8, and short-circuits the connecting terminals 1K and 2K.

Next, the operation will be explained. When a relatively large current flows through the line where the current is measured, the first and second primary coils 1a, 1 of the primary coil 1 of the current transformer
b are connected in parallel, the line current is shunted to the first and second primary coils 1a and 1b, and a relatively small current is generated in the secondary coil 2. In this case, the first
The bushing 6 has a first line connection terminal 9 and a first series/parallel switching conductor 11, and the same potential terminal 8 has a second line connection terminal 10 and a second series/parallel switching conductor 12. , are each attached by bolts (not shown).

4 is an enlarged side sectional view showing how the first line connection terminal 9 and the first series-parallel switching conductor 11 are attached to the first bushing 6 shown in FIG. 2, and FIG. 6 is a front view of the end of the first series-parallel switching conductor 11 shown in FIGS. 4 and 5. FIG. 4 to 6, the first bushing 6 has a conductor portion 601 on its end surface, and the conductor portion 601 is provided with a screw hole 602 into which the bolt 13 is screwed. The first line connection terminal 9 includes a through hole 901 at the same position as the screw hole 602 and into which the bolt 13 is inserted. 1st
The series-parallel switching conductor 11 has a through hole 111 at the same position and the same diameter as the through hole 901, into which the bolt 13 is inserted. That is, through holes 901 and 111 are provided in the first line connection terminal 9 and the first series/parallel switching conductor 11 at the same position and the same diameter as the screw hole 602 of the first bushing 6, and the bolts 13 The first line connection terminal 9 and the first series/parallel switching conductor 11 are attached to the first bushing 6 by being fastened together.

FIG. 7 is a plan sectional view taken along the line - in FIG. 1 when connected in series, and FIG. 8 is a connection diagram showing the connection state of FIG. 7. That is, when a relatively small current flows through the line where the current is measured, the first and second primary coils 1a and 1b of the primary coil 1 of the current transformer are connected in series, and the line current is directly passed through the primary coil. 1 to generate a relatively large current in the secondary coil 2. In this case, only the first line connection terminal 9 is attached to the first bushing 6, and only the second line connection terminal 10 is attached to the same potential terminal 8 with bolts (not shown). There is.

FIG. 9 is an enlarged side sectional view showing how the first line connection terminal 9 is attached to the first bushing 6 shown in FIG. 7, and FIG. 10 is a front view of FIG. 9. That is, only the first line connection terminal 9 is connected to the bolt 13.
It is attached to the first bushing 6 by tightening it.

Since the conventional current transformer is configured as described above, in the case of series/parallel switching, it is necessary to remove all the bolts 13, and the first and second line connection terminals 9 and 10 are inevitably removed. It will come off. For this reason, it was necessary to entrust the weight of the overhead line or the like to which the first and second line connection terminals 9 and 10 are compressedly connected to one of them during the series/parallel switching operation.
Furthermore, recently, for example, the first and second line connection terminals 9 and 10 as well as overhead wires are often made of aluminum conductors, and in this case, for example, the first and second line connection terminals 9 and 10 In order not to increase the contact resistance between the first bushing 6 and the same potential terminal 8,
The compound had to be reapplied every time the connection was changed, which had the disadvantage of requiring a great deal of labor and expense.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and the first and second line connection terminals 9, 10 are connected to the first bushing 6,
It is an object of the present invention to provide a current transformer that can perform series-parallel switching without disconnecting from terminals 8 of the same potential.

An embodiment of this invention will be described below with reference to the drawings. FIG. 11 shows the first line connection terminals 9, 10 to the first bushing 6 of the current transformation device according to this invention.
12 is a front view of FIG. 11, and FIG. 13 is a front view of the first series-parallel switching conductor 11 shown in FIGS. FIG. 2 is an end front view of the series-parallel switching conductor 11 of FIG. In the drawings, the same parts as in FIGS. 1 to 10 are designated by the same reference numerals. Note that the bolt 13 is referred to as a first bolt 13. 11 to 13, the first series-parallel switching conductor 11 is provided with a blind hole 112 into which the head of the second bolt 14 is inserted. The second bolt 14 connects the first series-parallel switching conductor 1
1, is inserted into the through hole 901 of the first line connection terminal 9, is screwed into the screw hole 602, and the first line connection terminal 9 is inserted into the through hole 901 of the first line connection terminal 9.
Only the first bushing 6 is attached to the first bushing 6.

Next, the operation will be explained. A blind hole 112 having a diameter larger than the head diameter of the second bolt 14 is provided in the first series-parallel switching conductor 11.
Only the first line connection terminal 9 is attached to the first bushing 6 by the second bolt 14 inserted into the through hole 90 of the first line connection terminal 9.
1 and the through hole 111 of the first series/parallel switching conductor 11 , the first line connection terminal 9 and the first series/parallel switching conductor 1
1 to the first bushing 6, the first bolt 13 can be attached during series/parallel switching work.
It is only necessary to attach and detach the first line connection terminal 9.
series/parallel switching work can be performed while the bushing 6 remains attached to the first bushing 6. Therefore, the weight of the overhead wires etc. connected to the first and second line connection terminals 9 and 10 can be constantly held by the second bolt 14. In addition, the first and second line connection terminals 9, 10 and the first bushing 6,
It is also necessary to reapply the compound for the contact surfaces with the same potential terminal 8 and the contact surfaces between the first and second line connection terminals 9 and 10 and the first and second series-parallel switching conductors 11 and 12. This saves a lot of effort and cost. In addition, series-to-parallel switching work at high places can be done easily and safely.

Note that the number of holes 112 may be one or more. Also, the number of first bolts 13 is the same as that of the second bolt.
It is desirable that the number of bolts 14 be greater than or equal to the number of bolts 14.

As described above, according to this invention, the series-parallel switching operation can be performed easily and safely, and a large amount of labor and cost can be saved.

[Brief explanation of the drawing]

Fig. 1 is a partial side sectional view showing the head of a conventional current transformer, Fig. 2 is a plane sectional view taken along the line - in Fig. 1 when wires are connected in parallel, and Fig. 3 shows the wiring state in Fig. 2. 4 is an enlarged side cross-sectional view showing how the line connection terminal and series-parallel switching conductor are attached to the bushing shown in FIG. 2, FIG. 5 is a front view of FIG. 4, and FIG. 6 is a wiring diagram. A front view of the end of the series-parallel switching conductor shown in Figures 4 and 5, Figure 7 is a plane sectional view taken along the line - in Figure 1 when connected in series, and Figure 8 shows the connection state in Figure 7. Connection diagram, Figure 9 is an enlarged side sectional view showing how the line connection terminal is attached to the bushing shown in Figure 7, Figure 10 is a front view of Figure 9, and Figure 11 is a current transformation according to this invention. An enlarged side sectional view showing an example of how the line connection terminal and the series/parallel switching conductor are attached to the bushing of the device, FIG. 12 is a front view of FIG. 11, and FIG. 13 is a diagram of FIGS. FIG. 3 is a front end view of the series-parallel switching conductor shown in the figure. In the figure, 1 is a primary coil, 1a and 1b are first and second primary coils, 1K, 1L, 2K, 2
L is the connection terminal, 2 is the secondary coil, 3 is the head tank, 4, 5, 6 are the first, second and third bushings, 601 is the conductor part, 602 is the screw hole, 7 is the lead wire, 8 are same potential terminals, 9 is a first line connection terminal, 901 is a through hole, 10 is a second line connection terminal, 11 is a first series/parallel switching conductor, 111 is a through hole, 112 is a hole, 12 is a second series-parallel switching conductor, and 13 and 14 are first and second bolts.
Note that the same parts in each figure are given the same reference numerals.

Claims (1)

[Claims for Utility Model Registration] 1. A plurality of primary coils connected in series or parallel, a secondary coil inductively coupled to the plurality of primary coils, and a device for each end of the plurality of primary coils. A bushing or a terminal with the same potential led out to the outside, a line connection terminal that connects the plurality of primary coils to the line, a series/parallel switching conductor that switches and connects the plurality of primary coils in series or parallel, the bushing or the same potential terminal. A first bolt for attaching the connecting terminal and the series-parallel switching conductor to the terminal in an overlapping manner; and a first bolt for attaching the connecting terminal to the bushing or the same potential terminal, which is inserted into a hole provided in the series-parallel switching conductor. 2. A current transformation device comprising two bolts, the diameter of the blind hole being larger than the diameter of the head of the second bolt. 2. The current changing device according to claim 1, wherein one or more holes are provided. 3. The current transformation device according to claim 1 or 2, wherein the number of the first bolts is greater than or equal to the number of the second bolts.