JPH0754989Y2 - Inverted current transformer - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a series-parallel switching structure of primary conductors in a so-called inverted current transformer in which an iron core and a secondary coil are housed in a head container provided on an upper portion of a porcelain insulator. Regarding

[Conventional technology]

Among the current transformers, in the case of the inverted current transformer, since the iron core and the secondary coil are housed in the head container, the internal structure becomes complicated. For this reason, conventionally, the series-parallel switching of the primary conductors in the inverted current transformer has hardly been performed.

However, in an upright current transformer having an iron core and a secondary coil housed in a lower container, only the connecting conductor on the primary side is housed in the upper container and the internal structure is simple. A primary / serial parallel switching structure has been proposed by Japanese Utility Model Application No. 59-10136 (hereinafter referred to as a prior application). In the conventional example and the invention example shown therein, two sets of primary coils of the current transformer are drawn out by four insulating terminals provided in the upper container, and the primary coils are switched in series and parallel by connecting bars. There is.

[Problems to be solved by the invention]

However, in the conventional example shown in the above-mentioned prior application, the internal wiring is complicated and there is a current crossing portion, and this portion is a weak point against overcurrent. Further, in the devised example in the above-mentioned prior application, there are inevitable drawbacks that there are many kinds of connection bars and the length of the bars is long, which is expensive and the switching work is complicated.

[Means for solving problems]

The present invention eliminates the drawbacks of the prior application by using the head vessel itself as a part of the connecting conductor, and enables primary-serial / parallel switching in an inverted current transformer, which has been rarely performed in the past. is there.

〔Example〕

FIG. 1 is a front sectional view of an embodiment of the present invention, FIG. 2 is a side view, and FIG. 3 is a plan sectional view. However, in FIG. 3 described above, the arrangement of the terminals and the bosses is shown in a horizontal direction differently from the upper and lower arrangements of FIGS. 1 and 2 for easy understanding of the structure.

Here, 1 is a metallic head container, 2 is an iron core and a secondary coil, 3 is an electric field mitigating shield provided on the outer periphery of the iron core and secondary coil 2, and 4 and 5 are primary conductors having a coaxial structure. Indicates. That is, an iron core and a secondary coil 2 having a multi-stage structure in which a secondary coil is wound around an annular iron core, and an electric field mitigating shield 3 surrounding the iron core and the secondary coil 2 are provided, and the primary conductors 4 and 5 of the coaxial structure are penetrated in the center thereof. Then, the whole is housed in a container 1 and filled with an insulating gas of a predetermined pressure.

In this case, while the iron core and the secondary coil 2 are surrounded by the shield 3, the lower end (not shown) of the iron core and the secondary coil 2 is held by the pipe-shaped support 6 which is grounded and fixed, and the ground potential is maintained. Is pulled downward through the inside of the column by a lead wire. Also, the electric field relaxation shield 3
Are shown in a simplified manner, and naturally, the iron core and the secondary coil 2 are configured so as not to form one turn.

Here, both ends of the primary conductors 4 and 5 are connected to terminals 7K, respectively.
It is held by 7L and 8K and 8L, and is pulled out to the outside of the head container 1. However, among the above terminals, 7K and 8K and 8L are all insulated by insulator 9,
Only the terminal 7L is directly attached to the head container 1 without being insulated as described later. The terminals 7K and 8L also serve as external wires, that is, terminals for connecting the current circuit to be measured, and the head container 1 is provided with bosses 10 and 11 for fixing the switching bar used when the primary conductors are connected in series. Further, 12 is a porcelain tube, and 13 is an electric field relaxation shield provided at the bottom of the head vessel 1, which is held at the ground potential.

The switching bar 14 is used to switch between the primary and the secondary conductors 4 and 5 of the current transformer.
Switching bar 14
8K and boss 10 as shown by dashed lines
And between terminal 7L and boss 11. In this way, since the bosses 10 and 11 are connected through the head container 1, the primary conductors 4 and 5 are connected in series. To make a parallel connection, connect the switching bars 14 and 15 as shown by the solid lines between terminals 8K and 7K, and between 7L and 8L.
The primary conductors 4 and 5 are connected in parallel.

In this way, the switching bars 14 and 15 can be used to switch the primary conductors 4 and 5 in series and parallel, and the switching bar 14
And 15 can have the same dimensions.

Here, the reason why only 7L of the terminals is directly attached to the head case 1 without being insulated is to keep the head case 1 at the primary potential even when the primary conductors are connected in parallel. That is, if all the terminals are insulated from the head container 1, the head container 1 becomes a primary potential through the terminals 7L and 8K when connected in series, but the head container 1 is completely disconnected from the primary conductors 4 and 5 when connected in parallel. .

Therefore, terminals connected to bosses 10 and 11 when connected in series
One of 8K and 7L, for example 7L as shown, is the head container 1
The head container 1 is always held at the primary potential through this terminal 7L. In this way, the terminal 7L can be connected to the terminal 8L by the switching bar 15 in the parallel connection, and the switching bar 15 can be left unconnected in the series connection, but from the standpoint of performing the serial / parallel switching operation, the terminal 8K can be used.
Similarly to the above, it is desirable to switch to the boss or the counterpart terminal by the switching bar.

Next, FIG. 4 shows an embodiment in which the primary conductors 4 and 5 are arranged in parallel to penetrate the iron core and the secondary coil 2. In this case, it is desirable from the viewpoint of electric field relaxation that the primary conductors 4 and 5 have a half-moon shape in each cross-section and face each other to be substantially circular as a whole, as shown in FIG.

[Effect of device]

As described above, according to the present invention, (1) in the inverted current transformer, the series-parallel switching of the primary conductors is possible.

(2) The switching bar is simplified and has the same shape, which facilitates the switching operation.

(3) Since the primary conductors do not intersect inside the upper container, there is no problem in strength against overcurrent.

And so on.

[Brief description of drawings]

1 is a front sectional view of an embodiment in which the primary conductors are arranged coaxially, FIG. 2 is a side view of the same, FIG. 3 is a sectional view of the same plane, and FIG. 4 shows an embodiment in which the primary conductors are arranged in parallel. Plane cross section,
FIG. 5 is a sectional view showing a state in which the primary conductors are arranged in parallel. 1 ... Head container, 2 ... Iron core and secondary coil, 4,5 ...
… Primary conductor, 7K, 7L, 8K, 8L …… Terminal, 9 …… Insulator, 10,
11 …… Boss, 14,15 …… Switch bar.

Claims (1)

[Scope of utility model registration request] 1. An inverted current transformer in which an iron core and a secondary coil formed by winding a secondary coil around an annular iron core and a primary conductor penetrating the iron core are housed in a head vessel, and the iron core is penetrated. And a first primary conductor and a second primary conductor that are insulated from the head container and are attached to one end of the first primary conductor and one end of the second primary conductor having a polarity opposite to that of the one end, respectively. First and second terminals that are connected and also serve as terminals for connecting an external line
And a third terminal connected to the other end of one of the first or second primary conductors and insulated and attached to the head container, and the other end of the other primary conductor connected to the head A fourth terminal attached to and connected to the partial container, first and second bosses attached to and connected to the head container, and third and fourth terminals to the first and second bosses, respectively. A first and a second switching bar of the same size for connecting in series to connect or connecting the third and fourth terminals to the first and second terminals respectively in parallel, An inverted current transformer characterized in that the first and second primary conductors are held by the terminals connected to respective ends.