JPH11162766A - Gas insulated transformer for meters - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas insulated transformer for meters capable of being manufactured small under favor of no requirement of a case for moisture absorbent. SOLUTION: Legs 17a and 18a of the lower end of a pair of frames 17 and 18 grasping and holding a both side of a ring iron core 6 wound by a high voltage coil 4 and a low voltage coil 3 are formed in the L-shaped section in parallel with mounting floor and extending to the outside of a grasping direction of the frames 17 and 18. A pair of ribs 17b and 17c, and ribs 18b and 18c are formed in the L-shaped inside recessed part on the both ends part in horizontal and longitudinal direction of the legs 17a and 18a, spaces of these ribs are covered by a field relaxing shield and an absorbent cover 19, and moisture absorbent 26 and 27 are received in the space formed inside of the cover.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas-insulated instrument transformer in which a plurality of instrument transformer elements are housed in a cylindrical container together with an insulating gas.

[0002]

2. Description of the Related Art Insulating transformers generally employ gas insulation when the voltage of the circuit used increases. FIG.
FIG. 1 is a plan view showing the internal arrangement of a conventional gas-insulated instrument transformer by cutting out a right half thereof, and shows three instrument transformer elements 2 (hereinafter simply referred to as element 2) inside a closed container 1. .) Are symmetrically arranged. FIG. 5 is an external view showing the structure of the element 2, and FIG. 6 is an enlarged sectional view taken along line BB of FIG. As shown in both figures, the element 2 coaxially supports the low-voltage coil 3 inside and the high-voltage coil 4 outside, and arranges the electric field relaxation shield 5 on the outer periphery of the high-voltage coil 4. A ring-shaped iron core 6 is disposed so as to make a circuit around the hollow portion of the low-voltage coil 3 and the outside of the high-voltage coil 4, and the core 6 is sandwiched and held by a pair of frames 7 and 8 from both sides. Iron core 6 facing 4
, Electric field relaxation shields 9 to 11 are disposed inside.

The electric field mitigation shield 9 comprises frames 7, 8
Are fixed by screws 13 via spacers 12, respectively. Also, the lower ends of the frames 7, 8 are formed with legs 7a, 7a,
8a are formed. The legs 7a, 8a are fixed to the bottom plate of the sealed container 1 with bolts or the like, so that the axes of the coils 3, 4 become horizontal, and the iron core 6 and the frames 7, 8 hang down below the coil axis. , Element 2 are held. In a state where the element 2 is installed in the closed container 1, the high-voltage coil 4 is connected to a high-voltage bus via an insulating spacer or a bushing (not shown), and the low-voltage coil 3 is connected via a low-voltage terminal box 30. Connected to instruments, etc.

[0004] In the gas-insulated instrument transformer constructed as described above, when moisture, dust, and the like are mixed with the insulating gas sealed in the sealed container 1, the dielectric strength is remarkably reduced. for that reason,
Strict control is required for water and dust in the sealed container 1 not only at the time of manufacturing but also at maintenance and inspection. Normal,
As shown in FIG. 4, the gas insulated instrument transformer is provided with a storage container 15 containing a moisture adsorbent such as synthetic zeolite in a closed container 1, and adsorbs and removes moisture in the closed container 1. I am trying to do it. FIG. 7 is a diagram showing the structure of the storage container 15. The storage container 15 is formed in a box shape, and a plurality of ventilation holes 16 are formed. The corners protruding in the state of being mounted in the sealed container 1 are formed by curved surfaces to prevent electric field concentration, prevent the dielectric strength from being lowered, and at the time of mounting the element 2, 2
To prevent scratching.

[0005]

Incidentally, it is necessary to store a moisture adsorbent in an amount corresponding to the volume of the closed container 1 in the storage container 15 described above, and the storage container 15 itself has an appropriate size. Become. Therefore, as shown in FIG. 4, when arranging the element 2, the element 2 must be arranged in consideration of the arrangement of the storage container 15, and the sealed container 1 is reduced in size. If it had been an obstacle.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a ring-shaped iron core having a high-voltage coil and a low-voltage coil disposed coaxially, and a pair of frames from both sides of the core. A transformer element for an instrument having a leg at the lower end of the frame, the lower end of which is fixed to the floor by mounting and fixing the lower end of the frame in a posture in which the core and the frame hang down below the coil axis by holding and holding the coil axis horizontally. In a gas-insulated instrument transformer, in which a plurality of are disposed in a cylindrical closed container, the shape of the leg at the lower end of the frame is L-shaped in cross section extending parallel to the mounting floor surface and outward in the direction of pressing the frame. A pair of ribs are formed in the L-shaped inner concave portions at both ends in the horizontal longitudinal direction of the legs, and the ribs are covered with a cover also functioning as an electric field reduction shield. And wherein the housing a moisture absorbent into a rectangular-shaped space formed on the side.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an external view showing an embodiment of an instrument transformer element used in a gas-insulated instrument transformer according to the present invention, and FIG. 2 is an enlarged sectional view taken along line AA of FIG. Since this embodiment is partially common to the elements shown in the conventional example, the common parts are denoted by the same reference numerals and the description thereof is omitted.
Only different parts will be described. In the figure, a pair of frames 1 for clamping and holding an iron core 6 constituting an element 2 from both sides.
The ribs 17b and 17b are formed on the outer sides of the upper surfaces of the legs 17a and 18a formed at the lower ends of the coils 7 and 18 and on both sides in the coil axial direction.
17c, 18b and 18c are formed.

The outer fold portions 19a and 19b of the electric field relaxation shield and adsorbent cover 19 having an L-shaped cross section are formed in the frame 17 at the ribs 17b and 17c and the leg portion 17a. With
It is fixed to the ribs 17b and 17c with screws 24. Similarly, the frame 18 is fixed to the ribs 18b and 18c and the leg 18a. Thus, the folded portions 19a and 19b and the leg portions 17 of the electric field relaxation shield and adsorbent cover 19 are formed.
A rectangular parallelepiped space surrounded by the ribs 17b and 17c on both sides and the ribs 18b and 18c is formed between the ribs 17a and 18a. Therefore, in the present invention, this space is used as a storage container for the moisture adsorbent. That is, when the electric field relaxation shield and adsorbent cover 19 is attached, the moisture adsorbents 26 and 27 such as synthetic zeolite packed in a cloth bag or the like are placed in the space.

As described above, according to the present invention, the element 2 itself can be added to the moisture adsorbents 26 and 2 only by slightly modifying the element 2.
Closed container 1 in which the storage container 7 is built in and the element 2 is installed
There is no need to separately install a storage container for the moisture adsorbent inside. In the embodiment of FIGS. 1 and 2, the frame 1
The electric field alleviation shields 20 and 2 correspond to the electric field alleviation shield and adsorbent cover 19 attached to the first and second electric fields 7 and 18.
The width of 1 also increases. Also, the folded portion 19 of the cover 19
Although not shown, vent holes for ventilation are formed in a and 19b.

FIG. 3 is a diagram showing the internal arrangement of a transformer for a gas-insulated instrument using the above-described element 2. As shown in FIG. As shown in the figure, only three elements 2 are arranged in the closed vessel 1, so that the coil axis of the element 2 is made almost radial so that the elements 2 are evenly distributed in three directions so that the most efficient arrangement is achieved. It is arranged. As a result, the outer diameter of the sealed container 1 is smaller than in the conventional arrangement, and the transformer for a gas-insulated instrument is downsized. In the embodiment shown in FIGS.
Although the legs 17a, 18a of the 18 are formed in an inverted T-shaped cross section, if attention is paid to forming a storage container for the moisture adsorbent, which is the gist of the present invention, the pressing direction of the legs 17a, 18a This means that the outside has an L-shaped cross section.

[0011]

As described above, according to the present invention, the leg at the lower end of the frame for clamping and holding the iron core of the instrument transformer element is formed so as to protrude outward in the clamping direction, and that portion is formed. By covering with the cover and storing the moisture absorbent in the space formed inside the cover, it becomes unnecessary to separately install a container for storing the moisture absorbent. as a result,
Since the container is not required, the size can be reduced.

[Brief description of the drawings]

FIG. 1 is an external view showing an embodiment of an instrument transformer element according to the present invention.

FIG. 2 is an enlarged sectional view taken on line AA of FIG. 1;

FIG. 3 is a diagram showing an internal arrangement of a gas insulation meter transformer using the element of FIG. 1;

FIG. 4 is a diagram showing a conventional example.

FIG. 5 is an external view of a part of FIG.

FIG. 6 is an enlarged sectional view taken along line BB of FIG. 5;

FIG. 7 is a view showing the structure of the storage container of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Closed container 2 Instrument transformer element 3 Low voltage coil 4 High voltage coil 5 Electric field relaxation shield 6 Iron core 17, 18 Frame 17a, 18a Leg 17b, 17c, 18b, 18c Rib 19 Electric field relaxation shield and adsorbent cover 19a, 19b Folded Part 20, 21 Electric field relaxation shield 26, 27 Moisture adsorbent

Claims (1)

[Claims] 1. A high-voltage coil and a low-voltage coil are coaxially disposed on a ring-shaped iron core, and the iron core is placed on both sides of the core.
For instruments with clamping and holding by a pair of frames, mounting the lower end of the frame in a posture where the core of the coil and the frame hang down below the coil axis with the coil axis horizontal and fixing to the floor surface at the lower end of the frame In the transformer for a gas insulated instrument configured by arranging a plurality of transformer elements in a cylindrical airtight container, the shape of the leg at the lower end of the frame is extended parallel to the mounting floor surface and to the outside in the pressure direction of the frame. It is formed in an L-shaped cross section, and at both ends in the horizontal longitudinal direction of the leg,
A gas comprising a pair of ribs formed in a V-shaped inner concave portion, a space between the ribs covered by a cover also serving as an electric field relaxation shield, and a moisture absorbing agent housed in a rectangular parallelepiped space formed inside the cover. Transformer for insulation meter.