JPS63117412A - Gas insulated transformer - Google Patents

Abstract

PURPOSE:To provide a gas insulated transformer equipped with thin magnetic shields which are easily mounted on an inner wall of a pressure container, by piling a plurality of sheets of band-shaped magnetic materials to compose the magnetic shields and bending the magnetic shields in conformity with a curved surface of the pressure container and fixing them on the inner walls. CONSTITUTION:Magnetic shields 10 are composed of a plurality of sheets of band- shaped magnetic materials 4 made of silicon steel bands piled on an inner wall of a pressure container 3 and they are bent in conformity with a curved surface of the container and pressed/fixed with bolts 6 at both their end parts. The magnetic shields 10 composed of a plurality of sheets of piled band shaped magnetic materials 4 exert reaction force 11 against their bending and are closely adhere to the inner wall of the pressure container 3 and are allowed to be fixed with the bolts 6 at both their end parts. Because the piled magnetic materials are not required to adhere to themselves and besides because molding in conformity with the curved surface is unnecessary, manufacturing processes are simplified and reduction in cost can be performed. Since the number of the bolts 6 is much decreased, a cross sectional area of a passing magnetic flux can be increased and the thickness of the magnetic shields 10 can be made small.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention provides a method for installing a transformer body consisting of an iron core and a coil in a pressure vessel filled with an insulating gas such as SFa gas at high gas pressure. This relates to a housed gas insulated transformer.

(Prior technology) Due to its nonflammability and explosion-proof properties, insulating oil has been replaced with oil-immersed transformers, which have been used in the past, without changing its basic structure. S with excellent characteristics
Gas insulated transformers that use insulating gas such as F6 gas to insulate and cool the transformer are attracting attention. Already a number, number 1
Although it has been put into practical use as a small capacity transformer with a relatively low voltage of about 0.00 KVA, in recent years, in view of its excellent advantages, research has been conducted to expand its application to higher voltage, larger capacity transformers.

Generally, the dielectric strength of gas increases as the gas pressure increases, so when applying a gas insulated transformer to a high voltage generator, it is desirable to increase the pressure of the insulating gas. In this case, the container housing the transformer body must have a structure that satisfies pressure vessel structural standards. Also, the gas pressure is 2K
g/cm2 .0 or more, it is advantageous for the container to have a curved surface such as a circular arc or an elliptical arc.

Figure 2 shows the configuration of a conventionally used gas insulated transformer. That is, the iron core 1 and the coil 2 wound around the iron core 1
A main body consisting of the following is housed in the pressure vessel 3. Moreover, FIG. 3 is a sectional view taken along the line AA in FIG. 2.

By the way, in a conventional gas insulated transformer having such a configuration, as the capacity of the transformer increases, the amount of leakage magnetic flux from the coil 2 also increases, causing damage to the transformer body and pressure vessel 3.
Local areas become heated. Therefore, in order to prevent local heating of the pressure vessel and reduce loss, a magnetic shield made of aluminum or copper plate or a magnetic material such as silicon steel strip is installed on the inner wall of the pressure vessel 3. It is being In particular, magnetic shields made of magnetic materials have been widely used in recent years because they have a large loss reduction effect.

FIGS. 4 and 5 show examples of how a magnetic shield made of a magnetic material is attached to a pressure vessel. That is, one block-shaped magnetic shield 5 is formed by stacking a plurality of magnetic materials 4 such as band-shaped silicon steel strips, and this magnetic shield 5 is arranged on the inner wall of the pressure vessel 3 and is secured by a plurality of bolts 6. Tightening is fixed. Note that the plurality of magnetic materials 4 constituting the block-shaped magnetic shield 5 are bonded to each other with adhesive in order to prevent chatter vibrations. The leakage magnetic flux 8 coming out from the coils 2a and 2b is transferred to the magnetic shield 5.
Since the air flows through the inside of the pressure vessel 3, local heating of the pressure vessel 3 can be prevented.

However, when constructing the block-shaped magnetic shield 5 by adhesive molding, the magnetic shield 5 must be created to match the curvature of the inner wall of the pressure vessel 3 in which the magnetic shield 5 is disposed, and the size of the pressure vessel Depending on the shape of the pod, the mold used to manufacture the magnetic shield had to be changed. Therefore, the manufacturing process of the magnetic shield has become complicated, and the manufacturing cost has also increased.

Furthermore, since the block-shaped magnetic shield 5 is made to match the curvature of the pressure vessel 3, in order to fix the magnetic shield 5 to the inner wall of the pressure vessel 3, a large number of Bolt 6 is required.

As a result, holes must be formed in the magnetic shield 5 for mounting a large number of bolts, and the cross-sectional area through which magnetic flux can pass is reduced. Therefore, in order to obtain a predetermined cross-sectional area, it was necessary to increase the number of laminated strip-shaped magnetic materials 4, and accordingly, the diameter of the pressure vessel had to be increased.

In addition, a large number of bolts had to be tightened, making the installation of a magnetic shield to a pressure vessel complicated.

(Problems to be Solved by the Invention) As mentioned above, in the conventional gas insulated transformer, the manufacturing process of the magnetic shield is complicated, the manufacturing cost is high, and
Since a large number of bolts are required to secure the magnetic shield, the cross-sectional area through which the magnetic flux can pass is reduced, so the thickness of the magnetic shield had to be increased.

Therefore, the present invention aims to eliminate the above-mentioned drawbacks, and its purpose is to provide a gas insulated transformer with a thin magnetic shield, which is easy to manufacture and can be easily installed on the inner wall of a pressure vessel. Our goal is to provide the following.

[Structure of the Invention] (Means for Solving the Problems) The gas insulated transformer of the present invention has a magnetic shield configured by laminating a plurality of strip-shaped magnetic materials, and the magnetic shield is aligned with the curved surface of the pressure vessel. It is bent and fixed to the inner wall of the pressure vessel via fixing means.

(Function) The gas insulated transformer of the present invention bends and attaches the magnetic shield disposed inside the pressure vessel to match the curved surface of the pressure vessel, and uses the reaction force of the magnetic shield to prevent the magnetic shield from bending. The magnetic shield can be attached closely to the inner wall of the pressure vessel, simplifying the installation work and manufacturing process of the magnetic shield.

(Example) Hereinafter, an example of the present invention will be specifically described based on FIG. Incidentally, the same members as those of the conventional type shown in FIGS. 2 to 6 are given the same reference numerals, and explanations thereof will be omitted.

Configuration of this embodiment* In this embodiment, as shown in FIG. 1, a transformer body consisting of an iron core 1 and a coil 2 is housed in a pressure vessel 3. Furthermore, on the inner wall of the pressure vessel 3, a magnetic shield 10, which is constructed by stacking a plurality of strip-shaped magnetic materials 4 such as silicon steel strips, is bent to fit the curved surface of the pressure vessel 3, and is bent at both ends in the longitudinal direction. , and are fixedly tightened by bolts 6.

Effect of this embodiment Since the magnetic shield 10 is attached to the inner wall of the pressure vessel 3, a reaction force 11 against bending acts on the magnetic shield 10, and the magnetic shield 10 comes into close contact with the inner wall of the pressure vessel 3. Therefore, since it is sufficient to fix the magnetic shield 10 with the bolts 6 at both ends, the work for attaching the magnetic shield to the pressure vessel is greatly simplified.

In addition, since the reaction force 11 acts on each stacked magnetic material 4, there is no need to glue the stacked magnetic materials together, and there is no need to mold the magnetic material 4 to fit the curved surface of the pressure vessel 3. The manufacturing process is simplified and manufacturing costs can also be reduced.

Furthermore, since the number of bolts 6 required to fix the magnetic shield 10 to the pressure vessel 3 can be significantly reduced, the cross-sectional area through which the magnetic flux of the magnetic shield 10 passes can be increased. As a result, the thickness of the magnetic shield 10 can be reduced, and the diameter of the pressure vessel 3 can also be reduced.
It becomes possible to reduce the size and weight of gas insulated transformers.

Embodiment by Nido et al.* Note that the present invention is not limited to the above-mentioned embodiment, and as a method of fixing the magnetic shield to the pressure vessel, claw-like attachment members may be used instead of bolts. good.

[Effects of the Invention] As described above, according to the present invention, the magnetic shield attached to the inner wall of the pressure vessel is constructed by laminating a plurality of strip-shaped magnetic materials, and the magnetic shield is attached to the curved surface of the pressure vessel. By simply bending them together and fixing both ends to the pressure vessel with bolts, we have created a thin magnetic shield that is easy to manufacture and easy to attach to the inner wall of the pressure vessel. A gas insulated transformer can be provided.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the gas insulated transformer of the present invention, Fig. 2 is a longitudinal sectional view showing the configuration of a conventional gas insulated transformer, and Fig. 3 is a cross section taken along line A-A in Fig. 2. Figure 4 is a side view of a conventional magnetic shield, Figure 5 is a sectional view showing an example of how a conventional magnetic shield is installed in a pressure vessel, and Figure 6 is a side view of a conventional magnetic shield installed in a gas-insulated transformer. FIG. 1... Iron core, 2... Coil, 3... Pressure vessel, 4
...Magnetic material, 5...Magnetic shield, 10...Magnetic shield, 11...Reaction force.

Claims (3)

[Claims] (1) In a gas-insulated transformer, in which a transformer body consisting of an iron core and a coil is housed in a pressure vessel filled with high-pressure insulating gas, a magnetic shield is constructed by laminating multiple strip-shaped magnetic materials,
A gas insulated transformer characterized in that the magnetic shield is bent to match the curved surface of the pressure vessel and fixed to the inner wall of the pressure vessel via fixing means. (2) The gas insulated transformer according to claim 1, wherein the means for fixing the magnetic shield is tightening bolts. (3) The gas insulated transformer according to claim 1, wherein the fixing means for the magnetic shield is a claw-like mounting member.