JP2006196725A - Electrostatically shielded transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatically shielded transformer capable of reducing the distance between the output winding and the iron core thereof, thus being capable of easily increasing the capacitance thereof, and therefore capable of safely and surely protecting an electric apparatus etc. connected to the output winding from a lightning surge. <P>SOLUTION: This electrostatically shielded transformer has the iron core, an input winding and the output winding wound about the iron core, and a grounded electrostatic shield disposed between the input winding and the output winding. The intermediate electrostatic shield 8 is disposed between the input winding 10 and the output winding 6, and the capacitance is made large between the iron core 2 and the output winding 6. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrostatic shielding shield transformer installed between a line and an electric device.

  There is an electrostatic shielding shield transformer as one of the protection means for protecting electrical equipment and the like connected to the line from lightning surges entering from the line. This electrostatic shielding shield transformer connects an electrostatic shielding shield transformer to a line between a commercial power line and an electric device, and prevents lightning surges entering from the power line.

  In a conventional electrostatic shielding shield transformer, an input winding connected to the commercial power line side and an output winding connected to the electrical equipment side are wound around an iron core, and the input winding and the output winding Between them, a grounded electrostatic shielding shield is arranged. When a lightning surge that has entered from the input winding connected to the commercial power line attempts to enter the output winding, an electrostatic shield is placed between the input and output windings. The shield shields the lightning surge and grounds it, so that the lightning surge is processed to a voltage not higher than a predetermined value on the output winding side to protect the connected electrical equipment and the like.

  As an example, Patent Document 1 discloses an electrostatic shielding shield transformer having the above-described configuration.

Japanese Patent Publication No. 7-89712

  In the conventional electrostatic shielding shield transformer described above, an input winding connected to the commercial power line side, an output winding connected to an electric device or the like as a load facility, and an input winding and an output winding. An electrostatic shielding shield placed between them grounds most of the lightning surge, but part of the lightning surge consists of the input winding and electrostatic shielding shield, and the electrostatic shielding shield and output winding. Due to the capacitance of the capacitor and the stray capacitance between the input and output windings, a voltage higher than the specified voltage can penetrate the output winding and the electrostatic shielding shield transformer can satisfy the specified regulations. It may disappear, and the connected electrical equipment may be damaged. In particular, there is a problem that this tendency becomes more prominent as the electrostatic shielding shield transformer has a lower power capacity.

  The smaller the power capacity of the electrostatic shielding shield transformer, the smaller the shielding effect of the electrostatic shielding shield. The larger the power capacity of the electrostatic shielding shield transformer, the greater the shielding effect. By the way, the lightning surge that enters the input winding enters regardless of the power capacity of the electrostatic shielding shield transformer, but is installed between the input winding and the output winding of the electrostatic shielding shield transformer. When the surface area of the electrostatic shielding shield is large, the shielding effect becomes large. However, the electrostatic shielding shield transformer having a small power capacity has a small electrostatic shielding shield because of its small shape, and therefore the shielding effect is small. become.

  An object of the present invention is to solve the problems of the above-described conventional electrostatic shielding shield transformer.

  In order to achieve the above-described object, the present invention is first arranged between an iron core, an input winding and an output winding wound around the iron core, and the input winding and the output winding. In an electrostatic shielding shield transformer having a grounded electrostatic shielding shield, an intermediate electrostatic shielding shield is disposed between the input winding and the output winding, and between the iron core and the output winding. It is configured to increase the capacitance, and the second is arranged between the iron core, the input and output windings wound around the iron core, and the input and output windings. In an electrostatic shielding shield transformer having a grounded electrostatic shielding shield, an intermediate electrostatic shielding shield is disposed between the input winding and the output winding, and between the iron core and the output winding. In addition, an output winding shielding shield is disposed on the iron core, intermediate electrostatic shielding shield and output winding. A shielding shield is obtained by the same ground.

  Since this invention has the structure mentioned above, there can exist the effect described below.

  In the electrostatic shielding shield transformer of the present invention, an iron core, an input winding and an output winding wound around the iron core, and an electrostatic shielding shield arranged between the input winding and the output winding and grounded In an electrostatic shielding shield transformer with an intermediate shield, an intermediate electrostatic shielding shield is disposed between the input winding and the output winding, and the capacitance between the iron core and the output winding is increased. Thus, the distance between the output winding and the iron core can be shortened, so that the capacitance can be easily increased and the voltage appearing on the output winding side can be suppressed to a small value. The electrical equipment connected to the output winding can be safely and reliably protected from lightning surges.

  An electrostatic shielding sheet comprising an iron core, an input winding and an output winding wound around the iron core, and an electrostatic shielding shield disposed between the input winding and the output winding and grounded. In an intermediate transformer, an intermediate electrostatic shielding shield is arranged between the input winding and the output winding, and an output winding shielding shield is arranged between the iron core and the output winding. Since the electrostatic shielding shield and the output winding shielding shield are grounded together, the lightning surge that has entered from the line cannot be shielded by the intermediate electrostatic shielding shield between the input winding and the output winding, and leaks out. Even if it enters the winding side, it is shielded by the output winding shield shield and grounded, and further, since the iron core, the intermediate electrostatic shield shield, and the output winding shield shield are grounded at the same potential, There is no voltage difference between them, so Lightning surge appearing in the output winding side is suppressed extremely small, thus, the connected electrical device or the like, safe from lightning surges, and can be reliably protected.

  Examples of the present invention will be described below. However, the present invention is not limited to the examples as long as the gist of the present invention is not exceeded.

  In FIG. 1, 1 is an electrostatic shielding shield transformer configured such that an electrostatic shielding shield is grounded, 2 is an iron core wrapped with an insulator 3 made of insulating paper or the like, and an insulator An output winding shielding shield 4 made of a thin conductor such as a copper plate is arranged on the iron core 2 wrapped with 3 so as to go around the iron core 2 wrapped with the insulator 3. In addition, the output winding shielding shield 4 is wrapped by the insulating body 5 made of the same insulating paper as the insulating body 3, and the insulating body 5 is arranged so as to surround the output winding shielding shield 4. In addition, an output winding 6 is disposed around the insulator 5 by winding a winding made of a copper wire a predetermined number of turns.

  Further, the output winding 6 is insulated by winding a tape-like insulator 7 made of insulated fiber or the like around the output winding 6. Before the output winding 6 is disposed on the iron core 2, the output winding 6 may be disposed on the iron core 2 after being wrapped with an insulator 7 so that the entire output winding 6 is covered. Good. Furthermore, an intermediate electrostatic shielding shield 8 made of a thin conductor such as a copper plate is disposed on the insulator 7 enclosing the output winding 6 so as to go around the insulator 7. Still further, the intermediate electrostatic shielding shield 8 is enclosed by an insulator 9 made of insulating paper or the like similar to the insulator 3, and a copper wire is wound around the insulator 9 a predetermined number of turns. The input winding 10 is arranged around the insulator 9 by being wound. Further, like the output winding 6, the input winding 10 is wound with a tape-like insulator 11 made of insulated fiber or the like, so that the input winding 10 is insulated. Has been. Similarly to the output winding 6, the input winding 10 is also encapsulated so that the entire input winding 10 is covered with an insulator 11 before being placed on the iron core 2. The iron core 2 may be disposed.

  Thereafter, the iron core 2, the output winding shield shield 4 and the intermediate electrostatic shield shield 8 are connected, and a ground terminal (not shown) for setting the same ground potential is provided, whereby the electrostatic shield shield transformer 1 is configured. Will be.

  FIG. 2 is a schematic configuration diagram showing the relationship between the input winding 10, the output winding 6, the iron core 2, the output winding shielding shield 4 and the intermediate electrostatic shielding shield 8 that constitute the electrostatic shielding shield transformer 1 of the present invention. The iron core 2 is disposed on the input winding 10 and the output winding 6. An intermediate electrostatic shielding shield 8 is disposed between the input winding 10 and the output winding 6, and an output winding shielding shield 4 is disposed between the output winding 6 and the iron core 2. The electrostatic shield shield transformer 1 is configured by connecting the iron core 2, the intermediate electrostatic shield shield 8 and the output winding shield shield 4 to the same potential and grounding them to the ground.

  FIG. 3 is an explanatory diagram showing the operation principle of the electrostatic shielding shield transformer 1 of the present invention.

In FIG. 3, the output winding shielding shield 4 and the intermediate electrostatic shielding shield 8 are arranged between the input winding 10 and the output winding 6, and the input winding 10, the intermediate electrostatic shielding shield 8, and the output are arranged. A capacitance C ₁ exists between the winding 6 and the output winding shielding shield 4. Now, when a lightning surge enters the input winding 10 side, the lightning surge tries to enter the output winding 6 side via the capacitance C ₁ between the input winding 10 and the intermediate electrostatic shielding shield 8. However, most lightning surges are absorbed by the ground E through the intermediate electrostatic shielding shield 8. However, some lightning surges try to enter the output winding 6 side via the capacitance C ₁ , but this part of the lightning surge is output winding arranged on the output winding 6 side. It is shielded by the shielding shield 4 and absorbed by the ground E.

In addition, lightning surges try to enter through the stray capacitance C ₀ between the input winding 10 and the output winding 6, but most lightning surges are due to the arrangement of the output winding shielding shield 4. By shortening the distance between the iron core 2 and the output winding 6, the shield is shielded by the output winding shielding shield 4 whose capacitance C ₁ is increased, and is connected to the ground E via the output winding shielding shield 4. Absorbed. Therefore, most lightning surges are absorbed by the ground E, and only a low safe voltage appears on the output winding 6 side.

As can be seen from the description of FIG. 3, the shielding effect is reduced by the stray capacitance C ₀ generated between the input winding 10 and the output winding 6. Further, the shielding effect can be further enhanced by enlarging the output winding shielding shield 4 as indicated by the dotted line.

As described above, the lightning surge that has entered the input winding 10 tries to enter the output winding 6 via the electrostatic capacitance C ₁ of the electrostatic shielding shield transformer 1, but the intermediate electrostatic shielding shield 8. However, most of them are grounded and grounded E, but some of them try to enter the output winding 6 side through the electrostatic capacitance C ₁ and the stray capacitance C ₀ of the electrostatic shielding shield transformer 1. The output winding shielding shield 4 disposed between the iron core 2 and the output winding 6 shortens the distance between the iron core 2 and the output winding 6 and increases the capacitance C ₁ associated therewith. The lightning surge is shielded by the output winding shielding shield 4 and absorbed by the ground E, whereby the output winding 6 side can be suppressed to a low safe voltage. Therefore, an electric device such as a load device connected to the output winding 6 side is protected from the lightning surge by the electrostatic shielding shield transformer 1.

  In addition, since the iron core 2, the intermediate electrostatic shielding shield 8 and the output winding shielding shield 4 are grounded to the same potential E, no potential difference occurs between them, so that the potential on the output winding 6 side is further suppressed. It will be.

FIG. 1 is a horizontal sectional view of an electrostatic shielding shield transformer according to the present invention. FIG. 2 is a schematic configuration diagram showing the relationship between the iron core, windings, and electrostatic shielding shield of the electrostatic shielding shield transformer of the present invention. FIG. 3 is an explanatory diagram showing the operating principle of the electrostatic shielding shield transformer of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electrostatic shielding shield transformer 2 ... Iron core 3 ... Insulator 4 ... Output winding shielding shield 5 ... Insulator 6 ... Output winding 7 ... Insulator 8 ... Intermediate electrostatic shielding shield 9 ... ········································································.

Claims (2)

  An electrostatic shielding shield having an iron core, an input winding and an output winding wound around the iron core, and a grounded electrostatic shielding shield disposed between the input winding and the output winding In the transformer, an intermediate electrostatic shielding shield is disposed between the input winding and the output winding, and the capacitance between the iron core and the output winding is increased. Features an electrostatic shielding shield transformer.   An electrostatic shielding shield having an iron core, an input winding and an output winding wound around the iron core, and a grounded electrostatic shielding shield disposed between the input winding and the output winding In the transformer, an intermediate electrostatic shielding shield is disposed between the input winding and the output winding, and an output winding shielding shield is disposed between the iron core and the output winding. An electrostatic shielding shield transformer, wherein the iron core, the intermediate electrostatic shielding shield, and the output winding shielding shield are grounded to the same ground.

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