KR100750649B1 - Voltage/current transformer for metering - Google Patents

Abstract

A voltage/current transformer for measuring an electric power usage is provided to prolong the lifespan of the voltage/current transformer by reducing an electric field between primary and secondary coils of the transformer and reducing the amount of current of portion discharge generated inside the voltage/current transformer. A voltage/current transformer for measuring an electric power usage includes a power input terminal(10), a power output terminal(11), a current transformer(20), and a voltage transformer(30). An iron core of the current transformer is arranged at a lower portion than an iron core of the voltage transformer. The iron cores of the voltage and current transformers are arranged to be normal to a bottom surface of a main body of the transformer. A secondary coil of the current transformer is wound around an overall surface of the iron core of the current transformer. A primary coil of the voltage transformer, which is arranged around one end of the iron core of the voltage transformer, is formed at a portion, which is displaced from a center point of the iron core of the voltage transformer by a predetermined angle. An electric field between the primary coil of the voltage transformer and the secondary coil of the current transformer is reduced.

Description

Transformer / current transformers for power supply and instrumentation {Voltage / current transformer for metering}

1 is a cross-sectional view of a conventional transformer current transformer,

Figure 2 is a front sectional view of a transformer transformer according to an embodiment of the present invention,

Figure 3 is a side cross-sectional view of a transformer current transformer according to an embodiment of the present invention,

4 is an explanatory view of a transformer primary coil of the present invention disposed at a position spaced a predetermined angle directly below the secondary coil of the current transformer.

* Description of the symbols for the main parts of the drawings *

10: power input terminal 11: output terminal 12: cloth prevention cover

13 insulating bolt 14 side wall 20 current transformer

21 current transformer primary coil 22 current transformer secondary coil 23 current transformer iron core

30: transformer 31: transformer primary coil 32: transformer secondary coil

33: transformer core 33a: center point of the transformer core

34 transformer coil lead wire 40 body 50 fixing member

60: carbon tape

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer current transformer, and more particularly, to a transformer current transformer for power supply and instrumentation that is installed between a high voltage power transmission line and a meter to convert high voltage and high current flowing from a power transmission line into low voltage and low current.

A transformer transformer of the related art is shown in FIG. 1. The conventional transformer current transformer 100 shown in FIG. 1 includes power input and output terminals 111 and 112 formed on an upper surface of a body 109 made of flame-retardant synthetic resin, and a current transformer primary coil into which high current flows from the power input terminal 111. A current transformer 103 formed of a current transformer secondary core 133 wound around the current transformer core 133 and a current transformer secondary coil 132 in which low current is induced, and positioned at an upper side of the body 109. The transformer is located on the inner lower side of the body 109 including a transformer primary coil 141 which receives a high voltage from the power input terminal 111, a transformer iron core 143, and a transformer secondary coil 142 where low voltage is induced ( 104).

However, in the above-described conventional transformer current transformer 100, as shown in FIG. 1, the secondary coil 141 of the transformer is positioned by the primary coil 141 of the transformer that is subjected to a high voltage directly under the secondary coil 132 of the current transformer. 132) and the primary coil 141 of the transformer due to electric field interference, etc. due to the electric field is not stabilized often the insulation breakdown occurred.

In addition, a minute partial discharge phenomenon occurs in the winding of the transformer current transformer, so that insulation may be destroyed or performance may be degraded when used for a long time.

The present invention has been made to solve the above-mentioned problems of the prior art, to reduce the electric field between the primary coil of the transformer and the secondary coil of the current transformer, and to reduce the amount of charge of the partial discharge generated inside the transformer current transformer durability. It is an object to provide an excellent transformer transformer.

Transformer transformer according to one aspect of the present invention is a power supply input and output terminals; A current transformer comprising a primary coil, a secondary coil, and an iron core on an upper side of the body to convert a high current from the power input terminal into a low current; A transformer having a primary coil, a secondary coil, and an iron core in the lower side of the body to convert a high voltage into a low voltage to convert a high voltage and a high current into a low voltage and a low current. The iron core of the winding core transformer is located just below the iron core of the current transformer, the iron core of the transformer and the iron core of the current transformer are all placed perpendicular to the bottom of the body, and the secondary coil of the current transformer is wound around the iron core of the current transformer. The primary coil of the transformer wound on one side of the iron core of the transformer is spaced at a predetermined angle directly below the lowermost end of the secondary coil of the transformer to relieve electric field concentration with the secondary coil of the transformer. It is characterized in that it is formed in the position.

Here, it is preferable that the primary coils of the transformer are positioned 45 degrees to 100 degrees apart directly below the lowest end of the secondary coil of the current transformer, and most preferably about 90 degrees apart.

In addition, the transformer current transformer for power supply instrument according to another aspect of the present invention is the power input, output terminal; A current transformer comprising a primary coil, a secondary coil, and an iron core on one side of the body to convert a high current from the power input terminal into a low current; A transformer having a primary coil, a secondary coil, and an iron core on the other side of the body to convert a high voltage to a low voltage to convert a high voltage and a high current into a low voltage and a low current, At least one of the primary coil and the secondary coil is characterized in that it is wrapped with a carbon tape.

In addition, at least one of the outer peripheral surface and the iron core of the primary coil of the transformer is characterized in that it is wrapped with a carbon tape.

In another aspect, the present invention is characterized in that the transformer coil lead wire connecting one of the power input and output terminals and the primary coil of the transformer is spirally wound in a spiral shape.

In addition to this, the primary coil of the current transformer is wrapped in multiple layers of carbon tape, and the transformer coil lead wire is inserted and fixed between the multiple layers of carbon tape surrounding the primary coil of the current transformer.

In addition, the transformer transformer current transformer of the present invention is characterized in that it further comprises a fixing connecting member for fixing the connection of the current transformer and the transformer between the current transformer and the transformer.

In addition, the transformer current transformer of the power supply instrument of the present invention is characterized in that the synthetic resin is the body of the transformer current transformer so that the transformer and the transformer completely surround the current transformer and the transformer so that a part of the transformer and the transformer is not exposed to the outside.

In addition, the transformer current transformer of the power supply instrument of the present invention is a pair of power input and output terminals are installed on the upper surface of the transformer transformer, a pair of protruding upward from the upper surface of the transformer transformer with the power input and output terminals. It further comprises a sidewall and the lower surface is in contact with the top of the pair of sidewalls and coupled to the power input and output terminals by an insulating bolt to cover the pair of sidewalls to further prevent theft of others. It is done.

In the molding method of the transformer current transformer according to the present invention, after assembling the parts constituting the transformer current transformer including the winding body of the transformer, it is put into a mold and preheated to the mold at a temperature of 60 ° C. to 100 ° C. Transfer to the vacuum tank and inject the flame-retardant resin into the mold under the temperature of 60 ℃ ~ 90 ℃ and the vacuum below 1torr, and then move the mold to the drying furnace to apply the pressure of 1kg / cm ² ~ 5kg / cm ² to 80 ℃ ~ 120 It is characterized by curing at a temperature of ℃ and molding.

In addition, the molding method of the transformer current transformer according to the present invention, after assembling the parts constituting the transformer current transformer, including the winding body of the transformer into a mold and preheated the mold to a temperature of 60 ℃ ~ 100 ℃, and then the mold Transfer to the vacuum tank and inject the flame-retardant resin into the mold under the temperature of 60 ℃ ~ 90 ℃ and the vacuum below 1torr, and then move the mold to the drying furnace to apply the pressure of 1kg / cm ² ~ 5kg / cm ² at 80 ℃ ~ 90 Curing by molding for 2 hours at 2 ℃, 2 hours at 90 ℃ ~ 100 ℃, 2 hours at 100 ℃ ~ 120 ℃.

Hereinafter, a transformer current transformer for a power supply and demand instrument according to an embodiment of the present invention will be described with reference to the drawings. Figure 2 is a front sectional view of a transformer transformer according to an embodiment of the present invention, Figure 3 is a side cross-sectional view of a transformer transformer according to an embodiment of the present invention, Figure 4 is a transformer transformer according to an embodiment of the present invention It is explanatory drawing of the thing in which a transformer primary coil is arrange | positioned at the position separated by predetermined angle directly under the lowest end of a transformer secondary coil. In the drawing, reference numeral 71 denotes a ground terminal, and 72 is a secondary terminal.

Transformer transformer current transformer (1) according to an embodiment of the present invention comprises a power input and output terminals (10, 11), a current transformer 20, and a transformer 30, made of a flame-retardant synthetic resin The power input and output terminals 10 and 11 are positioned on the upper surface of the body 40, the current transformer 20 is located above the body 40, and the transformer 30 is located below the body 40. .

The current transformer 20 converts a high current from the power input terminal 10 into a low current, and includes a current transformer primary coil 21, a current transformer secondary coil 22, and a current transformer iron core 23. Current transformer core 23 is an annular iron core and is disposed in a direction perpendicular to the bottom surface of the body 40, the current transformer secondary coil 22 is wound around the current transformer core core 23, the current transformer primary coil ( 21 is formed at a predetermined interval around the top of the current transformer core 23 as shown in Figure 2 and is connected to the power input and output terminals (10, 11). Therefore, a high current flows in the current transformer primary coil 21 and a low current is induced in the current transformer secondary coil 22.

The transformer 30 is composed of a transformer primary coil 31 subjected to a high voltage, a transformer secondary coil 32 from which a low voltage is induced, and a transformer iron core 33. The transformer core 33 is an inner coil type core and is disposed in a direction perpendicular to the bottom surface of the body 40, but is disposed perpendicular to the current transformer core 23. In addition, the transformer primary coil 31 is formed at a right angle with respect to the transformer iron core 33 around one side of the transformer iron core 33, and the transformer is directly below the current transformer secondary coil 22 as shown in FIG. 4. The center point 33a of the iron core 33 (in this embodiment, as shown in FIG. 4, the point where the lines connecting the edges facing each other in the square-shaped iron core with rounded corners intersect is referred to as the 'center point of the iron core' It is formed at a position spaced by a predetermined angle α with respect to. The transformer secondary coil 32 is formed between the transformer primary coil 31 and the transformer iron core 33.

In the conventional transformer current transformer 100 shown in FIG. 1, a transformer primary coil 141 is located at a transformer iron core 143 portion of the transformer secondary coil 132 directly below the transformer primary coil 141. Although the distance between the current transformer and the secondary coil 132 is close, an instability of the electric field occurs between the transformer primary coil 141 and the current transformer secondary coil 132, the insulation is often broken during long-term use, but the present invention In the transformer current transformer 1 of the transformer primary coil 31 is formed at a predetermined angle (α) spaced directly below the lowest end of the transformer secondary coil 22, the transformer primary coil 31 and the transformer secondary coil The electric field is relaxed between (22) so that the insulation will not be destroyed even after long-term use. Since the electric field between any two points is inversely proportional to the square of the distance, if the predetermined angle α is less than 45 degrees, the effect of electric field relaxation may not be sufficiently obtained. It is preferable that the degree is about 90 degrees, since it is not only structurally stable when it is about 90 degrees, but also excellent in the relaxation effect of the electric field. 2 and 3 show the case where the predetermined angle α is 90 degrees. When the predetermined angle α is 90 degrees, as shown in FIGS. 2 and 3, the transformer primary coil 31 is disposed parallel to the bottom surface of the body 40, and is perpendicular to the transformer core 33. Is placed.

In the transformer current transformer 1 of the present invention, the transformer primary coil 21, the secondary coil 22 wound around the entire iron core 23, and the outer surface of the transformer core 33 are semiconductive carbon tape ( 60) (carbon tape), the transformer primary coil 31 is wrapped in a semi-conductive carbon tape (60) on the outer peripheral surface. In the conventional transformer current transformer, minute partial discharge in the coil and the core or electric field concentration phenomenon occurred in the vicinity of the surrounding area, and insulation breakdown occurred in the long-term use. By wrapping the carbon tape 60, the electric field to the surroundings can be relaxed and the partial discharge can be significantly reduced.

In the transformer current transformer 1 of the present invention, the transformer coil lead wire 34 (transformer coil lead wire 34 connecting the power input terminal 10 and the transformer primary coil 31 is connected to the output terminal 11). As shown in FIG. 2, a spiral wound is formed in a spiral shape, and a part of the transformer coil lead wire 34 is formed by multiple layers of the transformer primary coil 21 to prevent shaking of the transformer coil lead wire 34. It is inserted and fixed between the wrapping carbon tape 60. When the transformer coil lead wire 144 in the transformer transformer 100 is formed as a straight line as shown in FIG. 1, an electric field is concentrated on the outer circumferential surface of the transformer coil lead wire 144, but the transformer coil lead wire 34 of the present invention is formed. Since it is formed by rolling in a spiral shape like a spring shape, it has the advantage of alleviating an electric field, thereby improving durability of the transformer.

In the transformer current transformer 1 of the present invention, a fixing connecting member 50 is formed between the current transformer 20 and the transformer 30 to fix the connection of the current transformer 20 and the transformer 30. By the fixing connection member 50, the position of the current transformer 20 and the transformer 30 is not misaligned even when the synthetic resin is formed to form the body 40 of the transformer current transformer 1, which is one of the molding processes.

In addition, in the transformer current transformer 1 of the present invention, the body 40 made of a flame retardant synthetic resin has a synthetic resin completely separating the current transformer 20 and the transformer 30 so that a part of the current transformer 20 and the transformer 30 are not exposed to the outside. Will be surrounded. In the conventional transformer current transformer 100, the iron core 143 of the transformer 104 was exposed to the outside of the body 109, but in the present invention, the transformer 30 including the iron core 33 is disposed inside the body 40 to be iron core. There is an advantage that can prevent the deterioration, change of properties, oxidation.

In addition, in the transformer current transformer 1 of the present invention, a pair of side walls 14 protruding upward from the upper surface of the body 40 of the transformer current transformer 1 with the power input and output terminals 10 and 11 interposed therebetween. In order to cover the pair of side walls 14, the cloth preventing cover 12 having a lower surface in contact with the top of the pair of side walls 14 and coupled to the power input and output terminals 10 and 11 by an insulating bolt 13 is provided. It can be formed to prevent the theft of others.

The following describes the molding method of the transformer current transformer of the present invention.

First, the components that make up the transformer current transformer, including the winding of the transformer, are assembled, and then put into a mold. The mold is then preheated to a temperature of 60 ° C. to 100 ° C. to allow for better adhesion between the injected resin and the internal components of the transformer. Thereafter, the mold is transferred to a vacuum tank, and a flame-retardant synthetic resin is injected into the mold under a temperature of 60 ° C. to 90 ° C. and a vacuum of 1 torr or less and degassed (bubble removed). Then, the mold is moved to a drying furnace to be molded by curing at a temperature of 80 ° C to 120 ° C while applying a pressure of 1kg / cm ² to 5kg / cm ² .

Preferred curing conditions in the molding method is 2 hours at 80 ℃ ~ 90 ℃, 2 hours at 90 ℃ ~ 100 ℃, 2 hours at 100 ℃ ~ 120 ℃ under a pressure of 1kg / cm ² ~ 5kg / cm ² It is hardening each. In this way, the resin can be cured slowly from a low temperature to a high temperature, so that the resin and its internal parts can be closely adhered to.

In the conventional method of transforming transformer, the flame-retardant synthetic resin is injected into a mold, and then subjected to a predetermined pressure, and then reduced to normal pressure, then moved to a curing furnace and cured. In this conventional molding method, pressure is applied before curing. When the resin is cured by reducing the pressure to atmospheric pressure, the synthetic resin is cured during the curing process, and thus, a fine gap is generated between the synthetic resin and the parts, thereby preventing the synthetic resin and the internal parts from being completely adhered to each other.

In the above-described forming method of the transformer current transformer according to the present invention, after the flame-retardant synthetic resin is injected into the mold, a predetermined pressure is not applied before curing, but the mold is moved to a drying furnace to apply a pressure of 1 kg / cm ² to 5 kg / cm ² . By curing at a temperature of 80 ° C ~ 120 ° C, the synthetic resin and the internal parts can be more closely contacted to provide a transformer with excellent durability without destroying the internal insulation even during long-term use.

In addition, in the method of forming a transformer current transformer according to the present invention, by eliminating the impregnation process for the primary coil of the transformer and current transformer in the prior art to reduce the number of processes to reduce the manufacturing cost, which is a factor of the characteristic change of the transformer current transformer By injecting the resin only under vacuum and not in the pressure process, the factor of change in the characteristics of the transformer current transformer was reduced.

According to the present invention, to reduce the electric field between the primary coil of the transformer and the secondary coil of the transformer, and to reduce the amount of partial discharge generated inside the transformer current transformer to provide a transformer transformer of excellent durability and high quality. Can be.

In addition, according to the molding method of the present invention, a transformer is provided that the synthetic resin and its internal parts are in close contact with each other and excellent in durability.

Claims (11)

Power input and output terminals; A current transformer comprising a primary coil, a secondary coil, and an iron core on an upper side of the body to convert a high current from the power input terminal into a low current; In a transformer current transformer having a primary coil, a secondary coil and an iron core in the lower side of the body and converting a high voltage to a low voltage to convert a high voltage and a high current into a low voltage and a low current, The iron core of the transformer, which is an iron-type wound core, is located directly below the iron core of the current transformer, and the iron core of the transformer and the iron core of the current transformer are all disposed in a direction perpendicular to the bottom surface of the body, and the secondary coil of the current transformer is The primary coil of the transformer wound around the iron core of the current transformer and disposed around one side of the iron core of the transformer is directly below the lowermost end of the secondary coil of the current transformer to mitigate field concentration with the secondary coil of the current transformer. A transformer current transformer is formed at a position spaced a predetermined angle from the center point of the iron core of the transformer in the room. The transformer transformer according to claim 1, wherein the predetermined angle at which the primary coil of the transformer is spaced directly below the lowest end of the secondary coil of the current transformer is 90 degrees. delete delete delete delete The method according to claim 1 or 2, A transformer transformer further comprising a connection member for fixing the connection between the transformer and the transformer between the current transformer and the transformer. The method according to claim 1 or 2, The body is made of a flame-retardant synthetic resin, transformer transformer current transformer and the flame-retardant synthetic resin surrounds the entirety of the current transformer and the transformer so that the iron core of the current transformer and the transformer is not exposed to the outside of the body. The method according to claim 1 or 2, The power input and output terminals are installed on the upper surface of the transformer current transformer, A pair of side walls protruding upward from the upper surface of the body of the transformer current transformer with the power input and output terminals interposed therebetween, and the bottom surface is in contact with the top of the pair of side walls and coupled to the power input and output terminals by insulating bolts. And a transformer preventing cover covering the pair of side walls. delete delete

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