JP2000331856A - Transformer for instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an instrument transformer as well as that with a zero- phase current transformer which allow reduction in the number of members and works, shorter work process, simplified fitting work, and improved workability in a distribution panel. SOLUTION: Through parallel rod-like conductors where the current of each phase of three-phase AC electric current flow, two instrument transformers 3 comprising a secondary coil 3b wound around iron cores 3a surrounding the conductor where the first phase current and the third phase current of the three-phase AC electric power flow, respectively, and a zero-phase current transformer 4 comprising a secondary coil 4b wound around iron cores 4a which surround three rod-like conductors while adjoining two instrument transformers 3, are provided. Here, the two instrument transformers 3, zero-phase current transformer 4, and three rod-like conductors are molded as one body except for each end part of the conductors.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an instrument transformer disposed in a switchgear applied to a power receiving and distribution facility.

[0002]

2. Description of the Related Art In a power receiving and distribution facility, an instrument transformer is used for measuring a rated current and detecting an overcurrent, and a zero-phase current transformer is used for detecting a ground fault current (zero-phase current). I'm using FIGS. 13A and 13B are external views showing a configuration example of a conventional primary conductor embedded type instrument transformer. FIG.
(B) is a front view. This instrument transformer comprises a rod-shaped conductor 18 (primary conductor) through which AC power is to flow, and a conductor 1
8, a secondary winding (not shown) is wound in a toroidal shape, and is made of a doughnut-shaped silicon steel core 19. The iron core 19 including the secondary winding and the conductor 18 leave both ends of the conductor 18. Thus, it is integrally molded with the epoxy resin 19a. In this instrument transformer, when an alternating current flows through the conductor 18, a secondary current is generated in the secondary winding, and the generated secondary current is measured by an ammeter or the like (not shown) and used for measurement control. .

FIG. 14 is an external view showing a configuration example of a conventional primary conductor penetrating type instrument transformer, in which (a) is a front view,
(B) is a side view. The instrument transformer includes a through-hole 20 through which an AC power line passes, and a donut-shaped silicon steel core 21 surrounding the through-hole 20 and having a secondary winding (not shown) wound in a toroidal shape. Has become. In this instrument transformer, when an alternating current flows through a power line passing through the through-hole 20, a secondary current is generated in the secondary winding, and the generated secondary current is measured by an ammeter (not shown) and the like. Used for control.

FIG. 15 is an external view showing a configuration example of a conventional zero-phase current transformer of a primary conductor penetrating type.
(B) is a side view. This zero-phase current transformer has a through-hole 22 through which each phase power line of the three-phase AC power should pass through collectively,
A permalloy iron core 23 is provided around the through hole 22 and has a secondary winding (not shown) wound in a toroidal shape. In this zero-phase current transformer, when one of the three power lines passing through the through-hole 22 is grounded, an imbalance occurs in the three-phase AC power flowing through the three power lines, and when the zero-phase current flows, A secondary current is generated in the secondary winding, and the generated secondary current is measured by an ammeter or the like (not shown) to operate the ground fault relay.

FIG. 16 is a vertical sectional side view of a closed switchboard showing the arrangement of a conventional instrument transformer and a zero-phase current transformer in the closed switchboard, and FIG. 17 is a vertical sectional back view thereof.
In this closed switchboard, two circuit breakers 9 are respectively arranged at the upper part and the lower part near the front side in the closed switchboard, and three conductors 10 arranged in parallel from the back side of each circuit breaker 9 are provided. The (cable) has two conductors 10 connected to the conductors (in the case of the primary conductor embedded type) of each of the instrument transformers 1 at the locations where they exit from the respective circuit breakers 9.

[0006] Each pair of two cables 11 and the center conductor 10 connected to the two outer conductors 10 through the conductors of each instrument transformer 1 is connected to the rear surface of the closed switchboard. Through the through-hole of one of the zero-phase current transformers 2 provided at the lower part near the side, and through the hole (not shown) provided at the bottom of the closed switchboard, and laid outside. When the instrument transformer 1 is of a primary conductor penetrating type, the conductor 10 and the cable 11 are integrated and penetrate through the through hole of the instrument transformer 1.

[0007]

In the conventional arrangement of the instrumentation transformer and the zero-phase current transformer in the closed switchboard as described above, the number of members is increased because they are arranged at different positions when assembled. As the number of work steps increases, the work space is narrowed after the instrument transformer and the zero-phase current transformer are installed in the panel, which hinders the work in the panel. In addition, when laying the cable, the cable needs to be passed through the zero-phase current transformer, which may damage the zero-phase current transformer, and the workability in the panel is not good.

As a technique for solving the above-mentioned problem, a "closed switchboard" formed by integrally molding a three-phase current transformer detector, a zero-phase current transformer, and a disconnection portion bushing at a disconnection portion, It is disclosed in JP-A-61-191203. The present invention has been made in view of the circumstances described above, and it is possible to reduce the number of members, reduce the number of work steps, shorten the work process, simplify the installation work, and improve the workability in the switchboard. An object of the present invention is to provide an instrument transformer including an instrument transformer and a zero-phase current transformer.

[0009]

According to a first aspect of the present invention, there is provided an instrument transformer comprising an instrument transformer and a zero-phase current transformer, wherein the instrument transformer and the zero-phase current transformer are integrally molded. It is characterized by becoming.

The meter transformer according to a second aspect of the present invention is a transformer for three-phase AC power, in which respective phase currents are to be passed, respectively.
Three rod-shaped conductors, a first phase and a third phase of the three-phase AC power.
Two instrument transformers each comprising a core surrounding each of the conductors through which phase currents are to be passed, and a secondary winding wound around the core, and adjacent to the two instrument transformers,
A zero-phase current transformer comprising an iron core surrounding two rod-shaped conductors and a secondary winding wound on the iron core, wherein the two instrument transformers, the zero-phase current transformer, and the three rod-shaped conductors Are molded integrally except for each end of the conductor.

A third aspect of the present invention is a transformer for an instrument, wherein each phase power line of the three-phase AC power is to be passed through in parallel.
Two gauges each comprising a through-hole, an iron core surrounding each of the through-holes through which the first-phase and third-phase power lines of the three-phase AC power should pass, and a secondary winding wound around the iron core. A transformer, adjacent to the two instrument transformers,
A zero-phase current transformer comprising an iron core surrounding two through-holes and a secondary winding wound on the iron core, wherein the two instrument transformers and the zero-phase current transformer are integrally molded. It is characterized by.

[0012] A meter transformer according to a fourth aspect of the present invention is a three-wire type parallel-connected rod-shaped conductor to which a positive-phase line, a negative-phase line, and a neutral line of single-phase AC power are connected, respectively. Two instrument transformers each comprising an iron core surrounding the conductor to which the positive-phase wire and the negative-phase wire are to be connected, respectively, and a secondary winding wound on the iron core, and adjacent to the two instrument transformers An iron core surrounding each of the three rod-shaped conductors; and three zero-phase current transformers each including a secondary winding wound around the iron core. The secondary windings are connected in series, and the two An instrument transformer, the three zero-phase current transformers, and the three rod-shaped conductors are integrally molded except for respective ends of the conductors.

According to a fifth aspect of the present invention, there is provided a transformer for an instrument, comprising three parallel through-holes through which a positive-phase line, a negative-phase line, and a neutral line of a three-wire single-phase AC power should pass, respectively. Two instrument transformers each comprising a core and a secondary winding wound around the core, respectively surrounding the through holes through which the phase line and the negative phase line should pass, and adjacent to the two instrument transformers. , Said 3
An iron core surrounding each of the two through holes and three zero-phase current transformers each having a secondary winding wound around the iron core. The secondary windings are connected in series, and the two instrument transformers and The three zero-phase current transformers are integrally molded.

[0014] The instrument transformer according to a sixth aspect of the present invention is a transformer for three parallel rod-shaped conductors to which a positive-phase line, a negative-phase line, and a neutral line of a three-wire single-phase AC power are to be connected, respectively. Two instrument transformers each comprising an iron core surrounding the conductor to which the positive-phase wire and the negative-phase wire are to be connected, respectively, and a secondary winding wound on the iron core, and adjacent to the two instrument transformers And an iron core surrounding each of the three rod-shaped conductors and three zero-phase current transformers each including a secondary winding wound around the iron core. The secondary windings are connected in parallel, and the two windings are connected in parallel. An instrument transformer, the three zero-phase current transformers, and the three rod-shaped conductors are integrally molded except for respective ends of the conductors.

According to a seventh aspect of the present invention, there is provided a transformer for an instrument, wherein three through-holes in parallel with which a positive-phase line, a negative-phase line, and a neutral line of a three-wire single-phase AC power should pass, respectively, Two instrument transformers each comprising a core and a secondary winding wound around the core, respectively surrounding the through holes through which the phase line and the negative phase line should pass, and adjacent to the two instrument transformers. , Said 3
A three-phase current transformer comprising an iron core surrounding each of the two through-holes and a secondary winding wound on the iron core, connecting the secondary windings in parallel, the two instrument transformers and The three zero-phase current transformers are integrally molded.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing an embodiment. Embodiment 1 FIG. 1 and 2 are external views showing the configuration of the instrument transformer according to the first embodiment of the present invention. This instrument transformer includes three parallel rod-shaped conductors 12 (primary conductors) to which respective phase currents of three-phase AC power are to flow, as shown in the front view of FIG. A doughnut-shaped silicon steel core 3 shown in FIG. 1 surrounding a conductor 12 through which a first phase current and a third phase current of the AC power are to flow, respectively.
a (core) and two instrument transformers 3 each including a secondary winding 3b wound in a toroidal shape around an iron core 3a.

This instrument transformer also has a permalloy core 4a (core) adjacent to the two instrument transformers 3 and surrounding the three rod-shaped conductors 12 in a track shape, and is wound toroidally around the iron core 4a. And a zero-phase current transformer 4 comprising a wound secondary winding 4b. The two transformers 3, the zero-phase current transformer 4, and the three rod-shaped conductors 12 are arranged in a side view in FIG. As shown in FIG.
a is integrally molded.

When an alternating current flows through the conductor 12, the instrument transformer 3 generates a secondary current in the secondary winding, and the generated secondary current is measured by an ammeter or the like (not shown) and used for measurement control. Used. The zero-phase current transformer 4 includes three rod-shaped conductors 12.
Any of the three power lines connected to
Unbalance occurs in the three-phase AC power flowing through the three conductors 12,
When the zero-phase current flows, a secondary current is generated in the secondary winding, and the generated secondary current is measured by an ammeter or the like (not shown) to operate the ground fault relay.

FIG. 3 is a vertical sectional side view of the closed switchboard showing the arrangement of the instrument transformer according to the present invention in the closed switchboard, and FIG. 4 is a vertical sectional back view thereof. In this closed switchboard, two circuit breakers 9 are respectively arranged at the upper part and the lower part near the front side in the closed switchboard, and three conductors 10 arranged in parallel from the back side of each circuit breaker 9 are provided. The (cable) exits from each breaker 9 and is connected to the conductor 12 of each instrument transformer 5 according to the present invention.

Two sets of three cables 11, each connected to each conductor 10 via their conductors 12 of each instrument transformer 5, pass through holes (not shown) provided at the bottom of the closed switchboard. It is laid outside. As described above, it is possible to reduce the number of members, reduce the number of work steps, shorten the work process, and simplify the mounting work. In addition, since the current transformer for the instrument is not provided in the lower portion of the switchboard near the rear surface, the switchboard Workability in the interior is improved.

Embodiment 2 FIG. FIGS. 1 and 5 are external views showing a configuration of an instrument transformer according to a second embodiment of the present invention. In this instrument transformer, each phase power line of three-phase AC power shown in the front view of FIG.
The doughnut-shaped silicon steel core 3a (see FIG. 1) that surrounds the three through-holes 13 arranged in parallel and the through-holes 13 through which the first-phase and third-phase power lines of the three-phase AC power should respectively pass. Core) and an iron core 3a and two instrument transformers 3 comprising a secondary winding 3b wound in a toroidal shape.

This instrument transformer is also adjacent to the two instrument transformers 3 and is wound in a toroidal form around a permalloy core 4a (core) surrounding the three through holes 13 in a track shape and the iron core 4a. -Phase current transformer 4 comprising secondary winding 4b
And two instrument transformers 3 and a zero-phase current transformer 4
As shown in the side view of FIG.
And are integrally molded.

When an AC current flows through the power line (cable) passing through the through-hole 13, the instrument transformer 3 generates a secondary current in the secondary winding, and the generated secondary current is not shown. It is measured by an ammeter and used for measurement control. In the zero-phase current transformer 4, when any one of the power lines passing through the three through-holes 13 is grounded, the three-phase AC power flowing through the three power lines becomes unbalanced, and the zero-phase current flows. , A secondary current is generated in the secondary winding, and the generated secondary current is measured by an ammeter or the like (not shown) to operate the ground fault relay.

The arrangement of the instrument transformer according to the present invention in the closed switchboard is the same as that shown in FIGS.
Description is omitted. However, the conductor 10 and the cable 11 are integral and penetrate through the through-hole 13 of the instrument transformer 5. As described above, it is possible to reduce the number of members, reduce the number of work steps, shorten the work process, and simplify the mounting work. In addition, since the current transformer for the instrument is not provided in the lower portion of the switchboard near the rear surface, the switchboard Workability in the interior is improved.

Embodiment 3 6 and 7 are external views showing the configuration of the instrument transformer according to the third embodiment of the present invention. This instrument transformer is composed of three parallel-connected three-wire single-phase AC power positive-phase, negative-phase, and neutral wires as shown in the front view of FIG. A donut-shaped silicon steel core 6a (core) shown in FIG. 6 surrounding the rod-shaped conductor 14 (primary conductor) and the conductors 14 to which the positive-phase line and the negative-phase line are to be connected, respectively, and the toroidal core 6a. And two instrument transformers 6 each having a secondary winding 6b wound in a spiral shape.

The instrument transformer also has a donut-shaped permalloy core 7a (core) adjacent to the two instrument transformers 6 and surrounding the three rod-shaped conductors 14, respectively, and a toroidal winding around the iron core 7a. And a zero-phase current transformer 7 composed of a secondary winding 7b provided with the two windings, two instrument transformers 6, three zero-phase current transformers 7, and three rod-shaped conductors 14 are connected to each other as shown in FIG. As shown in the side view, each end of the conductor 14 is molded integrally with an epoxy resin 14a except for the respective ends. The three secondary windings 7b are connected in series as shown in the circuit diagram of FIG.

In order to detect the zero-phase power of the three-phase AC power as in the first and second embodiments, it is necessary to consider the current values of the three phases and their phases. The zero-phase power of the three-wire single-phase AC power can be obtained by adding and subtracting current values flowing through the positive-phase line, the negative-phase line, and the neutral line. This addition / subtraction is performed by connecting the three secondary windings 7b in series or in parallel.

When an alternating current flows through the conductor 14, the instrument transformer 6 generates a secondary current in the secondary winding, and the generated secondary current is measured by an ammeter (not shown) or the like, and is used for measurement control. Used. The zero-phase current transformer 7 includes three rod-shaped conductors 14.
When one of the positive-phase line and the negative-phase line of the three power lines connected to each other is grounded and unbalance occurs in the single-phase AC power flowing through the three conductors 14, the zero-phase current is connected in series. The zero-phase current generated in the secondary winding is measured by an ammeter (not shown) or the like, and operates the ground fault relay.

FIG. 8 is a vertical sectional side view of the closed switchboard showing the arrangement of the instrument transformer according to the present invention in the closed switchboard, and FIG. 9 is a vertical rear view thereof. In this closed switchboard, two circuit breakers 9 are respectively arranged at the upper part and the lower part near the front side in the closed switchboard, and three conductors 10 arranged in parallel from the back side of each circuit breaker 9 are provided. The (cable) exits from each breaker 9 and is connected to the conductor 14 of each instrument transformer 8 according to the present invention.

Two sets of three cables 11 respectively connected to each conductor 10 via their conductors 14 of each instrument transformer 8 pass through holes (not shown) provided at the bottom of the closed switchboard. It is laid outside. As described above, it is possible to reduce the number of members, reduce the number of work steps, shorten the work process, and simplify the mounting work. In addition, since the current transformer for the instrument is not provided in the lower portion of the switchboard near the rear surface, the switchboard Workability in the interior is improved.

Embodiment 4 FIG. 6 and 10 are external views showing the configuration of the instrument transformer according to the fourth embodiment of the present invention. This instrument transformer has three parallel feedthroughs, through which the positive-phase line, the negative-phase line, and the neutral line of the three-wire single-phase AC power shown in the front view of FIG. Hole 15
And the through holes 15 through which the positive and negative phase lines should pass, respectively.
And two instrument transformers 6 each comprising a doughnut-shaped silicon steel core 6a (core) shown in FIG. 6 and a secondary winding 6b wound in a toroidal shape around the iron core 6a.

The instrument transformer also has a doughnut-shaped permalloy core 7a (core) and an iron core 7a adjacent to the two instrument transformers 6 and surrounding the three through holes 15 respectively.
And a zero-phase current transformer 7 composed of a secondary winding 7b wound in a toroidal shape, and two instrument transformers 6 and three zero-phase current transformers 7 are shown in a side view of FIG. As shown in the figure, the resin is molded integrally with the epoxy resin 15a. The three secondary windings 7b are connected in series as shown in the circuit diagram of FIG.

The instrument transformer 6 generates a secondary current in a secondary winding when an AC current flows through a power line passing through the through-hole 15, and the generated secondary current is measured by an ammeter (not shown) or the like. And used for measurement control. Zero-phase current transformer 7
When one of the positive phase line and the negative phase line of the three power lines penetrating each of the three through holes 15 is grounded and unbalance occurs in the single-phase AC power flowing through the three power lines, the zero-phase current is connected in series. The generated zero-phase current generated in the connected secondary winding is measured by an ammeter (not shown) or the like, and operates the ground fault relay.

The arrangement of the instrument transformer 8a according to the present invention in the closed switchboard is the same as that shown in FIGS. However, the conductor 10 and the cable 11 are integral and penetrate through the through hole 15 of the instrument transformer 8a. As described above, the number of parts,
The working process can be shortened and the mounting work can be simplified, and the current transformer for the instrument is not provided in the lower portion of the switchboard near the rear surface, so that the workability in the switchboard is improved.

Embodiment 5 FIG. 6 and 11 are external views showing the configuration of the instrument transformer according to the fifth embodiment of the present invention. This instrument transformer has three parallel-connected three-wire single-phase AC power positive-phase, negative-phase, and neutral wires as shown in the front view of FIG. A rod-shaped conductor 16 (primary conductor) and a core 6a (core) made of donut-shaped silicon steel shown in FIG. And two instrument transformers 6 each having a secondary winding 6b wound in a spiral shape.

The instrument transformer also has a donut-shaped permalloy core 7a (core) adjacent to the two instrument transformers 6 and surrounding the three rod-shaped conductors 16, and a toroidal winding around the core 7a. And a zero-phase current transformer 7 comprising a wound secondary winding 7b, two instrument transformers 6, three zero-phase current transformers 7, and three rod-shaped conductors 16 are connected to each other as shown in FIG.
As shown in the side view, the conductor 16 is integrally molded with an epoxy resin 16a except for each end. The three secondary windings 7b are connected in parallel as shown in the circuit diagram of FIG.

When an alternating current flows through the conductor 16, the instrument transformer 6 generates a secondary current in the secondary winding, and the generated secondary current is measured by an ammeter or the like (not shown) and used for measurement control. Used. The zero-phase current transformer 7 includes three rod-shaped conductors 16.
When one of the positive and negative phase lines of the three power lines connected to the power line is grounded and unbalance occurs in the single-phase AC power flowing through the three conductors 16, the zero-phase current is connected in series. The zero-phase current generated in the secondary winding is measured by an ammeter (not shown) or the like, and operates the ground fault relay.

The arrangement of the instrument transformer 8b according to the present invention in the closed switchboard is the same as that shown in FIGS. However, the conductor 10 is the same as the conductor 16. As described above, it is possible to reduce the number of members, reduce the number of work steps, shorten the work process, and simplify the mounting work. In addition, since the current transformer for the instrument is not provided in the lower portion of the switchboard near the rear surface, the switchboard is not required. Workability in the interior is improved.

Embodiment 6 FIG. 6 and 12 are external views showing the configuration of the instrument transformer according to the sixth embodiment of the present invention. This instrument transformer has three parallel feed-throughs, through which the positive-phase line, the negative-phase line, and the neutral line of the three-wire single-phase AC power should pass, respectively, as shown in the front view of FIG. Hole 17
And the through-holes 17 through which the normal phase line and the negative phase line should pass, respectively.
And two instrument transformers 6 each comprising a doughnut-shaped silicon steel core 6a (core) shown in FIG. 6 and a secondary winding 6b wound in a toroidal shape around the iron core 6a.

This instrument transformer also has a doughnut-shaped permalloy iron core 7a (core) and an iron core 7a adjacent to the two instrument transformers 6 and surrounding the three through holes 17 respectively.
And a zero-phase current transformer 7 composed of a secondary winding 7b wound in a toroidal shape. The two instrument transformers 6 and the three zero-phase current transformers 7 are shown in a side view of FIG. As shown in the figure, the resin is molded integrally with the epoxy resin 17a. The three secondary windings 7b are connected in parallel as shown in the circuit diagram of FIG.

The instrument transformer 6 generates a secondary current in the secondary winding when an AC current flows through a power line passing through the through hole 17, and the generated secondary current is measured by an ammeter (not shown) or the like. And used for measurement control. Zero-phase current transformer 7
When one of the positive and negative phase lines of the three power lines penetrating through the three through holes 17 is grounded and unbalance occurs in the single-phase AC power flowing through the three power lines, the zero-phase current is connected in series. The generated zero-phase current generated in the connected secondary winding is measured by an ammeter (not shown) or the like, and operates the ground fault relay.

The arrangement of the instrument transformer 8c according to the present invention in the closed switchboard is the same as that shown in FIGS. However, the conductor 10 and the cable 11 are integral and penetrate through the through-hole 17 of the instrument transformer 8c. As described above, the number of parts,
The working process can be shortened and the mounting work can be simplified, and the current transformer for the instrument is not provided in the lower portion of the switchboard near the rear surface, so that the workability in the switchboard is improved.

[0043]

According to the instrument transformer according to the first invention,
Since the instrument transformer and the zero-phase current transformer are integrally molded, the number of members is reduced, the number of work steps is reduced, the work process is shortened, the installation work is simplified, the workability in the switchboard is improved, and the switchboard is improved. The depth can be reduced.

According to the instrument transformer according to the second invention, each phase current of three-phase AC power is passed through three parallel rod-shaped conductors, and the core is wound around the core and the core, respectively. Two first-phase and third-phase currents of three-phase AC power flow through the two instrument transformers including the secondary windings. A zero-phase current transformer consisting of an iron core surrounding three rod-shaped conductors and a secondary winding wound on the iron core is adjacent to two instrumentation transformers, and two instrumentation transformers, a zero-phase current transformer And three rod-shaped conductors are molded integrally, leaving each end of the conductor. As a result, it is possible to reduce the number of members, reduce the number of work steps, shorten the work process, simplify the installation work, improve the workability in the switchboard, and reduce the depth of the switchboard.

According to the transformer for an instrument according to the third aspect of the present invention, the three through-holes in parallel are connected to the iron core and the secondary winding wound around the iron core, through which each phase power line of the three-phase AC power passes. The two instrument transformers respectively surround the through holes through which the first and third phase power lines of the three-phase AC power should pass. A zero-phase current transformer consisting of an iron core and a secondary winding wound on the iron core surrounds three through holes adjacent to two instrument transformers. The two instrument transformers and the zero-phase current transformer are integrally molded. As a result, it is possible to reduce the number of members, reduce the number of work steps, shorten the work process, simplify the installation work, improve the workability in the switchboard, and reduce the depth of the switchboard.

According to the meter transformer of the fourth invention, the three parallel bar-shaped conductors are connected to the positive-phase line, the negative-phase line, and the neutral line of the three-wire single-phase AC power, respectively. I have.
Two instrument transformers comprising an iron core and a secondary winding wound on the iron core surround the conductors to which the positive and negative phase lines are connected, respectively. Three zero-phase current transformers consisting of an iron core and a secondary winding wound on the iron core are adjacent to the two instrument transformers and surround the three rod-shaped conductors, respectively. The secondary windings of the three zero-phase current transformers are connected in series, and two instrument transformers, three zero-phase current transformers and three rod-shaped conductors are connected.
The conductors are integrally molded except for the respective ends. As a result, it is possible to reduce the number of members, reduce the number of work steps, shorten the work process, simplify the installation work, improve the workability in the switchboard, and reduce the depth of the switchboard.

According to the transformer for an instrument according to the fifth aspect of the invention, the three parallel through-holes are respectively passed by the positive-phase line, the negative-phase line, and the neutral line of the three-wire single-phase AC power. . Two instrument transformers, each of which includes an iron core and a secondary winding wound around the iron core, respectively surround the through holes through which the positive-phase line and the negative-phase line pass. Three zero-phase current transformers, each comprising an iron core surrounding the three through holes and a secondary winding wound on the iron core, are adjacent to the two instrument transformers and surround the three through holes, respectively. The secondary windings of the three zero-phase current transformers are connected in series, and the two instrument transformers and the three zero-phase current transformers are integrally molded. As a result, it is possible to reduce the number of members, reduce the number of work steps, shorten the work process, simplify the installation work, improve the workability in the switchboard, and reduce the depth of the switchboard.

According to the instrument transformer according to the sixth aspect of the invention, the three parallel bar-shaped conductors are connected to the positive-phase line, the negative-phase line, and the neutral line of the three-wire single-phase AC power, respectively. I have.
Two instrument transformers comprising an iron core and a secondary winding wound on the iron core surround the conductors to which the positive and negative phase lines are connected, respectively. Three zero-phase current transformers consisting of an iron core and a secondary winding wound on the iron core are adjacent to the two instrument transformers and surround the three rod-shaped conductors, respectively. The secondary windings of the three zero-phase current transformers are connected in parallel, two instrument transformers, three zero-phase current transformers and three rod-shaped conductors
Except for each end of the conductor, it is integrally molded. As a result, it is possible to reduce the number of members, reduce the number of work steps, shorten the work process, simplify the installation work, improve the workability in the switchboard, and reduce the depth of the switchboard.

According to the transformer for an instrument according to the seventh aspect of the invention, the three through holes arranged in parallel are passed by the positive-phase line, the negative-phase line, and the neutral line of the three-wire single-phase AC power, respectively. . Two instrument transformers consisting of an iron core and a secondary winding wound on the iron core have through holes through which the positive-phase line and the negative-phase line should pass, respectively.
Each is enclosed. Three zero-phase current transformers comprising an iron core and a secondary winding wound on the iron core are adjacent to the two instrument transformers and surround the three through holes, respectively. The secondary windings of the three zero-phase current transformers are connected in parallel, and the two instrument transformers and the three zero-phase current transformers are integrally molded.
As a result, it is possible to reduce the number of members, reduce the number of work steps, shorten the work process, simplify the installation work, improve the workability in the switchboard, and reduce the depth of the switchboard.

[Brief description of the drawings]

FIG. 1 is an external view showing a configuration of an embodiment of a meter transformer according to the present invention.

FIG. 2 is an external view showing a configuration of an embodiment of an instrument transformer according to the present invention.

FIG. 3 is a longitudinal sectional side view of the closed switchboard, showing the arrangement of the instrument transformer according to the present invention in the closed switchboard.

FIG. 4 is a longitudinal rear view of the closed switchboard, showing the arrangement of the instrument transformer according to the present invention in the closed switchboard;

FIG. 5 is an external view showing the configuration of an embodiment of the instrument transformer according to the present invention.

FIG. 6 is an external view showing a configuration of an embodiment of a meter transformer according to the present invention.

FIG. 7 is an external view showing a configuration of an embodiment of a meter transformer according to the present invention.

FIG. 8 is a longitudinal sectional side view of the closed switchboard, showing the arrangement of the instrument transformer according to the present invention in the closed switchboard.

FIG. 9 is a longitudinal rear view of the closed switchboard, showing the arrangement of the instrument transformer according to the present invention in the closed switchboard.

FIG. 10 is an external view showing a configuration of an embodiment of an instrument transformer according to the present invention.

FIG. 11 is an external view showing a configuration of an embodiment of an instrument transformer according to the present invention.

FIG. 12 is an external view showing a configuration of an embodiment of a meter transformer according to the present invention.

FIG. 13 is an external view showing a configuration example of a conventional transformer for an instrument having a primary conductor embedded therein.

FIG. 14 is an external view showing a configuration example of a conventional primary conductor penetrating type instrument transformer.

FIG. 15 is an external view showing a configuration example of a conventional zero-phase current transformer of a primary conductor penetration type.

FIG. 16 is a vertical sectional side view of a closed switchboard showing an arrangement of a conventional instrument transformer and a zero-phase current transformer in the closed switchboard.

FIG. 17 is a vertical rear view of the closed switchboard, showing the arrangement of a conventional instrument transformer and a zero-phase current transformer in the closed switchboard.

[Explanation of symbols]

3,6 Instrument transformer, 3a, 4a, 6a, 7a Iron core (core), 3b, 4b, 6b, 7b Secondary winding, 4,7
Zero-phase current transformer, 5, 8, 8a Instrument transformer, 10 conductors (cable), 12, 14, 16 conductors (primary conductor), 12a, 13a, 14a, 15a, 16a Epoxy resin, 13, 15 through hole .

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Claims (7)

[Claims] 1. An instrument transformer comprising an instrument transformer and a zero-phase current transformer, wherein the instrument transformer and the zero-phase current transformer are integrally molded. 2. Three parallel rod-shaped conductors through which respective phase currents of the three-phase AC power are to flow, respectively, and the first and third phase currents of the three-phase AC power to be flowed, respectively. Two instrument transformers each consisting of an iron core surrounding a conductor and a secondary winding wound on the iron core, and an iron core and an iron core adjacent to the two meter transformers and surrounding the three rod-shaped conductors. A zero-phase current transformer consisting of a wound secondary winding, the two instrument transformers, the zero-phase current transformer, and the three rod-shaped conductors, excluding the respective ends of the conductors. An instrument transformer characterized by being integrally molded. 3. Three parallel through holes through which each phase power line of three-phase AC power should pass, respectively, and said through holes through which first and third phase power lines of said three-phase AC power respectively pass. Two instrument transformers each comprising a core surrounding the hole and a secondary winding wound around the core; and a core and the core adjacent to the two instrument transformers and surrounding the three through holes. A transformer for an instrument, comprising: a zero-phase current transformer comprising a wound secondary winding, wherein the two transformers for an instrument and the zero-phase current transformer are integrally molded. 4. Three parallel bar-shaped conductors to which a positive-phase line, a negative-phase line, and a neutral line of a three-wire single-phase AC power are to be connected, respectively, and the positive-phase line and the negative-phase line are Two instrument transformers each comprising an iron core surrounding each of the conductors to be connected and a secondary winding wound on the iron core; and the three rod-shaped conductors adjacent to the two instrument transformers. 3 comprising an iron core surrounding each and a secondary winding wound on the iron core
Two zero-phase current transformers, the secondary windings are connected in series,
The transformer for an instrument, wherein the two transformers for an instrument, the three zero-phase current transformers, and the three rod-shaped conductors are integrally molded except for respective ends of the conductors. . 5. Three parallel through-holes through which a positive-phase line, a negative-phase line, and a neutral line of a three-wire single-phase AC power should pass, respectively, and the positive-phase line and the negative-phase line penetrate respectively. Two instrument transformers each comprising an iron core surrounding the through hole to be formed and a secondary winding wound around the iron core, and adjoining the two instrument transformers and surrounding the three through holes, respectively. An iron core and three zero-phase current transformers each having a secondary winding wound on the iron core, wherein the secondary windings are connected in series, and the two instrument transformers and the three zero-phase transformers are connected. A transformer for an instrument, wherein a flow device is integrally molded. 6. Three parallel bar-shaped conductors to which a positive-phase line, a negative-phase line, and a neutral line of a three-wire single-phase AC power are to be connected, respectively, and the positive-phase line and the negative-phase line are Two instrument transformers each comprising an iron core surrounding each of the conductors to be connected and a secondary winding wound on the iron core; and the three rod-shaped conductors adjacent to the two instrument transformers. 3 comprising an iron core surrounding each and a secondary winding wound on the iron core
Two zero-phase current transformers, the secondary windings are connected in parallel,
The transformer for an instrument, wherein the two transformers for an instrument, the three zero-phase current transformers, and the three rod-shaped conductors are integrally molded except for respective ends of the conductors. . 7. Three parallel through-holes through which a positive-phase line, a negative-phase line, and a neutral line of a three-wire single-phase AC power should pass, respectively, and the positive-phase line and the negative-phase line penetrate respectively. Two instrument transformers each comprising an iron core surrounding the through hole to be formed and a secondary winding wound around the iron core, and adjoining the two instrument transformers and surrounding the three through holes, respectively. A three-phase current transformer comprising an iron core and a secondary winding wound on the iron core, wherein the secondary windings are connected in parallel, and the two instrument transformers and the three zero-phase transformers are connected. A transformer for an instrument, wherein a flow device is integrally molded.