JP4148695B2 - Instrument transformer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a molded instrument transformer in which a primary winding and a secondary winding are covered with an insulating resin and an iron core is mounted.
[0002]
[Prior art]
An instrument transformer is a generic term for a current transformer (hereinafter referred to as CT), an instrument transformer (hereinafter referred to as VT), and an instrument transformer (Voltage Current Transformer hereinafter referred to as VCT). Is.
An instrument transformer connects a primary winding to the bus of a high-voltage, high-current power receiving facility, and outputs a low voltage and low current according to the transformation ratio from the secondary winding to operate relays and watt hour meters. Let
[0003]
In particular, an instrument transformer for power supply and demand is used in combination with a watt hour meter, a reactive power meter, or a maximum demand watt meter, and constitutes a part of a measuring device related to an electricity bill transaction.
In order to collect the correct electricity bill, an electromagnetic instrument transformer (for example, electromagnetic VT and CT) having an excellent transformation ratio characteristic that causes negligible errors is adopted as the instrument transformer. .
[0004]
Next, VCT will be described as an example of the prior art of such an instrument transformer with reference to the drawings. 4 is an external view of the CT / VT, FIG. 5 is an electrical connection diagram of the VCT, FIG. 6 is an external view showing the external shape of the VCT, and FIG. 7 is an explanatory diagram for explaining the storage arrangement of the VCT in the power receiving facility. FIG. 8 is an explanatory diagram for explaining the wiring inside the VCT.
For example, the VCT is installed in a power receiving facility of a 6.6 kV three-phase three-wire high-voltage consumer. This VCT is configured by integrally storing a VT and a CT assembled in a frame in an outer box.
[0005]
Each VT and CT has an appearance as shown in FIGS. 8A, 8B, and 8C, for example. As shown in FIG. 8A, the CT 300 includes a transformer main body 100 and an iron core 200.
As shown in FIGS. 4A and 4B, the transformer main body 100 has a cylindrical primary winding and a secondary winding arranged concentrically, and a primary terminal 110 which is each terminal of the primary and secondary windings. The secondary terminal 120 is provided and integrally covered with the insulating resin coating portion 130.
The insulating resin coating portion 130 is formed by curing an epoxy resin that is a solid insulation that has excellent physical characteristics such as electrical insulation performance and load bearing performance, stable chemical characteristics, and is easy to manufacture and handle. is there.
The CT is configured by inserting an iron core 200 (see FIGS. 8A, 8 </ b> B, and 8 </ b> C) through an iron core insertion window 140.
[0006]
These VT / CTs are connected as shown in FIG. 5 to complete an instrument transformer as shown in FIG.
In the connection diagram of FIG. 5, VT is connected in parallel between the U-phase and V-phase and V-phase and W-phase of the primary winding at both ends of the primary winding, and CT is the primary winding. Both ends are connected in series in two phases to the U-phase and W-phase on the bus side.
[0007]
The connection lead from the VT primary winding is connected to the primary cable connected to the CT primary winding and connected inside the outer box, and arranged on both sides of the outer box 1100 as shown in FIG. The primary cable extending from the bushing 1200 is connected to the bus at the power source side and the load side.
On the other hand, a secondary side connection terminal 1300 in which terminals are arranged by drawing lead wires from the secondary windings of VT and CT is provided, and low voltage and low current transformed from the bus side are supplied via the secondary side connection terminal 1300. , Electricity meter, reactive energy meter, maximum demand electricity meter, etc.
[0008]
By the way, the above-described VCT 1000 can be used within the VCT 1000 when the VCT 1000 is housed in a power receiving facility such as a cubicle in either the suspended arrangement shown in FIG. 7A or the stationary arrangement shown in FIG. 7B. Due to the direct connection of the primary winding to the bus via the primary cable and the size and shape restrictions, a two-phase CT is placed in the upper stage and a two-phase VT is placed in the lower stage in the outer box. It must be configured to be integrated.
When such a configuration is adopted, the wiring has been devised.
[0009]
This wiring will be described.
As shown in FIGS. 8A to 8C, the connection lead wire 500 is drawn from the primary winding of the VT (not shown) on the lower side and wired. In order to avoid a ground potential portion such as the iron core 200 of the transformer 300 or an outer box (not shown), the transformer 300 is fixedly held and led through a fixture called a lead spacer 400 and connected to the primary cable.
[0010]
The lead spacer 400 is disposed at a position sandwiched between two CTs 300, as is apparent from FIGS. 8A, 8B, and 8C, and a hole portion through which the lead spacer 400 penetrates. The connection lead wire 500 for VT connection is inserted into the cable.
[0011]
[Problems to be solved by the invention]
The lead spacer 400 used in the prior art is required to have a load-carrying performance capable of withstanding a bolt tightening force and a compressive force in addition to an electrical insulation performance. Bakelite, phenol resin, urea resin, melamine resin, Since the materials are limited, it is an expensive part.
[0012]
In addition, in order to lock the lead spacer 400 itself that holds the lead wire 500 for connecting the VT, a mounting frame processing is separately performed on the insulating resin coating portion 130 of the CT 300, which causes a high cost.
Furthermore, the presence of the lead spacer 400 is combined with the formation of a dead space by the insulating resin coating portion 130 which is necessarily formed in a substantially cylindrical shape from the cylindrical primary winding and the secondary winding of VT and CT. As a result, the mutual distance between each CT and VT was increased more than necessary, and the outer box was also large.
[0013]
Accordingly, an object of the present invention is to provide a small and low-cost VCT while eliminating the need for expensive parts such as lead spacers or processing for mounting, and easily performing electrical connection inside the outer box, and thus, high-pressure consumers such as cubicles. An object of the present invention is to provide an instrument transformer that can reduce the installation area of power receiving equipment.
[0014]
[Means for Solving the Problems]
In order to solve the above problem, the invention according to claim 1
Two pairs of current transformers are paired on the upper stage, and a plurality of instrument transformers are placed on the lower stage. A transformer for current transformer that is fixedly held in a state where a connecting lead wire drawn from the primary winding of the instrument transformer is inserted between the current transformers,
The current transformer is
An insulating resin coating that covers the primary winding and the secondary winding, and in which a primary terminal, a secondary terminal, and an iron core insertion window are formed;
A bonding protrusion provided on the insulating resin coating and having a bonding surface;
A plurality of linear grooves provided substantially in parallel on the joint surface of the joint projection;
An iron core that penetrates the iron core insertion window;
It is equipped with
The connecting lead wires are inserted into the holes formed by the linear grooves on both sides, with the connecting surfaces of the connecting projections of the two current transformers forming a pair in contact with each other.
[0015]
The invention according to claim 2
The instrument transformer according to claim 1,
Two phases of current transformers are arranged in the upper stage, and two phases of instrument transformers are arranged in the lower stage .
[0016]
The invention described in claim 3
The instrument transformer according to claim 1 or 2,
The linear groove is characterized Rukoto provided in a direction which is substantially parallel or substantially perpendicular to the extending direction of the primary pin or secondary pin.
[0017]
The invention according to claim 4
In the instrument transformer as described in any one of Claims 1-3 ,
The linear groove is semicircular cross-section, sectional △ form or, wherein any der Rukoto sectional □ form.
[0018]
The invention according to claim 5
In the instrument transformer as described in any one of Claims 1-4 ,
The insulating resin coating portion is a coating portion formed by curing an epoxy resin .
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of an instrument transformer according to the present embodiment, and FIG. 2 is a configuration diagram of a transformer main body.
Specifically, this instrument transformer is used in the VCT disposed in the power receiving facility of the 6.6 kV three-phase three-wire high-voltage consumer described above with reference to FIGS. A connecting lead wire drawn from the primary winding of the VT is inserted and fixedly held in a side-side space formed by arranging two phases of CT.
[0020]
In this case, as shown in FIGS. 1 (a) and 1 (b), the two-phase CT is provided with a pair of instrument transformers 30 including a transformer body 10 and an iron core 20, and this pair of instrument transformers. A connecting lead 40 is arranged between the containers 30.
As shown in FIG. 2, the transformer main body 10 includes an insulating resin coating portion 1, a joining protrusion 2, a primary terminal 3, a secondary terminal 4, an iron core insertion window 5, a linear groove portion 6, and a joining surface 7. ing.
[0021]
The insulating resin coating portion 1 is formed by coating an insulating resin typified by an epoxy resin in a state where a primary winding and a secondary winding (not shown) are overlapped, and the insulating resin coating portion 1 is cured. The primary terminal 3, the secondary terminal 4, and the iron core insertion window 5 are integrally formed.
[0022]
The bonding projection 2 protrudes from the insulating resin coating 1 and is integrally formed, but has at least a height that allows the linear groove 6 to be formed.
Since the epoxy resin that is integrally coated on the winding to form a solid insulator has an electrical insulation performance superior to that of the lead spacer and a load resistance performance that can withstand the bolt tightening force, A slight height may be formed, and the dead space generated between the pair of instrument transformers 10 shown in FIG. 1B is reduced.
[0023]
The primary terminal 3 is a terminal electrically connected to a primary winding (not shown), and is formed in a state protruding from the insulating resin coating portion 1.
The secondary terminal 4 is a terminal electrically connected to a secondary winding (not shown), and is formed in a state of protruding from the insulating resin coating portion 1.
[0024]
The iron core insertion window 5 is a hole through which the iron core 20 (see FIGS. 1A and 1B) passes.
The straight groove portion 6 has a substantially semicircular cross section so that the covering portion of the connecting lead wire 40 (see FIGS. 1A and 1B) can be brought into contact therewith. It is formed on the joint surface 7 which is a side surface. A plurality of (four in FIG. 1 and FIG. 2) linear groove portions 6 are formed on the surface of the joint surface 7 and are provided so as to be substantially parallel to each other.
[0025]
As is apparent from FIGS. 1 and 2, the straight groove portion 6 is provided in a direction substantially parallel to the extending direction of the primary terminal 3 and in a direction substantially perpendicular to the extending direction of the secondary terminal 4. ing. This is because the cables connected to the primary terminal 3 and the secondary terminal 4 are also wired so as to extend in the extending direction.
As a result, the connecting lead wire 40 and the cable connected to the primary terminal 3 are wired substantially in parallel, and the connecting lead wire 40 and the cable connected to the secondary terminal 4 are wired substantially vertically. There is an advantage that the wiring is arranged as a whole.
[0026]
The joint surface 7 is a surface that comes into contact with another transformer body 10 and is joined here to make a pair.
As is apparent from FIGS. 1 and 2, the bonding surface 7 is provided in a direction parallel to the extending direction of the primary terminal 3 and the extending direction of the secondary terminal 4.
Thereby, consideration is given so that the connecting lead wire 40 does not intersect the cable extending in the extending direction of the primary terminal 3 and the cable extending in the extending direction of the secondary terminal 4.
[0027]
Subsequently, the arrangement in the VCT arranged in the power receiving facility of the 6.6 kV three-phase three-wire high-voltage consumer will be described.
Although not shown in the figure, a cylindrical primary winding and a secondary winding are arranged concentrically, covered with an insulating resin such as an epoxy resin, and equipped with an iron core (for instruments of FIGS. 8A, 8B, and 8C) The same shape as the transformer 300) is arranged in the lower stage.
In the VT, both ends of the primary winding are connected in parallel in two phases between the U phase-V phase and the V phase-W phase on the bus side.
[0028]
Connection lead wires 40 are connected to connect both ends of the primary winding of each VT in parallel to the U-phase and V-phase primary cables and the V-phase and W-phase primary cables.
On the other hand, when the side surfaces of two CTs (see the instrument transformer 30 in FIGS. 1A and 1B) are brought into contact with each other, a hole is formed by the linear groove 6 having a substantially semicircular cross section on both sides. The
The connecting lead wire 40 drawn from the VT primary winding is inserted and fixed in this hole. And each CT that is arranged in two phases in the upper stage is connected to the U-phase and W-phase primary cables so that they are connected in series from the K terminal of the primary winding to the power supply side bus and from the L terminal to the load side bus. (See FIG. 5).
[0029]
The V-phase primary side cable is inserted from the power source side bus to the load side bus through the bushing through the bushing. The U-phase, V-phase, and W-phase primary cables extend to the outside so as to be connected to the busbar side via bushings arranged in the outer box on the power supply side and the load side (see FIG. 6).
[0030]
The present embodiment has been described above.
The straight groove portion 6 is not limited to a semicircular cross section, and may have a cross-section Δ shape, a cross-section □ shape, or an arbitrary shape. The joining projection 2 and the straight groove portion 6 are also cast from resin such as CT. It can be easily formed by simply replacing a part of the mold.
[0031]
Furthermore, the linear groove portion 6 of the joint surface 7 is not limited to use at the time of electrical connection by the VCT connection lead wire 40 accommodated in the outer box as described above, but for mechanical structure, for example, Press a metal rod, bolt, etc. against the recess to install and fix the instrument transformer alone, or simply lock the rope etc. to the recess and use it for transporting and transporting the instrument transformer alone, etc. May be.
[0032]
In this embodiment, by using the epoxy resin to form the insulating resin coating portion 1 having the bonding projection 2, only a fixing frame (not shown) such as CT can be used for CT alone including VT. Thus, it is possible to reduce the size while inserting and fixing and holding the connecting lead wire 40, and it is possible to reduce expensive parts such as lead spacers and mounting processing.
[0033]
Next, a second embodiment of the present invention will be described with reference to the drawings.
FIG. 3 is a configuration diagram of the transformer main body of the instrument transformer according to the present embodiment.
Transformer body 10 'of this embodiment is the same as that of 1st embodiment except linear groove part 6', The description which overlaps is abbreviate | omitted.
[0034]
The linear groove 6 ′ is formed to be perpendicular to the direction of the linear groove 6 of the first embodiment described with reference to FIG. In this case, as shown in FIG. 3, it is only necessary to project the joining protrusion 2 only as much as necessary, and when the pair of left and right formers 10 ′ are joined, the first embodiment is a dead space. A hole for inserting the connection cable is formed at the position, and the dead space can be reduced.
[0035]
The linear groove 6 ′ is not limited to the cross-section Δ shape, and may be a semicircular cross section, a square □ shape, or an arbitrary shape. The joining projection 2 and the linear groove 6 ′ are also made of resin such as CT. It can be easily formed by simply replacing a part of the casting mold.
Furthermore, the straight groove portion 6 ′ of the joint surface 7 is also used for mechanical structure, for example, by pressing a metal rod, bolt, etc. against the recessed portion to install and fix the instrument transformer alone, or simply use a rope or the like. You may latch to a hollow part and you may use for transportation transportation of the instrument transformer single-piece | unit.
[0036]
【The invention's effect】
According to the present invention, the insulating resin coating portion formed in a substantially cylindrical shape reduces the dead space formed when closely arranged, eliminates expensive parts such as lead spacers or processing for mounting, and easily inside the outer box Thus, it is possible to provide an instrument transformer that provides a small and low-cost VCT while performing electrical connection, and consequently reduces the laying area of a high-voltage consumer power receiving facility such as a cubicle.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an instrument transformer according to a first embodiment of the present invention.
FIG. 2 is a configuration diagram of a transformer main body.
FIG. 3 is a configuration diagram of a transformer main body of the instrument transformer according to the second embodiment of the present invention.
FIG. 4 is an external view of a CT / VT.
FIG. 5 is an electrical connection diagram of a VCT.
FIG. 6 is an external view showing an external shape of a VCT.
FIG. 7 is an explanatory diagram for explaining a storage arrangement of a VCT in a power receiving facility.
FIG. 8 is an explanatory diagram illustrating wiring inside a VCT.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Insulation resin coating | cover part 2 Joining projection part 3 Primary terminal 4 Secondary terminal 5 Iron core insertion window 6, 6 'Straight groove part 7 Joint surface 10, 10' Transformer main body 20 Iron core 30 Instrument transformer 40 Connection lead wire

Claims (5)

Two pairs of current transformers are paired on the upper stage, and a plurality of instrument transformers are placed on the lower stage. A transformer for current transformer that is fixedly held in a state where a connecting lead wire drawn from the primary winding of the instrument transformer is inserted between the current transformers,
The current transformer is
An insulating resin coating that covers the primary winding and the secondary winding, and in which a primary terminal, a secondary terminal, and an iron core insertion window are formed;
A bonding protrusion provided on the insulating resin coating and having a bonding surface;
A plurality of linear grooves provided substantially in parallel on the joint surface of the joint projection;
An iron core that penetrates the iron core insertion window;
It is equipped with
An instrument transformer characterized in that a connecting lead wire is inserted into a hole formed by a linear groove on both sides, with the joining surfaces of joining projections of two current transformers forming a pair in contact with each other . The instrument transformer according to claim 1,
A transformer for an instrument, wherein two phases of current transformers are arranged in the upper stage and two phases of instrument transformers are arranged in the lower stage . The instrument transformer according to claim 1 or 2,
The linear groove portions, instrument transformer, characterized in Rukoto provided in a direction which is substantially parallel or substantially perpendicular to the extending direction of the primary pin or secondary pin. In the instrument transformer as described in any one of Claims 1-3 ,
The linear groove is semicircular cross-section, sectional △ form or, instrument transformer, wherein either Der Rukoto sectional □ form. In the instrument transformer as described in any one of Claims 1-4 ,
The transformer for an instrument, wherein the insulating resin coating portion is a coating portion formed by curing an epoxy resin .

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