JPS6161691B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an on-load tap changer for a transformer, and more particularly to the arrangement of a sheath break and a current limiting resistor, and the connection structure thereof.

FIGS. 1 and 2 are wiring diagrams of a three-phase triangular connection on-load tap-change transformer, respectively. 1 is the main winding, 2 is the tap winding, 3 is the tap changer on load,
A, B, and C indicate line terminals, and U, V, and W indicate each of the three phases.

In the transformer shown in FIG. 1, tap windings 2 are provided at ends of the main winding 1 in the same direction for each phase.
The on-load tap changer in this type of transformer is
In order to ensure interphase insulation, three sets of single-phase load tap changers 4 are used, as shown in FIG. 3.

Further, in the transformer shown in FIG. 2, tap windings 2U and 2V for two of the three phases are connected adjacently. (In this specification, for convenience, the U-phase and V-phase tap windings are described as being adjacent to each other, but the invention is not limited to this. (The same is true for any connection.) The on-load tap changer in this type of transformer can reduce the insulation between the adjacent U-phase and V-phase on-load tap changers, as shown in Figure 4. A two-phase load tap changer 5 for the , U, and V phases combined into one set and a single-phase load tap changer 4 for the W phase constitute three phases, or as shown in FIG. In this way, it is possible to configure a three-phase load tap changer 6 in which three phases are combined into one set. This type of on-load tap changer therefore saves space compared to that of FIG.

In addition, in FIGS. 3 to 5, 7 is the switching switch of the on-load tap changer, 8 is also the tap selector, 9U, 9V, 9W are the folded parts in the switching switch 7, 10U, Similarly, 10V and 10W are current limiting resistors, and 11 is a transformer tank.

By the way, the switching switch of the on-load tap changer is a cylindrical container that is independent of the transformer tank, and two insulating supports each having an arcuate cross section are placed facing each other to form a vertically divided insulating tube. The sheath section and the current limiting resistor are mounted on the inside of this insulating support.For ease of assembly or maintenance, the sheath section and current limiting resistor of the same phase are mounted on the same insulating support. It is ready to be installed.

For this reason, in conventional on-load tap changers, as shown in Figures 3 to 5, the cross section and current limiting resistor in the same phase are arranged vertically, resulting in a long length of the changeover switch. This is one of the factors that prevents the on-load tap changer from becoming more compact.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to provide a load tap changer that is compact and easy to assemble and maintain.

In order to achieve this object, the present invention provides an on-load tap changer with at least one phase's cross section and current limiting resistor, each mounted on a different insulating support and disposed in the same plane. A fixed conductor fixed to an insulating support on the front current limiting resistor side and a fixed conductor fixed to an insulating support on the front current limiting resistor side are used to connect the conductor between this shingle break and the current limiting resistor. and a crossover conductor having spring properties that connects these fixed conductors, and is characterized in that the crossover conductor can be attached to and detached from the fixed conductor via its spring properties.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 6 to 9.

This embodiment is a three-phase one-set on-load tap changer used in a three-phase triangular connection transformer as shown in FIG. This on-load tap changer 12 is the sixth tap changer 12.
As shown in the figure, a tap selector 8 having an intermittent feed mechanism 15 at the top is provided below a switching switch 7 having a quick-cutting mechanism 13 at the top via a connecting portion 14. Note that 11 is a transformer tank.

The switching switch 7 includes an oil container 19 consisting of a mechanical box 16, an insulating cylinder 17, and a bottom plate 18.
9 accommodates three phase shields and current limiting resistors. Its arrangement is as follows.

The two-phase tap windings 9U and 9V corresponding to the adjacent two-phase tap windings (see Figure 2) are located in the container 1.
The current limiting resistors 10U and 10V for two phases corresponding to the current limiting resistors 10U and 10V for two phases are arranged in the same plane immediately above the portion of the terminal 9 closest to the bottom plate 18. In addition, the other 1 phase portion 9W
The current limiting resistor 10W and the current limiting resistor 10W are arranged in the same plane above the two phases with an appropriate insulation interval. An appropriate insulation interval is maintained between the one-phase sheath cut portion 9W and the current limiting resistor 10W with respect to the quick cutting mechanism 13 as well.

Inside the container 19, a pair of insulating supports 20A and 20B made of insulating pieces having an arcuate cross section are installed so as to constitute a vertically divided insulating tube, and a U-phase insulating support 20A is provided inside the one insulating support 20A. The fixed contact side and current limiting resistor 10U of the bow break section 9U and the fixed contact side of the W phase bow break section 9W are attached, and the V phase bow break section is attached to the inside of the other insulating support 20B. A fixed contact side of section 9V, a current limiting resistor 10V, and a W phase current limiting resistor 10W are attached. Further, the movable contact side of each sheath section 9U, 9V, 9W is attached to an insulated operating shaft 21 extending downward from the quick cutting mechanism 13 through the center of the container 19.

The tap selector 8 stores three phases of contacts in one insulating cylinder, and its arrangement is as follows:
This is the same as the conventional example shown in the figure. In other words, the U phase and V phase corresponding to the tap windings for two adjacent phases (see Figure 2)
The phase contacts are arranged at the top, and the W-phase contacts corresponding to the tap windings for the other one phase are arranged below with an appropriate insulation distance from the two phases.

The connection state of each phase is shown in FIG. In this figure, 7 is a switching switch, 8 is a tap selector, 9 is a bridge section, 9A is a fixed contact, 9B is a movable contact, and 10 is a current limiting resistor.

Since the U-phase sheath section 9U and the current limiting resistor 10U are attached to the same insulating support 20A, the connection between them is made by connecting the conductor 22 to the outer wall surface of the insulating support 20A, as shown in FIG. This can be done by following the . The same applies to the V phase. However, since the W-phase edge section 9W and the current-limiting resistor 10W are attached to different insulating supports 20A and 20B, the conductor connecting them is connected to the boundary between the two insulating supports 20A and 20B. You need to straddle it. For this reason, when assembling, each part is attached to two
There is an inconvenience that the conductor must be wired after the two insulating supports 20A and 20B are assembled into a cylindrical shape, and there is also an inconvenience that the conductor cannot be disassembled without first removing the conductor during maintenance. In consideration of this point, this embodiment has a configuration as shown in FIG. 9.

That is, different insulating supports 20A, 20
The conductor connecting the W-phase sheath section 9W and the current limiting resistor 10W attached to B and arranged on the same plane is a fixed conductor 23A solidified on the insulating support 20A on the side of the sheath section 9W. , a fixed conductor 23B fixed to the insulating support 20B on the current limiting resistor 10W side;
It consists of a crossover conductor 24 that connects these fixed conductors 23A and 23B. Fixed conductor 23A, 2
3B is provided with terminal fittings 25A, 25B facing each other at the edge portions of the insulating supports 20A, 20B, respectively. The crossover conductor 24 has a spring 26 and a contact 2
7, and a spring 26 is inserted between the terminal fittings 25A and 25B in a compressed state. That is, the crossover conductor 24 is held between the terminal fittings 25A and 25B by the repulsive force of the spring 26, and electrically connects the fixed conductors 23A and 23B.
The connecting conductor 24 can be easily attached and detached between the terminal fittings 25A and 25B by strongly compressing the spring 26.

In the above example, in the on-load tap changer of 3-phase, 1-set type, only the cutout and current limiting resistor for one phase were arranged on the same plane, but it is also possible to arrange them in the same way for all 3 phases. can. Further, the present invention is applicable not only to a three-phase, one-set type on-load tap changer, but also to a two-phase, one-set type or single-phase on-load tap changer.

As explained above, according to the present invention, the shield and current limiting resistor for at least one phase are arranged in the same plane, so the length of the switching switch is shortened and the load The time tap changer can be downsized. In addition, the conductor connecting the shingle section and the current limiting resistor that are placed on the same plane is a fixed conductor fixed to the insulating support on the shingle section side and a fixed conductor fixed to the insulating support on the current limiting resistor side. It consists of a fixed conductor and a springy crossover conductor that connects these fixed conductors, and the springy nature of the crossover conductor makes it removable, making it easy to assemble and disassemble for maintenance. be able to.

[Brief explanation of the drawing]

Figures 1 and 2 are wiring diagrams of a three-phase triangular connection on-load tap-changer transformer, respectively; Figure 3 is a schematic diagram of a conventional on-load tap-changer used in the transformer shown in Figure 1; 4 and 5 are schematic configuration diagrams of conventional on-load tap changers used in the transformer shown in FIG. 2, respectively, and FIG. 6 is a partially cutaway view of the on-load tap changer according to an embodiment of the present invention. 7 is a wiring diagram of the on-load tap changer, and FIGS. 8 and 9 are enlarged perspective views of essential parts of the on-load tap changer of FIG. 6, respectively. 9U, 9V, 9W...Shiya section, 10U, 10
V, 10W... Current limiting resistor, 12... On-load tap changer, 19... Container, 20A, 20B... Insulating support, 23A, 23B... Fixed conductor, 24...
...crossing conductor.

Claims (1)

[Claims] 1. An insulating support is provided in a container, and a sheath section and a current limiting resistor are attached to this insulating support, and each of the insulating supports is attached to a different insulating support and arranged in the same plane. The conductor that connects the shield section and the current limiting resistor for at least one phase is a fixed conductor fixed to an insulating support on the side of the shield section. , a fixed conductor fixed to the insulating support on the current limiting resistor side, and a crossover conductor having spring properties that connects these fixed conductors, and this crossover conductor connects the fixed conductor with the spring properties. An on-load tap changer characterized by being detachable. 2. The on-load tap changer according to claim 1, wherein the insulating support body is comprised of an insulating piece having an arcuate cross section and forming a vertically divided insulating tube.