JPS6046527B2 - On-load tap changer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an on-load tap changer used in a three-phase triangular connection transformer, and particularly to a structure in which three phases are combined into one set of switching switch and tap selector.

1 and 2 are wiring diagrams of a three-phase triangular connection on-load tap-changing transformer, respectively.

1 is a main winding, 2 is a tap winding, 3 is a load tap changer, A, B, and C are line terminals, and U, ■, and W are 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.

Therefore, it is necessary to use three sets of single-phase on-load tap changers 4, as shown in Fig. 3, in order to ensure insulation between each phase of the on-load tap changer in this type of transformer. , it has the disadvantage of taking up space. In addition, in FIG. 3, 5 is a switching switch of the single-phase load tap changer 4;
Reference numeral 6 is a sheath section therein, reference numeral 7 is a tap selector thereof, and reference numeral 8 is a transformer tank. Further, in the transformer shown in FIG. 2, the tap windings 2U and 2V for two of the three phases are connected adjacently.

In the specification, for convenience, the tap windings of the U phase and the
Phase or W (The same is true even if the tap windings of the 5U phase are connected next to each other.) The on-load tap changer in this type of transformer is the on-load tap changer of the adjacent U phase and ■ phase. As shown in Fig. 4, it is possible to reduce the insulation between the on-load tap changer 1 9 for two phases and the single-phase on-load tap changer 4 for the other 1 phase, as shown in Figure 4. Phase components can be constructed. This type of on-load tap changer therefore saves considerable space compared to that of FIG. However, even then, the tap of the three-phase star-connected transformer is cut off when the load is applied. Compared to a transformer that combines three phases into a set, it still requires a large space, the transformer tank that houses it is large, and the drive mechanism is also complicated. SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide an on-load tap changer for a three-phase triangular connection transformer that is compact by combining three phases into one set.

In order to achieve this object, the present invention provides an on-load tap changer applied to a three-phase triangular connection transformer in which tap windings for two of the three phases are connected adjacently. The switching switch is equipped with a switching mechanism, and has an intermittent feed mechanism at the bottom and an intermittent feed mechanism at the upper part, and has a switch for three phases stored in one container. A tap selector containing a fixed contact and a movable contact is installed, and a 2-phase shear portion and a current-limiting resistor corresponding to the 2-phase tap windings of the switching switch are installed. The current limiting resistor and each current limiting resistor are placed close to each other in the vertical direction on the same plane, and the current limiting resistor and current limiting resistor for one phase are placed close to each other in the vertical direction. They are arranged on the same plane with a suitable insulation interval maintained in the vertical direction, and each of the shear cutting parts is driven collectively by an insulated operating shaft connected to the quick cutting mechanism. It is characterized by what it did.

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 5 to 7.

This on-load tap changer 10 has a quick-cut mechanism 1 at the top.
A tap selector 15 with an intermittent feed mechanism 14 on the upper part is connected below the switching switch 12 with a connecting piece 13.
This is what was installed.

The switching switch 12 includes a mechanism box 16, an insulating tube 17, and a bottom plate 18.
The oil tank 19 is provided with an oil tank 19, and a three-phase shield and a current limiting resistor are housed in the oil tank 19. Its arrangement is as follows. The two-phase sheath cut portions 20U and 20■ corresponding to the adjacent two-phase tap windings (see Figure 2) are as follows:
It is arranged in the same plane at the part of the oil tank 19 closest to the bottom plate 18, and immediately above it, the corresponding two-phase current limiting resistors 21U and 21■ are also arranged in the same plane.

In addition, the other one-phase shield section 20W and current-limiting resistor 21
W is arranged in the same plane above the two phases with an appropriate insulation interval maintained. This 1-phase sheath section 20W and current-limiting resistor 21W are the quick-cutting mechanism 1.
1, an appropriate insulation interval is maintained. Oil tank 19
Inside, a pair of half-split insulating cylinders 22a and 22b are installed concentrically with the insulating cylinder 17, and the U-phase sheath section 20U
The fixed contact side of the current limiting resistor 21U and the fixed contact side of the W-phase sheath section 20W are connected to one half-split insulating tube 22a.
supported on the inner surface of the fixed contact side of the V-phase sheath section 20V and the current-limiting resistor 21V, and the W-phase current-limiting resistor 21W.
is supported by the inner surface of the other half-split insulating cylinder 22b.
Further, the movable contact side of each of the sheath cutting portions 20U, 20■, and 20W is supported by an insulated operating shaft 23 extending downward from the quick cutting mechanism 11 through the center of the oil tank 19. The terminal 24U on the fixed contact side of the U-phase shield section 20U and the terminal 24W on the fixed contact side of the W-phase shield section 20W are connected to one half of the insulating tube 20a and the insulating tube 17 in the radial direction. It penetrates and is drawn out to the outer surface of the insulating cylinder 17.

In addition, the terminal 24 on the fixed contact side of the phase gap 20■
Terminal 25 on the movable contact side of the V and W phase sheath section 20W
W (line terminal C) is the other half insulating tube 20b.
It penetrates the insulating cylinder 17 in the radial direction and is drawn out to the outer surface of the insulating cylinder 17. Furthermore, the edge section 20 of U phase and ■ phase
Terminals 25U and 25V on the movable contact side of U and 20V penetrate the bottom plate 18, are drawn out downward, and are connected to a common line terminal A. The tap selector 15 includes one insulating cylinder 26
The contacts for three phases are housed in the unit, and their arrangement is as follows.

Fixed contacts 27U, 27■ and movable contact 28 for two phases corresponding to tap windings for two adjacent phases (see Fig. 2)
U and 28V are arranged on the upper part of the insulating cylinder 26, and are arranged in the same plane for each phase.

Since the potential difference between the U-phase and ■-phase contacts is small, the vertical distance between the contactors of both phases is made relatively close. Further, the fixed contactor 27W and the movable contactor 28W for the other one phase are arranged in the same plane below them for the two phases, with an appropriate insulation interval maintained therebetween. Fixed contact 2 for each phase
7U, 27■, 27W are supported by an insulating cylinder 26,
The movable contacts 28U, 28■, 28W are connected to the intermittent feed mechanism 1.
4 and is supported by an insulating operation shaft (not shown) extending downward through the center of the insulating cylinder 26.

Lead wires 29U, 29V from the U-phase and ■-phase movable contacts 28U, 28V are drawn out through the intermittent feed mechanism 14 above the tap selector 15, respectively, and connected to the fixed contacts of the corresponding blade sections. It is connected to the side terminal 24U, 24V. In addition, the lead wire 29 from the W-phase movable contact 28W
W is pulled out below the tap selector 15, and the insulating cylinder 26
Pass through the outside of the terminal 2 on the movable contact side of the W phase or disconnection.
Connected to 4W. Furthermore, the fixed contact 27 of each phase
U, 27V, and 27W are connected to the taps of the tap windings of the corresponding phases, respectively. The above is the configuration of the on-load tap changer of this embodiment, and this on-load tap changer 10
is used by being suspended inside the transformer tank 8 by fixing the flange 30 provided on its upper part to the opening of the transformer tank 8.

When the on-load tap changer is configured as described above, the bottom plate 18 of the changeover switch and the intermittent feeding mechanism 14 for the tap selector are at the same potential as the line terminal A.

Moreover, between the two-phase sheath cut portions 20U, 20■ and the bottom plate 18, between the lead wires 29U, 29■, between the lead wires 29U,
Since there is only a potential difference equivalent to one tap between the 29V, the bottom plate 18, and the intermittent feed mechanism 14, the insulation interval in this area is significantly reduced. Moreover, the other one-phase sheath cut portion 20W and the current limiting resistor 21W are arranged in the same plane, so that the thickness in the vertical direction becomes thin. As a result, the switching switch 12
Even if the three-phase shield, cutout, and current-limiting resistor are housed all at once, it is extremely compact. moreover,
In this embodiment, the bending section 2 for two phases of the switching switch 12 is
0U, 20V and current limiting resistor 21U, 2]■, and the corresponding two-phase contacts 27U, 2 of the tap selector 15
Since 8U, 27■, and 28V are arranged close to each other above and below the bottom plate 18 and the intermittent feed mechanism 14, the vertical length required for these two phases is also significantly shortened. As a result of the above, it is possible to construct a compact on-load tap changer with a short overall length, in which the switching switch 12 and the tap selector 1j5 accommodate three phases, respectively, and are connected vertically.

In the above embodiment, contacts for two phases are placed in the upper part of the tap selector, corresponding to the two-phase cutout and current limiting resistor located in the lower part of the switching switch. As an example has been explained, when a one-phase shield and a fixed contact are placed at the bottom of the switching switch (two phases are placed at the top), the corresponding one is placed at the top of the tap selector. It is also possible to arrange contacts for two phases (at the bottom).

As explained above, according to the present invention, three phases can be accommodated in one set of the switching switch and tap selector by rationally arranging the folds and current limiting resistors in the switching switch. There is an advantage that a compact on-load tap changer for a three-phase triangular connection transformer can be obtained.

[Brief explanation of the drawing]

1 and 2 are wiring diagrams of a three-phase triangular connection on-load tap changer transformer, respectively, and FIG. 3 is a schematic configuration diagram of a conventional on-load tap changer used in the transformer of FIG. 1, 4 is a schematic configuration diagram of a conventional on-load tap changer used in the transformer shown in FIG. 2; FIG. 5 is a partially cutaway front view of the on-load tap changer according to an embodiment of the present invention; 6 and 7 are cross-sectional views taken along line PP and line Q-Q in FIG. 5, respectively. 10...Tap changer on load, 11...
・Quick cutting mechanism, 12...Switching switch, 14...
...Intermittent feed mechanism, 15...Tap selector, 19...Oil tank, 20U, 20■, 20W...
... conversion and fragmentation, 21U, 21■, 21W...
Current limiting resistor, 23...Insulated operation shaft, 26...
・Insulating tube, 27U, 27■, 27W...Fixed contact, 28U, 28V, 28W...Movable contact,
29U, 29■, 29W... Lead wire.

Claims (1)

[Scope of Claims] 1. An on-load tap changer applied to a three-phase triangular connection transformer in which tap windings for two of the three phases are connected adjacently, which is provided with a quick switching mechanism at the top. , an intermittent feed mechanism is provided above the switching switch which houses the wire breakers and current limiting resistors for three phases in one container, and the fixed contacts and current limiting resistors for three phases are housed in one container. A tap selector housing a movable contact is installed, and a two-phase break portion and a current-limiting resistor corresponding to the two-phase tap windings of the switching switch are provided.
Each shield section and current limiting resistor are arranged on the same plane in close proximity to each other in the vertical direction, and the shield section and current limiting resistor for the other one phase are arranged close to each other in the vertical direction, and the shield section and current limiting resistor for the other one phase are They are arranged on the same plane with an appropriate insulating interval maintained in the vertical direction, and each of the sheath cutting parts is driven collectively by an insulated operating shaft connected to the quick cutting mechanism. An on-load tap changer characterized by: 2. In claim 1, the fixed contacts and movable contacts for the two phases of the tap selector are arranged in the same plane, close to each other in the vertical direction for each phase, and The fixed contact and movable contact for one phase of
The movable contacts are arranged on the same plane with a suitable insulating distance maintained in the vertical direction from those of the phase components, and each of the movable contacts is collectively driven by an insulated operating shaft connected to the intermittent feed mechanism. and at the top of the tap selector,
Fixed contacts and movable contacts for two phases or one phase corresponding to the two-phase or one-phase folding section and the current limiting resistor arranged at the lower part of the switching switch are arranged. An on-load tap changer characterized by: 3. In claim 2, in the lower part of the switching switch, the shield part and the current limiting resistor for the two phases are arranged, and in the upper part, they are arranged for the other one phase. are arranged, fixed contacts and movable contacts for the two phases are arranged in the upper part of the tap selector, and those for the other one phase are arranged in the lower part. On-load tap changer. 4. In claim 3, the lead wire from the tap selector to the switching switch is such that the two-phase lead wire is drawn out above the tap selector through the intermittent feed mechanism, and One phase is pulled out below the tap selector,
An on-load tap changer characterized in that each is connected to a changeover switch of a corresponding phase.