JPS5935163B2 - On-load tap switching device with polarity switch for switching tap transformers with switchable tap-to-tap windings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a load changer, a tap selector, and a preselector, and the tap selector is composed of a cylindrical bar cage having an upper cage ring and a lower cage ring, and an actuating rod for a movable tap selector contact which can be pivoted step-by-step in the cage and located below the tap selector coaxially with the selector. 1 for connecting the center tap of the inter-tap winding to the potential of
A switching tap is provided with a polarity switch, which polarity switch can be actuated by a tap selector drive during the switching step causing actuation of said preselector. This invention relates to a load tap switching device for a transformer.

A load-on tab switching device of this kind is known from German Patent No. 194 2 567.

In on-load tap changers of this type, the polarity switch usually has a plurality of star-shaped switching contacts that can be pivoted about the switching axis, each of which has one common connection with the respective rod. It can be operated by the drive of the tap selector via an intermediate transmission. The object of the invention is to improve the known on-load tap changer and, inter alia, to simplify the arrangement of the contacts of the polarization switch and the drive connected to these contacts. This purpose is achieved in the present invention by providing that the polarity switch has one contact lever, which is connected and electrically connected to the lower cage ring, and which is connected to the lower cage ring, and which is connected to the lower cage ring. A cam provided at the lower end of the operating rod of the device allows a reciprocating swivel during the course of the switching step causing the switching of the preselector, and furthermore, The polarity switch is constituted by an insulating cylinder disposed below the tap selector, one fixed polarity switch contact is disposed inside this insulated cylinder, and this polarity switch contact This is achieved by the joint action of the contact lever and the contact lever. The advantages obtained by the invention are particularly as follows.

That is, since the operation of one or more polarity switch contacts is performed by the aforementioned operation rod of the tap selector,
The drive described above is greatly simplified. The aforementioned individual couplings and intermediate gears for actuating the polarization switch contacts are no longer required. Functional reliability is likewise improved, since the actuation of the polarity switch contact is directly linked to the actuating rod of the tap selector, so that the opening and closing of this polarity switch contact can be done simply by tapping. This only depends on the position of the selector or the switching step. A further advantage is that the polarity switch has its own insulating cylinder located below the tap selector. This insulating cylinder, to which the tap selector C is fixed, not only forms a good mounting surface for the on-load tap changer (e.g. during installation and transport), but also serves as a housing for the polarity switch contact. As a result, this polarizing switch contact is protected from external mechanical influences. Furthermore, the plurality of polarization switch resistors in this insulating cylinder are arranged in a particularly advantageous manner,
For this purpose, the wall of this insulating cylinder can be equipped with a special plug, into which the rod-shaped, porcelain polarization switch resistor mentioned above can be inserted in a secant manner. An embodiment of the present invention will be described in more detail with reference to the drawings.

As can be seen from FIG. 1, the on-load tap changer according to the present invention essentially consists of an on-load tap changer head 1, a load changer 2, a tap selector 3, a preselector 4 and a polarity switch 5. It is configured.

The on-load tap changer head 1 is arranged in the load changer 2 and essentially includes drive means for driving a central drive shaft 6, which is not shown in detail in the drawings. The tap selector 3 is designed as a cylindrical cage, with an upper cage ring 7 and a lower cage ring 8.
An insulating rod 9 is disposed between and supports a fixed tap selector contact 10. This tap selector 3
and the load changer 2 is an intermittent transmission 11 for the step-by-step operation of an operating rod 13 which can be pivoted around a tap selector column 12. (See Figures 2 and 3). This operating rod 13 serves for operating a movable tap selector contact, which is not shown in detail in the drawings. A preselector 4 is located to the side of the tap selector 3, and this brake selector is similarly operated by the intermittent transmission 11. Below the tap selector 3 is the polarity switch 5, and the insulating cylinder 14 of this polarity switch is screwed onto the lower basket ring 8t. This insulating cylinder 14 has an external connection terminal 15 to which a conductor 16 is connected which is connected to the corresponding tap selector contact 10. Further details of the polarization switch 5 and its operating device are shown in FIGS. 2 to 5.

The lower basket ring 8 of the tap selector 3 holds on one side the insulating rod 9 of this tap selector and on the other side also has three posts 17, which support the tap selector posts 1 mentioned above.
It is configured as a support for 2.

Around this tap selection post 12, the above-mentioned operating pin 1
3, a rotatable ring 18 is arranged,
This ring guides the operating rod 13, which is driven by the intermittent transmission device 11 (FIG. 1). The individual struts 17 of the lower cage ring 8 have legs 19 to which the insulating cylinders 14 of the polarization switch 5 are screwed. A contact lever 21 is supported by a bearing portion 20 in one of the pillars 17 of the lower cage ring 8. The contact lever is radially pivotable, and
It is permanently electrically connected to the lower basket ring 8 through two contact portions 22 and 23. spring 24
applies the necessary contact pressure to the contact part, and at the same time also applies force to the contact lever 21, so that this contact L-bar, at its lower contact 25, presses into the insulating cylinder 14. is pushed away from the stationary opposing contact 26 located at. The contact between the opposing contact 26 and the contact 25 is caused by a cam 27 attached to the operating rod 13.
caused by. During the switching step of the actuating rod 13, the aforementioned cam 27 correspondingly engages the rear part of the roller 28 located at the upper end of the contact lever 21, causing this contact lever 21 to move as shown in FIG. Move in the direction of the arrow. This further stretches the spring 24 and creates an abutment between the contact 25 and the opposing contact 26. During the course of a switching step on the tap selector 3, the cam 27 correspondingly moves out of the area of the roller 28 again, so that the spring 24 moves the contact lever 21 in the opposite direction. Rotate it in the direction
The corrosive connection between contact 25 and its counter contact 26 is thus eliminated. As can be seen particularly clearly from FIGS. 4 and 5, a plurality of plugs 29 are arranged linearly on the inner wall of the insulating cylinder 14, and each of these two plugs has one plug. Rod-shaped porcelain polarizing resistors 31 are inserted, so that the individual polarizing resistors form a dividing line in the cross section of the insulating cylinder 14.

At the same time, this rod-shaped polarization switch resistor 31 also assumes an inclined position pointing upwards or downwards, so that the individual polarization switch resistor' is thus formed in the cross section of the arm cylinder 14. The dividing lines intersect each other.
At this time, in the embodiment shown in FIGS. 4 and 5 (a series circuit of rod-shaped polarity switch resistors 31 is arranged in permutations A, b,
c,..., are lined up corresponding to k. In this case, the first plug corresponds to a and is electrically connected to the stationary counter contact 26 mentioned above, and the last plug, corresponding to kl, forms the connection terminal 15 for the conductor 16. Furthermore, said counter-contact 26 is also provided with an external connection terminal 30, by means of which a polarization switch resistor provided at any other position could be connected. According to the present invention, the advantage of the above-mentioned arrangement of the rod-shaped porcelain polarity switch resistor is that in the corresponding length of the polarity switch resistance l of the insulating cylinder 14, a very large number of polarity switch resistances can be arranged. can be housed in this insulating cylinder.Furthermore, even if air is trapped in the tube-shaped porcelain body, as a result of the porcelain polarity switch taking an inclined position, This air can be evacuated when the tap changer is inserted into the oil-filled transformer vessel.

The embodiments of the invention described above are in no way limited to unipolar on-load tap switching devices as illustrated.

It is also possible to use the same device for a three-pole load tab switching device, for which purpose three are arranged next to each other at a sufficient distance from each other in the area of one column 17. A contact lever 21 and three corresponding counter contacts 26 should be provided.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram of the on-load tap switching device with a polarity switch attached, Fig. 2 is a longitudinal sectional view of the polarity switch belonging to the on-load tap switching device according to Fig. 1, and Fig. 3 is the A cross-sectional view corresponding to the I-1 line in the figure, FIG. 4 is a cross-sectional view of an insulated cylinder of a polarity switch having a built-in polarity switch resistor, and FIG. 5 shows the arrangement of the polarity switch resistance. FIG. In the figure, 5 (or polarity switch), 3 (tap selector), 8 (lower cage ring), 13 (operating rod), 14 (insulated cylinder), 21 (contact lever), and 27 (cam) are shown.

Claims (1)

[Claims] 1. Consists of a load switcher, a tap selector, and a pre-selector, where the tap selector is composed of a cylindrical rod cage having an upper cage ring and a lower cage ring, and a movable tap. It has an actuating rod for the selector contact which can be pivoted step by step in this cage and is coaxial with the tap selector below the tap selector and is set at a certain potential. 1 for connecting the center taps of the inter-tap windings
a change-over tap transformer, which is provided with a polarity switch, which polarity switch can be actuated by a tap selector drive during the switching step causing actuation of said preselector; In the tap switching device for manual load, the polarity switch 5 has one contact lever 21, and this contact lever is pivotally attached to and electrically coupled to the lower cage ring 8. The contact lever 21 is the tap selector 3
A cam 27 provided at the lower end of the operating rod 13 of allows a reciprocating swivel during the course of the switching step causing the switching of the preselector, and also of the aforementioned polarity switch. 5 is constituted by an insulating cylinder 14 disposed below the tap selector 3, and one fixed polarity switch contact 26 is disposed inside this insulated cylinder, and this polarity switch contact A tap switching device on load, characterized in that the contact lever 21 and the contact lever 21 operate together. 2. Claims characterized in that, as the contact lever 21 of the polarity switch 5, the contact lever 21 supported on one support 17 of the lower cage link 8 is rotatable in the radial direction. The on-load tap switching device according to item 1. 3 The insulating cylinder 14 includes a plurality of rod-shaped polarity switch resistors 31, and the polarity switch resistances are arranged in the plugs 29 linearly arranged on the sloped wall of the insulating cylinder as follows. The load according to claim 1 or 2, characterized in that the polarity switch resistor 31 is inserted into the polarity switch resistor 31 and cuts the helical wire into a plurality of straight segments. Time tap switching device.