JPS6148767B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises one main winding for each phase, one fine adjustment winding with taps on the selector arm for voltage regulation, and one fine adjustment winding on the same leg of the transformer. at least one coarse adjustment winding arranged in the center of the changeover switch; An auxiliary whose contacts are connected to the starting end of a coarse adjustment winding having a higher potential immediately after the coarse adjustment winding to which the changeover switch belongs, and which can be connected to the coarse adjustment winding and the energized arm of the selector. This invention relates to the arrangement of contacts in a tap selector of a transformer equipped with taps.

In contrast, German Patent Specification No. 960 303 discloses a plurality of selector arms, one of which is energized and connected to a tap of a so-called fine-tuning winding. It is known to provide this in a load tap changeover switch. Additionally, an auxiliary tap is provided which is coupled to the end of the transformer winding which is connected in series with the fine adjustment winding. The energized selector arm is then connected to this auxiliary tap when the reversing switch for the fine adjustment winding is switched. This reversing switch is likewise coupled on the one hand to the series-connected windings and on the other hand to the ends of the fine-tuning winding, so that the voltage of the fine-tuning winding is always in series depending on the position of the reversing switch. It is added to or subtracted from the voltage of the connected winding.

Additionally, West German patent application publication number 2358885
It is known to connect a so-called coarse adjustment winding in series with a fine adjustment winding, such that the starting end of the coarse adjustment winding is coupled to the main winding of the transformer. A changeover switch is provided for the coarse adjustment winding, the center contact of which is connected to the beginning of the fine adjustment winding, and the outer contacts of which are respectively connected to the beginning and end of the coarse adjustment winding. Therefore, depending on the position of the changeover switch, the voltage of the coarse adjustment winding is added or not to the voltages of the main winding and the fine adjustment winding. In this publication no auxiliary tap is shown for the energized selector arm which is connected to the end of the coarse adjustment winding, but during actuation of the transfer switch belonging to the coarse adjustment winding. Said auxiliary tap must be provided to eliminate voltage jumps that occur.

An object of the present invention is to provide a tap selector for a transformer as described above, in which the number of turns of the winding between the contacts of the changeover switch and the number of turns of the fine adjustment winding can be reduced while keeping the voltage adjustment range of the transformer the same. As a result, it is an object of the present invention to provide a connection circuit in which stress caused by a surge voltage between contacts is reduced when a surge voltage occurs.

According to the present invention, in the contact arrangement of the tap selector mentioned above, the center contact of the changeover switch connected to the coarse adjustment winding having the highest potential is connected to the center contact of the reversal switch. The outer contacts of the switch are respectively coupled to the beginning and end of the fine adjustment winding, and the auxiliary taps are coupled to the center contacts of an auxiliary transfer switch, and the outer contacts of this auxiliary transfer switch are respectively coupled to the transformer main winding. and a central contact of an auxiliary transfer switch that is also connected to a coarse adjustment winding connected in series immediately before the coarse adjustment winding; On the other hand, an auxiliary transfer switch is connected to a coarse adjustment winding connected in series immediately after the transformer main winding, and is connected to this coarse adjustment winding by both of its outer contacts. This is achieved by ensuring that the contacts of the reversing switch and the respective auxiliary changeover switch are arranged on mutually separate levels of the tap selector.

Next, details of the present invention will be explained based on embodiments shown in the drawings.

In FIG. 1, the transformer main winding 51 is connected to the neutral point 50.
is connected and coupled to the coarse adjustment winding 54 by known means. Furthermore, a fine adjustment winding 55 with a tap 56 is arranged on the same leg of the transformer, and a selector arm 57
comes into contact with these taps. The selector arm 57 is coupled to a transformer phase conductor 59 whose voltage is controlled via an on-load tap changeover switch 58.

The outer contacts 7 and 8 of the changeover switch 60 are connected to the starting end 54a and the end 54b of the coarse adjustment winding 54. The center contact 9 of the changeover switch 60 is connected to the center contact 12 of the reversing switch 61. Further, the outer contacts 10 and 11 of the reversing switch 61 are connected to the beginning and end of the fine adjustment winding 55. An auxiliary tap 24 is further disposed within the trajectory along which the selector arm 57 passes in contact with the selector arm 57, and an auxiliary changeover switch 62
is electrically coupled to the central contact 21 of the. Further, the outer contacts 19 and 20 of the auxiliary changeover switch 62 are connected to the starting end 54a and the ending end 54b of the coarse adjustment winding 54.

This device operates as follows with the above connections. That is, the changeover switch 60 and the reverse switch 6
In the illustrated position 1, the voltage at phase conductor 59 is highest. The voltage drop in the upper part of the fine adjustment winding 55 and the voltage drop in the coarse adjustment winding 54 are added to each other. To reduce the voltage, the selector arm 57 in FIG. 1 is moved upward until the energized selector arm contacts the auxiliary tap 24. At this point, it is first selected whether to operate the reverse switch 61 or the changeover switch 60. In the embodiment, it is first assumed that reversing switch 61 is toggled. After the reversing switch 61 is toggled, one of the selector arms is switched to the lowest tap 56. At this point, the voltage on the lower part of the fine adjustment winding 55 is subtracted from the sum of the main winding 51 voltage and the coarse adjustment winding 54 voltage, so that when the selector arm 57 is subsequently actuated, The voltage is further reduced. At this point the auxiliary transfer switch 62 is toggled. As a result, the central contact 21 of the auxiliary changeover switch 62 is coupled with its outer contact 20, and the potential of the auxiliary tap 24 becomes equal to the potential of the starting end 54a of the coarse adjustment winding 54. Then, on the premise that the number of turns of the coarse adjustment winding 54 and that of the fine adjustment winding are approximately equal, one of the selector arms 57 is brought into contact with the auxiliary tap 24 again. While the energized selector arm 57 is connected to the auxiliary tap 24, the switching of the changeover switch 60 takes place, and one of the selector arms 57 is again switched to the lowest tap 56. Upon starting the selector arm 57, the voltage in the lower part of the fine-tuning winding 55 is then subtracted from the voltage from the main winding 51.

In the case of the reverse sequence of switching between the reversing switch 61 and the transfer switch 60, first the fine adjustment winding 55 is
The voltage of the upper part is added to the voltage of the main winding 51 and then the voltage of the lower part of the fine adjustment winding 55 is subtracted from the voltage of the main winding 51. Therefore, by adding the auxiliary changeover switch 62, the number of turns of the fine adjustment winding and the coarse adjustment winding can be reduced while keeping the voltage adjustment range the same, compared to the above-mentioned known device. I can do it. By doing so, surge voltages in these windings can be reduced as well.

As FIG. 2 shows, the contacts of the changeover switch 60 and the reversing switch 61 are arranged at separate levels within the tap selector, so that one level only includes the coarse adjustment winding 54 or the fine adjustment winding 54. Adjustment winding 5
Only a potential difference corresponding to the voltage drop at 5 appears. The changeover switch 60 and the reverse switch 61 are driven by a common drive shaft 63. Both of these switches have three connection positions, but two of these positions, namely the positions corresponding to the outer contact 10 of the reversing switch 61 and the outer contact 8 of the transfer switch 60, are interconnected. Ru. Similarly, the auxiliary changeover switch 62 is located on a separate level of the tap selector, but is actuated independently of the drive shaft 63. Naturally, the auxiliary changeover switch 62 is connected to the common drive shaft 6.
It is also possible to combine 3. However, in this case it would be necessary to provide four connection locations, as shown in detail in FIG. 2a.

The arrangement of FIG. 3 differs from that of FIG. 1 in that, in addition to the coarse adjustment winding 54, two further coarse adjustment windings 52 and 53 are provided. Auxiliary changeover switch 6
2 is one outer contact point 20 as in the case of FIG.
is coupled to the end of the coarse adjustment winding 54 via
The other outer contact 19 is connected to another auxiliary changeover switch 6
It is connected to the center contact 18 of 4. The outer contact 17 of the auxiliary changeover switch 64 is connected to the end of the coarse adjustment winding 53, and the other outer contact 16 is connected to the center contact 15 of the auxiliary changeover switch 65.
Contacts 13 and 14 on the outside of the auxiliary changeover switch 65
are connected to the starting and ending ends of a coarse adjustment winding 52 that is connected in series immediately after the main winding 51. By appropriate actuation of the auxiliary changeover switch, the auxiliary tap 24 is now activated.
can be made equal to the potential at the beginning or end of each coarse adjustment winding. Two further changeover switches 66 and 67 are then provided in a suitable manner for the changeover switch 60, the outer contacts of which are connected to the beginning and end of the coarse adjustment windings 53 and 52, respectively. In addition, the changeover switches 66 and 6
Contacts 3 and 6 at the center of 7 are connected to the starting end of a coarse adjustment winding connected in series immediately after the coarse adjustment winding to which changeover switches 66 and 67 belong, respectively. Therefore, in such an arrangement the three coarse adjustment windings can be selectively connected or unconnected, so that if the number of turns of these windings is reduced accordingly, the individual A higher voltage drop across the windings is obtained. Further, if the number of turns of these windings is equal to that in the known device or in the arrangement of FIG. 1, a further enlargement of the voltage adjustment range is obtained.

In order to ensure that the potential of the fine adjustment winding 55 assumes a specific value when the reversing switch 61 changes, the fine adjustment winding of FIG. Open/close contact 69 that can close the circuit
and a resistor 70 to the auxiliary tap 24. As shown in FIG. 4, contact 69 is located between contacts 10 and 11 on the outside of the reversing switch.

As explained above, the present invention includes a main winding for each phase, a fine adjustment winding having a tap on the selector arm for voltage regulation, and at least one fine adjustment winding located on the same leg of the transformer. coarse adjustment windings, and a changeover switch is connected to the beginning and end of each coarse adjustment winding by its outer contacts;
In addition, the center contact of each changeover switch is connected to the starting end of the coarse adjustment winding having a higher potential immediately after the coarse adjustment winding to which the changeover switch belongs, and
In a contact arrangement in a tap selector of a transformer with an auxiliary tap that can be connected to the coarse adjustment winding and the energized selector arm, the center of the transfer switch connected to the coarse adjustment winding having the highest potential. contacts are connected to the center contacts of a reversing switch, outer contacts of the reversing switch are connected to the beginning and end of the fine adjustment winding, respectively, an auxiliary tap is connected to the center contact of the auxiliary changeover switch, and The outer contacts of this auxiliary changeover switch are respectively connected to the ends of the coarse adjustment winding connected in series with the transformer main winding and to the coarse adjustment winding also connected in series immediately before the coarse adjustment winding. The center contacts of the connected auxiliary transfer switch are coupled to the central contacts of the connected auxiliary transfer switch, while the coupled auxiliary transfer switch of the coarse adjustment winding connected in series immediately after the transformer main winding is connected by its outer contacts. the transformer by being coupled to this coarse adjustment winding and in such a way that the contacts of the respective transfer switch and reversing switch as well as the respective auxiliary transfer switch are arranged at mutually distinct levels of the tap selector. The number of turns of the winding between the changeover switches and the number of turns of the fine adjustment winding can be reduced while keeping the voltage adjustment range of the switch the same, and as a result, when a surge voltage occurs, the stress caused by the surge voltage between the contacts is reduced. It has the effect of

[Brief explanation of the drawing]

FIG. 1 shows a connection circuit of a tap selector of the invention having one coarse adjustment winding and one fine adjustment winding, and FIGS. 2 and 2a each show the contacts in the connection circuit of FIG. 1. An outline of the arrangement is shown. Furthermore, the third
4 and 4 schematically show the connection circuit and contact arrangement of the tap selector of the present invention when it has three coarse adjustment windings. 1, 2, 4, 5, 7, 8, 10, 11, 13,
14, 16, 17, 19, 20... Contacts on the outside of the changeover switch, 3, 6, 9, 12, 15, 18,
21... Center contact of the changeover switch, 24... Auxiliary tap, 51... Main winding, 52, 53, 54...
...Coarse adjustment winding, 54a... Starting end of winding, 54b...
... End of winding, 55 ... Fine adjustment winding, 56 ... Tap, 57 ... Selector arm, 60, 66, 67 ...
Changeover switch, 62, 64, 65... Auxiliary changeover switch, 61... Reverse switch, 63... Drive shaft.

Claims (1)

[Scope of Claims] 1. One main winding for each phase and one fine adjustment winding with a tap on the selector arm for voltage regulation and a plurality of windings located on the same leg of the transformer. A changeover switch is connected to the start and end of each coarse adjustment winding by its outer contacts, and a center contact of each changeover switch is connected to the beginning and end of each coarse adjustment winding. It is connected to the starting end of the coarse adjustment winding having a higher potential immediately after the coarse adjustment winding to which the switch belongs, and has an auxiliary tap that can be connected to the coarse adjustment winding and the energized arm of the selector. In the contact arrangement in a transformer tap selector, the center contact of the transfer switch connected to the coarse adjustment winding with the highest potential is connected to the center contact of a reversing switch, and the outer contacts of this reversing switch are said auxiliary taps are connected to the beginning and end of the fine adjustment winding, and furthermore, an auxiliary tap is connected to the center contact of an auxiliary transfer switch, the outer contacts of which are each connected in series with the transformer main winding. The ends of the coarse adjustment winding are coupled to the center contacts of an auxiliary transfer switch which is also connected to the coarse adjustment winding coupled in series just before said coarse adjustment winding, while the main contact of the transformer main winding is An auxiliary transfer switch, which is immediately connected to the series-connected coarse adjustment winding, is connected to this coarse adjustment winding by its both outer contacts, and the respective transfer and reversing switches as well as their respective auxiliary Contact arrangement in a tap selector, characterized in that the contacts of the changeover switch are arranged at mutually distinct levels of the tap selector. 2. In the device according to claim 1,
Contact arrangement in a tap selector, characterized in that the changeover switch and the reversing switch are driven by a common drive shaft and the outer contacts, which do not change during the changeover operation, are connected to each other.