JPS5922366B2 - On-load tap changer for polyphase regulating transformers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a transformer for polyphase regulating transformers in delta connection or extended delta connection, comprising a load switch in each phase and a tap selector in each phase. The on-load tap switching device has two groups of load switches and tap selectors stacked one above the other in the axial direction, and each group has one load switch or tap selector.
The present invention relates to an on-load tap changer which can be operated using an insulated shaft and in which the individual load switches or individual tap selectors are insulated from each other with respect to the entire line voltage.

In such on-load tap changers, the load switches belonging to the individual phases are usually combined into one component group, and the same is true of the tap selectors belonging to the individual phases.

In this case, the load switch belonging to a certain phase and the tap selector belonging to that phase are located in one plane, and the connecting conductor between the tap selector and the load switch is radial from the tap selector. Therefore, they are located in the same plane. However, the connecting conductors leading out radially from the tap selector require a large amount of space due to the required inter-tap voltage for adjacent tap contacts, and therefore the number of tap contacts arranged in a circular manner is The number of tab contacts in the neutral point selector must be reduced.

Leading out the connecting conductor from the tap selector between phases is not considered. This is because the tap-to-tap voltage between the phases would then increase significantly, which would make the component group containing the tap selector extremely long. The disadvantage of having connecting conductors drawn out in the radial direction is that it is necessary to reduce the number of tap contacts on the tap selector, as in the case of neutral point type tap selectors, the connecting conductors are drawn out axially from the selector column. This can be prevented by pulling it out. However, this creates the additional difficulty that the axially led wires of the individual phases must be insulated from each other for the entire line voltage. However, in order to insulate the connecting conductor in this manner, the diameter of the selector column must be such that the connecting conductor is disposed within the column, and there is also a limit condition that it cannot be expanded arbitrarily. Therefore, in practice, it is almost impossible to control such high voltages with such a multiphase tap selector. A further disadvantage may also arise in that relatively long connecting conductors are required for the respective electrical connection between the tap selector and the load switch. It is an object of the present invention to improve a load tap changer of the type mentioned at the outset in such a way that it can be used even at relatively high voltages between the individual phases, and which, in itself, has an extremely conventional complete or circular configuration. The object of the present invention is to improve the tap contact by leaving it as it is and by eliminating the connecting conductor leading out in the radial direction from the tab selector. According to the present invention, this problem is solved as follows.

That is, the first configuration group is composed of a two-phase load switch and a one-phase tap selector provided below it in the axial direction. The second component group consists of a one-phase load switch and a tap selector arranged axially below it.
phase components), the lower phase of the tap selector of these two phases being connected to the upper load of the first component group via a connecting conductor led out axially from the tap selector. The upper phase of the tap selector is coupled to a switch, and the upper phase of the tap selector is connected to the tap selector through a connecting conductor drawn out in the axial direction from the tap selector to apply a load switching force that is adjacent to the tap selector in the axial direction. The solution is provided by an on-load tap switching device, which is characterized in that it is connected to the device. The advantage achieved by the invention is that the new on-load tap-switching device allows practically arbitrarily high voltages to be applied between the individual phases and eliminates the need for crossing connecting conductors.

In this new on-load tap changer, critical voltages occur only between the load switch and earth potential, between both load switch of one component group and between the two phases of the two-phase tap selector of the second component group. It is something. By shifting the position of the electrical connection conductor between the tap selector and the associated load switch, critical hazardous points are completely avoided. Another advantage over the known device is that in the case of the on-load tap changer according to the invention, at most two sets of load switches must be driven by the same insulated shaft. In the case of the arrangement of three sets of load switches in total, which are located one above the other in the axial direction, the load on the common insulating shaft will increase. This is because the load switch is generally operated by an energy storage device. The single-phase tap selector provided according to the invention with the two sets of load switches is then less important in terms of the required forces. This is because the common insulated shaft operates the tap selector via its own drive transmission associated with the tap selector. An embodiment of the invention is shown in the drawing and will now be described in detail.

As can be seen from the drawings, the novel on-load tap-changing device consists of two component groups 1, 2, which are arranged in a transformer casing 5 (not shown in detail) with respective drive parts 3, 4. It is suspended.

The drive parts 3, 4 of the two component groups 1, 2 are connected to each other via a lever 6. The configuration group 1 of this on-load tap switching device consists of two sets of load switches V arranged one above the other in the axial direction and located in a common oil tank 7.
It consists of L, UL and a single-phase tap selector US disposed below them in the axial direction. On the other hand, the second configuration group 2 is composed of 1
The tap selector S is located below the load switch WL in an axial direction that includes both tap selector phases WS and VS. In this case, the upper tap selector phase WS is connected together with the axially adjacent load switch WL via a connecting conductor drawn out in the axial direction above the tap selector S. The lower phase VS of the two-phase tab selector is connected to the upper load switch VL of the configuration group 1 via a connecting conductor 10 which also leads out in the axial direction from the tab selector. These connecting conductors 10 are then led out in the axial direction below the tab selector S. Next, in configuration group 1, the single-phase tap selector US connects to the adjacent load switch UL and the connecting conductor 11 drawn out axially from the tab selector as before.
connected via. Each component groove 1 and 2 has a central insulating shaft 12, 13 by which both the load switch VL, UL and WL as well as the tab selectors US and S are driven.

1 drive of the tap selector US, S is then driven by the drive transmission device 1.
4, 15, in which the central insulating shafts 12, 13 associated within the device engage, respectively. In this embodiment, for a device having three sets of load switches located one above the other, the central insulating shaft 12 of one of the structural groups is omitted, but this naturally affects the transmission of force. This is particularly advantageous.

Maximum of 2 sets of load switches VL, UL for each configuration group
It is particularly advantageous that the motor is driven by one insulated shaft 12. This is because the load switch is driven by an energy storage device and puts too much stress on the insulated shaft. The required force of the tap selector US, on the other hand, is not a major problem. This is because, as previously mentioned, the tap selectors US and S are operated via uniformly rotating drive transmissions 14 and 15. As is clear from the drawing, between the upper load switch VL to WL and the transformer casing 5 at earth potential, between both load switch VL, UL of the first component group as well as the second component group. There is a range of critical voltage stresses between the two tap selector phases WS, VS and of course between the two constituent groups 1 and 2 themselves, but between the last there is no problem at all, the so-called critical Shield rings 16 and 17 are provided to make the voltage stress uniform over a target range.

[Brief explanation of the drawing]

The drawing shows an embodiment of the on-load tap switching device according to the invention. DESCRIPTION OF SYMBOLS 1... First constituent group, 2... Second constituent group, 9, 10, 11... Connecting conducting wire, UL, VL, W
L...Load switch, S...Two-phase tap selector, US
...Single phase tap selector, VS, WS...Tap selector phase.

Claims (1)

[Claims] 1. An on-load tap switching device for a polyphase regulating transformer equipped with an individual phase load switch and an individual phase tap selector and configured in delta connection or extended delta connection,
The load switch and the tap selector are provided as two groups stacked one on top of the other in the axial direction, and the load switch or tap selector of each group is each operable using one insulated shaft, and In an on-load tap switching device in which the individual load switches or the individual tap selectors are insulated from each other with respect to the entire line voltage, the first configuration group 1 includes two phase load switches UL. , VL and a one-phase tap selector US provided axially below the connected conductor 11, from which the axially adjacent load switch UL and tap selector US are drawn out in the axial direction. The second configuration group 2 is composed of a one-phase load switch WL and two-phase portions WS and VS of a tap selector S provided below it in the axial direction. At this time, the lower phase VS of the tap selector S for these two phases is connected to the upper load switch VL of the first configuration group 1 via a connecting conductor 10 drawn out in the axial direction from the tap selector. connected, while the upper phase WS of the tap selector S is
An on-load tap switching device characterized in that the tap selector is connected to a load switch WL adjacent in the axial direction to the tap selector via a connecting conductor 9 drawn out in the axial direction from the tap selector.