JPS6115567B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a voltageless tap-changing transformer, and more particularly to a voltageless tap-changing transformer in which a large voltage is applied between the taps. Conventionally, in order to adjust the input and output voltages of transformers, on-load tap changers or non-voltage tap changers are sometimes used to create on-load tap change transformers or non-voltage tap change transformers. many. Among these, a rotary bridge type non-voltage tap changer is often used in the non-voltage tap changer from the viewpoint of cost and installation volume. FIG. 1 shows an example of the configuration of a conventional non-voltage tap changer using a rotary bridge type non-voltage tap changer. In Figure 1, 1 is the winding whose voltage is to be adjusted, 2 and 3 are its main windings, and 4a and 4b are tap windings connected in series to the main windings 2 and 3, respectively, to adjust the voltage. The number of turns corresponds to the range.
a to f are the tap windings 4a,
The lead wires drawn out from 4b are connected to terminals A to F of the rotary bridge type non-voltage tap changer 6 as shown in Table 1.

[Table] 7 is rotated around a rotating shaft 8 by an operating handle (not shown) outside the transformer tank, and bridges arbitrary adjacent terminals of the rotary bridging type non-voltage tap changer 6. It is a bridge piece. In the above configuration, if the bridging piece 7 is moved to the position shown by the solid line in FIG. Lead wires a and f of wires 4a and 4b are now connected, and the number of electrical turns of winding 1 is minimized. When the bridging piece 7 is brought to the position indicated by the dotted line in FIG. 1 by operating the operating handle, terminals B and C of the voltageless tap changer 6 are bridged, and the tap windings 4a, Lead wires b and f of tap winding 4b are now connected, and the number of electrical turns of winding 1 is greater than the minimum number by the number of turns between lead wires a and b of tap winding 4a. Similarly, when the position of the bridging piece 7 is rotated in the direction of the arrow, the lead wires of the tap windings 4a and 4b become b and e,
C and e are connected in this order, and c and d are connected in this order, and the number of electrical turns of the winding 1 increases sequentially, thereby making it possible to adjust the voltage to a predetermined value. However, according to this method, the voltage of the entire tap range, that is, the sum of the voltages induced in the tap windings 4 and 5, is inevitably applied between the terminals of adjacent voltageless tap changers. In the above example, it is between E and F when the bridging piece 7 is at the position indicated by the solid line. Further, the entire tap voltage is always applied between the leads c and d or a and f, that is, between the ends of the tap windings 4a and 4b. (In the above example, when the bridging piece 7 is at the position of the solid line, etc.) For this reason, if the tap range is wide or the amplitude of voltage oscillation in the tap winding with respect to the impulse voltage is large, it is necessary to A voltageless tap changer with a high withstand voltage must be used, and the insulation dimension between the ends of the tap windings 4a and 4b must be increased. A tap changer with a high withstand voltage requires a large dimension between the tap changer terminals, resulting in a large overall size, and requires a large installation volume, resulting in an overall large transformer. In addition, the price of the voltageless tap changer itself and the price of the transformer as a whole increase accordingly. On the other hand, if the insulation dimension between the ends of the tap winding is increased, the space factor of the winding itself is also reduced. The present invention has been made in view of the above points,
Even when the tap range is wide or the amplitude of voltage oscillation within the tap winding is large in response to the impulse voltage, a rotary bridging type non-voltage tap changer with low withstand voltage is used. To provide a no-voltage tap-change transformer that is compact and inexpensive without increasing the insulation dimensions of the transformer. The configuration of the present invention uses two non-voltage tap changers, and one of the non-voltage tap changers has a tap-side winding end of the first line end or the first main winding and a lead-out from the tap winding. Connect the first line end or half of the lead wire on the first main winding side, and connect the second line end or the tap side half of the second main winding to the other voltageless tap changer. Connect the line ends and half of the lead wires drawn from the tap winding on the second line end or second main winding side, and connect the middle one of the lead wires drawn out from the tap winding. It connects to both voltageless tap changers. An embodiment of the present invention will be explained in detail below with reference to FIG. In FIG. 2, 1 is a winding whose voltage is to be adjusted, 2 and 3 are its main windings, and 4 is a tap winding having a number of turns corresponding to a predetermined voltage adjustment range. b
-f is a lead wire drawn out from the tap winding 4 every corresponding number of turns so that a predetermined adjustment step voltage can be obtained. Further, a and g are lead wires drawn out from the tap side winding ends of the main windings 2 and 3, respectively. Among the lead wires b to f drawn out from the tap winding 4, the leads b and c on the first main winding 2 side are connected to the first voltageless tap changer 5, respectively.
The terminals e and f on the second main winding 3 side are connected to the terminals D' and B' of the second voltageless tap changer 6, respectively. Further, the central lead wire d drawn out from the tap winding 4 is connected to the terminal E of the first voltageless tap changer 5 and the terminal F' of the second voltageless tap changer 6. Furthermore, a lead wire a drawn out from the tap side winding end of the first main winding 2 is connected to the terminal F of the first voltageless tap changer 5, and is commonly connected to terminals B and D by a lead wire 9. . A lead wire g pulled out from the tap-side winding end of the second main winding 3 is connected to the terminal E' of the second non-voltage tap changer 6, and is commonly connected to terminals A' and C' by the lead wire 9. Connected. Connected as above, the first and second voltageless tap changers 5,
The rotating shafts 7 and 8 of the bridging pieces 10 and 11 of the two non-voltage tap changers 5 and 6 are made common, and the bridging pieces 1 of the two non-voltage tap changers 5 and 6 are operated by operating one non-voltage tap changer operating handle.
0 and 11 are configured to rotate by the same angle.
Table 2 shows the connection between each lead wire and the terminal.

[Table] Next, the effects of the present invention will be explained. When the bridging pieces 10 and 11 of the two voltageless tap changers 5 and 6 are set at the positions shown by the solid lines, they are pulled out from the tap side winding end of the first main winding 2. Lead wire a → terminal F of tap changer 5 → bridge piece 10 → terminal A of tap changer 5 → tap lead wire b → tap winding 4 → tap lead wire f, terminal B' of tap changer 6 → bridge piece 1
1 → terminal A' of the tap changer 6 → lead wire g pulled out from the tap side winding end of the second main winding. Eventually, the lead wires a and b, f and g
is connected, and the number of electrical turns of winding 1 becomes maximum. Furthermore, if the bridging pieces 10 and 11 are moved to the positions indicated by the dotted lines in Fig. 2 by operating the operating handles, the lead wires a and c and f and g will be connected in the same way as above, and the winding The number of electrical turns of wire 1 is less than the maximum by the number of turns between tapped leads b and c. Similarly, when the positions of the bridging pieces 10 and 11 are rotated in the direction of the arrow, the lead wires become a and c, e and g, a and d, e and g, a and d, and d and g. The number of electrical turns of the connected winding 1 is successively reduced to achieve a predetermined voltage adjustment. According to the above configuration, the maximum voltage applied between the terminals of the first and second voltageless tap changers 5 and 6 is the voltage induced between the tap lead wires b and d, and the voltage induced between the tap lead wires d and f, respectively. The voltage induced in this case is approximately half that of the conventional configuration. Also, the maximum voltage applied between the tap-side winding end of the first main winding 2 and the first main winding-side winding end of the tap winding 4 and the tap-side winding end of the second main winding 3. The maximum voltage applied between the winding end of the tap winding 4 on the second main winding side is the voltage induced between the tap lead wires b and d, and the voltage induced between the tap lead wires d and f, respectively. The voltage will also be half of the conventional voltage. Although the above explanation has been made regarding the case where the tap voltage is in four stages, the structure of the present invention can be adopted as long as the tap voltage is in two or more stages. Also, the first and second
It is clear that it is also possible to separate the rotating shafts of the voltageless tap changer and operate them separately. As described above, according to the present invention, the maximum voltage applied between the terminals of a voltageless tap changer and the maximum voltage applied between the winding ends is approximately half that of the conventional configuration. Even when the amplitude of voltage oscillation within the tap winding relative to the impulse voltage is large, a non-voltage tap changer with a relatively low withstand voltage can be used, and the insulation size between the ends of the winding can be made small. It becomes possible to manufacture a compact, low-cost, and high-quality non-voltage tap switching transformer. It is clear that the present invention also applies to the case where the tap winding is wound on an insulating cylinder separate from the main winding. Further, in the above embodiment, the case where the tap winding is connected to the main winding has been described, but the present invention can be similarly applied to the case where the tap winding is connected to the end of the line.

[Brief explanation of the drawing]

FIG. 1 is a wiring diagram showing an example of the configuration of a conventional voltageless tap-changing transformer, and FIG. 2 is a wiring diagram showing an example of the configuration of a voltageless tap-changing transformer according to the present invention. 2, 3... Main winding, 4... Tap winding, 5, 6
... Voltageless tap changer, a to g... Tap lead wires, A to F and A' to F'... terminals.

Claims (1)

[Claims] 1. In a voltageless tap-change transformer configured using a rotating bridging type voltageless tap-changer, the first line end or first main winding side of the lead wire drawn out from the tap winding. Connect the lead wires to the terminals of the first voltageless tap changer, and connect the lead wires at the second line end or the second main winding side to the terminals of the second voltageless tap changer, respectively, and the first
Of the tap lead wires connected to the terminals of the non-voltage tap changer, one of the lead wires on the second line end or second main winding side is also connected to the terminal of the second non-voltage tap changer. Further, the first line end or the winding end on the tap side of the first main winding is connected to some or all of the terminals of the first voltageless tap changer to which the tap lead is not connected, and 2 line end or the tap side winding end of the 2nd main winding.
A non-voltage tap-change transformer characterized in that the tap leads of the non-voltage tap-change transformer are connected to some or all of the unconnected terminals.