JPS6043649B2 - Voltage-free tap-changing transformer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a no-voltage tap-changing transformer, and particularly to a no-voltage tap-changing transformer in which a large voltage is applied between the taps.

Conventionally, in transformers, in order to adjust input and output voltages, on-load tap changers or non-voltage tap changers are used to create on-load tap change transformers or non-voltage tap change transformers. There are many.

Among these, there are two types of non-voltage tap changer: a wedge-type non-voltage tap changer and a finger-type non-voltage tap changer.However, due to cost and space considerations, wedge-type non-voltage tap changers are used. It is often advantageous to use FIG. 1 shows an example of the configuration of a conventional non-voltage tap changer using a wedge 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 4 and 5 are tap windings connected in series to the main windings 2 and 3, respectively, so that a predetermined voltage can be adjusted. The number of turns corresponds to the adjustment range.

Lead wires a to f are drawn out from predetermined adjustment step windings 4 and 5, respectively, and are connected to terminals g to m of a wedge type non-voltage tap changer 6 as shown in Table 1. Reference numeral 7 denotes a wedge which is rotated around the rotating shaft 6 by an operating handle (not shown) outside the transformer tank and bridges arbitrary adjacent terminals of the wedge type non-voltage tap changer 6.

In the above configuration, for example, if the operating handle d is moved to the position shown by the solid line in FIG. 1, the terminal g of the non-voltage tap changer 6 is bridged, and the tap winding 4 and 5 lead wires a (5f) are connected, and the number of electrical turns of winding 1 becomes the minimum.

Furthermore, when the wedge 7 is brought to the position indicated by the dotted line in FIG.
Lead wires b and f of tap windings 4 and 5 are now connected, and the number of electrical turns of winding 1 is smaller than the minimum number of leads a of tap windings 4 and 5.
The number of turns increases by the number of turns between and b. Similarly, when the wedge 7 is rotated in the direction of the arrow, the lead wires of the tap windings 4 and 5 are connected to b and E. ．． cl:. E. cl:
．． They are connected in the order of d1, and the number of electrical turns of the winding 1 increases sequentially to enable predetermined voltage adjustment. However, according to this method, the voltage of the entire tap range (the sum of the voltages induced in the tap windings 4 and 5) is inevitably applied between the terminals of the voltageless tap changers that are adjacent to each other.

Therefore, when the tap range is wide or when the amplitude of voltage vibration in the tap winding with respect to the impulse voltage is large, a voltageless tap changer with high withstand voltage between terminals must be used. A tap changer with high withstand voltage requires a larger dimension between the tap changer terminals, which increases the overall size and requires a large installation space.
The entire transformer becomes larger. Additionally, along with this, the price of the voltageless tap changer itself and the price of the transformer as a whole also increase. The present invention has been made in consideration of the above points, and it is possible to use a wedge type non-voltage tap changer with a low withstand voltage even when the tap range is wide or when the amplitude of voltage vibration in the tap winding with respect to the impulse voltage is large. Compact, low-cost, voltage-free. The purpose is to provide tap-changing transformers.

According to the present invention, two non-voltage tap changers are used, and one of the non-voltage tap changers is connected to a lead wire drawn out from a tap winding connected in series to the first main winding. , to the other voltage-free tap changer! connects the lead wire drawn out from the tap winding connected in series to the second main winding,
Furthermore, the initial objective can be achieved by appropriately connecting the terminals of each non-voltage tap changer. Hereinafter, 1 of the present invention
The embodiment will be explained in detail with reference to FIG.

In Fig. 2, 1 is the winding whose voltage is to be adjusted, 2 and 3 are its main windings, and 4.5 is the tap winding connected in series to the main windings 2 and 3, respectively, so that the predetermined voltage can be adjusted. The number of turns corresponds to the adjustment range.

Lead wires a to f are drawn out from the tap winding each time the number of turns corresponds to the predetermined adjustment step voltage so as to obtain a predetermined adjustment step voltage. Among the lead wires a to f, lead wire a is drawn out from the tap winding 4 connected in series to the main winding 2.
-c are terminals J, i, and g of the first voltageless tap changer 16;
are connected to each. Lead wires d-f drawn out from the tap winding 5 connected in series to the main winding 3 are respectively connected to terminals m'', k'', and h'' of the second voltageless tap switch 17. Among the terminals of the first and second voltageless tap changers 16 and 17, the terminals M, h, k, l'', g', and j'' to which tap lead wires are not connected are short-circuited by the lead wire 10 to maintain the same potential. Connect as above and connect the first and second non-voltage tap changers 16,
17 wedges 12 and 13 are made common, so that the wedges of two non-voltage tap changers 16 and 17 rotate by the same angle by operating the operation handle of one non-voltage tap changer. Configure. First, set the wedges of the two non-voltage tap changers 16 and 17 so that they are in the positions shown by the solid lines, then tap lead wire a → terminal j of tap changer 16 → wedge 12 → terminal of tap changer 16 h → terminal m of tap changer 16 - terminal k of tap changer 16 - tap changer 17g' → terminal 1'' of tap changer 17 → terminal j'' of tap changer 17
Electrical conduction occurs in the order of wedge 13→terminal h'' of tap changer 17→tap lead wire f, and eventually the tap lead wires a and f are connected, and the number of electrical turns of winding 1 becomes minimum. If wedges 12 and 13 are moved to the positions indicated by the dotted lines in Figure 2 by operating the operating handles, tap lead wires a and e will be connected in the same way as above, and the electricity of winding 1 will be connected. The target number of turns is greater than the minimum by the number of turns between tap lead wire e<5f.Similarly, as the positions of wedges 12 and 13 are rotated in the direction of the arrow, the lead wire of the tap winding are b and E,
．． bl:d. Dlc and d are connected in this order, and the number of electrical turns of the winding 1 increases sequentially to enable a predetermined voltage adjustment. According to the above configuration, the maximum voltages applied between the terminals of the first and second voltageless tap changers 16 and 17 are the voltage induced only in the tap winding 4 and the voltage induced only in the tap winding 3, respectively. This is approximately half of the conventional configuration.

Therefore, even in cases where the tap range is wide or where the amplitude of voltage oscillation within the tap winding relative to the impulse voltage is large, a voltageless tap changer with a relatively low withstand voltage can be used, making it possible to change the tap. The installation space for the device is smaller,
The entire transformer becomes smaller. In addition, the price of the voltageless tap changer itself and the price of the transformer as a whole can be reduced accordingly. Although the above explanation has been made for the case where the tap voltage has five steps, the present invention can be applied as long as the number of steps of the tap voltage is three or more steps.

It is also possible to separate the rotating shafts of the first and second voltageless tap changers and operate them separately. Further, the same method can be applied to a transformer in which the tap winding is connected to the line end.

[Brief Description of the Drawings] Fig. 1 is a wiring diagram showing one embodiment of a conventional no-voltage tap-changing transformer, and Fig. 2 is a wiring diagram showing one embodiment of a non-voltage tap-changing transformer according to the present invention. be. 1... Winding, 2, 3... Main winding, 4, 5... Tap winding, 9, 11... Operating shaft, 10... Lead wire,
16, 17... Voltageless tap changer.

Claims (1)

[Claims] 1 In a voltageless tap changing transformer configured using a Wetsuji type voltageless tap changer, the lead wire drawn out from the tap winding connected in series to the first line end or the first main winding is The lead wire connected to the terminal of the first non-voltage tap changer and drawn out from the tap winding connected in series to the second line end or the second main winding is connected to the terminal of the second non-voltage tap changer. By connecting the terminals of the first and second voltageless tap changers that are not connected to the terminals with lead wires, the number of steps is the sum of the number of steps of each tap winding. A non-voltage tap change transformer characterized by adjusting the voltage.