JPS6157689B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transformer winding in an induction electric appliance such as a transformer or reactor having a tap coil.

The winding structure of induction electric appliances generally uses either a disk winding structure or a cylindrical winding structure, but multiple cylindrical windings are preferred because they can increase the series capacitance between the windings. It's advantageous.

An example of a transformer winding having a high voltage winding with a tap that employs this multiple cylindrical winding will be described with reference to the drawings.

In FIG. 1a, 1 is an iron core, and 2 is a low-voltage winding, which are arranged concentrically outside the iron core 1. 3
is a multiple cylindrical high-voltage winding, which is arranged concentrically outside the low-voltage winding 2 and is composed of a plurality of cylindrical winding layers. 4 to 7 are body coil layers, and 8 is a tap coil layer. The tap coil layer is usually provided at the center of the winding, on the ground end side, or on the neutral point side in consideration of shock resistance voltage. In addition, 9,10
indicates line terminals, and 11 to 15 indicate tap terminals.

Figure 1b shows the wiring diagram of Figure 1a, with tap terminals 12-13, 12-14, 11-14, 11-
By sequentially changing the terminal connections 15 and 15, the voltage can be variably adjusted. Each body coil layer 4~
7 is generally constructed by winding a single insulated conductive wire 17 in a spiral shape on an insulating cylinder 16 in large numbers.

As shown in FIG. 3, the tap coil layer 8 is made by arranging three insulated conductors in parallel on an insulating cylinder 16 and winding them in a helical shape, and forming three insulated coil elements 8a, 8b,
It is composed of 8c. Each insulating ring element is connected as follows. That is, the body coil layer 5
The end of the winding of the insulated ring element 8a is connected to the beginning of the winding of the insulated ring element 8a to form a tap terminal 11, and the end of the winding of the insulated ring element 8a is connected to the crossover connection conductor 18 to form the tap terminal 1.
Set it to 2. Similarly, tap terminal 13 - insulated coil element 8b - crossover connection conductor 19 - tap terminal 14 -
The insulated coil element 8c, the crossover connection conductor 20, the tap terminal 15, and the body coil layer 6 are connected. Note that the order in which the insulated coil elements are connected in series is different from the order in which the insulated conductors are arranged side by side.

Such a tap coil is superior in terms of axial external thrust and stray loss when a short circuit current flows because no unbalance of ampere turns occurs in the axial direction in any tap connection.

Next, the initial impact potential distribution within the winding will be described in detail when an impact voltage due to lightning or the like is applied to one line end of the multiple cylindrical winding, the other end of which is grounded. In the case of multiple cylindrical windings, the series capacitance within the windings is sufficiently larger than the capacitance between the windings and the ground, so the potential gradient between the layers is distributed almost evenly. However, when considering one winding layer, in the outermost winding layer at the end of the line, the capacitance between the winding and the ground is relatively large compared to the series capacitance within the winding layer. Therefore, the internal potential gradient of the winding layer becomes uneven. This also affects the other winding layers, and the potential gradients of these winding layers also become uneven. That is, the internal potential gradient of each winding layer 4 to 8 appears as shown by the dotted line in FIG.
Therefore, since a particularly large potential difference appears in the outermost line end winding layer 7, a tap coil is usually provided in the center of the winding, so that even if an impulse voltage enters from either side of the line terminal 9 or 10, This prevents a large potential difference from appearing between the tap terminals.

However, in such a winding structure, 1. Since the series capacitance of the line end layer is not large,
Intralayer potential distribution is unfavorable.

2 The insulated conductors of the body coil winding layers 4 to 7 and the insulated conductors of the tap coil layer 8 usually have different cross-sectional dimensions and the number of insulated conductors wound is also different, so after winding the body coil winding layers 4 and 5, the tap coil layer is 8, it is necessary to perform winding preparation work such as replacing the insulated wire conductor winding drum, or to wind the body coil layers 6 and 7 again after winding the tap coil layer. Because of this, the winding efficiency is not good.

3. Because the tap coil crossover connection conductor is drawn out between the tap coil layer 8 and the body coil layer 6, the voltage equivalent to the maximum of one body coil layer and two tap steps will be applied to the transition connection conductor, so strong insulation is required. be.

4. Because the tap coil crossover conductor is drawn out inside the coil, the coil becomes large at the tap coil crossover conductor extraction part, and the space factor of the coil is poor.

It has the following disadvantages.

The present invention was made in order to solve the above-mentioned drawbacks, and the tap coils are arranged in parallel outside the outermost line end layer, and the outermost line end layer including the tap coils is composed of three or more insulated conductor elements arranged in parallel. Consisting of
The purpose is to connect the conductor elements in series in an order different from the order in which they are arranged. This increases the series capacitance between the insulated conductor elements and improves the potential distribution within the layer, preventing excessive voltage from being applied between the tap terminals and improving the winding workability of the transformer. The purpose is to provide a line.

Embodiments of the present invention will be described below with reference to FIGS. 5 and 6. In the figure, the same or corresponding parts as in FIGS. 1 to 3 are designated by the same reference numerals.

In the present invention, the tap coil layer 8 is arranged in parallel outside the outermost line end layer. It is formed from three or more juxtaposed insulated coil elements.
8a to 8c are insulated coil elements for tap coils, 8
d is an insulated coil element for the body coil, and each arrangement is arranged in the order of 8a-8c-8d-8b. 21 is a crossover connection conductor for a line terminal.

The above wire ring elements are connected as follows. That is, the winding end of the body coil layer 7 and the winding start end of the insulated wire ring element 8a are connected to form a tap terminal 11, and the winding end of this wire ring element 8a is connected to the crossover connection conductor 18 to form a tap terminal 12. do. Similarly, tap terminal 13 - wire ring element 8b - crossover connection conductor 19 - tap terminal 14 - wire ring element 8c - crossover connection conductor 20 - tap terminal 15 - wire ring element 8d -
The crossover connection conductor 21 is connected to the line terminal 10.

What should be noted here is that the order of series connection is different from the order of juxtaposition of the coil elements. With such a winding configuration, the charging voltage between adjacent coil elements becomes larger than that in Figure 2, so the series capacitance increases, and the potential distribution when an impact voltage is applied becomes significant. Because of this improvement, even if a tap coil is provided at the end of the line, the potential difference between the tap terminals will not become particularly large. However, if the wire ring elements are connected in the order in which they are arranged side by side, an excessive voltage will be applied to the boundary between the wire ring element groups, which is not preferable in terms of insulation.

FIGS. 7 and 8 show other embodiments of the present invention, and FIG. 7 shows that the tap coil layer provided as the outermost layer may be composed only of tap coil coil elements.

In addition, in FIG. 8, the body coil layer 7 and the outermost tap coil layer 8 are connected in an N-shape, and the voltage applied between the body coil layer and the outermost tap coil layer 8 is changed from the case of FIG. 5 to a 1 tap step voltage. Make it smaller. In this winding method, the tap coil layer 8
The winding start end of the body coil layer 7 is on the same side as the winding start end of the body coil layer 7. In the case of FIG. 5, the winding start end of the tap coil layer 8 is on the same side as the winding end end of the body coil layer 7.

As described above, according to the present invention, by connecting the tap coil to the line end and making the order in which the coil elements are connected in series different from the order in which they are juxtaposed, the potential distribution in the winding layer is improved and an impulse voltage is applied. Even if this happens, the potential difference between the tap terminals will not become large.
Further, by providing the tap coil outside the outermost line end layer, the preparation work for winding the winding is transferred only once from the body coil layer to the tap coil layer, thereby improving the working efficiency of the winding. In addition, the tapping work is easier, and the voltage applied to the tap lead is only for the tap coil layer (in Figure 5, for the three tap coil wire elements), so the insulation thickness can be reduced, and the tap connecting conductor does not pass inside the coil. Since there is no winding, the space factor of the coil is improved and an economical transformer winding can be obtained.

[Brief explanation of the drawing]

Figure 1a is a schematic diagram of a transformer using conventional multiple cylindrical windings with taps, Figure 1b is a similar wiring diagram, Figure 2 is a front view of the body coil layer of Figure 1, and Figure 3a is a FIG. 3b is a front view of the tap coil layer, FIG. 3b is a sectional view thereof, and FIG. 4 is a diagram of impulse voltage characteristics. Fig. 5a is a schematic diagram of a transformer using multiple cylindrical windings with taps according to the present invention, Fig. 5b is a wiring diagram, Fig. 6a is a front view of the tapped coil layer, and Fig. 6b is the same. 7a is a wiring diagram of another embodiment of the present invention, FIG. 7b is a sectional view of the tap coil layer, and FIG. 8 is a schematic diagram of a transformer of another embodiment of the present invention. . DESCRIPTION OF SYMBOLS 1... Iron core, 2... Low voltage winding, 3... High voltage winding, 4-7... Body coil layer, 8... Tap coil layer, 8a, 8b, 8c, 8d... Insulated coil element, 11-15 ...Tap terminal, 18-22...
Cross connection conductor. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In a transformer winding consisting of multiple cylindrical windings arranged concentrically around the iron core and having tap coils,
The tap coils are connected to the line ends and are arranged in parallel outside the outermost line end layer, and the outermost line end layer including the tap coils is formed by winding at least three or more insulated conductors in parallel in a spiral shape. 1. A transformer winding comprising two or more insulated coil elements arranged in parallel, the insulated coil elements being connected in series within the same winding layer in an order different from the order in which they are arranged.