JPS6132409A - On-load tap-changing transformer - Google Patents

Abstract

PURPOSE:To simplify the construction of a tap winding and to enable the miniaturization of a transformer by forming an integrated disk winding of coarse and dense tap windings winding a single strand for coarse tap winding and a single strand for dense tap winding placing in parallel. CONSTITUTION:A disk winding is made accumulating in the direction of axis plural with coils consisting of a disk coil wound from the outer side to the inner side and a disk coil wound from the inner side to the outer side placing a single strand (a) for making a coarse tap winding TW1 and a single strand (a') for making a dense tap winding TW2 in parallel. Taps A1, A2 are led out from the start and the end of the coarse tap winding TW1 for connecting to a transposition switch. The taps b1, b2, c1, c2, d1, d2, h1, h2, i1, i2 of the dense tap winding TW2 are each led out from each twin coil wound with the single strands (a), (a'). Integrally formed disk windings of a low voltage winding L, a high voltage winding H, the coarse tap winding TW1 and the dense tap winding TW2 are placed in this sequence from the side of an iron core C.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to an on-load tap-changing transformer.

[Background of the invention]

A shift-switching on-load tap-changing transformer is constructed, for example, as shown in Japanese Utility Model Publication No. 44-8184 when a wide range of voltage regulation is required.

In other words, an on-load tap-changing transformer has a low-voltage winding wound around an iron core, a high-voltage winding placed outside the low-voltage winding, a sparse tag winding placed outside the high-voltage winding, and a loosely tapped winding placed outside the high-voltage winding. It is composed of closely tapped windings arranged adjacent to each other on the outermost side. The loosely tapped winding is connected in series to the high voltage winding, and the closely tapped winding is connected in series to either the high voltage winding or the sparsely tapped winding via a transposition switch. In other words, the transposition switching device is used to connect taps that are drawn out from the high-voltage winding and also connected to the strands at the beginning of the loosely tapped winding, taps that are drawn out from the strands at the end of the loosely tapped winding, and taps that are connected to the strands at the end of the loosely tapped winding, and those that are connected to the strands at the end of the loosely tapped winding. It consists of a drawn tap and a contact connected to the tap drawn from this close tapped winding. If this contactor is connected to a tap drawn out from the high-voltage winding, the high-voltage winding and the densely tapped winding are directly connected in series, and the contactor is connected to the tap drawn out from the end of the loosely tapped winding. When connected, the loosely tapped winding is connected in series to the high voltage winding, and the closely tapped winding is connected in series to the loosely tapped winding. That is, the closely tapped winding is connected in series to the high voltage winding via the loosely tapped winding.

A tap is derived from each of the required number of turns in this close-tapped winding, and the multiple taps of this close-tapped winding are connected to the neutral point via a tap changer connected to the neutral point. The voltage is adjusted by connecting this tap changer to a desired tap among the plurality of taps of the closely tapped winding. In other words, when the contact of the transposition switch is switched to the tap side derived from the end of the loosely tapped winding, the loosely tapped winding is connected in series with the high voltage winding, and the voltage adjustment by tap switching of the tap changer is performed by the loosely tapped winding. The tap side where the contact is pulled out from the high voltage winding when the winding is used (the tap side at the beginning of winding of the sparsely tapped winding)
When switched to , voltage adjustment by changing the taps of the tap changer is performed without using the sparsely tapped winding.

In an on-load tap-changing transformer configured in this way, when a lightning impulse is applied to the high-voltage terminal of the high-voltage winding, the voltage between the high-voltage winding and the loosely tapped winding, and between the loosely tapped winding and the finely tapped winding is Voltage transfers between the loosely tapped winding and the closely tapped winding through the impedance (capacitance and inductance) that exists between the windings. The value and waveform (time lag) of this transition voltage in both windings are largely influenced by the above-mentioned impedance. Therefore, in a transformer with a conventional structure in which a loosely tapped winding and a closely tapped winding are wound separately, the transition voltage waveforms to both windings are different, resulting in a large voltage difference, or potential difference, between both windings. Occur. For this reason, it was necessary to strengthen the insulation of the tap changer and ensure an insulation distance between the windings, which hindered the miniaturization of transformers.

[Purpose of the invention]

The present invention has been made in view of the above points, and it is an object of the present invention to provide an on-load tap changeover transformer in which the structure of the tap winding is simplified and the size of the transformer can be reduced.

[Summary of the invention]

That is, the present invention includes a low/high voltage winding, a sparsely tapped winding connected in series to the high voltage winding, and a plurality of taps connected in series to the high voltage winding or the sparsely tapped winding via a transposition switch. In an on-load tap switching converter having a densely tapped winding, the strands forming the sparsely tapped winding and the strands forming the densely tapped winding are juxtaposed and wound from outside to inside. A plurality of twin coils consisting of a disc coil wound from the inside to the outside and a disc coil wound from the inside to the outside are stacked in the axial direction to form a disc winding in which the coarse and finely tapped windings are integrated, and the coarsely tapped winding is integrated with the coarsely tapped winding. The taps connected to the transposition switch are derived from the beginning and end of the winding, and the plurality of taps of the dense tap winding are derived for each arbitrary number of twin coils wound around the wire. This is characterized by the fact that the coarsely tapped wire is wound and formed by juxtaposing the strands forming the loosely tapped winding and the strands forming the densely tapped winding.
A disk winding is formed in which the densely tapped winding is integrated, and taps are led out from the beginning and end of the sparsely tapped winding, respectively, and the taps provided in the densely tapped winding are each connected to an arbitrary winding around which the winding is wound. is derived for each number of twin coils.

[Embodiments of the invention]

The present invention will be explained below based on the illustrated embodiments. An embodiment of the present invention is shown in FIGS. 1-3.

As shown in Figure 1, the on-load tap-changing transformer consists of a low-voltage winding L wound around an iron core C, a high-voltage winding H1 placed outside the low-voltage winding, and a high-voltage winding H placed outside the high-voltage winding H. It is composed of loosely and densely arranged tap windings TWI and TWz. In the figure, U is a high voltage terminal and Ul is a low voltage terminal.

In this embodiment of the on-load tap-changing transformer configured as described above, the strand a forming the sparsely tapped winding TW1 and the strand a' forming the densely tapped winding TWs are arranged side by side from outside to inside. A plurality of twin coils consisting of a disc coil wound and a disc coil wound from the inside to the outside are stacked in the axial direction to form a disc winding in which the coarse-fisted tap winding TWI and TWI are integrated. A tap AI is connected from the beginning and end of the tap winding TW1 to the shift switch SW (see FIG. 3).

While deriving A2, close tap winding TW! Multiple taps bl, b2. CI, C2, dl, d2゜hl, h
2. it and A2 were derived for each arbitrary number of twin coils wound with the windings a and a', respectively.

In this way, from K, the coarsely tapped winding TVV' is formed by winding and forming the strand a forming the loosely tapped winding TWs and the strand a' forming the finely tapped winding TWt in parallel.
1. TW! is formed, and taps At and A2 are derived from the beginning and end of the loosely tapped winding TW1, and the finely tapped winding TW! Tap b, 1 provided in
．． b, 2. C1°c2. dl, d2. hl, h2. il
, A2 are derived for each arbitrary number of twin coils winding the husband wires a and a', and form the tap winding TWI.

It is possible to obtain an on-load tap switching transformer that allows the structure of the TWs to be simplified and downsized. In other words, the on-load tag switching transformer has a low voltage winding L1 a high voltage winding H1 sparsely tapped windings from the iron core C side. TWI and dense tap volume mTW! The close tap winding TWs is divided into a plurality of winding units up to the upper winding unit, and the taps b1 . b2. c1. c2. dl, d2. hl.

h2. if, A2 has been derived. The loosely tapped winding TWs and the closely tapped winding TWs form an integrated disk winding, as shown in FIG. The wire a forming the strand is wound 1 from the top to the bottom in the order of 1 turn to 96 turns, and the tap A2 is derived from the end of the winding. This winding method is a well-known interleaving method. Closely tapped winding TWs replaces its element lsa/ with loosely tapped winding 'I'WI
The tap b1 is placed in parallel with the wire a, and the tap b1 is wound around the wire a' in the order of 1' to 12' turns to derive the tap b2. In other words, the loosely tapped winding TW is used between the winding turns.
s and the close tap winding TW2 are arranged alternately. Similarly, from tap C1, turn strand a' from 13' to 24'.
Wind it in the order of turns and derive tap C2. Similarly, the strand a/ is wound from the tap i1 in the order of 85' turns to 96' turns to derive the tap 12, but these taps b1 to b12 are cut to be slightly longer.

By doing this, the tap winding TW! Since it is divided into a plurality of winding units b-4, that is, twin coils, the twin coils can be connected in any order to form one continuous close-tapped winding T, Ws. For example, in Figure 3, from the high voltage winding H to the loosely tapped winding TW1 and the finely tapped winding TW.
Although up to 2 connections are shown, each winding unit b-t is % CI
・B, d...ilh are connected in the same order so that the winding method is the same. If the tap changer TC is at the lowest position, the tap winding TW is very close! The winding potential when C1b is inserted is the winding unit C1b with respect to the neutral point 0.
, d...the values increase in the order of i and h. A state in which the loosely tapped winding TW1 and the closely tapped winding TW2 are not inserted, that is, the shift switch SW is switched to the tap Al side, the tap changer TC is switched to the contact side of the shift switch SW, and the tap is set to the minimum to connect the high voltage terminal. When a lightning impulse voltage is applied from U, a large voltage is generated at each open end, but this differs depending on the connection order of the divided finely tapped windings TWs. This is because the mutual inductance, capacitance, and capacitance to ground differ slightly between the winding units. Although it is possible to estimate to some extent what kind of connection can minimize the transition voltage by calculating potential oscillations, it is not possible to accurately estimate complex waveforms.

The most reliable method for measuring actual transformer windings is to apply a low voltage simulated pulse. Therefore, by arbitrarily changing the connection of the close-tapped winding TW after the winding is fabricated as in this embodiment, it is possible to select the connection that provides the minimum transition voltage, and to insulate the turns between turns. Not only can it be connected to achieve a transition voltage that matches the strength, but it is also formed with a disk winding that integrates the coarse and fine tap windings TWs + TW, so the coarse and fine tap windings 'rw
t.

Since the TWs are formed of an integral disk winding, the structure of the tap windings TW, , TW can be simplified and the transformer can be made smaller. Actual measurements can also be performed when the applied voltage waveform, tap position, etc. are changed, and a connection that satisfies all conditions can be achieved.

In addition, in Fig. 3, if the close-tapped winding TWs are connected in the order of winding unit s, c, j...h, 1, then the close-tapped winding TWs is continuously wound from the top. It is the same as turning the winding and deriving the tap from the middle, so it is the simplest structure to manufacture the winding, and when the loosely tapped winding TWI and the densely tapped winding [IiI T W s are open ends, mutual capacitor coupling is possible. Since this is good, almost no potential difference occurs between the turns of the sparsely tapped winding TW1 and the densely tapped winding TW2. However, the open ends do not connect well to the ground side, so
A large voltage is generated. Therefore, a certain amount of generated voltage is allowed at the open end, and if it is desired to generate a large voltage between the turns, such a connection may be used.

Furthermore, it is also possible to completely replace the top and bottom of the tightly tapped TW wire without changing the winding direction. The power is the second
In the figure, tap 12 and hl are connected, tap d2 and cl, tap C2 and bl (hl and a2 are not shown), and when the tap is the minimum tap, tap 11 becomes the ground terminal and b2 is the open end. Connect so that In this case, the tap A2 of the sparsely tapped winding is the open end, and the tag A1 is the ground side. This is tap A2 at the open end of the sparse tag winding.
If tap b2 at the open end of the closely tapped winding is adjacent to the ground side of the loosely tapped winding, and close to the ground side of the closely tapped winding, a large voltage will be generated between the turns. Therefore, a certain degree of insulation strength is required, but each open end is grounded.The voltage generated between turns or at the open end varies depending on the connection method, but as in this example, a close tap winding@TW If , are made into a plurality of independent winding units, the most desirable connection can be selected from the relationship between the generated voltage and the insulation strength even after the winding is manufactured.

Another embodiment of the invention is shown in FIG.

In this embodiment, the sparsely tapped winding and the densely tagged winding are wound together as ordinary disc windings. That is, the loosely tapped winding was formed by winding the strand a- from 1 turn to 96 turns, and providing taps AI and A2 at the beginning and end of the winding, respectively. The close-tap winding was composed of a plurality of twin coils formed by winding a strand a and a strand a' arranged in parallel. That is, the close tag winding is wound up to 12' turns from II ethanon, and the tag b1. Twin coil with b2,
Twin coil wound from 13' turn to 24' turn, with taps cl and c2 provided at the beginning and end of the winding, respectively, 8
The coil was wound from 5' turn to 96' turn, and was constructed of twin coils with tags 41 and 42 provided at the beginning and end of the winding, respectively. By doing so, the sparsely tapped winding can be made into a continuous disk winding without any connections, so the winding can be manufactured easily. In addition, the close tag winding can achieve the most desirable connection in terms of the relationship between insulation strength and generated voltage by arbitrarily connecting a plurality of twin coils, and can achieve the same effects as in the case described above.

Note that it is also possible to divide the sparsely tapped winding into a plurality of pieces and change the vertical position of the winding. In this case, the sparsely tapped winding is not a continuous disk winding, so it is somewhat difficult to manufacture, but the voltage generated between the densely tagged winding and the O-ton can be suppressed by switching the vertical positions of the divided windings. Become.

In addition, the same effect can be obtained even if the disk winding is formed by a plurality of twin coils wound with coarse and fine taps at both ends, and a twin coil wound only with coarse taps in the middle part. be able to.

〔Effect of the invention〕

As described above, the present invention has simplified the structure of the sparse and dense tap windings, making it possible to make the transformer smaller. Tap-changing transformers can be obtained.

[Brief explanation of drawings]

FIG. 1 is a winding arrangement diagram of an embodiment of the on-load tap-changing transformer of the present invention, FIG. 2 is a winding connection diagram of sparse and dense tap windings of the same embodiment, and FIG. Wiring diagram of the winding shown in the figure,
FIG. 4 is a winding connection diagram of sparse and dense tap windings of another embodiment of the on-load tap-changing transformer of the present invention. C... Iron core, L... Low voltage winding, H... High voltage winding,
TWl... Loosely tapped winding, 'rw,... Closely tapped winding, SW... Transposition switch, TC... Tap switch,
0...neutral point, U...high voltage terminal, Ul...low voltage terminal, AI, A2...tap of loosely tapped winding, a...
Wire forming loosely tapped winding at... Wire forming densely tapped winding, b. c, d, h, i...Twin coil (winding unit of close tap winding), bl, b2. CI, C2, di. d2. hl, h2. il, A2...Tap derived from a twin coil with close tap winding.

Claims (1)

[Claims] 1. It has a low/high voltage winding, a sparsely tapped winding connected in series to the high voltage winding, and a plurality of taps connected in series to the high voltage winding or the sparsely tapped winding via a transposition switch. In an on-load tap-changing transformer having a densely tapped winding, the strands forming the sparsely tapped winding and the strands forming the densely tapped winding are juxtaposed and wound from outside to inside. A plurality of twin coils each consisting of a coil and a disc coil wound from the inside to the outside are stacked in the axial direction to form a disc winding in which the coarse and fine tap windings are integrated, and the winding of the sparse tap winding is Deriving the taps connected to the transposition switch from the beginning and end of the winding, and also deriving the plurality of taps of the densely tapped winding for each arbitrary number of twin coils around which the wire is wound. Features an on-load tap switching transformer.