JPH0249408A - Self-cooled stationary electromagnetic induction apparatus - Google Patents

Abstract

PURPOSE:To improve the cooling capacity of windings as well as to increase the current density of the windings by a method wherein a plurality of independent refrigerant passages, having at least either of a refrigerant inlet provided at the lower part of the winding and a refrigerant outlet provided at the upper part of the winding, are provided. CONSTITUTION:A winding 2, which is wound in vertical direction by providing gaps between the windings, on which a plurality of tabular coils are laminated in vertical direction through a gap, or between the turns of a helical coil 3, is provided, and each gap is utilized as a part of a plurality of independent refrigerant passages. Each of refrigerant passages 44 and 45 has at least either of the refrigerant inlets 40a and 41a provided at the lower part of each winding 2, and also either of the refrigerant outlet 42a and 43a provided at the upper part of each winding 2. As a result, the cooling capacity of the winding 2 can be improved, and the current density of the winding 2 can also be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a self-cooled stationary inductor such as a self-cooled transformer having a novel winding cooling structure.

[Conventional technology]

Figures 7 to 10 show an example of a conventional oil-filled self-cooling transformer, in which Figure 7 is a cross-sectional view showing the internal structure; Figure 8 is a cross-sectional view showing the configuration of the secondary winding; FIG. 9 is a partial plane cross-sectional view showing a part of the secondary winding, and FIG. 10 is a cross-sectional view showing the flow of insulating oil (hereinafter referred to as part) which is a refrigerant in the secondary winding. In these figures, (1) is the iron core, (2) is the winding, and in this example, a disk coil (3) is a type of plate-shaped coil that is radially wound in a plane using rectangular copper strips. Multiple secondary windings on the low voltage side stacked vertically, (4)
is the primary winding on the high voltage side wound in a cylindrical shape around the outer circumference of the secondary winding (2), (5) is the tank that accommodates the iron core (1) wound with the winding (2) I (4), (6) is oil. In addition,
Although the tank (5) is provided with a heat radiator, illustration thereof is omitted. Next, details of the configuration of the secondary winding will be explained with reference to FIGS. 8 and 9. (7) is the secondary winding (2) and iron core (1)
(8) is the secondary winding (2) and the secondary winding (4) (not shown in Figure 8, see Figure 7). ) is an outer insulating tube for insulating the disc coil (3) from the inner insulating tube (7).
The disk coils (3) are arranged horizontally on top with a vertical spacer (9a) interposed therebetween, and a plurality of disk coils (3), in this example, 9 These are stacked to form a secondary winding (2), and an outer insulating cylinder (8) is provided on the outer periphery of the secondary winding (2) via a vertical spacer (9b). Vertical spacer (9a)
, (9b), horizontal spacer 00 is shown in Fig. 8 IX-IX
As shown in FIG. 9, which is a cross-sectional view of the secondary winding (2), they are arranged at intervals radially in the radial direction of the secondary winding (2), and the inner insulating cylinder (7) and the vertical spacer (9a) Gap (6) between the secondary winding (2), gap between the outer insulating cylinder (8) and the secondary winding (2) due to the vertical spacer (9b) @
A gap of 0 between the disc coils (3) and the horizontal spacer QO forms an oil passage. Although the primary winding (4) shown in FIG. 7 is not shown in FIG. 8, it is disposed outside the outer insulating cylinder (8) in FIG. 8.

Next, the operation will be explained. In Fig. 10, the oil that cools the secondary winding (2) is distributed between the gaps (11), U, and Q.
3, and the secondary winding (2), that is, the disc coil (3), is heated by the loss generated by the current flowing through it, and the temperature rises and a difference in specific gravity occurs. The oil rises from the bottom to the top, and the rising oil is sent to a radiator (not shown)
and is returned to the lower part of the secondary winding (2). However, since the disc coils (3) are stacked vertically, the oil in the gaps between the disc coils does not flow in one direction; for example, it flows irregularly and locally as shown by the arrows in the figure. The cooling capacity decreases due to the natural convection of the flow, and the disc coil (
3) had problems such as localized overheating.

Another conventional oil-filled self-cooling transformer designed to solve the above problems is shown in FIGS. 11 to 15.

Figure H is a sectional view showing the flow of oil in the secondary winding, Figure 13 is a plan view of an oil guide that blocks one flow of oil and guides the flow in one direction, Figure 14. , FIG. 15 is a partial plan cross-sectional view of the secondary winding showing how the oil guide is arranged between the disk coils. In the figure, steps (3) to (to) are the same as in the conventional example described above, so explanations thereof will be omitted. In these figures, 01) and @ are the secondary winding (2) and the inner side,
A vertical spacer (9) is placed between the outer insulating cylinder (7) j (8).
a), the gap created by (9b), (to), αQ
is the gap inserted between the disc coil (3) and the horizontal spacer αQ? (a) This is an oil guide that blocks the vertical flow of oil inside and guides the flow horizontally.

The oil guide (to) is an annular insulating plate with a vertical spacer (
It has a notch (15a) to avoid interference with 9a), and the inner diameter is slightly larger than the outer diameter of the inner insulating cylinder (7), and the outer diameter is almost the same as the outer diameter of the disc coil (3). The gap 21) is made to the same size as the gap 21a in the vertical direction.
~(21f) to block the oil flow, and the gap (a)
It is designed so that there is no dimensional interference with the flow of oil. The oil guide M is also an annular insulating plate, and as shown in the plan view in Fig.
), the outer diameter of which is slightly smaller than the inner diameter of the outer insulating cylinder (8), and the inner diameter of which is approximately the same as the inner diameter of the disc coil (3). It is divided into gaps (22a) to (22e) to block the flow of oil. Note that FIGS. 14 and 15, which are partial plane cross-sectional views of the secondary winding showing the arrangement of the oil guides Qf9 and α, show the inner and outer insulating tubes (7) and (8), and the vertical and horizontal spacers. (9a) * (9b) - This is a schematic representation of the positional relationship with α0, for example, the inner insulating cylinder (
7) and the oil guide αυ, as shown in FIG. 14, there is no large gap, and the necessary locations are dimensioned so that oil leakage does not become a problem. That is, as shown in FIG. 11, the vertical gap? ◇, the gap created by dividing the canopy with oil guides αυ and αQ (
21a) ~(21f) p (22a) ~(22e)
and the gap α between the disk coil (3), one refrigerant passage (A) is formed which communicates the opening provided at the lower part of the secondary winding with the opening (C) provided at the upper part. It turns out that it is formed.

Another conventional example of an oil-filled self-cooling transformer is configured as described above, with gaps (21a) to (21f) p (22a
) ~(22e) , (The oil filling 13 is heated by the loss generated by the current flowing through the secondary winding (2), that is, the disc coil (3), and is heated by the secondary winding (2) by natural convection. It rises from the bottom to the top, but between 191 (
21a) (21f).

(22a) to (22e) and (to) collectively form one refrigerant passage (25) as described above, so the oil flows under the secondary winding as shown by the arrow in Figure n. It flows in through the opening (2) provided at the top, rises while being heated by the disk coil (3), and exits upward through the opening (c) provided at the top. In other words, the opening (2) provided at the bottom
is the oil inlet, and the opening provided at the top is the oil outlet. Therefore, in this conventional example, the oil in the gap between the disk coils flows in a fixed direction, and unlike the first conventional example (irregular and localized flow does not occur).

[Problem to be solved by the invention]

In the other conventional oil-filled self-cooling transformer mentioned above, the windings are cooled using a single refrigerant arranged so that the gaps between the disc coils (3) are all in series. This is done by oil flowing through the passages. Therefore, due to the long refrigerant circuit, the current density flowing through the windings causes heat and temperature rise due to the natural convection caused by the difference in specific gravity of the oil. However, the cooling capacity is low due to the small flow rate of the oil, and the current density in the secondary winding is low. There was a problem that the value had to be limited to a small value, and the amount of conductor used increased, making it uneconomical.

This invention was made in order to solve the above-mentioned problems, and the purpose is to obtain an economical self-cooled static electromagnetic inductor that has a high cooling capacity and can increase the current density of the winding. shall be.

[Means to solve the problem]

The self-cooled stationary electromagnetic induction device according to the present invention includes a plurality of plate-shaped coils stacked vertically with gaps in between, or spiral coils wound in the vertical direction with gaps between turns. a refrigerant inlet provided at the bottom of each of the windings and a refrigerant at the top of each of the windings; It has at least one outlet.

[Effect]

In this invention, since a plurality of independent refrigerant passages each having a refrigerant inlet provided at the lower part of the winding or a refrigerant outlet provided at the upper part are provided, the total flow rate of the refrigerant for cooling the winding is increased, and the cooling capacity is increased. improves.

[Embodiments of the invention]

FIGS. 1 to 3 are temperature distribution diagrams showing one embodiment of the present invention and showing a comparison of the increase in vertical spacer degree in the conventional example described above in order to provide a gap α force, and in the figures (3) to ( to) are the same as each of the above-mentioned conventional examples, so their explanation will be omitted. This is an inner insulating cylinder and corresponds to the trap of the inner insulating cylinder (7) (Fig. A partition tube 0◇ is provided in two vertical gaps having openings (40a) and (41a) at the bottom of the secondary winding (2).

0]). As shown in Figure 2, the inner partition tube 0 has many holes (3 holes) in the center for passing oil.
1a). (2) is an outer insulating cylinder and corresponds to the outer insulating cylinder (8) of the conventional example (Fig. 11).
The distance between the secondary winding (2) and the disk coil (3) is twice that of the conventional example, and an outer cylindrical partition tube (■) with a number of holes (33a) for passing refrigerant is provided in the middle. Opening at the top (4
two longitudinal gaps (6) with 2a), (4aa)
, (goods) are formed. Although not shown, a vertical spacer similar to the vertical spacer (9b) (Figs. U and 3) is inserted. Although not shown, the horizontal spacer QO of the above-mentioned conventional example is also inserted between the disc coils (3), thereby reducing the gap between the disc coils (3).
is provided. ) and (g) are the oil guides (to) of the other conventional examples mentioned above, oil guides similar to αQ, α force is a partition plate provided in the middle of the secondary winding (2), and The shape is a combination of the oil guide (G) shown in Fig. 14 and the oil guide αQ shown in Figs. In order to avoid interference with a vertical spacer (not shown) on its inner periphery, a notch (lsa
) (Fig. It has a notch similar to the notch (16a) of the conventional oil guide αQ (Figure n), with a gap (b) at the bottom of the hole (3Xa) and a gap (b) at the top of the hole (33a). 6) is blocked. (b) is provided above the hole (31a) with a gap ■
A closing plate (2) is provided below the hole (33a) to close the gap. By configuring the gaps ■, h]), (6), (to), and (to) as described above, the lower opening (40a) → gap ■ → the upper part of the secondary winding (2) Series circuit consisting of half disc coil gap 0 → refrigerant passage leading to upper opening (4Za)■
The refrigerant reaches the lower opening (41a) → the gap between the lower half disc coils of the secondary winding (2) → the gap → the upper opening (43a) Passage (c)
, that is, two independent refrigerant passages (b).

(c) is formed.

In the oil-filled self-cooling transformer configured as described above, oil fills the gaps (g), (z), (6), (g), and (to), and the secondary winding (2) , that is, plate-shaped coil (3)
The oil flows through the opening (40a) at the bottom as shown by the arrow in Figure 1, passes through the gap, and flows into the plate-shaped coil (40a). 3), the oil is heated to cool the plate-shaped coil (3) in the upper half of the secondary winding (2).
The refrigerant passes through the refrigerant passage ■ flowing out from the upper opening (42a) and the plate coil (3) in the lower half of the secondary winding (2) from the lower opening (41a). ) into the refrigerant passage which cools the refrigerant and flows out from the upper opening (43a) through the gap, i.e., the lower opening (40a),
(41a) is the oil inlet, the upper opening (42a), (43
Oil flows through the refrigerant passages (2) and (3) with a) as the oil outlet.

Note that the oil flowing out from the upper openings (42a) and (43a) rises further and reaches the tank (not shown).
5) Heat dissipation by the external heat radiator (Fig. 7),
It is cooled and returned to the bottom of the tank. In other words, in other conventional examples (Fig. 11), the gap α of the disc coil (3) was composed of one refrigerant passage (A) that was connected in series, whereas in the present invention In one embodiment, since two independent refrigerant passages (2) and (3) are provided, that is, oil flows through two parallel passages, the secondary winding (2) is different from the other conventional examples mentioned above. The total flow rate of cooling oil is increasing.

The flow rate of oil flowing through the gap (to) of the disc coil (3) as shown by the arrow in Figure U or Figure 1 is determined by the size of the disc coil and the loss occurring in the refrigerant passage (this is due to the loss in the refrigerant passage). (equivalent to the sum of the losses of the disc coils existing in
The following approximate formula has been obtained experimentally. That is, Q = VXS: k night---------- (g here, Q: flow rate of oil passing through the gap of the disc coil [rrL
3/S] ■: Flow rate of oil passing through the gap between the disc coils (-/biased) S: Cross-sectional area of oil passing through the gap between the disc coils Cm"3: Constant W: Loss occurring in the refrigerant passage [ W] Therefore, in the above-mentioned other conventional example (Fig. 11), since there is only one refrigerant passage (all gaps α1 are connected in series), if the loss occurring in the secondary winding (2) is Wl, then the refrigerant passage The loss occurring in w : W, and the oil flow ff1Q flowing through the refrigerant passage is calculated as Qt=1 by the above equation (1).
...Song/song interval (2) Next, in one embodiment of the present invention, since the secondary winding (2) is cooled by flowing oil through two parallel refrigerant passages, the above (1) ) loss occurring in the refrigerant passage (loss occurring in one passage)
is halved, so the flow rate of oil flowing in each of the refrigerant passages ■ and (c) is Q! By substituting W=Wl/2 into the above equation (1) (other conditions are the same as the other conventional examples above), Qt
= kV = o, sQ, +++++++++ curve <3) Since there are two independent cold curve passages, the total oil flow rate Q2t is Q, t '' 2 Qt ~ 1.6Q, ...・
......(4), and when the loss occurring in the secondary winding (2) is the same, the total oil flow rate is the above (4).
) is 1.6 times as shown in the formula. Therefore, in response to the increase in oil flow rate, the secondary winding (2) (disc coil (3))
Although the cooling capacity for cooling the secondary winding increases and the temperature rise of the secondary winding decreases, this relationship is shown in comparison with the other conventional example described above. In this figure, to is the temperature at the bottom of the winding, tl is the temperature at the top of the winding in another conventional example, and tt is the temperature at the middle and top (refrigerant outlet) of the winding in this example. When the loss occurring in the secondary winding (2), that is, the current density of the secondary winding (2), is set to the same value, the maximum temperature of the secondary winding becomes lower. Conversely,
If the maximum temperature of the secondary winding is kept the same as in the conventional example, the current density of the secondary winding can be increased by the increased cooling capacity.

FIG. 4 is a cross-sectional view showing oil flow in another embodiment of the present invention, in which the holder is an outer cylinder provided with a vertical spacer (not shown) between it and the outer partition cylinder. Yes, outer partition tube (
There is a refrigerant outlet (5) in the gap between (to) and the top of the winding.
3a). (Foundation) is the refrigerant inlet (50a) provided near the center of the secondary winding (2) and the secondary winding (2).
2) has a refrigerant outlet (52a) provided at the top of the secondary winding (2), as shown in the figure;
3a), which is another refrigerant passage as shown, which is independent of the refrigerant passage (b). The oil, which has been warmed by the secondary winding (2) and whose temperature has risen, flows out from the refrigerant outlet @a) and ■a) and rises. ) The temperature of the oil near the refrigerant inlet (51a) is not affected much, and oil having the same temperature as the oil at the other refrigerant inlet (51a) also flows into the refrigerant passage member.

FIG. 5 is a cross-sectional view showing the flow of oil in yet another embodiment, and 1 has a large number of holes (61a) * (61b), (61C) for passing the refrigerant in the lower, middle, and upper parts. The inner partition plate has an outer insulating cylinder, the first partition plate (163) has a number of holes (63a), (63b) for passing the refrigerant, and the second partition plate (163) also has a number of holes (163a). It is a partition plate, and these and oil guide α0. αQ, partition plate α, occlusion plate (b), @, ga and disc coil (3
), three independent refrigerant passages υθ, σe, and n are constituted by the gaps formed by the above. Refrigerant passage.

(c), (c) are refrigerant inlets (72a), (73a), (7) provided at the bottom of the secondary winding (2), respectively.
4a) and a common refrigerant outlet (70a). The oil flow in the refrigerant passage is shown by the arrow in the figure, and the refrigerant inlet (72) provided at the bottom of the secondary winding (2)
a), (73a) and (74a) are provided, so that cold oil always flows into the refrigerant inlets (72a) to (74a) of each passage, and Total oil flow rate (circulation amount)
Fig. 6 is a sectional view showing the oil flow in yet another embodiment, and shows the gap (113) between the disc coil (103) of the secondary winding (102). ) are connected in parallel, and three refrigerant passages are connected in series to provide two independent refrigerant passages. In the figure, - is the inner insulating cylinder, and iris are the many holes (8) for passing oil.
1a), and ■ is the refrigerant outlet hole (8).
3a) and (83b) are provided, and - is a closing plate that closes the gap between the inner insulating cylinder and the inner partition tube tan, and these members and the disc coil (103)
and two independent refrigerant passages a141. (spacer not shown) as shown in the figure. -, and oil flows as shown by the arrow in the figure. In addition, two independent refrigerant passages
In FIG. 2, the secondary winding (102) has refrigerant inlets (90a), (91a) provided at the bottom and refrigerant outlets (92a), (93a) provided in the outer partition tube, respectively.

In each of the above embodiments, the secondary winding is a disk coil, but the other windings may be disk coils, and for example, the secondary winding and the secondary winding may also be One consisting of disc coils arranged alternately in the axial direction, or a large number of conductors stacked in parallel in the radial direction and wound flat and spirally wound vertically with gaps between turns. Even with a turned spiral coil or the like, the refrigerant passage can be constructed in accordance with the gist of the present invention. The plate coil is
Even if it is not a disk coil, a rectangular plate coil, a disk coil formed by winding a round wire, etc. can produce the same effect.

Although some examples have been given regarding the number of refrigerant passages, the method of configuring the refrigerant passages, and the arrangement of the refrigerant inlets and outlets of the refrigerant passages, these may be modified as appropriate without impairing the purpose of the present invention. Just design it.

In addition, although the oil-immersed self-cooled transformer is shown, other self-cooled stationary electromagnetic induction devices such as reactors and induction voltage regulators may also be used (the refrigerant may be fluorocarbons, sulfur hexafluoride, air or other However, the above (1)
The formula is for the case where the refrigerant is oil, so in the case of other refrigerants, the degree of increase in the total flow rate of the refrigerant is as described in (1) above.
[Effects of the Invention] As explained above, the present invention has a plurality of independent refrigerant passages each having at least one of a refrigerant inlet provided at the lower part of the winding and a refrigerant outlet provided at the upper part of the winding. This increases the total flow rate of the refrigerant that cools the windings, improving the cooling capacity of the windings, making it possible to increase the current density of the windings and reducing the amount of conductors used. .

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of the present invention, and Figure 4 shows an embodiment of the present invention.
FIG. 5 is a sectional view showing the flow of oil in another embodiment of the invention, FIG. 6 is a sectional view showing the flow of oil in another embodiment of the invention, and FIG. Figures 7 to 10 show an example of a conventional oil-immersed transformer, with Figure 7 being a cross-sectional view showing the internal structure, and Figure 8 showing the configuration of the secondary winding. 9 is a partial plane sectional view of the secondary winding, FIG. 10 is a sectional view showing oil flow, FIGS. 1 to 3 show other conventional examples, and FIG. is a cross-sectional view showing the flow of oil in the secondary winding, Fig. 13 is a plan view of the oil guide, and Fig. 14 and Fig. 2 are the arrangement of the oil guide arranged between the disc coils. FIG. 3 is a partial plan cross-sectional view of the secondary winding showing the situation. In the figure, (2) ) (102) is the secondary winding, (3
) p (103) is a disk coil, (6) is oil, (to)
, (113) is the gap, t4oa)t(41a), (5
0a), (51a) * (72a) ~ (74a), (9
0a), (91a) are refrigerant inlets, (42a), (43a)
), (sza), (s3a), (70a) *(92a
), (93a) is the refrigerant outlet, ■, (c), (goods),
Open p (7G -4, (7η, Foundation), - are refrigerant passages. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A plurality of plate-shaped coils are stacked vertically with gaps between turns, or a spiral coil is wound vertically with gaps between turns, and each gap is separated by a plurality of independent windings. In a self-cooling stationary electromagnetic induction device used as a part of a refrigerant passage, each of the refrigerant passages has at least one of a refrigerant inlet provided at the bottom of each of the windings and a refrigerant outlet provided at the top of each of the windings. A self-cooled stationary electromagnetic inductor characterized by