JPS605555Y2 - Electrostatic ring of high voltage coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of an electrostatic ring for mitigating an electric field, which is disposed at the axial end of a large-capacity, high-voltage coil of a stationary induction electric device such as a transformer or a reactor.

FIG. 1 shows an end structural diagram of a typical example of a conventional large-capacity high-voltage coil.

The high-voltage coil 1 is made up of a plurality of stacked plate-shaped windings 3 each having an oil duct 2 inside and on both sides, and a sufficiently rounded electrostatic ring 4 is arranged at the axial end of the coil to act as a conductor at the end of the coil. At the same time, it serves to alleviate the concentration of electric field applied to the coil and to improve the potential distribution within the coil.

An L-shaped part 5 made of a solid insulator such as a presspod is placed in a direction perpendicular to the electric field to cover the inner and outer side surfaces of the coil 1 and the end face of the electrostatic ring 4 to strengthen the insulation and to prevent oil flow as shown by the arrow. It also serves as a guide for section 6.

The oil that has passed through the inner and outer diameter surfaces of the coil end and the inside of the duct 2 passes through the inner and outer diameter side surfaces of the electrostatic ring 4, and then passes through the L-shaped portion 5.
It snakes between the coils and exits the coil.

In this structure, the inner and outer diameter sides of the coil and the inner duct 2 of the winding
Since the cross-sectional area of the ducts on both sides of the electrostatic ring 4 is extremely small compared to the total cross-sectional area of the oil passages, the oil flow resistance is large and a sufficient flow of cooling oil cannot be expected.

As a structure to improve this, as shown in FIG. A structure is known in which a collar 24 is provided between the L-shaped portions 23 to cover the gap 22 from the side, thereby increasing the creepage distance.

However, in this structure, as shown in Figure 3, the coil 1
When leading out the lead 25 from the end in the axial direction of the coil, it is necessary to cut out a portion of the electrostatic ring 21 in order to maintain a distance between the lead 25 and the electrostatic ring 21.

In this case, as shown in Figure 4, if the width of the electrostatic ring is small, the width 41 of the cutout part will be narrow and mechanically weak, and will be subject to mechanical force when the coil is tightened or due to a short circuit in an electric appliance. In some cases, this narrowed part could cause damage.

As a countermeasure to this problem, as shown in Figure 5, the interval 22
It is conceivable to crush a portion of the protrusion 51 to form the protrusion 51 for reinforcement, but this has the drawback that it is not only laborious and expensive to work with, but also partially obstructs the oil flow.

The present invention has been devised in view of this point, and it is an object of the present invention to provide an electrostatic ring that is easy to manufacture and has sufficient mechanical strength, while eliminating the above-mentioned drawbacks.

According to the present invention, this object is achieved by providing the annular oil passage at the cutout portion so as to be offset from the three-point dividing point between the outer diameter of the outer ring and the inner diameter of the inner ring toward the side opposite to the cutout. .

6 and 7 are views showing an embodiment of the present invention, and the same reference numerals indicate the same functions as those described above.

The electrostatic ring 61 that covers the end face of the coil 1 is an inner ring 61
A and an outer ring 61B, forming an annular oil passage 62 between them through which cooling oil for the coil 1 passes.

In addition, a part of the electrostatic ring 61B is cut out at the lead part so that the lead part 25 is led out from the plate-like winding 3 at the end of the coil 1 and is spaced from the lead.

At the notch 63, the center 64 of the annular oilway 62 (
(Fig. 7) is the width of the electrostatic ring 61 (between the outer periphery of the ring 61B and the inner periphery of the ring 61A) from the center 65 of the opposite notch 6.
Pass through 3 sides.

Therefore, the width 4 at the notch 63 of the outer ring 61B
1 is larger and stronger than the conventional case in which the center of the annular oil passage 62 coincides with the center of the width of the electrostatic ring.

In this structure, the increase in oil flow resistance due to deviation between the center of the oil passage 62 and the center of the coil width is small, so there is little change in the resistance of the oil flow flowing inside the inner and outer coil ducts.

FIG. 7 shows a case where the electrostatic ring 61 and the oil pipe 62 are concentric.

FIG. 8 shows an electrostatic ring 81 according to another embodiment of the present invention, in which the same reference numerals indicate those having the same functions as those described above.

The electrostatic ring 81 has an inner ring 81A and an outer ring 81B.
Thus, an annular oil passage 82 is formed between the two.

The outer diameter of the outer ring 81B and the inner diameter of the inner ring 81A share the same center 0□, and the inner diameter of the outer ring 81B and the outer diameter of the inner ring 81A, in other words, the outer and inner diameters of the oil pipe 82 share the same center 02. The center 05 is located on the side opposite to the notch 63 from the center 01.

Therefore, the width 41 of the ring 81B at the notch 63 is wider and stronger than that of the conventional ring.

By making the oil pipe 82 eccentric in this way, the degree of eccentricity between the coil center and the oil pipe 82 is reduced compared to the arrangement shown in FIG. There is.

As is clear from the above explanation, the end face of the coil 1 is covered by the electrostatic ring 61.81 consisting of the inner rings 61A, 81A and the outer rings 61B, 81B divided into two via the annular oil passage 62°82, and the coil End drawer lead 25
In the case where a part of the electrostatic ring is cut out in order to increase the distance between the annular oil pipe 6 and
By making the centers of the electrostatic rings 61 and 82 pass on the opposite side of the notch from the center of the width of the electrostatic ring 61, 81, the width 41 of the outer rings 61B and 81B at the notch 63 is widened and mechanically strengthened. Ru.

In the above description, the drawer part 25 is drawn out from the outside of the coil, but the present invention can also be applied to the case where it is drawn out from the inside.

[Brief explanation of drawings]

Figures 1 to 3 are cross-sectional views of the ends of conventional high-voltage coils;
4 and 5 are partial plan views of the electrostatic ring shown in FIG. 3, FIG. 6 is a sectional view of the end of the high-voltage coil according to the embodiment of the present invention, and FIGS. 7 and 8 are partial plan views of the electrostatic ring shown in FIG. FIG. 3 is a plan view of an electrostatic ring. 1...High voltage coil, 25...Drawer lead, 61.81...Electrostatic ring, 61A, 8
1A...Inner ring, 61B, 81B...
...Outer ring, 62...Annular oilway, 63...
... Notch, 64 ... Center of annular oilway, 65 ... Center of electrostatic ring width.

Claims (1)

[Scope of utility model registration request] An electrostatic ring that covers an axial end face of a coil, in which a notch is provided in a part of the ring for leading out the coil lead, and the ring has an annular shape provided in the axial direction of the coil. In a ring consisting of an outer ring and an inner ring that are separated in the radial direction by an oil passage, the annular oil passage has an opposite cut at the notch portion from a bisecting point between the outer diameter of the outer ring and the inner diameter of the inner ring. An electrostatic ring of a high voltage coil characterized by being provided offset to the notch side.