JP2567069B2 - Multiple cylindrical winding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention comprises a plurality of concentric cylindrical windings used as windings for induction electric equipment such as transformers and reactors. It relates to multiple cylindrical windings.

(Prior Art) Generally, as a high-voltage winding of a high-voltage, large-capacity transformer, a multi-cylindrical winding with excellent winding workability is used together with an interleaved disk winding with excellent potential distribution in the winding. ing.
(See Japanese Patent Publication No. 54-26687) As shown in FIG. 4, the multiplex cylindrical winding is composed of a plurality of concentric cylindrical windings 1 formed by winding a coil conductor in a cylindrical shape. Each of the cylindrical windings 1a, 1b, ..., 1g is alternately connected to the adjacent cylindrical windings at the upper end and the lower end, and is connected in series as a whole. It is attached to the iron core 4 together with the wire 20.

A barrel shield 6 for improving the potential distribution is arranged outside the multiple cylindrical winding 10, or an electrostatic shield ring 7 for electrolytic relaxation is generally arranged at the end of each cylindrical winding 1a to 1g.

Since the electrostatic shield ring 7 is installed at the winding end portion where the winding conductor is continuously wound over the two layers, as shown in FIG. A large space is formed between the ring 7 and the ring 7. The dimension between the winding end and the electrostatic shield ring has a maximum deviation of d, and the dimensional deviation d corresponds to the conductor height when the parallel conductors forming the cylindrical winding are integrated, and its size is It has a strong correlation with the ease of vessels, etc.

By the way, in such an end structure of the cylindrical winding, insulation against the induced voltage generated between the winding ends of the cylindrical windings 1 which are adjacent to each other and are not connected in series is provided at the interlayer end as shown in FIG. It is maintained by the partial insulation distance D and the insulation of the electrostatic shield ring 7 and the winding conductor 11.

(Problems to be Solved by the Invention) The interlayer insulation distance D depends on the distance between the shield ring 7 and the end of the cylindrical winding 1. That is, since the portion where the shaping ring 9 made of an insulating material is present is the space section of the potential, the equipotential line within the interlayer insulation distance D drops at the shaping ring 9 portion and is located at the end of the cylindrical winding 1. The electric field is concentrated at the corners of the wound conductor 11. Therefore, although the electrostatic shield ring 7 is attached, since there is a potential space portion of the shaping ring 9, a sufficient electrostatic shield effect cannot be expected, the interlayer insulation distance D becomes large, and the overall size is reduced. However, there is a drawback that the weight becomes large.

The electric field strength at the corners of the wound conductor 11 is obtained by dividing the voltage generated between the interlayer insulation distances D by the interlayer insulation distance D,
It is a value obtained by multiplying the electric field concentration coefficient. Therefore, in order to reduce the electric field strength, it is necessary to reduce the electric field concentration coefficient or increase the interlayer insulation distance D more than necessary as in the conventional case.

To prevent the equipotential lines from dropping and to reduce the electric field concentration,
It is conceivable to match the shape of the electrostatic shield ring 7 itself with the shape of the end of the cylindrical winding, but since the inclination of the end is opposite in two layers, the work is extremely difficult and impractical.

It is also conceivable to apply a conductive layer such as a metal foil to the shaping ring 9 made of an insulator, but this is also not preferable because the fabrication of the shaping ring as an electrostatic ring core becomes complicated.

An object of the present invention is to provide a multiple cylindrical winding equipped with an electrostatic shield that can reduce the electric field concentration at the end of the cylindrical winding uniformly over the entire circumference in order to reduce the dimension of interlayer insulation.

[Structure of Invention]

(Means for Solving the Problems) The multiple cylindrical winding of the present invention has a cylindrical winding in which a plurality of layers are wound concentrically, and adjacent cylindrical windings are alternately connected at their upper and lower ends. In a multi-layered cylindrical winding that is wholly connected in series, an electrically insulating coating that does not flow a current different from that of the main conductor of the winding on the upper side of the upper several turns and the lower side of the lower end of each layer of the cylindrical winding. It is characterized in that a conductor is attached to it and wound together with the main winding conductor.

(Operation) The insulation dimension between the winding main conductor and the end shield conductor at the winding end is the total thickness of the winding main conductor insulation thickness and the end shield conductor insulation thickness. It is always constant over the entire circumference. The dimension between the main conductor and the end shield conductor is sufficiently smaller than the interlayer insulation dimension of the cylindrical windings that are adjacent to each other and are not connected in series, and the drop of the equipotential line in this portion is small. Therefore, the main conductor is sufficiently electrically shielded by the end shields, and the magnitude of the electric field acting on the corners of the main conductor becomes very small, so that there is no problem in electrical insulation. Therefore, the interlayer insulation dimension of the cylindrical winding can be reduced to the insulation dimension determined by the voltage generated between the ends of the cylindrical winding and the end shield, and the electrostatic shield effect can be sufficiently expected.

(Examples) The present invention will be described below with reference to the examples shown in FIGS. 1 and 2. In FIG. 1, the multiple cylindrical winding according to the present invention is composed of a plurality of concentric cylindrical windings 1a, 1b, ... 1g formed by winding a coil conductor in a cylindrical shape. Each of the cylindrical windings 1 and the adjacent cylindrical windings are alternately connected at the upper end and the lower end alternately and connected in series to form a multiple cylindrical winding 10. The multi-cylinder winding 10 thus configured is mounted on the iron core (not shown) together with the low voltage winding (not shown).

In the present invention, as shown in FIG. 2, a plurality of concentrically arranged cylindrical windings 1a to 1g have a plurality of windings of a winding end portion in which a conductor is wound across each layer and wound on the next layer. Winding main conductor
An end shield 8 in which an electrostatic shield conductor different from 11 is thickly insulation-coated is stacked adjacent to the outside of the main conductor 11 (upper end of the winding upper end and lower end of the lower end) to form a two-layer cylindrical winding 1a. , 1b
It is characterized by being continuously wound over.

In this case, the end shield 8 is wound so that the electric field concentration at the ends of the cylindrical windings 1a and 1b can be uniformly electrostatically shielded over the entire circumference of the end main conductor. Insert it inside. It is sufficient that the winding amount is such that the tip of the end shield 8 is invisible from the outside of the winding end. Further, the end shield 8 is fixed to the potential of the winding by pressing the bare conductors or connecting wires (not shown) at any one point of the adjacent main conductors.

In the multiplex cylindrical winding of the present invention configured as described above, the insulation dimension between the end shield 8 at the end of the cylindrical winding 1a to 1g and the winding end is determined by the insulation thickness of the winding main conductor and the end. The total insulation thickness of the partial shield conductor, which is always constant over the entire circumference of the winding. The dimension between the main conductor and the end shield conductor is sufficiently smaller than the interlayer insulation dimension of the cylindrical windings that are adjacent to each other and are not connected in series, and the drop of the equipotential line in this portion is small. Therefore, the main conductor is sufficiently electrically shielded by the end shields, and the magnitude of the electric field acting on the corners of the main conductor becomes very small, so that there is no problem in electrical insulation. Therefore, the interlayer insulation dimension of the cylindrical winding can be reduced to the insulation dimension determined by the voltage generated between the ends of the cylindrical winding and the end shield.
The electrostatic shield effect of the end shield 8 can be expected sufficiently.

Further, since the main-end shield 8 can be formed of a commonly used hand-held conductor, it is not necessary to manufacture a special electrostatic shield ring. Further, since the mounting can be easily carried out by winding the winding together with the main conductor, the winding having a stable quality can be obtained because of the extremely simple structure.

As for the structure of the conductor of the end shield 8, FIG. 3 (a) shows a general hand-held conducting wire 8a covered with an insulator 82. However, in order to alleviate the electric field of the end shield 8 itself. Further, as shown in FIG. 3 (b), a part of the conductor 8b can be formed into a semicircle. Further, when the electromagnetic force at the time of short circuit is not large as shown in FIG. 3c, the circular conductor 8c having the entire curvature can further reduce the electric field.

〔The invention's effect〕

As described above, according to the present invention, a multi-layered cylindrical winding having a cylindrical winding wound in a plurality of layers in a concentric cylindrical shape, and adjoining adjacent cylindrical windings alternately connected at the upper and lower ends is connected in series. On the outer side of each layer of the cylindrical winding, a conductor with an insulation coating that does not flow a current different from that of the winding main conductor is adjacently overlapped and wound with the winding main conductor, and continuously wound over two layers. By winding the wire, the electric field concentration at the end of the cylindrical winding can be alleviated uniformly over the entire circumference.Therefore, depending on the voltage generated at the end of the cylindrical winding and the breakdown strength of the interlayer insulating medium, The size can be reduced to a certain size and the winding space factor can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional perspective view showing an embodiment of the multiplex cylindrical winding according to the present invention, FIG. 2 is a constitutional view showing an end shield in an interlayer crossing portion of FIG. 1, and FIG. 3 is used for the end shield. And FIG. 4 is a sectional view showing each embodiment of the conductor shape to be applied, FIG. 4 is a configuration diagram showing a conventional multiplex cylindrical winding, FIG. 5 is a front view showing the upper end of the multiplex cylindrical winding of FIG. 4, and FIG. FIG. 5 is a cross-sectional view showing an enlarged end shield portion of FIG. 4. 1a to 1g …… Cylindrical winding 8 …… End shield 10 …… Multiple cylindrical winding 11 …… Main winding conductor

Claims (1)

(57) [Claims] 1. A multiple cylindrical winding having a cylindrical winding wound in a plurality of layers in a concentric cylindrical shape, wherein adjacent cylindrical windings are alternately connected at the upper end and the lower end, and the whole is connected in series. A multiplex cylindrical winding, characterized in that an electrically insulated coating conductor is superposed on each of the upper end portion and the lower end portion of the cylindrical winding and wound together with the winding main conductor.