SU905904A1 - Transformer active section - Google Patents

Description

one

The invention relates to electrical engineering, in particular to the active part of high-power high-voltage transformers with solid insulation.

The known construction of the paper-oil insulation of the active part of transformers, where the cooling channel is formed by interconnected metal plates J.

In this construction, metal interconnected plates distort the electric field in the insulation, and in one part (between the high voltage winding and the channel), the voltage increases by a factor of 2, and in the other part (between the channel and the low voltage winding or tank) is reduced by 2 times compared with the voltage in the absence of windings, it is not economically feasible to use in transformers, since the radial dimension of the inter-insulation insulation and, consequently, the size and weight of the transformer significantly increase and,

 The closest to the proposed invention in technical essence and the effect achieved is the active part of a transformer, containing concentrically arranged windings of higher and lower voltages and solid insulation between them with an axial cooling channel,

10 to the walls of which adjacent identical layers of insulated, adjacent to one another along the axis of the metal open concentric shielding coils, which

15 are pairwise connected to each other through a channel, and the number of which is equal to the number of the coil in the high voltage winding.

This design makes it possible to eliminate partial electric discharges in the cooling channel under the condition of non-distortion of the electric field in solid insulation, however

The technology for producing such a channel is very labor intensive, since a number of operations are required (procurement of metal plates, their isolation, installation of plates on the channel walls and pairing of galvanic connections, such as soldering), which prevent the mechanization of the manufacturing of the active part of the transformer. In addition, an increased electrical intensity occurs at the ends of the open shielding coils.

The aim of the invention is to mechanize the manufacture of the cooling channel and to eliminate the increased intensity of the electric field on the surface of the shielding coils.

The goal is achieved by the fact that in the active part of the transformer containing concentrically located windings of higher and lower voltages and solid insulation between them with an axial cooling channel, the walls of which are adjacent to the same layers of insulated adjacent one another along the axis of the metal open concentric shielding turns the turns are connected in series and laid by continuous winding, and the ratio of the number of shielding turns of each layer to the number of turns of the winding of the highest voltage equal to the ratio toldiny insulation between the duct and the lower voltage winding thickness to winding insulation method.

FIG. 1 shows the active part of the transformer, a schematic section; in fig. 2 - a layer of shielding coils, the general form; in FIG. The active part when the higher voltage winding has a linear input in the middle of the height.

The active part of a high-voltage high-voltage transformer consists of a winding of the highest voltage (HV), winding 2 of the lowest voltage (LV) adjacent to the winding of the HV insulation

3, adjacent to the winding HH Isolation

4, a cooling channel 5 and two layers 6 to eliminate partial electrical discharges in the indicated channel, each of which has the same number of shielding coils 7, insulated with coil insulation 8.

Layers 6, closely adjacent to each wall of the channel 5, are wound in the form of series-connected turns

7, with the ratio of the number of turns 7 to the number of turns of the HV winding paiSHO ratio of the insulation thickness 4 to the total insulation thickness 3 and 4. At this, the operating voltage on the coils 7 corresponds to the operating voltage in the insulation without installing layers 6.

The coils of the layers have the same winding voltage, while the operating voltage between the coils of the same layer number is absent.

Under the action of lightning pulses of a voltage of a single amplitude on the high voltage winding of the proposed active part, a potential arises on layers 6 and, which (with some error) is equal to

y - 7 S26 ....,. f b- W,. S ... S, J, r

l 5 6 + 526 (1)

- the number of turns of the winding

where w, w

t 6 1 and layer 6;

insula tion between

 26 winding I and layer 6 and between layer 6 and winding 2;

UJ is the frequency of natural oscillations of the layers 6; t - time

The number of turns of Wg selected according to the invention ensures that there is no oscillation, i.e.

- l

(2)

52.

Attitude

or corresponding to Sl6- -S26

The ratio of the electrical capacitances of the insulation between the windings and the layer gives the potential value on the cooling channel, which has the known structure of the active part.

The ratio indicates the magnitude of the operating potential on the channel of the proposed design of the active part.

Expression (2) provides the required isolation conditions. At the same time, the layer 6 of turns 7, being in isolation and perceiving the action of electric to magnetic fields, acquires the property of electromagnetic stability (non-oscillation), the property of not affecting the distribution of the electric field in the insulation. Two such layers together do not distort the electric field in the insulation. . exclude the radial intensity (potential difference between the layers is zero) in the cooled channel, as well as partial electric discharges in it. The ends of the coils are also excluded due to their serial connection and continuous winding from one wire, and the increased electric field strength on the surface of the coils is absent. These properties are created by a combination of signs: the presence of a winding (it induces a potential on each layer 6 in accordance with the relation); Placing the layers in the insulation (finding the layers in the insulation provides for them the capacitive component of the potential in accordance with the ratio e (, 2 (, the presence in the layer of the number of turns Wg corresponding to condition (2)) ensures that there is no voltage difference and partial discharges The channels in the channel are shown in Fig. 3: 1 and HV half-windings, 6 and 6 - half-layers of coils to eliminate partial electrical discharges, 9 - LV winding (or electrostatic shield on the core of the magnetic core). Semi-layers 6 and 6 have the same winding direction, respectively with half 1 and. When S 26 is equal, the number of turns, 5W. This invention mechanizes the manufacture of layers of coils in the cooling channel and eliminates the increased voltage of the electric field on the surface of the worm Formula of the invention The active part of the transformer containing concentrically located windings of higher and lower voltage and solid between them with an axial cooling channel, the walls of which are adjacent to the same layers of insulated adjacent to one another along the axis of the metal open concentrate Shielding coils, characterized in that, in order to mechanize production and eliminate the increased electric field strength on the surface of the shielding turns, the shielding turns are connected in series and laid by continuous winding, the ratio of the number of shielding turns of each layer to the number of turns of the higher voltage winding is equal to the ratio of the thickness of the insulation between the channel and the low voltage winding to the thickness of the insulation between the windings. Sources of information taken into account in the examination 1.Patent of France No. 1108219, cl. H 01 F 27/36, 1960. 2. USSR author's certificate according to application No. 2341573 / 24-07, cl. H 01 F 27/36, 1976.

FIG. one

I

1 OX 3 6 „5

t

/ ix

 4fie .Z

Claims (1)

Claim The active part of the transformer, containing concentrically located IQ windings of higher and lower voltage and solid insulation between them with an axial cooling channel, to the walls of which are adjacent identical layers of insulated adjacent U one to the other along the axis of the metal open concentric shielding coils, characterized in that, for the purpose of mechanization of manufacture and exclusion of ₂₀ increased electric field strengths on the surface of shielding coils, shielding coils are connected in series and • married by continuous winding, and 25 wearing the number of shielding turns of each layer to the number of turns of the higher voltage winding is equal to the ratio of the insulation thickness between the channel and • the low voltage winding to the insulation thickness between the windings.