SU1451801A1 - Stator of a.c. electric machine - Google Patents

Description

(21) 4235257 / 24-07

(22) 04.24.87

(46) 01/15/89. Bul № 2

(71) Institute of Electrodynamics, Academy of Sciences of Ukraine

(72) G. G. Happily, A. I. Titko, A. A. Bab, V. V. Kuzmin,

I.Ya.Cheremisov, V.B.Kaplunev and V.G.Rakogon

(53) 621.313.04 (088.8)

(56) USSR inventor certificate 1141512, cl. H 02 K 1/16, 1983.

USSR Author's Certificate No. 1176417, cl. H 02 K 1/16, 1983.

(54) AC ELECTRIC MACHINE STATOR

(57) The invention relates to the field of mechanical engineering. The purpose of the invention is to increase the load capacity

and increase reliability. The stator of an AC electrical machine contains a laminated heart / 1ik 1, winding 2, pressure plates 3 and fingers 4. The screen has three layers: two of them 5 and 6 are made of highly conductive material, and one 7 is made of ferromagnetic. Magnetic inserts 8 are installed under the screen. The inserts can be T-shaped. Since the magnetic inserts have a magnetic permeability in the radial direction higher than in the axial and tangential direction, "the flow will not divert to the outermost package. With the help of adjustable gaps between the inserts and the surfaces of the teeth, the magnetic fluxes passing through the teeth of the outermost package and the inserts are redistributed, and their losses in them are equalized. 2 hp f-ly, 6 cells

i

WITH

four

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00

The invention relates to electrical engineering, in particular, to electrical engineering, and can be used in electrical machines, in powerful ipyuo- and hydrogenerators, characterized by significant electro-magnetic and thermal loads of the end elements of the stator.

The purpose of the invention is to increase the load capacity (expansion of the range of loads, increase in power ::; and) and increase in reliability.

Figure 1 shows the end part of the stator of an electric machine, a longitudinal section; 2, 3 and 4 are examples of forms of magnetic inserts and their manufacture; FIGS. 5 and 6 are examples of electric stator power;, a; grades with a multi-layer screen and magnet inserts under it.

The stator of an AC electrical machine contains a laminated core 1, a winding 2, pressure plates 3 and fingers 4, a multilayer screen made, for example, of three layers: two layers 5.6 are made of highly conductive and one layer 7 is made of ferromagnetic material. Magnetic inserts 8 are installed under the screen. The winding rods 2 are held by 3 slots of the core 1 using wedges 9.

Between the inserts 8 and the surface of the teeth of the outermost package, there is a gap 10 of variable size, including and along the surface of the teeth (Fig.6). There is also a gap 11 between the inserts and the screen (FIG. 5), in particular between the inserts and the ferromagnetic part of the screen (FIG. 1). Magnetic insert (Fig.3,4) is placed when the core is blended. Due to the T-shape, they are prevented from moving in the radial and tangential directions.

The implementation of the inserts 8 flush with the screen allows them to be held by means of push fingers or push plates 3 of a tooth-like design (Fig. 6) from movements in the axial direction. Magnetic inserts 8 can be made of various shapes. If the ferromagnetic layer 7 of the screen is made with a greater curvature of the inner cylindrical surface than the layers 5, 6, then the inserts 8 have the form shown in FIG. 3. If the layers 5-7 of the screen are

„, Q -

five

0

at the same level (Fig. 6), the profile of the side surfaces of the inserts 8 does not change in the radial direction. The use of inserts 8 does not preclude the use of screens of such a form that protects the pressure plates from variable magnetic fluxes (figure 5).

The stator design of the electric machine, in which the inserts 8 are made of magnetodielectric, is most effective. One method of making inserts 8 is shown in FIG. 4. Inserts 8 are made of steel wire 12 with a diameter of 0.1-0.2 mm or plates glued onto fiberglass with a thickness of 0.15-0.2 mm. From fiberglass with glued wire, cut the billet of the required profile, fold it into a bag, and each billet is coated with epoxy putty with or without ferromagnetic filler. The inserts B made in this way conduct the magnetic flux only in the radial direction, and the losses generated therefrom are minimal.

When the electric machine is operating, the radial magnetic flux of the gap, the axial fluxes of the frontal windings, and the flux displaced from the gap, through magnetic inserts, are driven into the ferromagnetic charge portion of the screen and closed in it in the tangential direction. Since the magnetic inserts have a magnetic permeability higher in the radial direction than in the axial and tangential direction, the flow does not diverge into the outermost package. This is facilitated by the adjustable gap between the inserts and the package. The total losses are small, since the inserts are made of plates or magnetodielectric, the fluxes of magnetic fluxes passing through the teeth of the outermost package and the inserts are redistributed, and the losses generated in them are evened out. Thereby, a uniform distribution of losses in the end part of the stator core is achieved, and their losses are small. The temperature of the elements of the end part of the core, due to the indicated losses, is within the permissible limits.

These technical advantages cause an increase in the load capacity of turbo-generators.

including in modes with consumption of real active power, and an increase in the reliability of the operation of the machines, which makes it possible not to install an additional expensive compensating device for maintaining the mains voltage, to increase the QDC of the machines.

Claims (3)

Formula of gain 1, A stator of an electric current machine containing a laminated core with teeth, a winding, pressure plates and fingers, and multilayer screens of ferromagnetic and electrically conductive elements installed in the end portions of the core, characterized in that. In order to increase the load capacity and increase reliability, it is equipped with magnetic inserts installed on the side of the stator bore with gaps relative to the shields and end surfaces of the teeth. 2, Stator POP.1, characterized in that the magnetic inserts are T-shaped, the horizontal insertion shelf being placed between the electrically conductive layers of the screen. 3. STOP.1 and 2, characterized in that the magnetic inserts are made of anisotropic material, the magnetic permeability of which in the radial direction exceeds at least 1.5 times the permeability in other directions. Fig.z Fi.Ch. Phie. Fie.6