SU756549A1 - Combined excitation winding - Google Patents

Description

The invention relates to the field of windings of alternating current machines, single-machine synchronous frequency converters and number of phases. $

Single-machine synchronous frequency converters are known, which are a combination of magnetic systems of opposite-pole synchronous motors and generators in a common magnetic circuit and having two opposite-pole windings with pole numbers 2p ₁ and 2p _d on the stator and rotor; ⁵ constant current through the contact ring [1].

The disadvantages of such converters complexity of the design due to the presence on the rotor of two separate windings. 2 °

Known synchronous machines with switching the number of poles, in which by switching the excitation winding of the rotor, subdivided into corpses, receive the excitation fields: 2p - pole to switching and 2p _g - pole switching field £ 2].

The disadvantages of such machines - the complexity of the rotor design due to the presence of 30

field of excitation after switching the poles of higher harmonic fields.

Also known are single-machine, synchronous frequency converters, the excitation winding of which, made according to the principle of pole switching, creates simultaneously 2p _A and 2p _d polar field excitation fields of the engine and generator by disconnecting the excitation winding coil group [3].

The disadvantages of such a converter are the incomplete use of copper because of the disconnection of the group of coils of the excitation winding and the presence in the resulting field curve of a large number of harmonics, as a result of which the losses in steel increase, and the shape of the generator output voltage curve is distorted.

The purpose of the invention is to simplify the design, increase the use of copper and improve the shape of the field curve of the combined excitation winding, creating at the same time 2p = 4 and 2p = 8 pole field.

This goal is achieved by the fact that for a single-layer winding, made in uniformly distributed grooves of four consistently agree

756549

four

but connected coil groups with concentric coils, the axis of which is shifted by (-g rad, the sides of the coils of the first and third lezhau groups within the continuous zone at +

+ happy, and the second and fourth - in y - 72 happy, along the axis of each group, the zone in R ^and D is free from the coils, and compared to the coils of the outer and adjacent groups of the first and third, the outer and two adjacent groups of the second and the fourth number of turns is more: for the inner coil of all groups - twice, and for the other coils of groups - three times.

FIG. 1 shows a diagram of the known 2p = 4 pole excitation winding and its integral NS curve; in fig. 2 is a diagram of the known 2p = 8 pole excitation winding and its integral curve HC ′; FIG. 3 - the scheme of the proposed combined excitation winding and its integral curve NA.

The winding (figure 1) is made in a known manner in 48 slots with four coil groups I, II, III and IV and its wound part occupies 2/3 pole division 2p = 4 pole field. The arrows indicate the directions of the direct current when powering the winding through its outputs I 1 and I 2. D The integral NA curve is constructed along the directions of the current in the winding and when decomposed into a Fourier series gives the basic 2p = 4 pole harmonic of the NA with a minimum content of odd higher harmonics not multiples of three.

The winding (figure 2) is also made in 48 slots in a known manner and its winding part takes up 2/3 pole division 2p ₂ = 8 pole field. The integral curve of the NA when decomposing in a Fourier series gives the main 2p ₂ = 8 pole harmonic NA with a minimum content of odd higher harmonics that are not a multiple of three.

The amplitude of the NS windings of FIG. 1 and 2 are the same.

If one superimposes the HC curves of FIG. 1 and 2, we obtain the resulting integral curve NS (fig.Z), the ordinates of which are marked with numbers 1, 2 and 3. To obtain such a resultant curve NS, the combined excitation winding should be performed with the numbers of turns of the coils proportional to the corresponding ordinates of the resulting integral curve NA.

In fact, the proposed combined excitation winding (FIG. 3) is made in 48 slots, consists of four in series according to connected coil groups with concentric coils, the axes of which are shifted by%% rad. Group numbers are labeled I, II, III, IV and the winding pins are labeled I and II. The sides of the coils of groups I and III are

within the solid zone in y + happy, and II and IV - glad. Along the axis of each group, the zone in rad is free from coils. Compared to the outer coils and its neighboring groups 1 and III, the outer and two neighboring groups II and IV have more turns: for the inner coil of all groups, it is twice as large, and the other coils of the groups are three times.

To obtain the same copper filling factor for the grooves, the copper sections of the turns of the coils should be taken inversely proportional to their number of turns.

The proposed excitation winding is characterized by simplicity of design, high use of copper and a minimum content of higher harmonics in a field curve with 2p = 4 and 2p = 8 poles ..

It can be used, for example, on the rotor of single-machine synchronous frequency converters and the number of phases, or a two-frequency synchronous generator having two contact rings.

Claims (1)

Claim Combined excitation winding, for example, single-machine synchronous frequency converters and phase numbers single-layer, made in evenly distributed grooves of four in series according to connected coil groups with concentric ^ atushki, whose axes are shifted to rad, different in that use of copper and improve the shape-off curve 2p and 2p = 4 = 8-pole side coils of the first and third groups ^ lie within a continuous zone in the a ⁺ and REDg and the second and fourth - in% - rad at about and of each group, the zone in rad is free from the coils, and compared to the coils of the outer and its neighboring groups, the first and third, outer and two adjacent groups of the second and fourth number of turns are larger, for the inner coil of all groups - twice, and others group coils - three times. -