SU855868A1 - Synchronous machine combined excitation winding - Google Patents

Description

(54) COMBINED WARMING UP OF SYNCHRONOUS MACHINE EXCITATION

one

The invention relates to the windings of AC electric machines, for example, single-machine synchronous frequency and phase converters.

Single-machine synchronous frequency converters are known, which are a combination of magnetic systems of alternating-pole synchronous motors and a generator in a common magnetic circuit and having two opposite-pole windings with pole numbers 2p and Zp on the stator and rotor; separate rotor windings are supplied with direct current through slip rings flj.

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

Synchronous machines are known with switching the number of poles in which by switching the excitation winding of the rotor, divided into groups, the field of excitation is obtained: 2p polar before switching and 2p2 polar after switching QiJ.

However, such machines have a complex rotor design due to the presence of four slip rings, as well as increased steel losses due to the B excitation field, after switching poles, higher field harmonics.

Single-machine converters of synchronous type frequency converters, whose excitation winding, made according to the principle of pole switching, also creates 2p and 2p-pole motor excitation fields, are also known. body and generator due to the disconnection of the excitation coil group zT

The disadvantages of such a converter are the incomplete use of copper due to the disconnection of the coil winding group.

Claims (3)

20 excitation and the presence in the resultant field of the excitation field of a large number of harmonics, as a result of which the losses in the converter increase in steel, and also the shape of the generator output voltage curve is distorted. The purpose of the invention is to simplify the design, increase the use of between and improve the forms, 1 field curve of the field winding with and field. This goal is achieved by the fact that for a single-layer winding made in uniformly distributed grooves of four series-connected coil-type groups with concentric: housings, styrene points of the first and third groups lie within continuous zones in T, respectively, their axes are shifted by T (rad and in their axes, the zone in 7G // 2 is free from coils, the second and fourth groups concentrically cover the first and third groups, are connected oppositely, and their initial sides lie next to the initial sides of the first and third groups, respectively twenn in zones in TG and: glad ,, and compared to the coils of the outer and the coils of the first group, the outer group of the second, the inner group and the neighboring group of the fourth number of turns: for the inner and two adjacent coils of the first group and the third one - four times, and the other coils of the first and fourth groups - five times, the second and third groups - three times. Figure 1 shows the circuit 2p 2-pole excitation winding and its NA curve; - scheme of the well-known 2p2,8-pole excitation winding and its integrand on the NS curve; Fig. 3 shows the scheme of the proposed combined excitation winding and the integral curve of the HC. The winding (Fig. 1) is made in a known way in 48 slots with two sets of bands and its coiled pair takes 2/3 pole division 2p, | Pole floor. Arrows (fig.i) show the direction of direct current. When powering the winding through its terminals and 1 and u2. The integral curve NA (Fig ..) is constructed along the direction of gravity in the winding and, when decomposed in the Fourier series, gives the main 2p, -2 full harmonic of the NA. with a minimum content of odd higher fapMOHHK, not a multiple of three. The winding (FIG. 2) is also made in 48 grooves in a known manner and its 84 winding part occupies 2/3 pole division of the 2p2 pole pole. When decomposing the integral NA curve (Fig. 2 in the Fourier series, we obtain the main 2p2 8-pole harmonic with the minimum content of odd higher harmonics that are not a multiple of three. The winding (Fig. 2) is also made in 48 slots of the known1 {o-method and its wound part occupies 2/3 pole division 2p2 of 8-pole-a-L. When decomposing the integral curve of the NA (Fig.27 in Fourier series, we get the main 2p 8-pole harmonic with a minimum content of odd higher harmonics that are not a multiple of three. Amplitude NA windings (fig. and 2 are assumed to be the same. If one imposes HC curves (fig .I and 2, we obtain the resultant HC integral curve (Fig. 3), the ordinates of which are indicated by numbers 1,3, 4 and 5. To obtain such a resultant HC curve, the combined excitation winding should be performed with the number of turns of the coils proportional to the corresponding ordinates of the resultant integral curve HC. Thus, the proposed combined excitation winding (fig.Z consists of 4 series-connected coil groups, and W, IV with concentric coils. The coils of groups 1 and 1, the initial and final sides lie within continuous zones in ff and t, respectively; 7G happy TZ tL IH their axes are shifted to rad and on their axes the zone в - glad is free from the coils. The second and fourth groups concentrically cover groups 1 and I1, are connected oppositely to them and their initial sides lie next to the initial sides of groups 1 and P, respectively, in zones in ft and Tjlt are pleased, and compared to external and neighboring coils of group i and outer the groups I, the inner and neighboring groups of the IV, the number of turns is greater: for the inner and two adjacent to it coils of groups 1 and III - four times, and the other coils of groups I and IV - five times, P and III three times. To obtain the same copper fill ratio of the grooves, the copper cross sections of the turns of the coils should be applied inversely proportional to their number of turns. The proposed combined field winding is characterized by simplicity of construction, high use of copper and a minimum content of higher harmonics in the winding floor curve. Such a winding may be applied, for example, on a rotor of a single-machine synchronous frequency converter and a number of phases, or a two-frequency synchronous generator, having two contact rings. Claims The combined excitation winding of synchronous machines, for example, single-machine synchronous frequency converters and number of phases, is made in uniformly distributed grooves of four series-connected coil groups with concentric coils, in order to simplify the design, increase copper utilization and improve shape the curve of the field with 2p and 2p 8-poles, the sides of the first and third groups of katuyek lie within, continuous zones in TTT / li and 5-tr / f2, respectively, rad, their axes are shifted by It rad and about their axes in (G / SHRZD is free from coils, the second 8 ″ and fourth groups concentrically cover the first and third groups, are connected oppositely and their initial sides lie next to the initial sides of the first and third groups, respectively 2- / r / i and 3-I / 72rad, and compared with the coils of the outer and adjacent sleighs of the first group, the outer group of the second, inner line and its neighboring group, the fourth number of turns is more: for the inner and two adjacent coils of the first group and the third - four times, and the other coils of the first and the fourth - five times, the second and third, three times. Sources of information taken into account during the examination 1.Zagrdsky V. Combined electrical machines. Chisinau, Moldovska map, 1972, p.14. 2. Shuisky V.P. Calculation of electric cars. M ,, Energie, 1968, p. 118-120. 3. Sumakov B.A., Semenov N.P. One root synchronous frequency converter. - Izv.Vuzov, Electromechanics, 1967, № 2, 180-185.