RU2293427C2 - ASYMMETRIC THREE-PHASE SLOT-PITCH WINDING WITH 2p = 6c POLES IN z = 21c SLOTS - Google Patents

Abstract

FIELD: electrical and electromechanical engineering; three-phase induction and synchronous machines including slip-ring induction motors.

SUBSTANCE: proposed m = 3-phase, m' = m = 3-band double-layer fractional-slot lap winding placed in z= 21c slots, with slot number per pole per phase q = z/3p = 7/3 is assembled of 3pc coil groups 1G through 9G with coil grouping 3 2 2 2 2 3 2 3 2 repeated c times. Novelty is that concentric windings have slot pitches y_si = 5, 3, 1 and turn numbers (1 - x)w_c, (1 + x)w_c, (1 - x)w_c for three-coil groups 1G, 6G, 8G, respectively, slot pitches y_si = 4, 4 and turn numbers (1 + x)w_c, (1 - x)w_c, respectively, for two-coil groups 3G, 4G, 7G, 9G, and for coil groups 2G, 5G at slot pitch y_s = 3 turn numbers equal (1 - x)w_c (1 - x)w_c in coil group 2G, coil turn numbers equal (1 - x)w_c, (1 - x(1 - x)w_c in coil group 5G; turn number in remaining coils of coil groups equals w_c, where c = 1, 2, 3, ...; 2w_c is turn number in slots completely filled with winding; x = 0.6.

EFFECT: reduced asymmetry and differential scatter ratios.

1 cl, 4 dwg

Description

The invention relates to three-phase windings of electric machines of alternating current of asynchronous motors (HELL) and synchronous generators (SG).

Known two-layer loop m = 3-phase fractional windings are known, performed at 2p poles in z grooves from m′p coil groups with equal-step or concentric coils with an average pitch of grooves y _to ≈z / 2p, the number of grooves per pole and phase q = z / m′p = b + c / d, where m ′ = 2m = 6 or m ′ = m = 3 is the number of phase zones per pair of poles, c / d <1; according to symmetry conditions, the 2p / d ratios are integer, d / m are non-integer [Voldek A.I. Electric cars. L .: Energy, 1978, S. 392-394].

Grouping coils in groups of fractional asymmetric (d / m - integer) windings are given in rows and depend on c / d [Livshits-Garik M. Windings of AC machines. / Per. from English L .: SEI, 1959, p. 254], for example 3 2 2 2 2 2 3 2 3 2 for q = 7/3; Due to phase asymmetry, differential scattering increases.

The invention aims at reducing the asymmetry coefficients, the differential scattering of an asymmetric m ′ = 3-zone winding at q = 7/3.

The solution of this problem is achieved by the fact that for m = 3-phase asymmetric test winding with 2p = 6s poles in z = 21s grooves, performed by a two-layer m ′ = 3-zone with the number of grooves per pole and phase q = z / 3p = 7 / 3 of 3pc coil groups 1G ... 9G with a group of 3 2 2 2 2 3 2 3 2, repeated with time:

concentric coils have _groove steps y _pi = 5, 3, 1 with the number of turns (1-x) w _k , (1 + x) w _k , (1-x) w _k for groups of three-coil 1G, 6G, 8G, y ' _pi = 4,2 with the number of turns (1 + x) w _k , (1-x) w _k for double-coil groups 3G, 4G, 7G, 9G, and for groups 2G, 5G with y _p = 3 - (1+ x) w _to , (1-x) w _to turns of coils in 2G and (1-x) w _to , (1 + x) w _to 5G with w _to turns in other coils of groups, where c = 1, 2, 3, ..., x = 0.6, and 2w _k is the number of turns of the slots completely filled with the winding.

Figure 1 shows a scan of the groove layers of the proposed winding with c = 1, 2p = 6, z = 21 with numbers 1 ... 21 from the bottom, 3p = 9 groups with numbers 1G ... 9G from above, alternating phase zones A-B -From the upper, XYZ lower layers and the blackened grooves contain 2 (1) w _to turns at 2w _to turns in the remaining grooves, and the shifts of the axes of the groups are marked from the bottom, in Fig. 2 a diagram of the shifts of the groups, their phase EMF E _A E _B , E _C , relative to the axis of symmetry 8G; figure 3, 4 on a triangular grid constructed polygons of the MDS winding for the coils is equal to - (figure 3) and unequal (figure 4). The winding, Fig. 1, is connected with series-consonant inclusion of the groups: 1G, 4G, 7G in phase I, 2G, 5G, 8G in phase II, 3G, 6G, 9G in phase III with beginnings from 1G, 2G, 3G; phases can mate in Y and Δ. With c = 2, 3, ... the winding has 2p = 6s = 12, 18, ... poles, z = 21s = 42, 63, ... grooves and 3pc = 18, 27, ... groups.

D=

, K_нес%=(F/D) [Петров Г.Н. Электрические машины, ч.2. Асинхронные и синхронные машины. М.-Л.: ГЭИ, 1963, c.162] вычисляется коэффициент несимметрии К_нес%=2,56% при К_об=(Е_АС+2Е_ВА)/

·21=0,78544.For winding 1 EMF groups are determined from the coefficients of shortening concentric coils K _yi = sin (90y _pi / τ _n) = sin (180 ° at _pi / 7) at the pole pitch τ _p = z / 2p = 3.5: K _yi = (1-x) 0.781832 (for _pi = 5), (1 + x) 0.974928 (for _pi = 3), (1-x) 0.433884 (y _pi = 1) for E _gb = 2.190643-х0.240787 for groups of three-coil (large), (1 + х) 0.974928 (y ′ _pi = 4), (1-х) 0.781832 (y ′ _pi = 2) with E _{g. m} = 1.75676 + x0.193097 of groups 3G, 4G, 7G, 9G of two-coil (small). The diagram of FIG. 2 is constructed for 2p = 6, z = 21, α _n = 360 ° / z = 120 ° / 7 at angles of displacement of the axes of the groups of FIG. 1: 8G → 9G = 2.5α _n p = 120 ° + 0 , 5α _p and 8G → 7G = 240 ° -0.5α _p ; 8G → 1G = 5α _p p = 240 ° + α _p and 8G → 6G = 120 ° -α _p ; 8G → 2G = 7.5α _p p = 360 ° + 1.5α _p and 8G → 5G = 360 ° -1.5α _p ; 8G → 3G = 9.5α _P p = 120 ° + 0.5α _P ; and 8G → 4G = 240 ° -0.5α _P , according to which: E _B = E _{8G (b)} + 2E _{2G (m)} cos1.5α _n = 5.356214 + x0.493353 is a vertical vector, where for non-concentric groups 2G, 5G - 2x [cos1.5α _p -cos (1.5 + 0.5 · 3) α _p ] 0.974928 = x0.734141; E ² _A = (2E _{4G (m)} ) ² + E ² _{1G (b)} -4E _{4G (m)} E _{1G (b)} cos (180 ° -1.5α _n - by the cosine theorem and for x = 0 - E _A = E _C = 5,56893, γ angle on (Figure 2) is defined by the sine theorem 2E _4D / sinγ = E _A / sin (180 ° -1,5α _n) where γ = 15,8872 ° angles and then of phase EMF shifts are equal to φ _BA = φ _BC = 120 ° -α _n + γ = 118.7443 and φ _AC = 122.5114 °. Linear EMFs are determined from phase EMF and shift angles a = Е _BA = b = Е _BC = 9 , 40165, c = E _AC = 9.76540 and then according to the expressions: S = a + b + c, A = (a ² + b ² + c ² ) / 6, B =

D =

, K _carried% = (F / D) [Petrov G.N. Electric cars, part 2. Asynchronous and synchronous machines. M.-L.: SEI, 1963, p. 162], the asymmetry coefficient K be _carried% = 2.56% at K _about = (E _AC + 2E _VA ) /

21 = 0.78544.

(z-3x)=0,88384 и z′=21-3x=19,2 - эквивалентное число полностью заполненных обмоткой пазов, т.е. она имеет больший К_об и меньший К_нес% (в 2,56/0,63=4,1 раза).Similarly, for the non-uniform winding of FIG. 1 at x = 0.6: E _B = 5.65223, E _A = E _C = 5.65885, γ = 16.688 °, φ _VA = φ _BC = 119.5452 °, φ _AC = 120.9096 °, a = E _BA = b = E _BC = 9.7732, c = E _AC = 9.8460, K _carried% = 0.63, K _rev = (E _AC + 2E _VA )

(z-3x) = 0.88384 and z ′ = 21-3x = 19.2 is the equivalent number of grooves completely filled by the winding, i.e. it has a larger K _about and a smaller K _carried% (2.56 / 0.63 = 4.1 times).

From the MDS polygons of Figs. 3, 4 (with unit current vectors of phase zones A-Z-B-X-C-Y in the center) according to a triangular grid and the relations

the differential scattering coefficient σ _D% is determined, which characterizes the quality of the winding by the harmonic composition of the MDS with the square of the average radius j = 1 ... z of the groove points R ² _{d the} radius R _{o of the} circle for the main harmonic Determination and optimization of the parameters of three-phase windings along the MDS polygons // Electricity, 1997, No. 9, p. 53-55]:

According to (1) - (2): at x = 0, K _r = 0.78544 - R ² _d = 81/21, R _o = 21 · 0.78544 / 3π and σ _D% = 25.93; when x = 0.6 and K _r = 0.88384 - R ² _d = 77.76 / 21, R _o = 19.2 · 0.88384 / 3π, σ _D% = 14.22%, i.e. σ _D% decreases by 25.93 / 14.22 = 1.82 times. Given the changes in K _about , K _carried% , σ _{d%, the} winding of Fig. 1 with x = 0.6 has a high efficiency K _eff = (0.88384 / 0.78544) (2.56 / 0.63) (25 93 / 14.22) (19.2 / 21) = 7.65; at the optimal value x = x _opt - K _carried% = 0.

The proposed m = 3-zone winding in comparison with m = 6-zone for z = 21, 2p = 6, q = z / 6p = 7/6, for _n = 3, the grouping 211111121111112111, K _rev = 0.9250 , K _carried% = 0.82, σ _D% = 14.65 has a reduced K _carried and σ _D with half as many groups.

Its application allows to reduce additional losses in the rotor and magnetic noise in the blood pressure with short-circuit rotor, improve the shape of the voltage curve in the SG.

Claims (1)

Three-phase asymmetric fractional winding at 2p = 6s poles in z = 21s grooves performed by a two-layer m = 3-zone with the number of grooves per pole and phase q = z / 3p = 7/3 of 3pc coil groups 1G ... 9G with group 3 2 2 2 2 3 2 3 2 repeated with times, characterized in that the concentric coils have _groove steps y _pi = 5, 3, 1 and the number of turns (1-x) w _k , (1 + x) w _k , (1-x) w _к for three-coil groups 1Г, 6Г, 8Г, respectively, the steps along the grooves y ′ _pi = 4, 2 and the number of turns (1 + x) w _к , (1-х) w _к , respectively, for dvuhkatushechnyh groups 3G, 4G, 7G, 9G, and for coil groups 2G, 5G at the grooves at step _n = 3, the number of turns katu ek is equal to (1 + x) w _k (1-x) w _k in the coil group 2T and the number of coils are coils (1-x) w _k (1 + x) w _k in the coil group 5G, with the number of turns in the remaining coils of the coil groups is w _k where c = 1, 2, 3, ...; 2w _to - the number of turns of the grooves, completely filled with a winding; x = 0.6.

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