RU2293421C2 - ASYMMETRIC THREE-PHASE FRACTIONAL-SLOT WINDING WITH 2p = 6c POLES PLACED IN z = 66c SLOTS - Google Patents

Abstract

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

SUBSTANCE: proposed asymmetric fractional-slot double-layer lap winding with 2p = 6c poles in z = 66c slots, m' = 3 bands, and slot number per pole per phase q = z/3p - 22/3 has 3pc coil groups 1G through 9G with coil grouping 8 7 7 7 7 8 7 8 7 repeated c times. Novelty is that concentric coils have slot pitches y_si = 18 - 2(i - 1) and turn numbers (1 - x)w_c for coils with i = 1, 8 and turn number (1 + x)w_c for coil with i = 4 in eight-coil groups 1G, 6G, 8G; slot pitches y'_si = 17 - 2(i - 1) and turn number (1 + x)w_c for coil with i = 4 in all seven-coil groups, turn number (1 - x)w_c for coil with i = 1 in coil groups 3G, 4G and with i = 7 in coil groups 7G, 9G; for coil groups 2G, 5G slot pitches y_s = 11 - (1 + x)w_c for coil with i - = 7 in coil group 2G and with i = 1 in coil group 5G; turn number in remaining coils of coil groups equals w_c, where c = 1, 2, 3, ...; i = 1 - 8 and i = 1 - 7 are coil numbers in coil groups starting from external one; 2w_c is turn number in slots completely filled with winding.

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 the symmetry conditions, the 2p / d ratios are integer, d / m are 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 877778787 for q = 22/3; Due to phase asymmetry, differential scattering increases.

The invention is famous for the task of reducing the asymmetry coefficients, the differential scattering of an asymmetric m ′ = 3-zone winding at q = 22/3.

The solution of this problem is achieved by the fact that for m = 3-phase asymmetrical test winding with 2p = 6s poles in z = 66s grooves, a two-layer m ′ = 3-zone with the number of grooves per pole and phase q = z / 3p = 22 / 3 of 3pc coil groups 1G ... 9G with a group of 877778787, repeated with time:

concentric coils have _groove steps y _Pi = 18-2 (i-1) with the number of turns (1-x) w _{to the} coils with i = 1.8 and (1 + x) w _{to the} coils with i = 4 for groups of eight-coil 1G, 6G, 8G, y ' _Pi = 17-2 (i'-1) with the number of turns (1 + x) w _{to the} coil with i' = 4 for seven-coil groups with (1) w _{to the} turns of the coil with i '= 1 in 3G, 4G and with i' = 7 in 7G, 9G, and for groups 2G, 5G with y _П = 11-1 (1 + х) w _{to the} coil with i '= 7 in 2G and with i' -1 in 5G with w _to turns in the remaining coils of the groups, where c = 1, 2, 3, ..., i = 1 ... 8 and i '= 1 ... 7 are the numbers of the coils of the groups, starting from the outer , x = 0.5, and 2w _to - the number of turns of the grooves, completely filled with a winding.

Figure 1 shows a scan of the groove layers of the proposed winding with c = 1, 2p = 6, z = 66 with numbers 1 ... 66 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 with respect to the axis of symmetry 8G; in figure 3, 4 on a triangular grid are constructed polygons of the MDS winding for coils equal- (figure 3) and not equal-sized (figure 4). The winding of Fig. 1 is connected with series-consonant inclusion of groups: 1G, 4G, 7G in phase I, 2G, 5G, 8G in phase II, 3G, 6G, 9G in phase III with beginnings of 1G, 2G, 3G; phases can mate in Y and Δ. With c = 2, 3, ... the winding has 2p = 6s = 12, 18, ... poles, z = 66 with = 132, 198, ... grooves and 3pc = 18, 27, ... groups.

For the winding of FIG. 1, EMF groups are determined by the shortening coefficients of concentric coils K _yi = sin (90y _Pi / τ _P ) = sin (90 ° at _Pi / 11) with pole division τ _P = z / 2p = 11; To _yi = (1-x) 0.540641 (for _Pi = 18 and 4), (1 + x) 0.9898214 (for _Pi = 12) for groups of eight-coil (large) with E _tb = 6.39169 + х0.09146, (1-х) 0.654861 (y ' _Пi = 17 or 5), (1 + х) 1.0 (y' _Пi = 11) at Е _tm = 5.911215 + х0.3451393 for groups 3G, 4G, 7G, 9G seven-coil (small).

, 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%=0,27% при К_об=(Е_АС+2Е_ВА)/

·66=0,82475.The diagram of Fig. 2 is constructed for 2p = 6, z = 66, α _P = 360 ° / z = 60 ° / 11 at the angles of shift of the axes of the groups of Fig. 1: 8G → 9G = 7.5α _P p = 120 ° + 0 , 5α _P and 8G → 7G = 240 ° -0.5α _P ; 8Г → 1Г = 15α _П p = 240 ° + α _П and 8Г → 6Г = 120 ° -α _П ; 8G → 2G = 22.5α _P p = 360 ° + 1.5α _P and 8G → 5G = 360 ° -1.5α _P ; 8G → 3G = 29.5α _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 _P = 18.093781 + x 0.8069011 is a vertical vector, where for non-concentric groups 2G, 5G-2x [cos1.5α _P -cos (1.5 + 3.3) α _P ] = x0.89836125; E ² _A = (2E _{4G (m)} ) ² + E ² _{1G (b)} -4E _{4G (m)} E _{1G (b)} cos (180 ° -1.5α _П ) - by the cosine theorem and for x = 0- E _A -E _C = 18,1699, the angle γ in (2) is defined by the sine theorem 2E _4D / sinγ = E _A / sin (180 ° -1,5α _n) where γ = 5.31313 °, and then the angles of phase EMF shifts are equal to φ _BA = φ _BC = 120 ° -α _П + γ = 119.8586 and φ _AC = 120.2828 °. From the phase EMF and the angles of their shifts, the linear EMF a = E _BA = b = E _BC = 31.3829, c = E _AC = 31.5159 are determined and then by the expressions: S = a + b + c, A = (a ² + b ² + s ² ) / 6, B =

, D =

, K _carried% = (F / D) [Petrov G.N. Electric cars, part 2. Asynchronous and synchronous machines. M.-L.: SEI, 1963, C.162] the coefficient of asymmetry is calculated K _carried% = 0.27% at K _about = (E _AC + 2E _VA ) /

66 = 0.82475.

(z-3x)=0,859523 и z′=66-3x=64,5 - эквивалентное число полностью заполненных обмоткой пазов, т.е. она имеет больший К_об и меньший К_нес% (в 0,27/0,04=6,6 раза).Similarly, for the non-uniform winding of FIG. 1 at x = 0.5: E _B = 18.49723, E _A = E _C = 18.47103, γ = 5.3793 °, φ _VA = φ _BC = 119.9247 ° , φ _AC = 120.1505 °, a = E _VA = b = E _BC = 32.0033, c = E _AC = 32.0170, K _carried% = 0.041, K _rev = (E _AC + 2E _VA )

(z-3x) = 0.859523 and z ′ = 66-3x = 64.5 is the equivalent number of grooves completely filled by the winding, i.e. it has a larger K _about and a smaller K _carried% (0.27 / 0.04 = 6.6 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 but 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 MDS polygons // Electricity. 1997, No. 9, p. 53-55]:

According to (1) - (2): at x = 0, K _rev = 0.82475-R ² _d = 2262/66, R _o = 66 · 0.82475 / 3π and σ _D% = 2.75; at x = 0.5 and K _rev = 0.85952-R ² _d = 2322/66, R _o = 64.5 · 0.85952 / 3π, σ _D% = 1.68%, i.e. σ _D% decreases by 2.75 / 1.68 = 1.64 times. Given the changes in K _about , K _carried% , σ _{d%, the} winding of Fig. 1 with x = 0.5 has a high efficiency K _eff = (0.85952 / 0.82475) (0.27 / 0.04) (2 75 / 1.68) (64.5 / 66) = 11.0; at the optimal value x = x _opt -K _carried% = 0.

The proposed m ′ = 3-zone winding, in comparison with m ′ = 6-zone at z = 66, 2p = 6. q = z / 6p = 11/3, for _P = 9, grouped 433333343333334333, K _about = 0.9138, K _carried% = 0.29, σ _D% = 1.96 has reduced K _carried and σ _d at half as much number of 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 = 6 with poles in z = 66 with grooves, performed by a two-layer m = 3-zone with the number of grooves per pole and phase q = z / 3p = 22/3 of 3pc coil groups 1G ... 9G with a group 8 7 7 7 7 8 7 8 7, repeated with times, characterized in that the concentric coils have _groove steps y _pi = 18-2 (i-1) and the number of turns (1-x) w _k for coils with i = 1.8 and the number of turns (1 + x) w _k for a coil with i = 4 for eight-coil groups 1G, 6G, 8G, _groove steps y ′ _pi = 17-2 (i-1) and the number of turns (1 + x ) w _k for the coil with i = 4 for all seven-coil groups, the number of turns (1) w _k for the coil with i = 1 in the coil load ppg 3G, 4G and with i = 7 in the coil groups 7G, 9G, and for coil groups 2G, 5G the groove steps are equal for _n = 11- (1 + x) w _k for the coil with i = 7 in the coil group 2G and with i = 1 in the 5G coil group, while the number of turns in the remaining coils of the coil groups is w _k , where c = 1, 2, 3, ...; i = 1 ... 8 and i = 1 ... 7 are the numbers of the coils of the coil groups, starting from the outside; 2w _to - the number of turns in the grooves, completely filled with a winding; x = 0.5.

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