RU2270509C2 - ELECTRICAL-MACHINE THREE-PHASE SINGLE/DOUBLE-LAYER WINDING WITH 2p=2c POLES IN z=21c SLOTS (q=3.5) - Google Patents

Abstract

FIELD: electrical and electromechanical engineering; three-phase induction and synchronous machines.

SUBSTANCE: proposed three-phase single/double-layer winding with 2p = 2c poles in z = 21c slots, q = 3/5, has concentric-coil groups three times uniformly offset through 2q = 7 slots with 2w_c turns in each slot. Novelty is that in order to reduce differential dissipation σ_d in proposed fractional-pitch (q = 3/5) winding, each coil group has five coils with slot pitches y_si = 14, 12, 10, 10, 8, 6 and turn numbers w_c/ 2w_c, 2w_c, (1+ x)w_c, (1 - x)w_c, respectively, where c = 1, 2, 3, ... at x = 0.30.

EFFECT: reduced differential dissipation in proposed winding.

1 cl, 2 dwg

Description

The invention relates to the windings of electrical machines, can be used on a stator of three-phase asynchronous and synchronous machines, a phase rotor of asynchronous motors (HELL).

Known loop two-layer (single-layer) symmetrical m = 3-phase, m '= 2m = 6-zone windings performed by 2-pole in z grooves from 6p (3p) coil groups with equal-step or concentric coils with their average step in grooves y _{to k} ≈τ _p = z / 2p, the number of grooves per pole and phase q = z / 6р whole or fractional [Voldek A.I. Electric cars. L .: Energy, 1978, S. 392-393]. Fractional windings at q = z / 6p = N / d and d≥2 create harmonic MDS in the series ν = 6k / d ± 1 [ibid, p. 450], including even and lower ones (ν <1) with increasing differential scattering σ _d , where ± k is an integer giving the order of harmonic ν> 0 when it is forward (+) or counter (-) rotated.

Closest to the proposed one is a three-phase one-two-layer winding at 2p = 4 poles and z = 42 grooves (q = 3,5), made of 3p = 6 equally spaced coil groups with concentric coils with groove steps with 2q = 7 grooves for _pi = 14, 12, 10, 6 and the number of turns w _k , 2w _k , 2w _k , 2w _k at 2w _{to the} turns of each groove [Technical catalog of OJSC ELDIN, Yaroslavl, 2002, p.30 - synchronous generators type SJ200, SJ225 - prototype].

The invention aims to reduce the differential scattering of the winding of the prototype. The solution of this problem is achieved by the fact that for a three-phase one-two-layer winding with 2p = 2s poles in z = 21s grooves (q = 3,5), made of 3p coil groups with concentric coils uniformly displaced by 2q = 7 at 2w _{to the} turns each groove and c = 1, 2, 3, ...:

each group contains five coils with _groove steps at _pi = 14, 12, 10, 8, 6 with the number of turns w _k , 2w _k , 2w _k , (1 + x) w _k , (1-x) w _k , where x = 0.30.

Figure 1 shows a scan of the groove layers with the upper frontal parts of the proposed winding at c = 1, 2p = 2, z = 21 with numbers 1 ... 21 (bottom) and 3p = 3 with coil groups with numbers 1G, 2G, 3G ( above) with alternations of phase zones in the sequence AZBXCY; figure 2 built on a triangular grid (with its side per unit length) polygons of the MDS windings of figure 1 at x = 0.5 (external) and the prototype (internal). With c = 2, 3, ... the winding has 2p = 2s = 4, 6, ... poles and z = 21c = 42, 63, ... grooves with 3p = 6 - (1G ... 6G), 9 - (1G ... 9G) groups and their consonant inclusion in phases (1G and 4G, 2G and 5G, 3G and 6G in phases I, II, III at 2p = 4), and the phases can be conjugated by a star or a triangle.

1 for winding said winding factor is determined from the coefficients of concentric coils By shortening _yi = sin (90 ° from _pi / τ _n) for _n τ = z / 2p = 10,5: _yi = 0.866025 K (y _pi = 14) , 2 · 0.974928 (for _pi = 12), 2 · 0.997204 (for _pi = 10), (1 + x) 0.930874 (for _pi = 8), (1-x) 0.7818315 (for _pi = 6) and then

From the outer polygon MDS figure 2 (in the center shows the unit vectors of the currents of the phase zones A-Z-B-X-C-Y) on 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 its MDS, where R ² _d is the square of the average radius j = 1 ... 2q of the groove points, R _o is the radius of the circle for the main harmonic [Popov V.I. Determination and optimization of the parameters of three-phase windings along the MDS polygons // Electricity, 1997, No. 9, p. 53-55]:

then, according to (1) - (3), from the condition d (σ _d ) / d (x) = 0, the optimal x _opt = 0.30, corresponding to σ _{d% min, is} calculated: for x _opt = 0.30 - K _rev = 0 , 938244, R ² _d = 277.69 / 7, R _o = 42 · 0.938244 / 2π and σ _{d% min} = 0.854, and at x = 0-σ _d% = 0.883. For the winding of the prototype at K _about = 0.910565, R ² _d = 263/7 (according to the inner polygon of figure 2) and σ _d% = 1,414, i.e. σ _d% at x _opt = 0.30 decreases by 1.414 / 0.854 = 1.66 times, which characterizes the high efficiency of the proposed winding. Taking into account the increase in K _{about, the} efficiency of the non-uniform winding in Fig. 1 is (0.938244 / 0.910565) (1.414 / 0.854) = 1.71 with an average pitch of the coils in the grooves at _s.pp = (72 + 2x) / 7 = 10.37 (for winding according to the prototype at _p.s. = _70/7 = 10.0).

Thus, the proposed winding is characterized by a reduced coefficient of differential scattering σ _d% , increased K _about and more efficient at x _opt = 0.30 in K _eff = 1.71 times in comparison with the winding of the prototype. Its use in synchronous generators improves the shape of the initial voltage curve, and, for example, on the HF stator, it allows to reduce additional losses in steel and asynchronous moments from harmonic fields, improve vibroacoustic characteristics, increase efficiency and cosφ ₁ , and overload capacity of the machine.

Claims (1)

Three-phase one-two-layer electric machine winding with the number of pluses 2p = 2 with poles in z = 21 with grooves, q = 3,5, made of 3p coil groups with concentric coils uniformly shifted by 2q = 7 grooves with the number of turns 2w _k in each groove , characterized in that each coil group contains five coils with _groove steps y _pi = 14, 12, 10, 8, 6 and with the numbers of turns w _k , 2w _k , 2w _k , (1 + x) w _k , ( 1-x) w _k, respectively, where c = 1, 2, 3, ... with a value of x = 0.30.

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