RU2270510C2 - ELECTRICAL-MACHINE THREE-PHASE SINGLE/DOUBLE-LAYER WINDING WITH 2p=2c POLES IN z=27c SLOTS (q=4.5) - Google Patents

Abstract

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

SUBSTANCE: proposed three-phase single/double-layer lap winding with 2p = 2c poles in z = 27c slots, q = 4/5, has concentric-coil groups 3 times uniformly offset through 2q = 9 slots with 2w_c turns in each slot and c = 1, 2, 3, .... Novelty is that in order to reduce differential dissipation σ_d in m' = six-band fractional-pitch (q = 4,5) lap winding, each group has six coils with slot pitches y_si = 18, 16, 14, 12, 10, 8 and turn numbers w_c/ 2w_c, 2w_c, (1+ x)w_c, (1 - x)w_c, respectively, at x = 0.13.

EFFECT: reduced differential dissipation in fractional-pitch lap 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 the phase q = z / 6p whole or fractional [Voldek A.I. Electric cars. L .: Energy, 1978, S. 392-393]. Fractional windings with q = z / 6p = N / d and d≥2 create harmonic MDSs 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 with 2p = 4 poles and z = 54 grooves (q = 4,5), made of 3p = 6 equally spaced coil groups with concentric coils with groove steps with 2q = 9 grooves for _pi = 18, 16, 14, 12, 8 and the number of turns w _to , 2w _to , 2w _to , 2w _to , 2w _to at 2w _to turns of each groove [Technical catalog of ELDIN, Yaroslavl, 2002, p . 30 - synchronous generators of the type SJ250 - 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 = 27c grooves (q = 4,5), made of 3p coil groups with concentric coils uniformly shifted by 2q = 9 grooves at 2w _to turns each groove and c = 1, 2, 3 ...:

each group contains six coils with _groove steps at _pi = 18, 16, 14, 12, 10, 8 with the number of turns w _k , 2w _k , 2w _k , 2w _k , (1 + x) w _k , (1- x) w _k , where x = 0.13.

Figure 1 shows a scan of the groove layers with the upper frontal parts of the proposed winding at c = 1, 2p = 2, z = 27 with numbers 1 ... 27 (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), according to the prototype (internal). With c = 2, 3, ... the winding has 2p = 2s = 4, 6, ... poles and z = 27c = 54, 81, ... 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.

For the winding of Fig. 1, the winding coefficient is determined by the shortening coefficients of the concentric coils K _yi = sin (90 ° y _pi / τ _p ) at τ _p = z / 2p = 13.5; _Yi = 0.866025 K (y _pi = 18), 2 × 0.957990 (y _pi = 16), 2 × 0.998308 (y _pi = 14), 2 × 0.984808 (y _pi = 12) ( 1 + x) 0.918216 (for _pi = 10), (1-x) 0.802123 (for _pi = 8), 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 = 0.13 is calculated, which corresponds to σ _{d% min} : for x _opt = 0.13 - K _rev = 0 , 94263, R ² _d = 594.0969 / 9, R _o = 54 · 0.94263 / 2π and σ _{d% min} = 0.578, and at x = 0 - σ _d% = 0.582, i.e. winding can also be performed at x = 0. For the winding of the prototype at K _about = 0.92805, R ² _d = 577/9 (according to the inner polygon of figure 2) and σ _d% = 0.777, i.e. σ _d% at x _opt = 0.13 decreases by 0.777 / 0.578 = 1.34 times, which characterizes the effectiveness of the proposed winding. Given the increase in K _{about the} efficiency of the winding in figure 1 is equal to K _eff = (0.94263 / 0.928055) (0.777 / 0.578) = 1.37 with an average step of the coils in the grooves at _p.cp = (120 + 2x) / 9 = 13.36 (for the winding according to the prototype for _p.s. = _118/9 = 13.11).

Thus, the proposed winding is characterized by a reduced coefficient of differential scattering σ _d% , increased K _about and more efficient at x _opt = 0.13 in K _eff = 1.37 times in comparison with the winding of the prototype. Its use in synchronous generators improves the shape of the output 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 single-layer electric machine winding with the number of poles 2p = 2 s in z = 27 s grooves, q = 4,5, made of 3p coil groups with concentric coils uniformly shifted by 2q = 9 grooves with the number of turns 2w _to each groove, different the fact that each coil group contains six coils with _groove steps in _pi = 18, 16, 14, 12, 10, 8 and with the numbers of turns w _k , 2 w _k , 2 w _k , 2 w _k , (1+ x) w _k , (1-x) w _k, respectively, with a value of x = 0.13.

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