RU2267202C2 - THREE-PHASE TWO-LAYER SPLIT (q=1,5) POLE-SWITCHING, MADE IN ACCORDANCE TO RELATION 2P1/2P2 = 2/1, WINDING - Google Patents

Abstract

FIELD: electric engineering and electric-mechanical industry, can be implemented in three-phase two-speed and multi-speed asynchronous engines with short-circuit rotor.

SUBSTANCE: in three-phase two-layer split (q=1,5) pole-switching in relation 2p₁/2p₂=2/1 winding with connection of phases in acc to circuits Y/YY or Δ/YY, made in z=6p₂q grooves from N_cg=6p₂ coil groups with coils step by grooves y_g≈z/2p₁ with splitting of each phase on two portions with non-even groups in one portion, even groups in other portion and with a os from middle points in each phase, in acc to invention, at q=1,5 concentric groups, non-even and two-coiled, have coil steps y_gi=3,1 with coil numbers w_c and (1-x)w_c, and even one-coiled groups - y_g=2 with number of coils (1+x)w_c, where z=18 for 2p₁/2p₂=8/4, z=36 for 2p₁/2p₂=16/8, 2w_c - number of coils for each groove for value of x=0,57.

EFFECT: evened out EMF and resistances of greater and lesser coil groups of m= 3 -phase two-layer split winding for q = z/6p₂ = 1,5, to allow its manufacturing as pole-switching symmetric winding with pole numbers satisfying condition 2p₁/2p₂=2/1.

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Description

The invention relates to three-phase pole-switched in the ratio 2: 1 windings (PPO) of AC electric machines and can be used on a stator of three-phase two-speed and multi-speed asynchronous motors (HELL) with a squirrel-cage rotor.

Known loop two-layer symmetrical m = 3-phase PPO with the number of poles in the ratio 2p ₁ / 2p ₂ = 2/1 with phase connection schemes Y / YY or Δ / YY, performed in z grooves of N _kg = 6p ₂ coil groups with q = z / 6p ₂ coils in each when they step in the grooves at _n ≈ z / 2p ₁ and the division of each phase into two identical parts with odd groups in one and even in another with additional conclusions of the midpoints in each phase, where q is a whole number [Sergeev P.S. and others. Design of electrical machines. M .: Energy, 1970, p. 450-451]. With a fractional number q = z / 6p ₂ = b + 0.5 (b = 1, 2, 3, ...) m = 3-phase windings have unequal alternating large (b + 1) -coil and small b-coil groups [Voldek A.I. Electric cars. L .: Energia, 1978, p.409-411], which does not allow them to be performed as such software.

In the invention, the task is to align the EMF and the resistances of large and small coil groups of m = 3-phase fractional winding at q = 1.5, which allows it to be performed as a PPO with pole numbers in relation to 2p ₁ / 2p ₂ = 8/4.

The solution of this problem is achieved by the fact that for a three-phase 2-layer fractional (q = 1.5) pole-switched in relation to 2p ₁ / 2p ₂ = 2/1 windings with phase connection according to the schemes Y / YY or Δ / YY, performed in z = 6p ₂ q grooves of N _kg = 6p ₂ coil groups with a pitch of coils in grooves at _p ≈z / 2p ₁ when dividing each phase into two parts with odd groups in one and even in another with additional conclusions of the midpoints in each phase: at 2p ₁ / 2p ₂ = 8/4 poles and q = 1.5 groups the odd double-coil concentric have coil steps at _pi = 3, 1 with the numbers of turns w _k and (1-x) w _k , and even one pellet - at _n = 2 with the number of turns (1 + x) w _k , where z = 18, 2w _k - the number of turns of each groove with a value of x = 0.57.

Figure 1 shows the reamers of the groove layers of the proposed two-layer three-phase winding with q = 1.5 and z = 18 grooves with numbers 1 ... 18 and N _kg = 12 coil groups with numbers 1G ... 12G: from above - for 2p pole ₂ = 4 with alternations of phase zones in the sequence AZBXCY, where groups 1G, 4G, 7G, 10G of the first phase are numbered, and from the bottom for pole 2p ₁ = 8 with alternations of phase zones in the sequence A-B-C for the top and X, Y Z of the lower layer; in Fig.2 ... 5 constructed (on a triangular grid) polygons of the MDS winding of Fig.1 for the poles 2p ₂ = 4 (Fig.2) and 2p ₁ = 8 (Fig.3) with equal-coil coils (x = 0) , and in Figs. 4 and 5, MDS polygons with unequal coils for x = 0.5.

Phase compounds, for example, Y / YY for PPO at 2p ₁ / 2p ₂ = 8/4 poles correspond: Y - for a pole 2p ₁ = 8 with leads of phases a, b, c starting with odd groups in series in each phase, in one part and even in another with additional conclusions (a ', b', c ') from their midpoints (for example, in phase a of groups 1G, 7G, 10G, 4G with an additional conclusion a' from the end of 7G and the beginning of 10G) therefore, the PPO for 2p ₁ = 8 has m '= m = 3 phase zones per pair of poles with alternations in the lower scan of FIG. 1; YY - for 2p ₂ = 4 with leads a ', b', c '(leads a, b, c are shorted) with parallel-on switching on of the same groups (for example, in phase a' - groups 10G, 4G and -7G, -1G), therefore, the software for 2p ₂ = 4 has m '= 2m = 6 phase zones per pair of poles with alternations in the upper scan of Fig. 1 with AZBXCY zones (starting from group 4G).

The winding of _figure 1 has the steps of the coils along the grooves at _pi = 3, 1 (for _c.p. = z / 2p ₁ -0.25 = 2) with the numbers of turns w _to and (1) w _to double-coil groups (odd ), y _n = 2 with the number of turns (1 + x) w _to single-coil groups (even), where the value of "x" is determined from the condition of obtaining the same EMF of large and small groups for the pole 2p ₂ = 4 corresponding to the compound YY. By coefficients shortening coils K _yi = sin (90 ° from _pi / τ _n) determined for each of the polarity EMF E _g the large and small coil groups when the pole pitch τ _p = z / 2p and 2w _k = 2 turns of the groove: for 2p ₁ = 8, with τ _n = z / 2p ₁ = 18/8 = 2,25 - K _yi = 0.86603 (y _pi = 3), (1-x) 0.64279 (y _pi = 1) and E _g.b = Σ (K _yi w _ki ) = 1.508813-x0.64279 - for large (odd) groups, E _gm = K _y = (1 + x) 0.984808 (y _n = 2) - for small ( even) groups and the winding coefficient for 2p ₁ = 8 is

2p ₂ when τ = 4 _n = z / 2p ₂ = 18/4 = 4.5 - K _yi = 0.86603 (y _pi = 3), (1-x) 0,34202 (y _pi = 1) and E = 1.208045 _g.b-h0,34202 - for large groups, E _gm = K _y = (1 + x) 0,642788 (y _f = 2) - for small groups and condition E _g.b = E _{gm the} value x = 0.57 is determined; winding coefficient for 2p ₂ = 4 is

and the average step of the coils at x = 0.57 is equal to at _cp = Σ (at _pi w _ki ) / 3 = 2 + x / 3 = 2.19. The average steps of the groups are equal for _gb = 3 + 1-x = 3.43 - for large, for _gm = 2 (1 + x) = 3.14 - for small groups, i.e. virtually _g.b ≈u _gm therefore proposed neravnovitkovaya coil of Figure 1 when x = 0.57 is practically identical emf and resistance (resistive and inductive scattering) for all of the coil groups.

Of the polygons of MDS figure 2 ... 5 in terms of

the differential scattering coefficient σ _d , which characterizes the quality of the winding by the harmonic composition of its MDS, is determined for each POS pole, where R ² _d is the square of the average radius i = 1 ... 2q of the groove points relative to the center of the polygon, and R _o is the radius of the circle for the main harmonic MDS [Popov V.I. Determination and optimization of the parameters of three-phase windings along MDS polygons // Electricity, 1997, No. 9, p. 53-55].

From the MDS polygons of Fig. 2 ... 5 (with the side of a triangular grid per unit length) by the cosine theorem according to (1) - (3) are determined:

for 2p ₂ = 4 at x = 0 (Fig. 2) - R ² _d = Σ (R ² _i ) / 3 = 10/3, R _o = 18 · 0.61694 / 2π and σ _d% = 6.71 ; when x = 0.57 (Fig. 4) - R ² _d = (10 + 2x + 3x ² ) / 3, R _o = 18 · 0.6741 / 2π and σ _d% = 8.28, i.e. σ _d.p2 increases by 8.28 / 6.71 = 1.23 times;

for 2p ₁ = 8 at x = 0 (Fig. 3) - R ² _d = 2.0, R _o = 18 · 0.83121 / 4π, σ _d% = 41.09; when x = 0.57 (Fig. 5) - R ² _d = (6-2x + 3x ² ) / 3, R _o = 18 · 0.8962 / 4π, σ _d% = 18.02, i.e. σ _d.p1 decreases by 41.09 / 18.02 = 2.28 times.

If the efficiency of the non-uniform PPO in Fig. 1 is characterized by the products of the winding coefficients according to (1) - (2) as they increase and differential scattering according to (3) when they decrease, then at x = 0.57 its efficiency coefficient is K _eff = (0 , 6741 · 0.8962 / 0.61794 · 0.8312) (6.71 · 41.09 / 8.28 · 18.02) = 2.2, which characterizes a high degree of efficiency of the proposed winding.

Thus, the proposed non-uniform PPO in Fig. 1 at x = 0.57 is characterized by its full symmetry for the poles 2p ₁ = 8 and 2p ₂ = 4, has high winding coefficients and reduced differential scattering σ _dp1 for the larger pole 2p ₁ = 8. The value of the “x” indicator of the unequal coils during the actual design of a three-phase asynchronous motor with such a software may differ from the found value x = 0.57 by ± (2 ... 3)%.

The equal-turn (x = 0) PPO at q = l, 5 is inoperative due to its asymmetry for the 2p ₂ pole (with connection to the double star YY) and significant surge currents.

Claims (1)

Three-phase two-layer fractional (q = 1.5) pole switchable with respect to 2p ₁ / 2p ₂ = 2/1 winding with phase connection according to the Y / YY or Δ / YY schemes, performed in z = 6p ₂ q grooves from N _kg = 6p ₂ coil groups with a pitch of coils in grooves at _n ≈z / 2p ₁ when dividing each phase into two parts with odd groups in one, even in the other and with additional outputs of midpoints in each phase, characterized in that the coil groups are concentric odd two-coil the steps of the coils U _n = 3, 1 with the number of turns w _k and (1-x) w _k , and even single-coil - y _n = 2 with the number of turns (1 + x) w _k , g de z = 18 for 2p ₁ / 2p ₂ = 8/4, z = 36 for 2p ₁ / 2p ₂ = 16/8, 2w _k is the number of turns of each groove with a value of x = 0.57.

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