RU2261516C2 - THREE-PHASE, DOUBLE-LAYER, FRACTIONAL-SLOT (q=2.5), 2p1/2p2=2/1 POLE-CHANGING WINDING - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: proposed fractional-slot (q = 2.5) double-layer pole-changing winding whose phase leads are connected in Y/YY or Δ/YY has N_cg = 6p₂ coil groups placed in z = 6p₂q slots with slot pitch y_s = z/2p₁, each phase being divided into two parts with odd-numbered groups in one part, even-numbered ones, in other part, and additional leads, brought out of midpoints in each phase. With 2p₁/2p₂ = 8/4, 12/6, and 16/8, odd-numbered concentric three-coil groups have coil pitches y_si = 6, 4, 2 at turn number (1 - x)w_c, (1 + x)w_c (1 - x)w_c, and even-numbered double-coil groups have coil pitch y_si = 5, 3 at turn number w_c, (1 + x)w_c, where z = 30 for 2p₁/2p₂ = 8/4, z = 45 for 2p₁/2p₂ = 12/6, z = 60 for 2p₁/2p₂ = 16/8; 2w_c is turn number per slot at x = 0.54.

EFFECT: equalized internal voltages and resistances among large and small coil groups of proposed winding.

1 cl, 3 dwg

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 _l / 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 at their step along the grooves Y _p ≈ 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 symmetrical PPO.

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 = z / 6p ₂ = 2.5, which allows it to be performed as a symmetrical PPO with pole numbers 2p ₁ / 2p ₂ = 8 / 4, 12/6, 16/8.

The solution of this problem is achieved by the fact that for a three-phase 2-layer fractional (q = 2.5) pole switchable with respect to 2p _l / 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 coil spacing along the grooves y _n ≈z / 2p ₁ when dividing each phase into two parts with odd groups in one, even in the other with additional conclusions of the midpoints in each phase: at 2p ₁ / 2p ₂ = 8/4, 12/6, 16/8 poles, q = 2.5, the concentric groups of the odd three-coil have coil steps Y _pi = 6, 4, 2 with the number of turns (1-x) w _k , (1 + x) w _k , (1-x ) w _k , and even two-coil ones - y ' _pi = 7.5 with the number of turns w _k , (l + x) w _k , where z = 30 for 2p _l / 2p ₂ = 8/4, z = 45 for 2p ₁ / 2p ₂ = 12/6, z = 60 for 2p ₁ / 2p ₂ = 16/8 and 2w _k is the number of turns of each groove with a value of x = 0.54.

Figure 1 shows the reamers of the groove layers of the proposed two-layer three-phase winding at 2p ₁ 2p ₂ = 8/4, q = 2.5 and z = 30 grooves with numbers 1 ... 30, N _kg = 12 coil groups with numbers 1G. ..12G: from above - for a 2p ₂ = 4 pole with alternations of phase zones in the AZBXCY sequence, where groups 1G, 4G, 7G, 10G of the first phase are numbered, and from below - for a 2p ₁ = 8 pole with alternations of phase zones in A- sequence BC for the upper and X, Y, Z of the lower layer; 2 and 3 are constructed (on a triangular grid) the polygons of the MDS winding of FIG. 1 for the poles 2p ₂ = 4 (external) and 2p ₁ = 8 (internal) with coils equal to (2) and unequal (FIG. 3) for x = 0.5. PPO for 2p ₁ / 2p ₂ = 12/6 (z = 45) And 2p ₁ / 2p ₂ = 16/8 (z = 60), repeat the parameters of the winding of figure 1 when it is repeated twice for 2p ₁ / 2p ₂ = 16/8.

Phase compounds, for example, Y / YY for PPO at 2p ₁ / 2p ₂ = 8/4 poles correspond: Y - for a 2p ₁ = 8 pole with leads of phases a, b, c starting with the successive-consistent inclusion of odd groups in each phase in one part and even parts 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 software 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 Fig. 1 for three-coil groups (odd) has grooves along the grooves of _pi = 6, 4, 2 (for _c.av. = z / 2p ₁ + 0.25 = 4) with the number of turns (1-x) w _k , (1 + x) w _k , (1-x) w _k , and for double-coil groups (even) - y ' _pi = 5.3 with the number of turns w _k , (1 + x) w _k , where the value " x "is determined from the condition of obtaining the same EMF of large and small groups for the 2p ₂ pole corresponding to the compound YY. By coefficients shortening coils By _yi = sin (90 ° y _pi / τ _n) determined for each of the polarity EMF e _g small groups at the pole pitch τ _p = z / 2p and 2w _k = 2 turns of the groove: for 2p ₁ = 8 if τ _n = z / 2p ₁ = 3,75-K _yi = (1-x) 0,587785 (V _pi = 6), (1 + x) 0.99452 (y _pi = 4), (1-x ) 0.74315 (y _pi = 2) and E _tb = ∑ (K _yi W _ki ) = 2.325452-x0.33641 - for large groups, K _yi = 0.86603 (y ' _pi = 5), (1 + х) 0.951057 (у ' _пi = 3), E _tm = 1.817082 + x0.951057 - for small groups and the winding coefficient for the 2p ₁ pole is equal to

for 2p ₂ = 4 for τ _n = z / 2p ₂ = 7.5-K _yi = (1-x) 0.951057 (y _pi = 6), (1 + x) 0.74315 (for _pi = 4) , (1-х) 0.406737 (у _pi = 2) and E _tb = 2,100938-x0,614649 - for large groups, K _yi = 0,86603 (у ' _pi = 5), (1+ x) 0.587785 (Y ' _pi = 3), E _tm = 1.453811 + x0.587785 - for small groups and from the condition E _tb = E _{tm the} value x = 0.54 is determined; winding coefficient K _ob.r2 for 2p ₂ pole is equal

and the average step of the coils at x = 0.54 is equal to y _p . _cp = 4-x / 5 = 3.892. Summary steps in _{g.b gm} and big and small groups for x = 0.54 y equal _g.b = 12-4x = 9,84, _gm = y 8 + 3 = 9.62, m. e. are approximately equal, therefore the resistances (active and inductive scattering) of large and small groups are almost identical.

Thus, the proposed unequal winding of FIG. 1 at x = 0.54 has the same EMF, resistance for 2p _{2 of} all groups, which ensures the symmetry of the PPO for the 2p ₂ pole with the connection in YY.

Of the polygons MDS figure 2 and 3 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 j = 1 ... 2q of the groove points relative to the center of the polygon and R _o is the circle radius 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 FIGS. 2, 3 according to (1) - (3) for the grid side per unit length (in the center of the polygons, the unit current vectors of phase zones A-Z-B-X-C-Y are shown) for the values x = 0, x = 0.54 by the cosine theorem we determine:

for 2p ₂ at x = 0 (Fig. 2) - R ² _d = ∑ (R ² _j ) / 5 = 59/5, R _o = 30 · 0.71095 / 2π, σ _d% = 2.40, and when x = 0.54 (Fig. 3) - R ² _d = (59-2x + 4x ² ) / 5, R _o = 30 · 0.70805 / 2π and σ _d% = 3.40, i.e. σ _d.p2 increases by 3.40 / 2.40 = 1.42 times;

for 2p ₁ at x = 0 (FIG. 2) - R ² _d = 23/5, R _o = 30 · 0.82851 / 4π and σ _d% = 17.58; when x = 0.54 (figure 3) - R ² _d = (23-2x + 8x ² ) / 5, R _o = 30 · 0.89489 / 4π, σ _d% = 6.27 and the value of σ _{d. p1} decreases by 17.58 / 6.27 = 2.8 times.

If the efficiency of the non-uniform PPO in Fig. 1 is estimated by the products of its winding coefficients according to (1) - (2) and differential scattering according to (3), then at x = 0.54 its efficiency coefficient is K _eff = (0.7081 · 0, 8949 / 0.7110 · 0.8285) (2.40 · 17.58 / 3.40 · 6.27) = 2.13, which characterizes a high degree of efficiency of the proposed winding.

Thus, the proposed non-uniform PPO in Fig. 1 at x = 0.54 is characterized by its full symmetry for 2p ₁ and 2p ₂ poles, has high winding coefficients, significantly reduced differential scattering σ _dp1 for a larger 2p ₁ pole. The value of the “x” indicator of the non-uniformity of the coils in the actual design of a three-phase HELL with such a PPO can differ from the found value x = 0.54 by ± (2 ... 3)%. An equal-turn (x = 0) PPO at q = 2.5 has deteriorated electromagnetic parameters due to its asymmetry for the 2p ₂ pole (with connection to a double star YY) and the presence of surge currents.

Claims (1)

Three-phase two-layer fractional (q = 2.5) pole switchable with respect to 2p ₁ / 2p ₂ = 2/1 winding with phase connection according to the Y / YY or Δ / YY scheme, performed in z = 6p ₂ q grooves from N _kg = 6p ₂ coil groups with pitch 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 conclusions midpoints in each phase, characterized in that at 2p ₁ / 2p ₂ = 8/4, 12/6, 16/8 concentric groups of odd three-coil have coil steps at _pi = 6, 4, 2 with the number of turns (1-x) w _k , (1 + x) w _k , (1-x ) w _k and the even dvuhkatushechnye - y _'pi = 5, 3 Islami windings w _k (1 + x) w _k, where z = 30 for 2p ₁ / 2p ₂ = 8/4, z = 45 for 2p ₁ / 2p ₂ = 12/6, z = 60 for 2p ₁ / 2p ₂ = 16/8, 2w _k - the number of turns of each groove with a value of x = 0.54.

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