RU2261513C2 - THREE-PHASE, DOUBLE-LAYER, FRACTIONAL-SLOT (q=5.5), 2p1/2p2=2/1 POLE-CHANGING WINDING - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: proposed 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 = 4/2, 8/4, and 12/6, odd-numbered concentric six-coil groups have coil pitches y_si = 13 - 2(i - 1) at turn number (1 - x)w_c of coils with i = 1, 6, and turn number (1 + x)w_c of coil with i = 3; even-numbered three-coil groups have coil pitch y'_пi=12-2(i-1) with turn number (1 + x)w_c of coil with i = 3 at w_c turns of remaining coil groups, where z = 33 for 2p₁/2p₂ = 4/2, z = 66 for 2p₁/2p₂ = 8/4, z = 99 for 2p₁/2p₂ = 12/6; i = 1 ... 6 is coil number in group starting from external one; 2w_c is turn number per slot at x = 0.52.

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 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 at their step along the grooves y _п ≈ z / 2р 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.

The invention aims at aligning the EMF and the resistances of large and small coil groups of m = 3-phase fractional winding at q = 5.5, which allows it to be performed as a symmetrical PPO with the number of poles 2p ₁ / 2p ₂ = 4/2, 8 / 4, 12/6.

The solution of this problem is achieved by the fact that for a three-phase two-layer fractional (q = 5.5) pole-switched in relation to 2p _l / 2p ₂ = 2/1 windings with phase connection according to the schemes Y / YY or Δ / YY, performed at z = 6p ₂ q grooves from N _kg = 6p ₂ coil groups with coil spacing in grooves U _п ≈z / 2p ₁ when dividing each phase into two parts with odd groups in one, even in the other and with additional conclusions of midpoints in each phase: at 2p _l / 2p ₂ = 4/2, 8/4, 12/6 poles, g = 5.5, odd six-coil concentric groups have coil steps at _pi = 13-2 (i-1) with the number of turns (1-x) w _{to the} coil yk with i = 1, 6 and (1 + x) w _{to the} coil with i = 3, and even five-coil ones - y ^' _pi = 12-2 (i-1) with the number of turns (1 + x) w _{to the} coil with i = 3 at w _{to the} turns of the remaining coils of the groups, where z = 33 for 2p _l / 2p ₂ = 4/2, z = 66 for 2p ₁ / 2p ₂ = 8/4, z = 99 for 2p ₁ / 2p ₂ = 12 / 6, i = 1 ... 6 is the number of the coil in the group, starting from the outer, 2w _k is the number of turns of each groove with the value x = 0.52.

Figure 1 shows the reamers of the slot layers of the proposed two-layer three-phase winding at 2p ₁ / 2p ₂ = 4/2, q = 5.5 and z = 33 grooves with numbers 1 ... 33, N _kg = 6 coil groups with numbers 1G ... 6G: from the top for the 2p ₂ = 2 pole with alternating phase zones in the AZBXCY sequence, where groups 1G and 4G of the first phase are numbered, and from the bottom for the 2p ₁ = 4 pole with alternating phase zones in the sequence A-B-C 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 poles 2p ₂ = 2 (external) and 2p ₁ = 4 (internal) with coils equal to (2) and unequal (FIG. 3) for x = 0.5. PPO for 2p ₁ / 2p ₂ = 8/4 (z = 66) and 2p ₁ / 2p ₂ = 12/6 (z = 99) repeat the parameters of the winding of figure 1 when it is repeated two and three times.

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 figure 1 for six-coil groups (odd) has the steps of the coils along the grooves y _pi = 13-2 (i-1) = 13, 11, 9, 7, 5, 3 (y _k.cp = z / 2p _l - 0.25 = 8) with the number of turns (1-x) w _{to the} coils with i = 1, 6 and (1 + x) w _{to the} coils with i = 3, and for five-coil groups (even) - y ^' _pi = 12 -2 (i-1) = 12, 10, 8, 6, 4 with the number of turns (1 + x) w _{to the} coils with i = 3 when w _{to the} turns in the remaining coils of the groups, where the value of "x" is determined from the conditions for obtaining identical EMFs of large and small groups for the 2p ₂ pole corresponding to its compound YY. By velocity factor K _yi = sin (90 ° V _pi / τ _n) coils for each of the polarity determined by the emf E _r large, small coil groups when the pole pitch τ _p = z / 2p and 2w _k = 2 turns of the groove: for 2p ₁ = 4 at τ _p = z / 2p ₁ = 8.25-K _yi = (1-x) 0.618159 (y _pi = 13), 0.86603 (at _pi = 11), (1 + x) 0.989821 (for _pi = 9), 0.971812 (for _pi = 7), 0.81458 (for _pi = 5), (1-x) 0.540641 (for _pi = 3) and E _gb = Σ (K _yi W _ki) = 4,8010339-h0,16898 - for large (odd-numbered groups), R _yi = 0.75575 (y _^'pi = 12) .945001 ^(y' _pi = 10), (1 + x) 0.998867 (y ^' _pi = 8), 0.909632 (y ^' _pi = 6), 0.690079 (y ^' _pi = 4) and E _ym = 4.299329 + x0.99887 - for small groups ( even) and the winding coefficient for the 2p ₁ pole is equal to

for 2p ₂ = 2 for τ _n = z / 2p ₂ = 16.5-K _yi = (1-x) 0.945008 (y _pi = 13), 0.86603 (y _pi = ll), (1 + x ) 0.75575 (for _pi = 9), 0.618159 (for _pi = 7), 0.458227 (for _pi = 5), (1-x) 0.281733 (for _pi = 3) and E _g. = 3.92490-х0.47099 - for large groups, K _yi = 0.909632 (у ' _пi = 12), 0.814576 (У' _пi = 10), (1 + х) 0.690079 (у ^' _пi = 8), 0.540641 (y ^' _pi = 6), 0.371663 (y' _pi = 4) and E _gm = 3.326591 + x0.690079 - for small groups and from the condition E _gb = E _{gm is} determined by the value x = 0.52; To _r.p2 for the pole 2p ₂ is

and the average step of the coils at x = 0.52 is equal to U _sr = Σ (for _pi w _ki ) 11 = 8-8x / 11 = 7.622.

Summary steps in _{g.b gm} and big and small groups for x = 0.52 y equal _g.b = 48-7h = 44,36, y 40 = _gm + 8x = 44,16, ie. e. are practically identical, 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 = 0.52 has the same EMF, resistance for 2p _{2 of} all groups, which ensures the symmetry of the PPO for the 2p ₂ pole when connected 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 MDF, is determined for each POS pole, where R _D ² is the square of the average radius j = 1 ... 2q of the slot 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 Fig. 2, 3 according to (1) - (3) with the grid side per unit length for x = 0 and x = 0.5, by the cosine theorem we determine:

for 2p ₂ at x = 0 (Fig. 2) - R _d ² = Σ (R _j ² ) / 11 = 531/11, R _o = 33 · 0.65923 / π, σ _d% = 0.67 and at x = 0.52 (Fig. 3) - R ² _d = (531 + 30x + 9x ² ) / 11, R _o = 33 · 0.6696 / π and σ _d% = 0.89, i.e. σ _d.p2 increases by 0.89 / 0.67 = 1.33 times;

и σ_Д%=3,53; при х=0,52 (фиг.3) - R² _д=(215+22x+17x²)/11, R_o=33·0,86654/2π, σ_Д%=1,40 и значение σ_д.р1 снижается в 3,53/1,40=2,52 раза.for 2p ₁ at x = 0 (Fig. 2) - R _D ² = 215/11, R _o = 33 · 0.8273 / 2π

and σ _D% = 3.53; when x = 0.52 (Fig. 3) - R ² _d = (215 + 22x + 17x ² ) / 11, R _o = 33 · 0.86654 / 2π, σ _D% = 1.40 and the value of σ _{d. p1} decreases by 3.53 / 1.40 = 2.52 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 = 0.52 its efficiency coefficient is K _eff = (0.6696 · 0, 8665 / 0.6592 · 0.8273) (0.67 · 3.53 / 0.89 · 1.40) = 2.02, which characterizes a high degree of efficiency of the proposed winding.

Thus, the proposed non-uniform PPO of FIG. 1 at x = 0.52 is characterized by its full symmetry for the 2p ₁ and 2p ₂ poles, has high winding coefficients and reduced differential scattering σ _d.p1 for the 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 = 0.52 by ± (2 ... 3)%. An equal-turn (x = 0) PPO at q = 5.5 has degraded 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 = 5.5) 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 = _4/2 , 8/4, 12/6 concentric groups the odd six-coil groups have coil steps at _pi = 13-2 (i-1) with the number of turns (1-x) w _{to the} coils with i = 1, 6 and (1 + x) w _to coil i = 3, and even pyatikat antiplaque - y _'pi = 12-2 (i-1) from the number of turns (1 + x) w _to coil i = 3 at w _to the rest coils reels groups where z = 33 for 2p _1/2 = 2p 4 / 2, z = 66 for 2p ₁ / 2p ₂ = 8/4, z = 99 for 2p ₁ / 2p ₂ = 12/6, i = 1 ... 6 - the number of the coil in the group, starting from the outside, 2w _to - the number of turns of each groove with a value of x = 0.52.

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