RU2261515C2 - THREE-PHASE, DOUBLE-LAYER, FRACTIONAL-SLOT (q=4.5), 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 five-coil groups have coil pitches y_si = 11 - 2(i - 1) at turn number (1 - x)w_c of coil with i = 1, 5 and at turn number(1 + x)w_c of coil with i = 3, and even-numbered four-coil groups have coil pitch y'_si = 10 - 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 = 27 for 2p₁/2p₂ = 4/2, z = 54 for 2p₁/2p₂ = 8/4, z = 81 for 2p₁/2p₂ = 12/6; i = 1... 5 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 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 symmetrical PPO.

In the invention, the task is to align the EMF and the resistances of large and small coil groups m = 3-phase fractional winding at q = 4.5, 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 = 4,5) 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 at z = 6p ₂ q grooves of N _kg = 6p of ₂ coil groups with spacing of coils in grooves of _p ≈ 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: at 2p ₁ / 2p ₂ = 4/2, 8/4, 12/6 poles, q = 4.5, odd five-coil concentric groups have coil steps at _pi = 11-2 (i-1) with the number of turns (1-x) w _{to the} coil k with i = 1, 5 and (1 + x) w _to coils with i = 3, and even four-coil ones - у ' _пi = 10-2 (i-1) with the number of turns (1 + x) w _to coils with i = 3 at w _{to the} turns of the remaining coils of the groups, where z = 27 for 2p ₁ / 2p ₂ = 4/2, z = 54 for 2p ₁ / 2p ₂ = 8/4, z = 81 for 2p ₁ / 2p ₂ = 12 / 6, i = 1 ... 5 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 = 4.5 and z = 27 grooves with numbers 1 ... 27, 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 the 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 = 54) and 2p ₁ / 2p ₂ = 12/6 (z = 81) 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 to: Y - for a 2p ₁ = 8 pole with leads of phases a, b, c starting with the consistently-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 five-coil groups (odd) has grooves along the grooves at _pi = 11-2 (i-1) = 11, 9, 7, 5, 3 (at _cf = z / 2p ₁ +0, 25 = 7) with the numbers of turns (1-x) w _{to the} coils with i = 1, 5 and (1 + x) w _{to the} coils with i = 3, and for four-coil groups (even) - у ' _пi = 10-2 (i-1) = 10, 8, 6, 4 with the number of turns (1 + x) w _{to the} coils with i = 3 for w _{to the} turns in the remaining coils of the groups, where the value of "x" is determined from the condition of obtaining identical EMFs of large and small groups for the 2p ₂ pole corresponding to the compound YY. By velocity factor K _yi = sin (90 ° from _pi / τ _n) coils are determined for each of the polarity 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 = 6.75-K _yi = (1-x) · 0.54951 (for _pi = 11), 0.86603 (for _pi = 9), (1 + x) 0, 99,831 (y _pi = 7) 0.91822 (y _pi = 5), (1-x) · 0.642788 (y _pi = 3) and _g.b E = Σ (K w _{yi Ki)} = 3.974846 -x0,193989 - for large groups (odd), K = 0.727374 _yi (y _'pi = 10) 0.95799 (y' _pi = 8), (1 + x) 0.98481 (y _'pi = 6), 0.802123 (y ' _pi = 4) and E _gm = 3.472295 + x0.98481 - for small (even) groups and the winding coefficient for the 2p ₁ pole is equal to

K _about.p1 = (E _gb + E _gm ) / 9 = 0.82746 + x0.08787; (1)

for 2p ₂ = 2 for τ _n = z / 2p ₂ = 13.5-K _yi = (1-x) 0.957990 (for _pi = 11), 0.86603 (for _pi = 9), (1 + x ) 0.72374 (y _pi = 7) 0.54951 (y _pi = 5), (1-x) 0.34202 (y _pi = 3), and E = 3.44292 _g.b-h0,57264 - for large groups, K = 0.918216 _yi (y _'pi = 10) .802123 (y' _pi = 8), (1 + x) 0.642788 (y _'pi = 6), 0.4488 (y' _pi = 4) and E _gm = 2.811926 + x0.642788 - for small groups and from the condition E _gb = E _{gm the} value x = 0.52 is determined; To _r.p2 for the pole 2p ₂ is

K _rev.p2 = (E _gb + E _gm ) / 9 = 0.694983 + x0.007795, (2)

and the average step of the coils at x = 0.52 is equal to at _cp = Σ (at _pi w _ki ) / 9 = 7-x / 9 = 6.942.

Summary steps in _{g.b gm} and big and small groups for x = 0.52 y equal _g.b = 35-7h = 31.36, y = 27 _gm + 6x = 31,12, 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 with 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 with the connection in YY.

Of the polygons MDS figure 2 and 3 in terms of

и R_o=zK_об/p (3)σ _d% = [(R _d / R _o ) ² -1] 100 at

and R _o = zK _r / p (3)

- квадрат среднего радиуса j=1...2q пазовых точек относительно центра многоугольника и R_o - радиус окружности для основной гармонической МДС [Попов В.И. Определение и оптимизация параметров трехфазных обмоток по многоугольникам МДС//Электричество, 1997, №9, с.53-55].the coefficient of differential scattering σ _d , which characterizes the quality of the winding according to the harmonic composition of its MDS, is determined for each POS pole

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 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, 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:

, R₀=27·0,6950/π, σ_д%=0,91, а при x=0,52 (фиг.3) -

, R_о=27·0,6990/π, σ_д%=1,28, т.е. σ_д.р2 возрастает в 1,28/0,91=1,41 раза;for 2p ₂ when x = 0 (figure 2) -

, R ₀ = 27 · 0.6950 / π, σ _d% = 0.91, and at x = 0.52 (Fig. 3) -

, R _o = 27 · 0.6990 / π, σ _d% = 1.28, i.e. σ _d.p2 increases by 1.28 / 0.91 = 1.41 times;

, R_о=27·0,8275/2π и σ_д%=5,46; при х=0,52 (фиг.3) -

, R_о=27·0,8732/2π, σ_д%=2,01 и значение σ_д.р1 снижается в 5,46/2,01=2,72 раза.for 2p ₁ with x = 0 (figure 2) -

, R _o = 27 · 0.8275 / 2π and σ _d% = 5.46; when x = 0.52 (figure 3) -

, R _o = 27 · 0.8732 / 2π, σ _d% = 2.01 and the value of σ _d1 decreases by 5.46 / 2.01 = 2.72 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 = (0.6990 · 0, 8732 / 0.6950 · 0.8275) (0.91 · 5.46 / 1.28 · 2.01) = 2.05, 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)%. The equal-turn (x = 0) PPO at q = 4.5 has degraded electromagnetic parameters due to its asymmetry for the 2p ₂ pole (with connection to the double star YY) and the presence of surge currents.

Claims (1)

Three-phase two-layer fractional (q = 4,5) 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 of the odd five-coil have coil steps at _pi = 11-2 (i-1) with the number of turns (1-x) w _{to the} coils with i = 1, 5 and (1 + x) w _to coils with i = 3, and even four tushechny - y ' _pi = 10-2 (i-1) with the number of turns (1 + x) w _{to the} coils with i = 3 for w _{to the} turns of the remaining coils of the groups, where z = 27 for 2p ₁ / 2p ₂ = 4 / 2, z = 54 for 2p ₁ / 2p ₂ = 8/4, z = 81 for 2p ₁ / 2p ₂ = 12/6, i = 1 ... 5 - the number of the coil in the group, starting from the outside, 2w _to - the number of turns of each groove with x = 0.52.

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