RU2227360C2 - Nine-phase double-pole winding - Google Patents

Abstract

FIELD: electrical and electromechanical engineering. SUBSTANCE: proposed nine-phase winding designed for use in multiphase squirrel-cage induction motors supplied with power from semiconductor frequency changers is double-layer 2p = 2 pole lap winding placed in z = 54 slots at q = z/2pm = 3 slots per pole per phase; it is assembled of 2 pm coil groups with q concentric coils in each group: at m = 9 phases and m = 2 m = 19 phase zones winding has 18 coil groups numbered 1G through 18G with slot pitch Yni = 20, 18, 16, coil turn number being (1+x)W_c, W_c, (1+x)W_c for each group. Interconnected in first phase are groups 1G and 10G, and group numbers in each next phase are alternating at intervals of two groups relative to groups of first phase, where 2W_c is turn number of each slot and value x = 0.20; sign (-) in front of group number points to differential connection with phase groups connected in series or in parallel. EFFECT: improved mmf harmonic composition; reduced differential dissipation factor. 1 cl, 2 dwg

Description

The invention relates to the windings of electrical AC machines and can be used, for example, on a stator of asynchronous motors (HELL) with a squirrel-cage rotor, powered by semiconductor frequency converters (IF).

Known loop symmetrical 2p-pole m≥3-phase, m '= 2m-zone two-layer AC windings, performed in z = 2pmq grooves from 2pm coil groups with a total number of q = z / 2pm grooves per pole and phase with concentric coils [ 1-3].

Closest to the proposed one is m = 3-phase, m ’== 2m = 6-zone 2-pole two-layer winding, performed at q = z / 6p = 3 in z = 6pq = 3 grooves from 6p uniformly displaced coil groups.

In the invention, the task is to perform in z = 54 grooves of a two-layer winding at 2p = 2 poles and m = 9 phases with improved harmonic composition of the MDS and reduced differential scattering.

The solution of this problem is achieved by the fact that for a two-layer 2p = 2-pole winding performed by a loop in z = 54 grooves with q = 3 grooves per pole and a phase of 2pm coil groups with q concentric coils in each: at m = 9 phases, m '= 2m = 18-phase zones, the winding contains 18 coil groups with numbers from 1G to 18G with coil steps in grooves at _pi = 20, 18, 16 and their number of turns (1 + x) w _k , w _k , (1- x) w _k for each group in the first phase group of compound 1D and -10G and group numbers each subsequent phases alternate with intervals in the two groups with respect to groups of the first phase rD 2w _k - number of turns of each slot, and x = 0.20, and the sign (-) at room group defines its counter switch in series or parallel connection of phase groups.

Figure 1 shows a scan of the groove layers of the proposed two-layer loop winding with concentric coils at 2p = 2 poles, z = 54 grooves, m = 9 phases, m '= 2m = 18-phase zones in the sequence A-A'-A "- Z-Z'-Z "-B-B'-B '' - X-X'-X"-C-C'-C"-Y-Y'-Y". 18 reel groups with numbers from 1G to 18G (top) and slot numbers 1 to z = 54 (bottom); figure 2 - construction of the polygon of the MDS winding in figure 1, where the center shows the vectors of the symmetric m '= 2m = 18-phase system of currents of phase zones when they are shifted angle α _f = 20 °.

Winding factor of the winding is determined by the coefficients of shortening concentric coils By _yi = sin (90 ° V _pi / τ _n) when the pole pitch τ _p = z / 2p = 54/2 = 27, and the neravnovitkovosti coils: K _on = Σ (K _yi w _ki ) / qw _k = 0.862122 + x0.03870, y _p.p. = Σ (for _pi w _ki ) / qw _k 18 + 4x / 3 (1) with y _pi = 20, 18, 16 and number of turns ( 1 + x) w _to outdoor, w _k for medium, (1-x) w _k for the inner coil and the average step in _p.sr.

при a1=1-2=2-3=2b=

, радиус точки i=3 относительно центра

квадраты радиусов точек

и по [2-3]:

и

(2)The slot points i = 1 ... 54 of the MDS polygon in figure 2 are built in the directions of the currents of the phase zones in the grooves (figure 1). For points i = 1, 2, 3 of one repeating part of the winding at x = 0, the MDS of one groove layer per unit length and ac = bc = 3 are determined (by the theorems of sines and cosines):

with a1 = 1-2 = 2-3 = 2b =

, the radius of the point i = 3 relative to the center

squares of radii of points

and according to [2-3]:

and

(2)

where R is the radius of the circle for the main harmonic MDS and σ _D is the differential scattering coefficient.

и

, откуда по условию [3] d(σ_д)dx≡d(R_д/K_об)²/dx=0 определяется оптимальное значение х=x_опт=0,20, при котором σ_д достигает значения σ_д%мин=0,104 (для K_об=0,8699), т.е. при х=0,2 σ_д% снижается в 0,117/0,104=1,13 раза и по (1) у_п.ср=18,267. В сравнении с обмоткой при m=3, m’=6, 2р=2, z=54, q=9, у_п=18, K_oб=0,82746, R $\genfrac{}{}{0ex}{}{\text{2}}{\text{д}}$ =203 и σ_д%=0,349 предлагаемая обмотка имеет в 0,349/0,104=3,36 раза меньшее значение σ_д%, что значительно снижает добавочные потери в стали и индуктивное сопротивление фазы АД с такой обмоткой. Применение ее в АД с к.з. ротором при питании от ППЧ 9-фазного тока позволяет втрое снижать фазный ток в сравнении с 3-фазными ППЧ, что снижает стоимость управляемых вентилей при упрощении схемы ППЧ.According to (1) - (2) at x = 0 - K _rev = 0.86212, R = 54 · 0.86212 / π, R $\genfrac{}{}{0ex}{}{\text{2}}{\text{d}}$ = 219.853203 and σ _d = 0.117 or in percent - σ _d% = 0.117. For unequal coils in figure 2: (a1) ² = (b2) ² = (1 + x) ² + (1-x) ² -2 (1-x ² ) cosl20 ⁰ = 3 + x ² , then

and

, whence by the condition [3] d (σ _d ) dx≡d (R _d / K _rev ) ² / dx = 0, the optimal value x = x _opt = 0.20 is determined, at which σ _d reaches the value σ _{d% min} = 0.104 (for K _rev = 0.8699), i.e. at x = 0.2, σ _d% decreases 0.117 / 0.104 = 1.13 times, and according to (1) for _p.p. = 18.267. Compared with the winding at m = 3, m '= 6, 2p = 2, z = 54, q = 9, at _n = 18, K _about = 0.82746, R $\genfrac{}{}{0ex}{}{\text{2}}{\text{d}}$ = 203 and σ _d% = 0.349, the proposed winding has 0.349 / 0.104 = 3.36 times lower σ _d% , which significantly reduces the additional losses in steel and the inductive resistance of the HELL phase with such a winding. Its use in blood pressure with short circuit with a rotor when powered by a 9-phase current frequency converter, it allows a three-fold reduction in phase current in comparison with 3-phase inverter, which reduces the cost of controlled valves while simplifying the inverter circuit.

Sources of information

1. Voldek A.I. Electric cars: Textbook for high schools. L .: Energy, 1978, p. 420-450.

2. Popov V.I. Determination of differential scattering of multiphase windings. Electricity. - 1987, No. 6, p. 50-53.

3. Popov V.I. Optimization of electromagnetic parameters of three-phase fractional windings. Electricity. - 1996, No. 10, pp. 8-34.

Claims (1)

Nine-phase 2p = 2-pole winding with z = 54 grooves, made of a two-layer loop with q = 3 grooves per pole and a phase of 2rm coil groups with q concentric coils in each, characterized in that for m = 9 phases and m '= 2m = 18 phase zones, the winding contains 18 coil groups with numbers from 1G to 18G with coil steps in grooves U _pi = 20, 18, 16 and their number of turns (1 + x) W _to , W _to , (1-x) W _k for each group, in the first phase the groups 1G and -10G are connected, and the group numbers of each subsequent phase alternate with an interval of two groups relative to the groups of the first phase, where 2w _k is the number of turns o of each groove and the value x = 0.20, and the sign (-) in front of the group number means its counter inclusion when the phase groups are connected in series or in parallel.

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