JPH04265645A - Stator wiring structure of synchronous motor - Google Patents

Abstract

PURPOSE:To reduce the manhour in wiring and reduce the resistance in wiring by reducing the number of layers of the unit coil while maintaining the wiring distribution of multilayer wiring and electric equivalence, concerning the stator structure of a synchronous motor. CONSTITUTION:The synchronous motor driven by plural-phase AC is so constituted that, though the distributions of the stator windings 18b are not the same with every pair of poles N and S, those may be the same with every plural pairs of poles N and S and N and S, and that each phase U, V, and W may be balanced electrically inside that plural pairs of electrodes.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator winding structure for a synchronous motor.

0002

2. Description of the Related Art For example, in a three-phase AC driven synchronous motor, the simplest stator winding is a single-layer winding as shown in FIG. In this motor, six J-degree slots correspond to each pole pair, which is a combination of magnets. However, in a synchronous motor having such a structure, so-called slot ripple is likely to occur.

[0003] To avoid this, the number of slots corresponding to each pole pair is often devised so that it is not an integer. This technique generally results in a so-called multilayer winding in which a plurality of unit coils are arranged in one slot, and in distributed winding instead of concentrated winding. Quadrupole pair 2 in Figure 2
FIG. 3 shows a 36-slot multi-layer winding instead of a 4-slot one using the above-mentioned technique.

0004

However, multi-layer winding means an increase in the total number of unit coils, leading to an increase in the number of winding man-hours. Furthermore, the number of crossover wires increases, leading to an increase in winding resistance that is not involved in the generation of back electromotive force, resulting in power loss.

Therefore, the present invention reduces the number of winding steps and winding resistance by reducing the number of layers in a unit coil while maintaining the winding distribution and electrical equivalence of multilayer winding. With the goal.

[0006]

[Means for Solving the Problems] In view of the above object, the present invention provides a synchronous motor driven by multiple phase alternating current, in which the stator winding distribution is not the same for each pole pair, but is provided for each pole pair. Provided is a stator winding structure for a synchronous motor, characterized in that the windings are the same and each phase is electrically balanced within the plurality of pole pairs. In addition, in a synchronous motor driven by multi-phase balanced AC drive, a plurality of N unit coils arranged in one slot are a mixture of unit coils of two phases, and one phase has an N1 of N/2 or more. another phase has N2 unit coils, another phase has N2 unit coils of the one phase, and N1 unit coils of the other phase; There is provided a stator winding structure for a synchronous motor, characterized in that the N2 unit coils are alternately arranged between slots in which each crossover wire connecting unit coils of the same phase is the shortest.

[0007]

[Function] In the conventional type winding structure shown in Fig. 3, each phase (three phases in Fig. 3) outputs a balanced wave for each pole pair, but there is a pattern in which the balance of each pole pair is affected. without any
A plurality of pole pairs are balanced, and several of the plurality of pole pairs are repeated to form the entire synchronous motor.

Furthermore, by making the distribution coefficients the same, electrical equivalence is completely maintained, and the unit windings of the same phase in each slot are grouped together, the number of unit coils and the winding resistance can be reduced. This is accomplished by the following means.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in more detail below based on embodiments shown in the accompanying drawings. FIG. 2 shows 8 on the surface of the rotor core 10.
Pole magnets 12, that is, four pole pairs of magnets are pasted and fixed, and the stator 14' has 24 slots 1.
6', and a synchronous motor is shown in which one unit coil 18' is disposed in each slot 16' to be driven by three-phase U, V, W balanced alternating current.

For the reasons already mentioned, FIG. 3 shows a synchronous motor in which the stator of FIG. 2 has 36 slots 16 and two unit coils 18a are disposed in each slot 16. As an embodiment of the present invention, FIG. 1 shows a motor in which the stator winding structure of the synchronous motor shown in FIG. 3 has been devised to achieve the above-mentioned object. In this case, since only one phase of winding is disposed in each slot 16, it goes without saying that it is only necessary to dispose one unit coil 18b in each slot 16.

The process of converting the stator winding structure shown in FIG. 3 to the stator winding structure shown in FIG. 1 will be explained below. In the case shown in FIG. 3, in correspondence with claim 2, the number of phases is three phases U, V, W, N=2 (pieces), N1=1 (pieces), N
This is the case when 2=1 (pieces).

Table 1 (a) shows a schematic arrangement of 18 consecutive slots in the clockwise direction of the stator corresponding to the two pole pairs shown in FIG. Starting from the smallest number, it can be seen that the unit coils +U and -W are arranged in the slot numbered 2. Considering replacing the -W unit coil with the +U unit coil in another slot, in this example, since the +U and -W unit coils are arranged in the slot number 11, the +U unit coil is replaced with the +U unit coil in the other slot. It is replaced with a unit coil.

[Table 1]

Next, one +V and one -U unit coil are arranged in the slot numbered 5, but the question here is which unit coil should be replaced. It is also one of the objects of the present invention to shorten the crossover wire, and claim 2
From the point of view of the shortest crossover wire as described in , the +V unit coil should be replaced with the -U unit coil. That is, the U-phase unit coils in the slots numbered 1 and 2 and the number 5
The structure in which the U-phase unit coil in slot No. 6 and the U-phase unit coil in slot 6 are connected by a crossover wire has the shortest length of the crossover wire. Therefore, the +V unit coil in the number 5 slot is replaced with the -U unit coil in the number 14 slot.

[0014] Considering the slot number 8 in the same way,
-V unit coil is replaced with +W unit coil in slot number 17. The state in which the replacement has been completed in this way is shown in Table 1 (b). Since there are only unit coils of the same phase in each throttle, the two unit coils 18a can be made into one unit coil 18b with twice the number of turns, and (
c) and FIG. 1 shows the results.

Next, FIG. 4 shows a synchronous motor that is electrically equivalent to the synchronous motors shown in FIGS. 1 and 3, and was designed for the purpose of reducing the number of slots by half. Inside, unit coils 18a are arranged in four layers.Therefore, the unit coils are the same as those shown in Fig. 3, and the total number is also 72.As a second embodiment of the present invention, this A stator winding structure of a motor that reduces the number of unit coils by half and obtains only the effect of halving the number of slots compared to the motors shown in FIGS. 1 and 3, and eliminates the disadvantage of doubling the number of unit coils. .

As in the case of Table 1, Table 2 (a) schematically shows the slots of FIG. 4 arranged side by side together with the unit coils in each slot. Corresponding to claim 2, the number of phases is 3 phases U, V.
, W, N=4 (pieces), N1=3 (pieces), N2=1
In the case of (pieces), a replacement is performed to reduce the number of unit coils by half.

[Table 2]

The -W unit coil in the slot numbered 1 is replaced with the +U unit coil in another slot. In this case, the slots having N2 unit coils of +V, that is, only one, are those with numbers 6 and 15, and the remaining unit coils are both -W, so they may be replaced with any of them. For example, replace it with the +U unit coil in slot number 6. Next, the +V unit coil in slot No. 4 is replaced with the +W unit coil in slot No. 9, and the same procedure is repeated to obtain Table 2 (b). Since two or four identical unit coils are arranged in each slot, each two unit coils are combined into one unit coil 18b as shown in (c).

Here, a motor with the winding arrangement shown in (a) of Table 1, ie, the motor shown in FIG. 3, and a motor with the winding arrangement shown in (c) of Table 1, ie, the motor shown in FIG. Evaluate the winding distribution state proportional to each back electromotive force for the motor (not shown) with the winding arrangement shown in Table 2 (c), and check that both are equivalent for the two-pole pair or the motor as a whole. shows.

The stator angle corresponding to one pair of magnet poles is an electrical angle of 360°, and each unit coil 18a shown in FIG. 3 has the same number of turns as the unit coil 18a shown in FIG. Note that since the unit coil 18b has twice the number of coil turns, the unit coil 18b should be evaluated with twice as much weight as the unit coil 18a.

The evaluation formula for the winding distribution state is expressed as Φ. First, the U phase in the case of Table 1(a) is evaluated using the following equation. ΦU(1a)=2sin(θ+20°)+sin(
θ+60°)-2sin(θ+220°)-sin
(θ+180°)+2sin(θ+20°)+sin
(θ+60°)-2sin(θ+220°)-si
n(θ+180°) = 2 sin(θ+0°)+4 sin(θ+20°)
+4 sin (θ+40°) +2 sin (θ+60°) Similarly, in the case of V phase and W phase, the equation is as follows. ΦV(1a)=2sin(θ+120°)+4s
in(θ+140°)+4sin(θ+160°)+
2sin(θ+180°)ΦW(1a)=2si
n(θ+240°)+4sin(θ+260°)+4
sin(θ+280°)+2sin(θ+300°
)

[0021]Evaluation formulas ΦU(
1a), ΦV(1a), and ΦW(1a), it can be seen that they are in an equilibrium state with the phases shifted by 120°.

Next, the evaluation formulas for each phase of U, V, and W in the case of Table 1(c) are as follows. ΦU (1c) = 2 sin (θ + 20°) + 2 sin
(θ+60°)-2sin(θ+180°)-2s
in(θ+220°)+2sin(θ+20°)−2
sin(θ+220°)=2sin(θ+0°)
+4sin(θ+20°)+4sin(θ+40°)+
2sin(θ+60°) ΦV(1c)=2sin(θ+120°)+4s
in(θ+140°)+4sin(θ+160°)+
2sin(θ+180°)ΦW(1c)=2si
n(θ+240°)+4sin(θ+260°)+4
sin(θ+280°)+2sin(θ+300°
)

From the above, ΦU(1c), ΦV(1c
), ΦW(1c), the phase is 120°, respectively.
It can be seen that they are in a state of equilibrium with a slight deviation. Furthermore, ΦU(
1a)=ΦU(1c), ΦV(1a)=ΦV(1c),
It can also be seen that ΦW (1a) = ΦW (1c). Therefore, it can be seen that the back electromotive force is the same in both the case of Table 1(a) and the case of Table 2(c), and it can be said that both motors are electrically equivalent.

Next, when the case shown in Table 2(c) is evaluated for each phase, the results are as follows. ΦU(2c)=4sin(θ+40°)−4sin
(θ+200°)+2sin(θ+360°) −
2 sin (θ + 240°) + 4 sin (θ + 40°)
-4sin(θ+200°)+2sin(θ+36
0°) -2sin(θ+240°)=4sin
(θ+0°)+8sin(θ+20°)+8sin(θ
+40°)+4sin(θ+60°)ΦV(2c)=
4 sin (θ + 120°) + 8 sin (θ + 140
°) + 8 sin (θ + 160°) + 4 sin (θ +
180°) ΦW(2c) = 4sin(θ+240
°)+8sin(θ+260°)+8sin(θ+2
80°)+4sin(θ+300°)

It can be seen that each phase U, V, W is in an equilibrium state shifted by 120°, and ΦU(2c)=ΦU(1c)×2,Φ
V(2c)=ΦV(1c)×2, ΦW(2c)=ΦW(
1c)×2. This is because Table 2 shows the 4 magnet pole pairs, that is, the entire motor, and Table 1 shows the 2 pole pairs, that is, half the motor. When compared as a whole, the evaluation formulas for each phase are the same. As mentioned above, Table 1(c)
Since the motor in Table 2(a) is electrically equivalent to the motor in Table 2(a), it can be said that the motor in Table 2(c) is electrically equivalent to the motor in Table 2(a). It can be easily confirmed that Table 1(c) and Table 2(a) are equivalent by creating an evaluation formula similar to the above.

If the present invention is applied once again to the winding arrangement shown in Table 2(c), it is possible to provide a structure in which only a single-phase winding coil is disposed within each slot 16''.

[0027]

[Effects of the Invention] As is clear from the above description, according to the present invention, the number of layers of unit coils in each slot can be reduced while maintaining electrical equivalence, and the number of winding man-hours can be reduced. As well as a reduction in winding resistance can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a motor showing a stator winding structure according to the present invention.

FIG. 2 is a cross-sectional view of a motor showing one conventional stator winding structure.

FIG. 3 is a sectional view of a motor showing another conventional stator winding structure.

FIG. 4 is a sectional view of a motor showing still another conventional stator winding structure.

[Explanation of symbols]

10...Rotor 12...Magnet 14...Stator 16...Slot 18a, 18b...unit coil U, V, W...phase

Claims (2)

[Claims] Claim 1: In a synchronous motor driven by multiple-phase alternating current, the stator winding distribution is not the same for each pole pair, but is the same for each multiple pole pair, and within the multiple pole pairs, each phase A stator winding structure of a synchronous motor characterized by electrically balanced. [Claim 2] In a synchronous motor driven by multi-phase balanced AC drive, a plurality of N unit coils arranged in one slot are a mixture of unit coils of two phases, and one phase is N/2 unit coils. It has N1 unit coils, and the other phases are N1 unit coils.
It has two unit coils, and the unit coil of the one phase is N.
2 unit coils, and each of the N2 unit coils between the other slots in which the connecting wires connecting the unit coils of the same phase are the shortest among the other slots having N1 unit coils of the other phase. A stator winding structure of a synchronous motor characterized by having the following elements arranged interchangeably.