JPH0348741B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a polyphase armature winding for an AC rotating electrical machine, which is a fractional groove winding.

[Technical background of the invention and its problems]

In a multiphase AC rotating electric machine, a plurality of axial grooves are provided on the inner peripheral surface of a cylindrical armature core, and armature windings are wound around the grooves to form an armature. There are three ways to wind the armature winding: lap winding, wave winding, and chain winding, which are selected depending on the type and characteristics of the rotating electrical machine.
Regarding the number of grooves, there are cases where the number of grooves per pole is an integer number, and cases where the number is an integer number, that is, a fraction.The former is called integer groove winding, and the latter is called irregular number groove winding or fractional groove winding. Widely used. Fractional groove winding is generally employed in rotating electric machines with a relatively large number of poles. The reason for this is that although the selection range for the number of parallel circuits in fractional groove winding is narrow, the number of grooves can be selected that is not an integer multiple of the number of poles, so there is a greater degree of freedom in design, and it also has advantages such as making it easier to create a good voltage waveform. This is because there is.

In a fractional groove winding, the number of grooves q per pole is generally expressed by the formula q=a+c/b (where a, b, and c are integers and c/b is an irreducible fraction). Also, if the number of grooves is Z and the number of phases is m, the number of grooves for each phase is N=
It is expressed as Z/m. In the present invention, the number of grooves for each pole and each phase is q.
This relates to the case of a fractional groove winding where q=a+c/b and the number N of grooves in each phase is an odd number. As a specific example, in terms of number of poles, number of grooves, and number of phases, 6 poles, 45 grooves,
This is a three-phase case.

In this case, in the conventional three-phase lap winding method, N=45/
3 = 15, the coil arrangement is as shown in Figure 1, and the coils for one phase are 2, 3, 2, 3.
It consists of combinations of 1, 2, and 3 coils, and each coil has 15 coils. In Figure 1, 1 to 45 represent the groove numbers, U, V, and W represent the U-phase, V-phase, and W-phase coils, respectively, and ,,, the direction of the current is opposite to the U, V, and W coils. Indicates the direction. In the example in Figure 1, the coil pitch is #1 to #8.
It is 93.33% short-section volume. When connecting these coils in parallel, as shown in Figure 2, 2
It is divided into a first series coil group A, in which 1, 3, and 2 coils are connected in series, and a second series coil group B, in which 3, 2, and 3 coils are connected in series, and both groups A, The number of coils B is not the same, resulting in unbalance and cannot be put to practical use. In FIG. 2, groove numbers 1, 2, etc. are given as subscripts to each upper coil U to clarify which groove the coil is placed in. Further, u is a power supply terminal, and x is a terminal on the opposite side.

In order to improve this, the inventor considered constructing a practically usable winding using N-1 coils. This case will be explained with reference to FIGS. 3 and 4.

Figure 3 shows the same number of grooves as Figure 1 of the conventional example mentioned above.
45, the number of poles is 6, and the number of phases is 3. As shown in Figure 1, the coil pitches are 93.33% short-pitch winding for #1 to #8. That is, the upper coil _U1 entering groove #1 and the lower coil entering groove #8 form one coil. In the figure, U,
They are represented by V and W, and the subscript numbers corresponding to the groove numbers are omitted. Then, the first
In the figure, the number of coils for each phase is one less than the number of grooves for each phase, N=15. In other words, the number of coils for each phase is N
-1 piece. Therefore, in this example, 15-1=14
The number of coils is . Therefore, as can be seen from FIG. 3, regarding the U phase, the coil with groove number #25 is missing. That is, the coil that goes from the upper coil #25 to the lower coil #32 is omitted.

Similarly, for the V phase, the coil with groove number 45 is missing so that the number of coils is 14. That is, the coil that goes from the upper coil #45 to the lower coil #7 is omitted.

Similarly, for the W phase, the coils from the upper coil of groove number #5 to the lower coil of #12 are omitted, resulting in a total of 14 coils.

When connecting these coils to two parallel circuits, for the U phase, two or three coils are connected as shown in Figure 4.
It is divided into a first series coil group A, which is connected in series with 2 coils, and a second series coil group B, which is similarly connected in series with 2 coils, 3 coils, and 2 coils. Number of series coils is 7 each
Since they are addressed to each individual and are the same, they are almost balanced. However, in this case, the voltage vectors induced in the first series coil group A and the second series coil group B have a slight phase difference and are not completely balanced. This will be explained in more detail.

With the coil arrangement shown in Figure 3, the voltage vectors induced in each coil represented by the upper coil in each groove are shown as e ₁ , e ₂ ...e ₄₄ , with the groove number subscripted to e, as shown in Figure 5. become that way. In FIG. 5, the vector indicated by the dashed line arrow indicates that the current flows in the opposite direction to the vector indicated by the solid line arrow. This is connected to two parallel circuits for each phase as shown in Figure 4 (Figure 4 shows U
(phases only shown), the resultant vector is e _A for the first series coil group A and e _B for the second series coil group B, each at 120°,
It is balanced with the V-phase and W-phase vectors with a phase difference of 240°. However, there is a phase difference between the vectors e A and e B of the first and second series coil groups _A and _B.
Next, try searching for this.

Since the groove pitch θ is θ=360/Z×number of poles/2=360/45×6/2=24°, the absolute value of the induced voltage of a certain coil is E
Then, the voltage vector and composite vector of each coil are as follows. e ₁ = Eε ^J0 , e ₂ = Eε ^J24 ,
e ₁₆ = Eε ^J0 , e ₁₇ = Eε ^J24 , e ₃₀ = Eε ^-J24 , e ₃₁ = Eε ^J0
,
e ₃₂ = Eε The synthesis of ^J24 is e _A , e ₈ = Eε ^-J12 , e ₉ =
Eε ^J12 , e ₁₀ = Eε ^J36 , e ₂₃ = Eε ^-J12 , e ₂₄ = Eε ^J12 , e _3
8
=Eε ^-J12 , e ₃₉ The composition of =Eε ^J12 is e _B. Calculating this, e _A = e ₁ + e ₂ + e ₁₆ + e ₁₇ + e ₃₀ + e ₃₁ + e ₃₂ = 3E + 3Eε ^j24 + Eε ^-24 = E [3 + 3 (cos24゜+jsin24゜) + (cos24゜−jsin24゜)] = (6.6541 8 +j0.813474）E =6.703719E∠6.96982゜e _B =e ₈ +e ₉ +e ₁₀ +e ₂₃ +e ₂₄ +e ₃₈ +e ₃₉ =3Eε ^j12 +3Eε ^-j12 +Eε ^j36 =E[3(cos12゜+jsin12゜)+3(cos12゜−jsin12゜) + (cos36゜+jsin36゜)〕 = (6.677905+j0.587785)E = 6.7037232E∠5.03017゜The magnitudes of both composite voltage vectors e _A and e _B are almost the same, but the phase difference α is α ≒6.97゜-5.03゜=1.94゜, there is a slight unbalance, and a circulating current flows through the parallel circuit consisting of the first and second series coil groups A and B, although it is not so much that it cannot be used for practical purposes. This will cause increased losses. This is the same for each phase.

[Purpose of the invention]

An object of the present invention is to provide a multiphase armature winding that makes it possible to create a balanced parallel circuit even when the number N of grooves in each phase is an odd number.

[Summary of the invention]

The present invention is a fractional groove winding that is wound around an armature core having 45 grooves, and the number of grooves q for each pole and each phase is q = 2 + (1/2), and the number of grooves for each phase is 15. In the lap-wound multiphase armature winding, the number of coils for each phase is 14, and these are divided into the first and second coil groups, and these two coil groups both have 2 coils. Formed by 2 continuous coils and 1 3 continuous coil, each coil is represented by the coil above each groove according to the number of turns of each coil, and the groove number is added to the phase code, and the opposite direction of current is marked with a bar. When referring to U2, U17, U
The number of turns of coils 32 and 8, 23 and 38 are U1, U16, U30, U31 and 9, 10,
The number of windings of the coils U24 and 39 is approximately 0.88 times, and the other phases are formed in the same manner, and the consecutive coils of the first coil group are connected in the order of 2, 3, 2. Connect the continuous coils of the second coil group in the order of 2, 3, 2, and insert the unstored coil groove of the second coil group into the reference groove (No. 5 ), three coils are formed with an electrical angle of 480 degrees as a reference point, each coil is stored in a groove using a lap winding method, and then the first coil group and second coil group are connected in parallel and the terminals are taken out and formed. It is. As a result, it is possible to create a balanced parallel circuit, which has the advantage of supporting dual voltages and standardizing the iron core.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 3 to 5. The coil arrangement is as shown in FIG. 3 described in the technical background leading to the present invention, and the parallel circuit is also as shown in FIG. 4. and the fifth
In order to make the phase difference α shown in the figure zero, for the U phase, e ₂ of the first series coil group A,
Coils U ₂ , U ₁₇ , which generate voltage vectors e ₁₇ , e ₃₂ ,
U ₃₂ and e ₈ of the second series coil group B,
Coil ₈ that produces voltage vectors e ₂₃ , e ₃₆ ,
The number of turns of each coil ₂₃ , ₃₈ is e ₁ , e ₁₆ , e ₃₀ ,
Coils _{U 1 ,} U ₁₆ , U ₃₀ , U _{31 , 9 , 10 , 24} , ₃₉ that generate voltage vectors e 31 , _{e 9} , _{e 10 ,} e ₂₄ , e ₃₉
The number of turns of each coil should be approximately 0.88 times. V phase,
This also applies to the W phase. That is, in the V phase, V ₇ , V ₂₂ ,
In the W phase, the coils of V ₃₇ , ₁₃ , ₂₈ , ₄₃ are
The number of turns of the coils W ₁₂ , W ₂₇ , W ₄₂ , ₃ , ₁₈ , and ₃₃ is approximately 0.88 times that of the other coils.

Next, the effect will be explained.

Let's find the condition of e _A = e _B with the turns ratio set to 0.88 as x.

e _A =3E+3Exε ^j24 +Eε ^-j24 =E[3.913545+2.740635x +j(1.220211x−0.406737)] Also, e _B =3Eε ^j12 +3Exε ^-j12 +Eε ^j36 =E[3.743457+2.93444 4x +j (-0.623736x+1.211521) ] Here, e _A − e _B = 0 is calculated from the real part: 0.170088−0.193809x=0 x=0.170088/0.193809=0.8776063, and from the imaginary part: 1.618258−1.843947x=0 x=1.618258/1.843947=0. 8776054 i.e. x When ≒0.88, the first series coil group A
and the voltage vector e _A of the second series coil group B
and e _B are almost equal in size, the phase difference α approaches zero, and a balanced winding with almost no circulating current flows. The same applies to the V phase and W phase.

By making two parallel circuits possible in this way, it is possible to use a power supply voltage of 1:2, for example 200V.
Can be shared with 400V. i.e. 200V
Now, let's make a circuit twice as large, for example, 2 x Y wiring,
In the case of 400V, a single circuit, for example a 1×Y connection, is sufficient.

Also, by adopting twice the circuit at 200V,
When modifying to 400V class, you can change the coil connection without rewinding the armature winding, i.e. from 2 x Y to 1.
Modification is possible by simply changing to ×Y, and the time required for modification is short, making it possible to respond economically with short delivery times.

Generally, the number of grooves in the armature core is an even number, but this number cannot be increased in small capacity models due to dimensional limitations. To solve this problem, an odd number of grooves is required. For example, for 6 poles, the number of grooves is 36
Generally speaking, 54 grooves are used, but if 54 grooves cannot be accommodated due to the dimensions as mentioned above, 45 grooves will be needed as an intermediate number. It becomes effective.

In this way, the 45 grooves are 2, 4, 6, 8, 10, 12,
Balanced three-phase winding with 14 or 15 poles is possible, which has a wide range of applications, and the iron core can also be shared, which is very effective in terms of standardization.

[Effects of the Invention] As explained above, according to the present invention, even when the number N of grooves in each phase is an odd number, it is possible to create a balanced parallel circuit, and it is possible to handle double voltage. The effects on design and production are extremely large, such as being able to be modified to a different voltage, or to standardize the iron core.

[Brief explanation of drawings]

Fig. 1 is a coil layout diagram showing a conventional multi-phase armature winding, Fig. 2 is a wiring diagram showing one phase when the number of parallel circuits of the windings in Fig. 1 is 2, and Fig. 3 is a diagram of the main winding. A coil layout diagram showing an embodiment of the polyphase armature winding of the invention,
FIG. 4 is a wiring diagram showing one phase when the number of parallel circuits of the windings in FIG. 3 is two, and FIG. 5 is an induced voltage vector diagram of the windings in FIG. 3. 1 to 45 are groove numbers, U, V, W,... are the coils of each phase, U ₁ , U _2, etc. Those with groove numbers as subscripts are the coils in which the upper coil is placed in the groove, A is the coil. First series coil group of parallel circuit, B
is the second series coil group in parallel circuit.

Claims (1)

[Claims] 1 Fractional groove winding wound around an armature core with 45 grooves, where the number of grooves q per pole per phase is q = 2 + (1/2), and the number of grooves per phase is 15. In the winding type polyphase armature winding, the number of coils for each phase is 14, and these are divided into the first and second coil groups, and both of these two coil groups have 2 continuous coils × Formed with 2 and 3 continuous coils x 1, each coil represented by the coil above each groove is designated by the number of turns of each coil, and the groove number is added to the phase code, and the opposite current direction is referred to with a bar. Time U2, U17, U32
And the number of turns of coils 8, 23, and 38 is U
1, U16, U30, U31 and 9,10,
The number of turns of the coils 24 and 39 is approximately 0.88 times as large, and the other phases are formed in the same manner.The consecutive coils of the first coil group are connected in the order of 2, 3, 2, and between these consecutive coils, the windings are reversely connected to the first coil group. Connect the continuous coils of the second coil group in the order of 2, 3, 2, and insert the unstored coil groove of the second coil group into the reference groove (No. 5 ), three coils were formed at an electrical angle of 480 degrees, and each coil was stored in a groove using a lap winding method, and then the first coil group and second coil group were connected in parallel, and the terminals were taken out and formed. A polyphase armature winding featuring: