JPS633545B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a pole number changing motor equipped with an armature winding that can change the connection of the windings to a pole number ratio of 2:3. As a noise countermeasure for dryer fans and ventilation fans, the demand for pole-change electric motors with high and low rotational speeds has increased particularly recently. This is to reduce noise by operating at low speed late at night. Also, as an energy saving measure, it is possible to reduce the speed during light loads to save power according to the load. In addition, the load characteristics of fans, pumps, etc. are proportional to the cube of the rotation speed, and 1 to 2 (4/8 poles) has the disadvantage that the output on the low speed side is too small. A three-pair pole conversion motor is required. Conventionally, in the case of a pole ratio of 1 to 2, it is possible to easily change the pole number with a single winding, but with 4/6 poles, etc., there is a winding corresponding to each pole number, and a 4 pole winding is required. line and 6
Since the pole winding and the winding are wound separately, it is necessary to increase the size of the groove in which the winding is housed. As a result, the electric motor becomes large, resulting in an uneconomical design, and has the drawback of becoming an expensive electric motor that uses a large amount of material, which goes against the grain of resource conservation. Further, in the conventional method using a single winding, each phase is not balanced and an unbalanced current flows. In addition, since unbalanced losses occur, the temperature rise becomes large and there is a risk of burning out the windings. SUMMARY OF THE INVENTION An object of the present invention is to provide a pole-changing motor having a three-phase armature winding that can change the number of poles into a two-to-three relationship with a single winding. Hereinafter, as an embodiment of the present invention, three phases P ₁ = 4 poles, P ₂ = 6 poles, P ₂ /P ₁ shown in FIGS. 1 to 4 will be described.
= 1.5 and the number of stator grooves Z ₁ = 54 will be explained. In this case, in the two-layer overlapping winding method, the number of winding groups per unit is 54/3=18. Let α ₁ be the phase difference (electrical angle) between adjacent grooves when P ₁ = 4 poles, and α ₂ be the phase difference (electrical angle) between adjacent grooves when P ₂ = 6 poles. α ₁ = (180/Z ₁ )・P ₁ = 40/3, α ₂ = (180/
Z ₁ )・P ₂ = 20. Figure 1 shows the voltage vector of a winding according to the present invention, in which wire groups are arranged in different numbers so that the voltage vector of each winding becomes a balanced three-phase winding.
Figure 2 shows the case of 6 poles. e ₁ represents the voltage of the winding placed in the groove of well 1, e ₂ represents the voltage of the winding placed in the groove of well 2, e ₃ , e ₄ ... e _Z similarly represents the voltage of each winding. . The dotted line indicates that the polarity is reversed from that of the solid line. (For example, if the solid line is the N pole, the dotted line is the S pole.) From this vector diagram, the U-phase winding group is e ₁ - _{e 2} -
A group of three windings e ₃ and two windings e ₆ - e ₇ , e ₁₃ - e ₁₄ and e ₁₇ - e ₁₈ are connected in series to form _one group A.
e ₂₈ ― e ₂₉ ― e ₃₀ , e ₃₃ ― e ₃₄ , e ₄₀ ― e ₄₁ , and
Let e ₄₄ - _{e 45} be connected in series to form A ₂ group. In the same way, for the V phase, add 3 pieces e ₃₇ - e ₃₈ - e ₃₉ and e ₂₆
―e ₂₇ , e ₂₂ ―e ₂₃ and e ₁₅ ―e ₁₆ are connected in series to form B ₁ group, and e ₁₀ ―e ₁₁ ―
Three e ₁₂ and e ₄₂ - e ₄₃ , e ₄₉ - e ₅₀ and e ₅₃ - e ₅₄ are connected in series to form B ₂ group. Similarly, for the W phase, add three e ₄₆ - e ₄₇ - e ₄₈ and e ₅₁ .
e ₃₅ - e ₃₆ and e ₂₅ and e ₄ - e ₅ are connected in series to form C ₁ group, e ₁₉ - e ₂₀ - e ₂₁ , and e ₂₄
and e ₃₁ - e ₃₂ , e ₅₂ and e ₈ - e ₉ are connected in series.
C ₂ groups. This is organized and summarized in Table 1.

[Table] ₁ - ₂ - ₃ indicates a line ring group, indicating that it consists of three pieces, ₁₃ - ₁₄ indicates a line ring group consisting of two pieces,
This shows that the polarity is opposite to that of e ₁ - e ₂ - e ₃ . Take out the terminals from both ends of the windings of group _A1 , and let the _e1 side be _U2 , and the _e17 side be _V1 . Similarly, for the A ₂ group winding, the e ₂₈ side is U ₂ , and the e ₄₄
Let the side be _U1 . Similarly, for B ₁ group, set e ₁₅ side to W ₂ , and set e ₃₉ side to W 2.
Let it be W ₁ . Similarly, for B ₂ group, connect e ₁₀ side to W ₂
and let the e ₅₃ side be V ₁ . Similarly, for the C ₁ group, the e ₄₆ side is set to V ₂ , and the e ₄ side is set to U _1.
shall be. Similarly, for the _C2 group, the _e19 side is set to _V2 , and the _e8 side is set to _W1 . Connect this as shown in Figure 3, turn on U ₂ , V ₂ , and W ₂ , and short-circuit U ₁ - V ₁ - W ₁ to form a 4-pole winding, and connect U ₂ , V ₂ , and W ₂ to Leave open, U ₁ , V ₁ ,
By connecting W ₁ to the power supply respectively, it becomes a 6-pole winding. The above connection diagram is shown in Figure 4. The magnetomotive force distribution due to this winding is shown in Figures 5 and 6.
As shown in the figure, Fig. 5 shows the case where U ₂ , V ₂ , and W ₂ are connected to the power supply, and U ₁ - V ₁ - W ₁ is short-circuited, that is,
This is the case where P ₁ =4 poles. In Figure 6, U ₁ , V ₁ , W ₁ are connected to the power supply, and U ₂ ,
This is the case when V ₂ and W ₂ are open, that is, when P ₂ =6 poles. In both cases, the current in the U phase is 1, and the V and W phases are -1/
It shows the magnetomotive force at the time when it becomes 2. As can be seen from Figures 5 and 6, when operating with the smaller number of poles, the same number of magnetic poles as the smaller number of magnetic poles are formed in each phase winding, and the resultant magnetomotive force wave distribution is smaller than the smaller one. Forms magnetic pole distribution. The same goes for the larger number of poles, and each number of poles can be obtained. In this example, the number of grooves Z ₁ =54 for 4/6 poles is shown.
In other words, the number of continuous grooves for each wire ring group of U phase and V phase is 3K.
= 2 sets of 3 pieces, 2K = 6 sets of 2 pieces, W
Number of continuous grooves per phase wire ring group 3K = 2 sets of 3 pieces and 2K =
There are 4 sets of 2 pieces and 4 sets of K=1 piece. Of course, even if K=2 or more, the same operation as in the above example can be performed. As described above, according to the present invention, it is possible to obtain a pole number changing electric motor having a three-phase armature winding capable of changing the number of poles into a 2:3 relationship with a single winding. This means that the 4-phase winding and the 6-pole winding are not wound separately as in the past, but can be constructed with a single winding, which reduces the groove dimensions, making the motor more compact and saving material resources. can be realized. Furthermore, this one has a winding pattern consisting of two phases (U phase, V phase) having 8 wire ring groups and the other phase (W phase) consisting of 10 wire ring groups. At this time, by increasing the number of wire ring groups for each phase than the number of poles for each size, the voltage balance between each phase is improved and each phase is balanced. This prevents unbalanced current from flowing and eliminates loss, so temperature rise can be suppressed and motor characteristics can be improved.

[Brief explanation of the drawing]

Figures 1 and 2 are voltage vector diagrams when the pole-change motor according to the present invention is applied to different numbers of poles, Figure 3 is a wiring diagram showing its connection state, and Figure 4 is a developed diagram of its windings. , FIG. 5, and FIG. 6 are magnetomotive force distribution diagrams of the pole number changing motor of the present invention. e ₁ , e ₂ ... e ₅₄ ... Voltage of the winding in the groove, α ₁ , α ₂ ... Phase difference between adjacent grooves, u ₁ , V ₁ , W ₁ , u ₂ , V ₂ , W ₂
...Exit symbol.

Claims (1)

[Claims] 1. In a pole change motor with a three-phase armature winding that enables pole number change with a pole number ratio of 2 to 3 by changing the connection with a single winding of a two-layer overlapping winding method, the number of grooves can be changed. There are 54 wire rings, and each wire ring group has 8 wire rings per phase. Each wire ring group has 2 sets of 3 continuous grooves and 6 sets of 2 continuous grooves. The 10 wire ring groups consist of 2 sets of 3 continuous grooves, 4 sets of 2 continuous grooves, and 4 sets of 1 groove per wire ring group, and one other phase having this wire ring group. A pole change electric motor characterized by being composed of wires.