KR930008989B1 - Asynchronous induction motor for three phase squirrel-cage rotor - Google Patents

Abstract

The induction motor can easily adjust a motor power by changing its number of poles when the power needs of load are changed. The motor has 3 stator windings as usual, but for a delicate power adjustment, the a-phase is composed of a multiple of 6 coil group winding, the b and the c-phase are composed of multiple of 8 coil group winding. The number of turns in the a- phase coil group winding is greater than those of turns in the b- and the c-phase coil group winding, so that the electrical balances between a-, b-, c-phase are obtained. Also the magnetic balances are obtained by adjusting the connecting method and the inserting method.

Description

3-phase induction motor

1 is a view showing an example of a conventional coil structure.

2 is a diagram of a conventional three-phase induction motor Connection diagram.

3 is another view of the conventional three-phase squirrel cage induction motor Connection diagram.

4 is a Y connection diagram of a conventional three-phase squirrel cage induction motor.

5 is another Y connection diagram of a conventional three-phase induction motor.

6 is a view showing an example of a coil structure according to the present invention.

7 is a three-phase induction motor according to the present invention Connection diagram.

8 is another embodiment of the three-phase squirrel cage induction motor according to the present invention Connection diagram.

9 is a Y connection diagram of a three-phase squirrel cage induction motor according to the present invention.

10 is another Y connection diagram of the three-phase squirrel cage induction motor according to the present invention.

FIG. 11 is a diagram illustrating the internal connection of a motor showing a direction and a position in which a coil is locked to a stator in a three-phase induction motor according to the present invention.

* Explanation of symbols for main parts of the drawings

S1: stator a, b, c: coil

1, 2, 3, 4, 5, 6, 7, 8, 9: Terminal 41: Slot

The present invention relates to a three-phase squirrel cage induction motor, and more particularly, to a three-phase squirrel cage induction motor that can easily adjust the output of the motor by changing the number of poles when the required output of the load changes.

Conventional three-phase squirrel cage induction motor has a problem that it takes a lot of expense and time because the motor itself must be replaced when the required output of the load changes.

On the other hand, another conventional technique is that the coil of each phase is installed in multiples of 2, as shown in Fig. 1, to take out the intermediate terminals (7, 8, 9), 4 poles depending on the combination of terminals Final, 8 poles In the pole number fluctuations such as wiring, 4-pole Y-connection, and 8-pole Y-connection, changes to multiples were made.

That is, as shown in FIGS. 2 and 3 When 3-phase AC voltage is applied to each of R, S, and T terminals by connection, a rotating field is generated by a constant voltage, for example, AC220V, and the motor rotates, and the rotation speed N is N = 120f / p ( Since f is the frequency of the power supply, p is the number of poles, the rotational speed N is determined in inverse proportion to the number of poles p. Here, the number of poles is 4 or 9 poles so that the rotation speed and output is converted to 2 or 1/2 times.

For example, if the input voltage changes from 220V to 380V, If the wiring is changed from Y to Y, as shown in Figs. 4 and 5, when Y-phase is applied to each terminal of R, S and T, three-phase AC voltage is applied to each coil (a, b, c). Than the voltage applied to R, S, T As much voltage is applied, three-phase 220V is applied to each coil (a, b, c) even if three-phase 380V is applied to the R, S, and T terminals. It rotates at the same output and rotation speed (rpm) as the wiring.

However, the conventional three-phase induction motor as described above can not only change the output of the change of 2 times to 1/2 times, there was a problem that the change of elaborate output, such as 1.33 times or 0.75 times is impossible. .

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to provide a multiple of 6 and a multiple of 8 by winding the number of coil groups wound around the coil 8/6 to 6/8. It is to provide three-phase squirrel cage induction motor which can change output by double.

In order to achieve the above object, the three-phase squirrel cage induction motor according to the present invention has three coils of three-phase coils wound on the stator, and a coil group is installed in multiples of six, and the second and third coils are coil groups. It is characterized in that it is made up of multiples of eight.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

6 is a view showing an example of the coil structure according to the present invention, Figure 7 is a three-phase induction motor of the present invention 8 is another embodiment of the three-phase squirrel cage induction motor according to the present invention. Fig. 9 is a Y connection diagram of the three-phase induction motor according to the present invention, and Fig. 10 is another Y connection diagram of the three-phase induction motor according to the present invention. It is a wiring diagram inside the motor which shows the direction and the position where the coil is wound on the stator in the motor.

According to the present invention, as shown in FIGS. 6 to 11, one coil (a) of the three-phase coils (a, b, c) wound on the stator (S1) has a coil group of six multiples and the other The two coils (b, c) are three-phase induction motors in which the coil group is connected by multiples of eight.

The number of coils wound around the coil group constituted by the coil (a) is 8/6 times more than the number of coils wound on the coils (b, c), so that the coil (a) and the coil (b, c) between Electrical equilibrium is achieved at.

On the other hand, the magnetic equilibrium between the three coils is achieved by adjusting the connection and insertion method of the Kongli terminal.

That is, in FIG. 11, a cross section of the stator S1 formed in the 36 slots 41 is shown. In the same figure, the coil a is shown by the solid line, the coil b is shown by the dashed-dotted line, and the coil c is shown by the dotted line, respectively.

The coils a, b and c are wound in the slot 41 of the stator in the form as shown in FIG. 11 in solid, dashed and dashed lines, and arrows indicate the winding direction of the coil.

Nine terminals 1, 2, 3, 4, 5, 6, 7, 8, and 9 are drawn out from the coils a, b, and c so that power is applied to the coils through these terminals. When current flows through the coils a, b, and c, the magnetic field is distributed on the circumference of the stator S1 according to the direction of the current flowing in each coil wound in the direction of the arrow.

TABLE 1

When operating in the form of 220V 6-pole as shown in [Table 1], 1, 4, and 9 of the nine terminals (1, 2, 3, 4, 5, 6, 7, 8, 9) shown in FIG. Terminal 8 is combined into one terminal, terminals 2, 5 and 9 are combined into one terminal, and terminals 3, 6 and 7 are combined into one terminal, Three-phase voltages are applied to the pair terminals.

On the other hand, in case of operating with 220V 8 poles, terminals 1 and 6 are connected together in FIG. 11, terminals 2 and 4 are connected together, and terminals 3 and 5 are connected together. Phase power is supplied, terminal 7 is connected to R terminal (not shown in FIG. 11), terminal 8 is connected to S terminal (not shown in FIG. 11), terminal 9 is connected to T terminal ( (Not shown in FIG. 11).

In case of operating with 380V 6 poles, as shown in [Table 1], three-phase voltage is applied through terminal 7, terminal 8 and terminal 9, terminal 1, terminal 2 and terminal 3. Is connected to each of the R, S, and T terminals so that power is not applied, and terminals 4, 5, and 6 are connected to one terminal so that power is not applied.

In addition, when the stator (S1) is operated with 8 poles of 380V, three-phase voltage is applied through terminals 1, 2, and 3, and terminals 4, 5, and 6 are one terminal. It is connected to the state that power is not applied, and terminal 7, terminal 8, and terminal 9 are separated, respectively, and the power is not applied.

In the present invention, as shown in Figure 6, the coil (a) is installed in multiples of six, that is, the coil group in six, the remaining coils (b, c) are installed in multiples of eight, or eight, in the middle of each coil If the wire is pulled out and connected with the 8th degree, it will be 8-pole rotation, but if it is connected with the 7th degree, it will be 6-pole connection, and since the rotation speed is higher than with the wiring shown in FIG. 8, output will become large.

In the case of the Y dog line, when connected with the ninth degree, the operation is performed in the state of 380V 6 poles, and when it is configured as the tenth degree, the Y dog line becomes the 380V 8 pole Y dog line, and the rotation speed is lower than that of FIG.

Therefore, when changing from three-phase 220V to three-phase 380V, it is necessary to convert from the wiring form shown in FIG. 8 to the wiring form shown in FIG. will be.

As described above, according to the three-phase squirrel cage induction motor of the present invention, the number of coil groups wound on the coil is set to a multiple of 8 by a multiple of 6, so that the output can be changed to 8/6 times or 6/8 times the load change. There is a very good effect to cope with the power change.

Claims (5)

In the three-phase induction motor, one coil (a) of the three-phase three coils wound on the stator (S1) is provided with a coil group six times, and the other two coils (b, c) has a coil group of 8 Three-phase squirrel cage induction motor, characterized in that the drain is installed. According to claim 1, when the stator (S1) is operated with a 220V 6-pole terminal 1, 4, 8 is connected to one terminal, terminals 2, 5, 9 are connected to one terminal, 3 , 3-phase induction motor, characterized in that the terminal 6, 7 is connected to one terminal to apply power. The terminal 1 and 6 are connected to one terminal, and the terminals 2 and 4 are connected to one terminal when the stator S1 is operated at 220V 8-pole. Is connected to one terminal to supply power, and terminal 7 is connected to R terminal, terminal 8 to S terminal, terminal 9 to T terminal, and power is not applied. Electric motor. According to claim 1, wherein when the stator (S1) is operated with 8 poles of 380V, three-phase voltage is applied through terminals 1, 2, and 3, terminals 4, 5, and 6 Is connected to one terminal so that the power is not applied, and the three-phase squirrel type is characterized in that the seventh terminal, the eighth terminal, and the nineth terminal are separated from each other and the power is not applied. Induction motor. According to claim 1, when the stator (S1) is operated by 380V 6-pole three-phase voltage is applied through the terminal 7, terminal 8 and terminal 9, the terminal 1, terminal 2 and terminal 3 Is connected to each of R, S, and T terminals so that no power is applied, and terminal 4, terminal 5, and terminal 6 are connected to one terminal so that power is not applied. Three-phase squirrel cage induction motor characterized by.