JP3105232B2 - 2 stator induction motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention comprises a single rotor and two stators,
The present invention relates to a two-stator induction motor capable of generating a phase difference between rotating magnetic fields generated around a rotor conductor facing a plurality of stators and generating a high torque from a low speed to a high speed.

[Conventional technology]

For torque control and speed control of an induction motor having a two-stator configuration, there is a method of changing a phase difference between stators known from the related art. The method of changing this phase difference is to provide a phase difference by rotating the stator as mechanical, to provide some kind of phase difference by changing the connection of the stator winding as electrical, Further, there are various kinds such as those in which star delta switching is combined.

The above methods use various methods depending on the load or application, such as when the torque and speed of the induction motor are freely changed to cope with the load, when the speed at startup is smoothly increased, etc. .

[Problems to be solved by the invention]

The present invention responds to a load by providing several kinds of stepwise phase changes, and can be said to be an electric method.

The electrical method in the prior art is performed by switching the connection of the stator windings, and the phase difference can be implemented at electrical angles of 0 °, 60 °, 120 °, and 180 °. It was over ten and expensive.

Further, some induction motors are provided with a star-delta switching device for the purpose of improving the startability, but the wiring between the star-delta switching device and the motor is complicated despite a single stator. Was. In other words, the star-delta switching device cannot be provided directly on the motor because the device is large and the switching depends on human power or another power source, and the wiring between the star-delta switching device and the motor is structurally Many large-capacity cables were required.

In most cases, switches or star-delta switching devices that switch the phase difference are switched by opening and closing the contacts. Temporary disconnection of the load current due to this switching causes fluctuations in the generated torque, and the load caused by the operation of the switch The temporary interruption of the current shocked the device driven by the induction motor.

SUMMARY OF THE INVENTION An object of the present invention is to provide an inexpensive two-stator induction motor that has the minimum required number of switches required for switching while having the torque characteristics at the phase difference, and is free from shocks due to switching.

[Means for solving the problem]

According to the present invention, there are provided two rotor cores which are axially mounted on the same rotation shaft with a space or a non-magnetic core interposed therebetween, and
A rotor integrally formed by providing a plurality of conductors communicating with the two rotor cores; two stators arranged in parallel to each of the two rotor cores; A particular one of the stators produces a phase difference between a rotating magnetic field generated around a rotor facing the rotating stator and another stator generating a rotating magnetic field around the rotor facing the rotating stator. In a two-stator induction motor having a voltage phase shifter, the voltage phase shifter sets a phase difference of the rotating magnetic field between the two stators to 0 ° by closing an open / close switch, and sets the two phase shifters together. First stator winding with series delta connection
And a parallel connection with the first connection on / off switch, wherein the phase difference of the rotating magnetic field is set to 120 ° by closing the on / off switch, and the windings of the two stators are connected in series delta connection. The second connection on / off switch, the semiconductor element connected in series to the parallel first and second connection on / off switches, and the first and second connection on / off switches and the semiconductor element are controlled by an arbitrary signal. A means for solving the above-mentioned problem is provided by including a control unit.

Further, according to the present invention, the voltage phase shifter sets the phase difference of the rotating magnetic fields of the two stators to 0 ° by closing an open / close switch, and connects the windings of the two stators in series delta connection. A first connection opening / closing switch, wherein the phase difference of the rotating magnetic field is set to 120 ° by closing the opening / closing switch, and the windings of the two stators are connected in series delta connection. And a semiconductor element connected in series with the first and second connection on / off switches connected in parallel with each other, and closing the on / off switch to reduce the phase difference of the rotating magnetic field by 120 °. And a third connection on / off switch connected in parallel to a series circuit of the first and second connection on / off switches and the semiconductor element, wherein the windings of the two stators are in series delta connection;
Means for solving the above-mentioned problem are constituted by the first, second and third connection on / off switches and a control unit for controlling the semiconductor element by an arbitrary signal.

And providing a connecting member for mutually resistance-short-circuiting any adjacent one of the plurality of conductors in the space or the non-magnetic core portion between the two rotor cores;
Further, the voltage phase shifter is integrated with the two-stator induction motor to provide a means for solving the above-mentioned problem.

(Operation)

The operation of the first invention will be described. Each of the first connection on / off switch and the second connection on / off switch is configured to provide a phase difference of 0 ° and 120 ° between the stators. Therefore, when only the first connection switch is closed and the power is turned on, the phase difference is 0 °. Conversely, when only the second connection switch is closed and the power is turned on, the phase difference is 120 °. When the first connection switch and the second connection switch are simultaneously closed and the power is turned on, the phase difference becomes 60.
It becomes ゜.

That is, 0 °, 60 °,
It is possible to provide three phase differences of 120 °.

The above works in the following manner. First, when the second connection switch is turned on and the power is turned on, the phase difference between the stators is started at 120 °. The load is activated by a torque characteristic curve with a phase difference of 120 °.

Next, after an elapse of an arbitrary time or at an arbitrary rotation speed, the first connection on / off switch is turned on while the second connection on / off switch is kept as it is to change the phase difference to 60 °. Load is phase difference 60
The motor is further accelerated by the torque characteristic of ゜ and the rotation of the motor is increased. Finally, when an arbitrary time elapses after turning on the first connection on / off switch or reaches an arbitrary rotation speed and the second connection on / off switch is released, the phase difference becomes 0 °, and the load is driven by the torque characteristics of a general induction motor.

As described above, the phase difference can be changed in three stages only by opening and closing the first and second two connection opening / closing switches, and the number of contacts is far smaller than that of the related art.

Further, in the present invention, a semiconductor element is provided in series with the first and second connection on / off switches. This semiconductor element is an element capable of steplessly controlling between interruption and conduction by the firing angle. That is, by controlling the firing angle of the semiconductor element together with the change of the phase difference by the first and second connection on / off switches, it is possible to further change the torque characteristic at each phase difference. In particular, the effect of relieving the impact at the time of starting is great. For example, at the time of starting with a phase difference of 120 °, the output torque can be easily changed gradually from zero to the torque characteristic of this phase difference.

Further, as described above, since either the first or second connection on / off switch is always in the ON state, the contact capacity of the first and second connection on / off switches can be reduced, and the generated torque can be obtained without interrupting the load current. Does not become zero. Further, since there is a stage in which both the first and second connection opening / closing switches are turned on and used, even if one or both of the switches are turned on due to an accident of the opening / closing switch, for example, welding of contacts, etc. It does not lead to an accident.

Next, as a function of the second invention, a third connection on / off switch capable of switching the phase difference of the rotating magnetic field to 120 ° is provided in parallel with the series circuit of the first and second connection on / off switches and the semiconductor element. The operation of the provided one will be described.

A general process from start to operation will be described step by step. With the semiconductor element in a non-conductive state (ignition angle 180 °), a second connection open / close switch (phase difference 12
0 °) alone to gradually change the firing angle of the semiconductor element from non-conduction to conduction (firing angle 0 °), the voltage applied to the stator winding gradually increases, and a phase difference of 120 ° Starts gradually with torque characteristics.

Next, when the firing angle is changed to the conductive state, after turning on the third connection on / off switch (120 ° phase difference), the firing angle of the semiconductor element is interrupted and the second connection on / off switch is opened.
Subsequently, the first connection on / off switch (phase difference 0 °) connected in series with the semiconductor element is turned on, and the firing angle of the semiconductor element is gradually changed from non-conduction to conduction. A series delta connection having a phase difference of 120 ° and a series delta connection having a phase difference of 0 ° by the first connection on / off switch simultaneously appear on the stator winding, and the stator winding becomes a parallel star connection having a phase difference of 60 °. This is as described in the above operation, that is, the first connection on / off switch (0 ° phase difference)
And the second connection opening / closing switch (120 ° phase difference) are simultaneously turned on.

After the firing angle of the semiconductor element is made conductive, the third connection on / off switch is opened while the firing angle of the semiconductor element is kept on. Induction motors lead to operating torque.

As described above, the operation of the first invention is to change the torque characteristics at the start and at each phase difference by changing the phase difference in multiple stages with the minimum number of connection opening / closing switches. It has become possible to obtain an improved startability and a change in torque at low cost.

The operation of the second invention is that, in addition to the operation of the first invention, the change in torque is not stepwise, but is gradually changed from a phase difference of 120 ° to a phase difference of 60 °. A change in the generated torque due to a change in the phase difference to the characteristic is eliminated, and the startability can be improved and the phase difference can be switched without shock.

Next, in the space or the non-magnetic core portion between the two rotor cores of the two-stator induction motor, a connection for mutually resistance-short-circuiting any adjacent one of the plurality of rotor conductors. The operation when a material is provided will be described.

First, when a phase difference is provided by the operation of the first or second aspect of the present invention without a connecting member, as the phase difference increases, the voltage induced in the rotor decreases and the generated torque decreases. Further, when the phase difference is made 180 ° by another method, the voltage induced in the rotor finally becomes zero. The change in the torque characteristics at this time indicates the same change in the torque characteristics as in the primary voltage control. In this case, the present invention has a great effect that a simple open / close switch can be used instead of an expensive device required for primary voltage control.

On the other hand, in the case where the connecting member is provided, if a phase difference is provided by the operation of the first or second invention, a current flows through the connecting member as the phase difference increases, and the phase difference is reduced by 180 by another method. When ゜ is set, the current flows to the rotor conductor via the connecting member. That is, it has a torque characteristic of a phase difference of 180 °, and the change in the torque characteristic due to the change in the phase difference shows the same torque characteristic as the proportional change.

However, the operation has been described in the case where the connecting members are provided between all the adjacent rotor conductors and short-circuited with each other. However, the resistance is short-circuited between arbitrary arbitrary adjacent ones of the plurality of rotor conductors. When the connecting member is provided, as the phase difference increases, the current flows through the connecting member in the same manner as described above, but since the connecting member is provided between arbitrary conductors, the current flowing is limited, and the transition is proportional to the primary voltage control. Have a unique torque characteristic due to the interaction of

By the way, if the voltage phase shifter is provided with the connection on / off switch, and a semiconductor element and a control unit for controlling the opening and closing of the switch by an arbitrary signal, the phase difference can be changed, and the output torque characteristic can be changed. This makes it possible to cope with a load fluctuation such as causing the motor to automatically control the induction motor using a signal such as a rotation speed, a load current, or simply a timer. It is common knowledge that a general induction motor requires an expensive and large device to change the rotation speed and torque.

When connecting the induction motor of the present invention to a power supply and connecting a voltage phase shifter comprising first and second connection changeover switches, the number of wires required for a three-phase specification is three power supply wires, The equipment requires six, nine in total. When the phase shifter is provided on the power supply side, six wires are required from the motor side and three wires are required from the power supply side, and it is difficult to deal with the field. Here, by integrating the phase shifter with the electric motor, three wires from the power supply side are sufficient. If a general motor also becomes large, the work of wiring six wires for starting the Y- △ becomes complicated, but the present invention changes the torque characteristics of the induction motor by using a voltage phase shift device with two switches, and Since the phase shift device is integrated with the induction motor, the number of wires is only three for the power supply. Therefore, even if the motor becomes large, it is sufficient to check only the three wirings and the rotation direction of the power supply, even if the motor becomes large, so that the cost of wiring materials can be reduced and the work can be simplified.

Embodiment The present invention will be described in detail mainly as a voltage phase shifter of a two-stator induction motor having a cage rotor, but it is needless to say that the present invention is not limited to this. In some cases, a two-stator induction motor having a wound rotor is used.

The present applicant has already described in detail the structure and operation of an induction motor comprising a plurality of stators, which is a part of the structure of the present invention, as Japanese Patent Application No. 61-128314.

Referring to FIG. 1, one embodiment of an electric motor which forms a part of the configuration of the present invention will be described. Reference numeral 1 denotes a two-stator induction motor according to the present invention, and the induction motor 1 has the following configuration. The rotor cores 2 and 3 made of a magnetic material are mounted on the rotor shaft 4 at arbitrary intervals. A non-magnetic core 5 is provided between the rotor cores 2 and 3, or a space is provided between the rotor cores 2 and 3. Rotor core
A plurality of conductors 6 are provided in communication with 2, 3 to form an integral rotor 7, and both ends of the plurality of conductors 6 connected in series are short-circuited by short-circuit rings 8,8. . In this embodiment, the conductors 6 provided on the rotor 7 are the rotor cores 2,.
In the portion of the non-magnetic core 5 between the three, each of the plurality of conductors 6 is connected via a connecting member 9 through which a current flows due to the phase difference of the rotating magnetic field.

A first stator 12 and a second stator 13 provided with windings 10 and 11 on outer portions facing the rotor cores 2 and 3 are arranged side by side on a machine frame 14, and the first stator 12 and the second stator 13 is fixed to the machine frame 14.

Next, an embodiment according to the first invention of the present invention is shown in FIGS.

FIG. 2 shows a connection diagram of the first invention, which is as follows.

One terminal U ₁ , V ₁ , W ₁ of each coil of the stator winding 11 is connected to a three-phase power source R, S, T, and the other terminal X ₁ , Y ₁ , Z _{1 is connected} to a semiconductor element T. It is connected to one terminal of the connection opening and closing switches S ₁ through. In addition, one terminal U ₂ , V ₂ , W ₂ of each coil of the stator winding 10 is connected to the other terminal of the wiring switch S ₁ , and the other terminal X ₂ , Y ₂ , Z ₂ is connected to the terminal Connected to V ₁ , W ₁ , U ₁ . That is, connected to the phase difference angle of the rotating magnetic field to produce a rotating magnetic field generated with the stator winding 11 after the input of the connection opening and closing the switch S ₁ of the stator winding 10 is connected to the 0 ° series delta by an electrical angle is there.

The one terminal of the connection opening and closing the switch S ₂ is connected in parallel to one terminal of the connection opening and closing the switch S _1, the other terminal connected to one terminal V _2, W _2, U ₂ of the stator windings 10 It is. That the introduction of connection closing switch S _2, and connected so that the phase difference angle of the rotating magnetic field to produce a rotating magnetic field formed with the stator windings 11 of the stator winding 10 is connected to a 120 ° series delta by an electrical angle It is.

Further, the connection opening switch S ₁ and the connection opening and closing switch S ₂
Further, a control unit 15 for controlling the opening and closing of the semiconductor element T by an arbitrary signal is provided, and the open / close switch, the semiconductor element and the control unit constitute a voltage phase shifter 18.

The operation in the above configuration will be described. The description will be made in the order from start to operation.

The connection closing switch S ₂ is turned on first, connection off switch
If take a three-phase power R with opened S _1, S, and T, and the stator winding 10 and stator windings 11 are energized in a state of being connected in series △ to a power supply via a semiconductor element T Will be. This is shown in FIG. If the firing angle is set to 0 ° using a triac or a thyristor connected in parallel with the opposite polarity to the semiconductor element T, the sharing voltage E ₁ , E ₂ , E ₃ , E
₁ ′, E ₂ ′, E ₃ ′ are half of the line voltage of the power supply, and E ₁
The phase difference angle θ between E ₁ ′, E ₂ and E ₂ ′ and E ₃ and E ₃ ′ is θ = 120 °. Therefore, the phase difference angle θ between the two rotating magnetic fields generated by the stator windings 11 and 10 is θ = 120 °.

The torque characteristic at this time is a characteristic of θ = 120 ° shown in FIG. Further, if the firing angle of the semiconductor element T is set to 180 °, no current flows in each coil, so that the shared voltage of each coil becomes zero and the torque acting on the rotor becomes zero.

Therefore, when starting up, if the firing angle of the semiconductor element is started from 180 ° and the firing angle is gradually reduced, the shared voltage of each coil gradually increases, and the torque acting on the rotor gradually increases. When the torque becomes larger than the load torque, the rotor starts to rotate, and when the firing angle is set to 0 °, the rotation speed increases to a slip l _{1 at} the intersection of the load characteristic and the torque characteristic of θ = 120 ° shown in FIG. . As described above, since the torque is smoothly controlled in the region A of FIG. 4 by controlling the firing angle, a smooth start can be performed.

Then the rotational speed further increases than the speed corresponding to the slippage l ₁ of FIG. 4 is charged connection closing switch S _1.

Since connection closing switches S ₁ and S ₂ is turned on in this state, connection state of each coil of the stator windings 11 and 10 is as shown in FIG. 5 [a]. When this is deformed, it becomes as shown in FIG. 5B. Accordingly, when the firing angle of the semiconductor element T is set to 0 °, the shared voltages E ₁ , E ₂ , E ₃ , E ₁ ′,
E ₂ ′ and E ₃ ′ are the line voltage of the power supply. And the phase difference angle θ between E ₁ and E ₁ ′, E ₂ and E ₂ ′, and E ₃ and E ₃ ′ is θ = 60 °. Therefore 2 of stator windings 11 and 10
The phase difference angle θ between the two rotating magnetic fields is θ = 60 °. The torque characteristic at this time is the characteristic of the upper limit of θ = 60 ° in the region B shown in FIG. When the firing angle of the semiconductor element T is set to 180 °, the torque characteristic at that time becomes θ = 60 in the B region shown in FIG.
This is the lower limit characteristic of ゜.

In short, if the firing angle of the semiconductor element T is controlled in the connection state of FIG. 5, smooth torque control will be performed in the region B of FIG. Thus the rotational speed of the rotor is gradually being smoothly accelerated to a speed corresponding to the slippage m ₁ from the speed corresponding to sliding l ₁ of FIG. 6.

Wherein sliding m ₁ is a slip at the intersection of the torque characteristic and the load torque when theta = 0 ° as described later. Where the fifth
The firing angle of the semiconductor element T is the firing angle so rises above the speed corresponding to m ₁ slip rotational speed to 0 ° in connection state of FIG kept to 0 ° forward.

Next, the state is switched to the final operation state. That opens the connection closing switch S _2. Since connection closing switch S ₁ in this state is turned to the connection opening and closing switch S ₂ is open, wire connection of the coils of the stator windings 11 and 10 is 8
It looks like the figure.

When the firing angle of the semiconductor element T is set to 0 ° in this connection state, the shared voltages E ₁ , E ₂ , E ₃ , E ₁ ′, E ₂ ′, and E ₃ ′ of each coil become 1% of the line voltage of the power supply. / 2, E ₁ and E ₁ 'and E ₂ and E _2' and E
The phase difference angle θ between ₃ and E ₃ ′ is θ = 0 °. Therefore, the phase difference angle θ of the rotating magnetic field generated by the stator windings 11 and 10 is θ = 0 °.

The torque characteristic at this time is the characteristic of θ = 0 ° in FIG. The characteristic of θ = 0 ° is the same as the torque characteristic of the conventional induction motor. Therefore, if the firing angle of the semiconductor element T is controlled in the connection state of FIG. 8, the torque is controlled in the region C of FIG. 7, and if the firing angle is set to 0 °, the torque of FIG. it can be increased to the speed of the final operational state corresponding to sliding m ₁ at the intersection of the theta = 0 ° torque characteristic and the load torque shown in.

Here, the torque in the region C shown in FIG. 7 is the same as that according to the conventional primary voltage control method of the induction motor.

 The above control is summarized in Table 1.

Next, braking when stopping the rotor will be described.

If configured in the thyristor with the parallel connection of the semiconductor element T of each phase shown in FIG. 2 in the opposite polarity, the third view of connection state that is charged with connection closing switch S ₂ opens the connection closing switches S ₁ state or eighth view of connection state that is charged with connection closing switch S ₁ in the open state of the connection opening and closing switch S _2, the firing angle of the one of the thyristors of the thyristor connected in parallel with opposite polarity 180 ° If the firing angle of the other thyristor is set to 0 ° while holding the current, the current flowing through each coil becomes a half-wave rectified current and includes a DC component, so that the rotor is braked.

Therefore, if the firing angle of one thyristor of the thyristors connected in parallel with the opposite polarity is maintained at 180 ° and the firing angle of the other thyristor is controlled, the DC component current flowing through each coil is controlled. The rotor brake can be controlled.

When the brake is applied in the connection state shown in FIG. 3, θ =
Strong braking in high speed area for 120 ゜, 8th
In the connection state shown in the figure, since θ = 0 °, a strong brake is applied in a low speed region. Further, there is a moderate braking action even in connection state of FIG. 5 which together put connection closing switch S _1.

Therefore, it is possible to switch so that an appropriate brake can be applied according to the load.

Next, an embodiment according to the second invention of the present invention is shown in FIG. 9 and subsequent figures.

FIG. 9 is a connection diagram of the second invention. One terminal U ₁ , V ₁ , W ₁ of each coil of the stator winding 11 is connected to a three-phase power source R, S, T, and the other terminal X ₁ , Y ₁ , Z _{1 is connected} to a semiconductor element T. It is connected to one terminal of the connection opening and closing switches S ₁ through. Also, one terminal U ₁ , V ₂ , W ₂ of each coil of the stator winding 10 is connected to the other terminal of the connection switch S ₁ , and the other terminal X ₂ , Y ₂ , Z ₂ is connected to the terminal Connected to V ₁ , W ₁ , U ₁ . That is, connected to the phase difference angle of the rotating magnetic field to produce a rotating magnetic field generated with the stator winding 11 after the input of the connection opening and closing the switch S ₁ of the stator winding 10 is connected to the 0 ° series delta by an electrical angle is there.

One of the connection on / off switches S ₂ is a connection on / off switch
Connected in parallel to one terminal of the S _1, the other is connected to one terminal V _2, W _2, U ₂ of the stator windings 10. That 12 phase difference angle of the rotating magnetic field to produce a rotating magnetic field generated with the stator winding 11 after the input of the connection opening and closing switch S ₂ of the stator windings 10 are in electrical angle
They are connected so as to be connected to a series delta of 0 °. Furthermore with one connection opening and closing the switch S ₃ is connected to a terminal X _1, Y _1, Z ₁ of each coil of the stator winding 11, the other stator winding
10 are connected to terminals V ₂ , W ₂ , and U ₂ of each coil. That is, connected to the phase difference angle of the rotating magnetic field to produce a rotating magnetic field generated with the stator winding 11 after the input of the connection opening and closing switches S ₃ of the stator winding 10 is connected to a 120 ° series delta by an electrical angle is there.

Further, the connection opening switch S ₁ and the connection opening and closing switch S ₂
And a connection closing switches S ₃ and the semiconductor element T is provided a control unit 16 to open and close control by any signal, and constitutes a voltage phase shifting device 18 in the opening and closing switch and the semiconductor element and a control unit.

The operation in the above configuration will be described. The description will be made in the order from start to operation. First, the wiring switch S ₂
Is turned on, and ₃ with the connection open / close switches S ₁ and S ₃ open.
Taking advantage of the phase power supplies R, S, T, the stator winding 11 and the stator winding 10
Is excited in a state of being connected to the power supply via the semiconductor element T in series delta. This is shown in FIG.

If the firing angle is set to 0 ° using a triac or a thyristor connected in parallel with the opposite polarity to the semiconductor element T, the sharing voltages E ₁ , E ₂ , E ₃ , E ₁ ′, E ₂ ′, E ₃ ′
Becomes 1/2 of the line voltage of the power supply, and the phase difference angle θ between E ₁ and E ₁ ′, E ₂ and E ₂ ′, and E ₃ and E ₃ ′ becomes θ = 120 °. Therefore, the phase difference angle θ between the two rotating magnetic fields generated by the stator windings 11 and 10 is θ
= 120 °.

The torque characteristic at this time is the characteristic of θ = 120 ° in FIG. Further, if the firing angle of the semiconductor element T is set to 180 °, no current flows in each coil, so that the shared voltage of each coil becomes zero and the torque acting on the rotor becomes zero.

Therefore, when starting, the firing angle of the semiconductor element T is set to 180 degrees.
Starting from ゜ and gradually reducing the firing angle, the shared voltage of each coil gradually increases, the torque acting on the rotor gradually increases, and when the torque exceeds the load torque, the rotor starts rotating, If the firing angle is 0 °, the rotational speed is increased to slip l ₂ of intersection between the load torque theta = 120 ° the torque characteristic shown in FIG. 11. In this way, the torque is smoothly controlled in the region A of FIG. 11 by controlling the firing angle, so that a smooth start can be performed.

Then perform the following operations the rotational speed further increases than the speed corresponding to the slippage l ₂ of Figure 11. That is, first back and put connection closing switch S ₃ the firing angle of the semiconductor element T from 0 ° to 180 °. Since S ₁ and connection closing switch S ₂ and S ₃ is turned is opened in this state, connection state of each coil of the stator windings 11 and 10 is as shown in Figure 12. Therefore, the semiconductor element T is connected to the connection switch S ₃
When the firing angle of the semiconductor element T is returned from 0 ° to 180 °, there is no change in the current flowing through each coil, and the torque characteristic is the same as that of θ = 120 ° in FIG. There is no change.

Then by opening the connection closing switch S ₂ connection off switch
Turning on the S _1. In this state, the connection switch ON / OFF switch S ₃
Since S ₁ is being turned is connected close switch S ₂ is open and, connection state of the coils of the stator windings 11 and 10 are made as FIG. 13, the firing angle of the semiconductor element T is At 180 °, the torque characteristic remains the same as θ = 120 ° in FIG. 11 and does not change.

Next, when the firing angle of the semiconductor element T is set to 0 ° in this connection, the terminals X ₁ and U ₂ , Y ₁ and V ₂ , and Z ₁ and W _{2 of the} coil are short-circuited. shared voltage E _1, E _2, E ₃ of, E ₁ ',
E ₂ ′ and E ₃ ′ are as shown in FIG.

That is, the shared voltages E ₁ , E ₂ , E ₃ , E ₁ ′, E ₂ ′, E
₃ ′ is the line voltage of the power supply And the phase difference angle θ between E ₁ and E ₁ ′, E ₂ and E ₂ ′, and E ₃ and E ₃ ′ is θ = 60 °. Therefore 2 of stator windings 10 and 11
The phase difference angle θ between the two rotating magnetic fields is θ = 60 °. The torque characteristic at this time is the characteristic of θ = 60 ° in FIG.

Since the torque at θ = 60 ° is larger than the torque at θ = 0 ° described later, the control of the firing angle of the semiconductor element T in the connection state of FIG. Keep the firing angle δ at which torque close to the torque is generated. This firing angle is a value close to 0 °.

In short, in the connection state of FIG. 13, the firing angle of the semiconductor element is started from 180 ° and is gradually reduced, and the angle is set slightly before 0 °, and smooth torque control is performed in the region B of FIG. Will be. Thus the rotational speed of the rotor is gradually being smoothly accelerated to a speed corresponding to the slippage m ₂ from a speed corresponding to the slippage l ₂ of Figure 11.

Next, it switches to the last operation state. That opens the connection closing switch S _3. Since connection closing switch S ₁ is being turned is connected close switch S ₂ and S ₃ are opened in this state, connection state of each coil of the stator windings 11 and 10 is as shown in Figure 15.

When the firing angle of the semiconductor element T is set to 0 ° in this connection state, the shared voltages E ₁ , E ₂ , E ₃ , E ₁ ′, E ₂ ′, and E ₃ ′ of each coil become 1% of the line voltage of the power supply. / 2, E ₁ and E ₁ ′, E ₂ and E ₂ ′ and E ₃
And the phase difference angle θ between E ₃ ′ is θ = 0 °. Therefore, the phase difference angle θ of the rotating magnetic field generated by the stator windings 11 and 10 is θ = 0 °.

The torque characteristic at this time is the characteristic of θ = 0 ° in FIG. 11, and the characteristic of θ = 0 ° is the same as the torque characteristic of the conventional induction motor.

Therefore, if the firing angle of the semiconductor element T is controlled from the firing angle corresponding to δ to 0 ° in the connection state of FIG.
The torque is to be controlled in the area of C in FIG.
The rotation speed of the rotor can be increased from slip m ₂ to a speed corresponding to slip n ₂ , that is, the final speed in the operating state. The torque in the area indicated by C in FIG. 11 is the same as that obtained by the primary voltage control system of the conventional induction motor.

 The above control is summarized in Table 2.

In the above description, the connection state shown in FIG.
When the region is controlled, the firing angle of the semiconductor element T in any one phase may be maintained at 180 ° without being controlled. This is useful for preventing mutual interference between the semiconductor elements T of each phase, and there is no change in torque characteristics.

Incidentally, when configured with thyristors connected in parallel to each phase of the semiconductor element T in the reverse polarity, the state or Figure 15 was opened S ₁ and S ₃ by introducing a connection state, that is S ₂ of FIG. 10 connection state or in the open state of the S ₂ and S ₃ by introducing the S _1, ignition of the firing angle of the one of the thyristors by 180 ° holding the other thyristor of the thyristor connected in parallel with opposite polarity If the angle is set to 0 °, the current flowing through each coil becomes a half-wave rectified current and includes a DC component, so that the rotor is braked.

Therefore, if the firing angle of one of the thyristors connected in parallel with the opposite polarity is maintained at 180 ° and the firing angle of the other thyristor is controlled, the DC current flowing through each coil is controlled. , Can control the rotor brake.

When the brake is applied in the connection state shown in FIG. 10, a strong brake is applied in a high-speed area, and in the connection state shown in FIG. 15, a strong brake is applied in a low-speed area. Therefore, it is possible to switch so that an appropriate brake can be applied according to the load.

In the first and second embodiments described above, it is assumed that each of the plurality of conductors 6 of the rotor is connected via the connecting member 9 through which current flows due to the phase difference of the rotating magnetic field. However, here, the case where there is no connecting material 9 which can be similarly performed (A) and the case where a connecting material is provided between adjacent arbitrary conductors 6 among a plurality of conductors of the rotor (B) Consider the torque characteristic curve.

FIG. 16 shows a torque characteristic curve (A) when there is no coupling material and a torque characteristic curve (B) when a coupling material is provided between arbitrary adjacent conductors 6 among a plurality of conductors of the rotor. The torque characteristic curve (A) shows the same change in the torque characteristic as when the primary voltage control is performed, and the torque characteristic curve (B) shows the proportionality obtained by changing the primary voltage control and the resistance value of the secondary rotor. It shows a change similar to the torque characteristic obtained by summing up the transition.

In order to obtain a torque characteristic curve similar to the primary voltage control in the torque characteristic curve (A), an expensive power supply voltage control device for controlling the primary voltage was generally required. It became feasible with two open / close switches. Further, in order to realize the same torque characteristics as obtained by the sum of the primary voltage control and the proportional transition in which the resistance value of the secondary rotor is changed in the torque characteristic curve (B), the primary voltage and the secondary side Although it was common to require expensive and complex devices to control both the rotor's secondary resistance and the present invention, the present invention provides a method for controlling the rotor's secondary resistance between any adjacent one of a plurality of conductors of the rotor. The proportional transition of the secondary resistance value of the wound induction motor and the primary voltage control were performed simultaneously by the total of providing the connecting material and providing the phase difference with the two open / close switches. It has become possible to obtain a torque characteristic with a small current.

FIG. 17 shows an example of a connecting member provided on the rotor for obtaining the torque characteristic curve (B) by a front sectional view of the rotor. The number and the mounting position of the connecting members are changed depending on the desired torque characteristics, the balance of the rotor, and the like.

By the way, if a phase switching device composed of the connection opening / closing switches S ₁ , S ₂ , S ₃ and a semiconductor element is provided on the motor side, only three wires are required from the power supply side to the motor, as seen in a general large motor. It is possible to provide an electric motor that can be operated at a high torque from a low speed to a high speed without requiring complicated wiring for Y- △ starting.

Next, control of the voltage phase shifter will be described with reference to FIGS. First, in the configuration of FIG. 18, the induction motor 1 is connected to a three-phase power supply 22 having a switching device. Further, the induction motor is integrally provided with a voltage phase shifter 20, and the voltage phase shifter is connected to a control unit 21 incorporating a sequence circuit including a timer. Subsequently, the configuration of FIG. 19 will be described. The induction motor 1 is a three-phase power supply 22 having a switchgear.
Connected to The induction motor is integrally provided with a voltage phase shifter 20. The voltage phase shifter is connected to a control unit 23 composed of a hard logic circuit or the like, and the control unit 23 has a speed of the motor. The signal of the speed detector 2 for detecting is connected.

The above operation will be described. Each control unit 21, 23
The above-described connection switch and the semiconductor element of the voltage phase shifter 20 are controlled by a timer by a timer or a signal of the detector 24. For example, in the case of the control unit 21, a general Y
− △ Since starting is switched in about 10 seconds as standard, the phase difference is 12
Start at 0 ° and switch to steady operation with a phase difference of 0 °
For example, the time for starting the phase difference 120 ° and switching to the next phase difference 60 ° is 4 to 5 seconds after the start, and the time for switching from the phase difference 60 ° to 0 ° is 4 to 5 seconds after switching to the phase difference 60 °. Set later, the phase shifter 20 sequentially switches the phase difference from 120 ° to 0 ° in three stages. Needless to say, the above-mentioned time limit should be changed depending on the load.

In the case of the control unit 23, the control unit may include a simple logic circuit or a microprocessor as necessary, which is based on the current state of the art, but receives a signal from the detector 24, A circuit that converts the signal as necessary, a circuit that compares the converted signal with a predetermined reference value, a circuit that stores a predetermined reference value, and a signal output that outputs a signal by the previous comparison It will have a circuit and the like. The phase difference is changed by sequentially switching the voltage phase shifter 20 with the signal of this signal output circuit. Although the speed detector 24 is used here as the detector, means for detecting the state of the electric motor, such as a device for detecting the number of revolutions, is used.

The torque characteristics of the two-stator induction motor according to the present invention vary slowly from a phase difference of 180 ° to 120 ° although it depends on the characteristics of the motor. It can be used without much difference compared with four-stage phase control of {120, 60}, 0 ゜.

(Effect)

As described above, the two-stator induction motor has its voltage phase shifter constituted by a connection opening / closing switch, a semiconductor element, and a connection opening / closing switch, and a control section for controlling the semiconductor element by an arbitrary signal. Since switching is performed by providing three stages of phase difference angles of 0 °, it is possible to smoothly start up and drive the vehicle by the torque characteristics according to each phase difference angle. More specifically, the voltage phase shifter is composed of a minimum number of connection on / off switches and semiconductor elements to reduce shock due to changes in torque characteristics.

In addition, various expensive devices of the prior art, such as a voltage control device, an inverter, and a secondary resistor, do not require an expensive control device, and only the phase difference angle can be switched according to the load torque. Instead, it is possible to provide a torque characteristic that can cope with various loads by the configuration of the connecting member of the rotor conductor.

Also, since the wiring to the motor is simply formed with a voltage phase shifter integrated into the motor, in the case of a three-phase power supply, three wires are required for the motor and anyone can recognize the direction of rotation unless the rotation direction is mistaken. Wiring is possible.

Therefore, it is possible to further diversify the torque, expand the applications of the 2-stator induction motor capable of smoothly starting and increasing the rotation from a low speed to a rated rotation range, and further contribute to any field requiring a high-torque motor. It became so.

[Brief description of the drawings]

1 is a side sectional view of a two-stator induction motor, FIG. 2 is a connection diagram of a voltage phase shifter, FIG. 3 is a connection diagram at a phase difference angle θ = 120 °, and FIG. 4 is a phase difference angle θ = FIG. 5 is a diagram showing an example of a torque characteristic of 120 °, FIG. 5 is a connection diagram [a] at a phase difference angle θ = 60 ° and a modified connection diagram [b], and FIG. 6 is a phase difference angle θ = 60 °. FIG. 7 is a diagram showing an example of a torque characteristic at a phase difference angle θ = 0 °, FIG. 8 is a connection diagram at a phase difference angle θ = 0 °, and FIG. FIG. 10 is a connection diagram showing a phase difference angle θ = 120 °, and FIG. 11 is a diagram showing an example of a torque characteristic of each phase difference angle.
12 is a connection diagram at a phase difference angle θ = 120 °, FIG. 13 is a connection diagram at a phase difference angle θ = 60 °, and FIG. 14 is a connection diagram at a phase difference angle θ = 60 °.
FIG. 15 is a connection diagram at a phase difference angle θ = 0 °, and FIG. 16 is a torque characteristic curve (A) in the case where there is no connecting member and an arbitrary connection between a plurality of conductors of a rotor. The figure which shows an example of the torque characteristic curve (B) at the time of providing a connection material in FIG.
FIG. 17 is a front sectional view of the rotor when a connecting member is provided between arbitrary ones of a plurality of conductors of the rotor, FIG. 18 is a control block diagram by a timer sequence, and FIG. 19 is a control block diagram by a logic circuit. It is. 1 ... multiple stator induction motor, 2, 3 ... rotor core, 4
... rotor shaft, 5 ... non-magnetic core, 6 ... rotor conductor, 7 ... rotor, 8 ... short-circuit ring, 9 ... connecting material, 10,1
1 ... stator winding, 12 ... first stator, 13 ... second stator, 14 ... machine frame, 15 ... control unit, 16 ... control unit, 18 ...
Voltage phase shifter, 20 ... Phase shifter, 21 ... Control unit, 22 ...
Power supply side, 23 ... Control unit, 24 ... Speed detector.

Claims (4)

(57) [Claims] 1. A semiconductor device comprising: two rotor cores which are axially mounted on the same rotation shaft with a space or a non-magnetic core interposed therebetween; and a plurality of conductors communicating with the two rotor cores are provided. An integrally formed rotor, two stators arranged side by side opposite to each of the two rotor cores, and a specific stator among the two stators face each other. A two-stator induction motor having a voltage phase shifter that causes a phase difference between a rotating magnetic field generated around the rotating rotor and a rotating magnetic field generated around the rotor opposed to the other stator. The first phase shifter sets a phase difference of the rotating magnetic field between the two stators to 0 ° by closing an on / off switch, and sets a winding of the two stators to a series delta connection. The phase difference of the rotating magnetic field is set to 120 ° by closing the connection open / close switch and the open / close switch. And a second connection on / off switch connected in parallel with the first connection on / off switch, wherein the windings of the two stators are connected in series delta connection, and the first and second connection on / off switches in parallel. 2. A two-stator induction motor, comprising: a semiconductor element connected in series with the first and second connection switches; and a controller for controlling the first and second connection on / off switches and the semiconductor element by an arbitrary signal. 2. A motor having two rotor cores mounted on the same rotation shaft with a space or a non-magnetic core interposed therebetween, and a plurality of conductors communicating with the two rotor cores are provided integrally. , A stator formed in parallel with each of the two rotor cores, and a specific one of the two stators faces the rotor. A two-stator induction motor having a voltage phase shifter for producing a phase difference between a rotating magnetic field generated around the rotor and a rotating magnetic field generated around the rotor opposed to the other stator; The voltage phase shifter is configured to close the on / off switch to set the phase difference between the rotating magnetic fields of the two stators to 0 ° and to make the windings of the two stators a serial delta connection. Closing the switch and the on / off switch to make the phase difference of the rotating magnetic field 120 ° and A second connection on / off switch connected in parallel with the first connection on / off switch, and the first and second connection on / off switches in parallel, wherein the windings of the two stators are connected in series delta connection. A semiconductor element connected in series, and the first and second connection opening and closing, wherein the phase difference of the rotating magnetic field is set to 120 ° by closing an on / off switch, and the windings of the two stators are connected in series delta connection. A third connection on / off switch connected in parallel to a series circuit of the switch and the semiconductor element; and a control unit for controlling the first, second, and third connection on / off switches and the semiconductor element by an arbitrary signal. A two-stator induction motor characterized in that: 3. The two-stator induction motor according to claim 1, wherein the plurality of conductors are provided in the space between the two rotor cores or in the non-magnetic core portion. A two-stator induction motor, wherein a connecting member for short-circuiting resistance between adjacent arbitrary conductors is provided. 4. The two-stator induction motor according to claim 1, wherein the voltage phase shifter is a two-phase stator.
A two-stator induction motor integrated with a stator induction motor.