JP2919492B2 - Multiple stator induction motor - Google Patents

Description

The present invention relates to a single rotor, a plurality of stators, and one of the plurality of stators as a rotating stator. The present invention relates to a multiple stator induction motor having a voltage phase shifter and capable of changing the rotation speed and generated torque of a rotor by adjusting the voltage phase shifter, and more particularly to a DC braking stop device.

[Conventional technology]

Conventionally, various types of electric braking means have been used as braking devices for three-phase induction motors. Among them, DC braking has been used for a crane hoisting motor for a long time.

[Problems to be solved by the invention]

This direct current braking has a drawback because it uses direct current, but has the characteristic that the braking time can be adjusted by the magnitude of direct current excitation.

By the way, a general induction motor composed of a single stator and a single rotor requires a device for adjusting the DC excitation.

In other words, this DC excitation has not been used in various types of devices because it is necessary to set DC excitation in advance for each device.

[Means for solving the problem]

In the present invention, the braking force of the DC braking is diversified by the operation of the voltage phase shifter of the multiple stator induction motor according to the present invention while taking advantage of the characteristics of the DC braking, so that the hoisting machine, the ropeway, and the sudden braking can be used. It is an object of the present invention to provide a multiple stator induction motor having various braking functions such as high-speed braking and the like.

According to the present invention, in a multiple stator induction motor including a single rotor including a plurality of rotor cores, a plurality of stators, and a voltage phase shifter, a power supply switching circuit and a DC generation circuit are provided in a power supply circuit of the motor. And a switching device for the DC generation circuit, wherein during braking, the DC of the DC generation circuit is supplied to the stator winding by opening and closing either the power switching device and the switching device or only the switching device. The magnitude of the braking force is changed by a voltage phase shifter to solve the above-mentioned problem.

Furthermore, the switching device of the DC generation circuit is provided in parallel with the power supply switching device, and a bypass circuit having a polarity opposite to that of the DC generation circuit is provided, and the DC generation circuit and the bypass circuit have diodes as main components. Accordingly, the above-mentioned problem is solved.

Incidentally, in the induction motor of the present invention, the voltage phase shift device may be any one of the rotation of the stator or the switching of the connection of the stator winding, or may be based on other induction.
The phase difference generated by each voltage phase shifter constitutes the means of the present invention.

(Operation)

The operation of the present invention is as follows.A multi-stator induction motor according to the present invention, as is well known, changes the torque characteristic curve by rotating the stator, thereby reducing the torque in a wide range of rotational speeds. The purpose of the present invention is to diversify and expand its applications.However, when the induction motor is braked by DC excitation, a change in the phase difference of the rotor conductor by the voltage phase shifter causes the DC excitation to change. The braking torque changes in accordance with each phase difference (electrical angle), and can be diversified.

Further, when the switching device of the DC generation circuit is provided in parallel with the power switching device, the electrical capacity required for the switching device is extremely small and inexpensive as compared with the case where the switching device is provided in series. In other words, when provided in series with the power switch, the electrical capacity required for the switch requires the same capacity as that of the power switch, but when connected in parallel, only the DC excitation current flowing in the DC generation circuit is considered. I just need.

Furthermore, when a bypass circuit having a polarity opposite to that of the DC generation circuit is provided on the stator winding on which the DC generation circuit operates, a large current generated when the power supply switching device is opened and the DC generation circuit is closed is defined as the bypass circuit. This is solved by looping with the winding.

If the DC generation circuit and the bypass circuit are constituted by diodes, the cost is much lower than that constituted by other elements.

〔Example〕

Although the present invention will be described in detail mainly with reference to a two-stator induction motor having a cage rotor, it goes without saying that the present invention is not limited to this. Further, as described above, there may be a plurality of stator induction motors having a winding type rotor, and in some cases, the torque characteristics may be further diversified by simultaneously switching the star connection and the delta connection of the stator windings. . The configuration between the rotor cores may also use a space, a non-magnetic material, a magnetic material, or the like.

The applicant has already described in detail the structure and operation of a multiple stator induction motor which is a part of the structure of the present invention as Japanese Patent Application No. 61-128314.
A description will be given based on FIGS.

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 multiple stator induction motor according to the present invention. The multiple stator induction motor 1 has the following configuration. The rotor core 2.3 made of a magnetic material is mounted on the rotor shaft 4 at an arbitrary interval. Rotor core 2,
Between the three, a non-magnetic core 5 is interposed or a space is provided. Each of the plurality of conductors 6 provided on the rotor cores 2, 3 is connected to and connected to the rotor cores 2, 3 to form an integral rotor 7, and the plurality of conductors connected in series are formed. 6 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,.
The three nonmagnetic cores 5 are connected to each other via a resistance material 9 that is energized when a current having an arbitrary vector difference flows.

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.
A sliding bearing 15 is provided between the first stator 12 and the second stator 13, and the second stator 13 is fixed to the machine frame 14. A gear 17 is fitted on one outer peripheral surface of the first stator 12. A driving gear 21 is mounted on a rotating electric motor 20 fixedly mounted on the outer peripheral portion of the machine frame 14, and the driving gear 21 is engaged with a gear 17 fitted on the first stator 12.
With this configuration, the first stator 12 rotates concentrically with the rotor 7 by the operation of the rotation motor 20 to form the rotation stator 16. Thus, the rotation of the first stator 12 and the second stator 13 constitute a voltage phase shifter.

The form of the windings 10 and 11 of the first stator 12 and the second stator 13 may be either △ connection or Y connection, and the connection of the power supply is not limited to series or parallel.

Next, a specific configuration in which the present invention is implemented in the above-described electric motor 1 is shown in FIG. 2 to FIG.

First, FIG. 2 shows the simplest example. Power supply 30 and power supply 30
A power switchgear 31 and a switchgear 33 for DC generation circuits 32a and 32b composed of diodes are provided between the plurality of stator induction motors 35 connected to the motor. A bypass circuit 34 is connected in parallel to the stator winding on which the DC generation circuit 32 operates.

Here, the plural stator induction motor 35 has a △ connection, but for convenience of description, the plural stator windings are simply illustrated and not a single stator.

By the way, in the present embodiment, the switchgear 33 needs to have the same electrical capacity as the power switchgear 31.

The resistance r of the DC generator 32a determines the value of the DC exciting current. In addition, the change in the braking force is caused by the phase difference of the voltage induced on the rotor 7 due to the rotation of the rotating stator 16. by.

The SW of the bypass circuit 34 operates in conjunction with the switching circuit 33.

Next, FIGS. 3 and 4 show the second and third embodiments. In this embodiment, the description of the same components as those of the first embodiment will be omitted. The DC generation circuits 38a and 38b are connected to the power switch 31.
The switch SW ₃₈ of the DC generation circuit ₃₈ is connected in parallel with the power supply switch 31 in series with the DC generation circuit.
In this case, the electrical capacity of the switchgear SW ₃₈ depends on the DC generation circuit.
It is determined by the current of 38 and is generally much smaller than the electrical capacity of the power switchgear 31.

FIG. 4 shows a DC generation circuit 40 using a diode bridge and a DC generation circuit using full-wave rectification.

Next, the operation of the first to third embodiments will be described. In the first embodiment, the switch 33 of the bypass circuit 34 is closed at the same time as the opening and closing device 33 is opened to stop braking. Half-wave rectified DC current flows through the plurality of stator induction motors 35, and the conductor of the rotating rotor generates electric power by a power generating action. In the case of a cage rotor, it is radiated as heat inside the rotor. When the rotor stops, the power switch device 31 is opened to cut off the power.

The operations of the second and third embodiments are substantially the same as those of the first embodiment. However, unlike the first embodiment, the switching devices SW ₃₈ and S
Since the W ₄₁ and the SW ₄₂ are arranged in parallel with the power switching device 31, there is no need to directly cut off the main power of the motor, so that the electrical capacity of the switch may be small. In the third embodiment, an example of full-wave rectification using a diode bridge as a DC generation circuit has been described.

The operation of the second and third embodiments will be briefly described. The power switch 31 is opened to stop braking, and the switch SW ₄₁ , S
Close the W _42, to close the SW of the bypass circuit 34. After the motor is braking stops, everything opens the previous SW _41, SW _42, SW circuit is opened.

FIG. 5 shows the operation of the present invention, that is, the operation in the case where a DC generation circuit is provided in a plurality of stator induction motors.

FIG. 5 shows the braking torque characteristics with respect to the number of rotations when the phase difference of the voltage induced in the rotor is changed by rotating the rotation stator.

As is apparent, the braking torque characteristic changes according to each phase difference, and the braking torque changes greatly as the phase difference increases. In the figure, a braking torque characteristic having a phase difference of 0 ° is a braking torque characteristic used as DC braking of a general induction motor. Since general DC braking can only obtain a braking torque characteristic of 0 °, it is necessary to adjust the exciting current by the DC circuit. However, in the present invention, the exciting current is determined and the braking torque is determined by the rotation of the rotating stator. Can be selected steplessly, and the braking torque can be easily adjusted.

As described above, the braking torque can be adjusted and selected steplessly over a wide range of rotation speed, and it is no longer necessary to change the braking method and device according to the load.

Further, since the switching device of the DC generation circuit is provided in parallel with the power switching device, the switching device has a small electric capacity and is inexpensive. Furthermore, since the DC generation circuit is configured by a diode, the configuration is simple in terms of cost.

Next, a case where a three-phase power source is used and the phase difference between the two stators is changed by connection switching will be described. This means that the phase difference is 0 ゜, 6
Since it can be set at 0 °, 120 °, and 180 °, four-stage braking is possible.

Specifically, the rotating stator 16 of the induction motor 1 shown in FIG. 1 is used as a fixed stator similarly to the second stator 13, and one of the windings 10 of the first stator 12 or the second stator 13 is used. Or
This is done by switching the 11 connections.

The connection switching is described in detail in Japanese Patent Application No. 63-170287 filed by the present applicant, and at least the following four connection methods are conceivable. A so-called series-connection, series-Y connection, parallel-connection, and parallel-Y connection. FIGS. 6 to 9 show these connection diagrams and the respective phase differences.

FIG. 10 shows a braking torque characteristic of DC braking at each phase difference due to connection switching.

The method of switching the connection of one stator winding among a plurality of stators has a limited usable range, but the phase difference can be changed according to the start, the operation, and the transition to the intermediate state. According to the present invention, it is possible to generate a braking torque by phase switching according to operation, low speed, and stop.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to this invention comprised as mentioned above, it is possible to generate | occur | produce a high constant torque according to a load from a low speed rotation to a rated rotation of a several stator induction motor, and to perform a low speed rotation from a rated rotation to a stop. Until then, various braking torques can be generated according to the load. In addition, their configurations are simple and inexpensive according to the present invention.

Therefore, by providing a phase shift in the voltage induced in the rotor conductor by the two stators, it is possible to diversify the torque and generate a high torque from a low speed to a rated rotation range. This has made it possible to make a greater contribution to all fields that require expanded applications and high-torque motors.

[Brief description of the drawings]

1 is a side sectional view of a plural stator induction motor, FIG. 2 is a circuit diagram showing a first embodiment, FIG. 3 is a circuit diagram showing a second embodiment, and FIG. 4 is a third embodiment. FIG. 5 is a circuit diagram showing an example of a braking torque by the rotating stator of the present invention, FIG. 6 is connection switching in series △ connection, FIG. 7 is connection switching in series Y connection, and FIG. △ Connection switching in connection,
FIG. 9 is a diagram showing a braking torque characteristic by the connection switching in the parallel Y connection, and FIG. 10 is a diagram showing the braking torque characteristics by the switching of the stator winding connection of the present invention. 1 ... multiple stator induction motor, 2, 3 ... rotor core, 4
... rotor shaft, 5 ... non-magnetic core, 6 ... conductor, 6 ...
... rotor conductor, 7 ... rotor, 8 ... short-circuit ring, 9 ... resistance material, 10, 11 ... stator winding, 12 ... first stator, 13 ...
... Second stator, 14 ... Machine frame, 15 ... Bearing, 16 ... Rotating stator, 17 ... Gear, 20 ... Rotating electric motor, 21 ... Driving gear, 30 ... … Power switchgear, 32… DC generator circuit, 33… Switchgear, 34… Bypass, 35… Multiple stator induction motor (stator), 38… DC generator circuit,
40: DC generation circuit, SW ₃₃ , SW ₃₈ , SW ₄₁ , SW _42: Switching circuit contact, SW: Switching circuit contact of bypass circuit, r: Current control resistance of DC generation circuit.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁶ , DB name) H02K 17/00-17/44 H02K 16/00-16/04 H02P 3/00-3/26

Claims (6)

(57) [Claims] 1. A rotor having a plurality of rotor cores provided on a same rotating shaft with an arbitrary space therebetween, and a plurality of conductors provided in communication with the plurality of rotor cores. A plurality of stators provided around each of the rotor cores facing each other,
A voltage transfer that changes the phase difference between a rotating magnetic field generated around a rotor core facing an arbitrary stator of the plurality of stators and a rotating magnetic field generated around a rotor core facing another stator. In a multiple stator induction motor provided with a phase device, a power supply switching circuit, a DC generation circuit, and a switching device for the DC generation circuit are provided in a power supply circuit of the induction motor, and the power switching device and the switching device are provided during braking. A plurality of stator induction motors, wherein the DC of the DC generation circuit is supplied to the stator winding by opening or closing only one of the switching devices or only the switching device, and the magnitude of the braking force is changed by the voltage phase shift device. . 2. The voltage phase shifting device according to claim 1, wherein at least one of the plurality of stators comprises a rotating stator concentrically rotating with the rotor. 2. The multiple stator induction motor according to 1. 3. The multiple stator according to claim 1, wherein the voltage phase shifter switches connection of windings wound around at least one of the plurality of stators. Induction motor. 4. The multiple stator induction motor according to claim 1, wherein the switching device for the DC generation circuit is provided in parallel with the power switching device. 5. A stator winding on which a DC generation circuit operates,
The multiple stator induction motor according to any one of claims 1 to 4, wherein a bypass circuit having a polarity opposite to that of the DC generation circuit is provided. 6. The multiple stator induction motor according to claim 1, wherein the DC generation circuit and the bypass circuit mainly include a diode.