JPH03128647A - Multiple stator induction motor - Google Patents

Abstract

PURPOSE:To enable generating a high torque according to a load from a low- speed rotation to a rated rotation by providing the power supply circuit of a motor with a power switching device and a DC generation circuit and switching device for the DC generation circuit. CONSTITUTION:A power switching device 31 and a switching device 33 for DC generation circuits 32a, 32b composed of diodes are provided between a power supply 30 and a multiple stator induction motor 35 connected with the power supply 30. Also, a bypass circuit 34 is connected in parallel with a stator winding, on which the DC generation circuits 32a, 32b operate. In this case, the resistance (r) of the DC generation circuit 32a determines the value of DC exciting current and the change of a braking force ia caused by the phase difference of voltage induced in a rotor 7 due to the rotation of a rotating stator 16. Thus, torque characteristics are changed by the rotation of the stator so that the diversification of torque is provided in a rotational speed over a wide range, while a DC exciting controlling torque is changed according to each phase difference so that various control torques can be generated according to a load.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a single rotor, a plurality of stators, and one of the plurality of stators as a rotating stator. The present invention relates to a multi-stator induction motor having a voltage phase shifter, in which the rotational speed of the rotor and the generated torque can be varied by adjusting the voltage phase shifter, and more particularly to a DC braking and stopping device thereof.

[Conventional technology]

Conventionally, various types of electric braking means have been used as braking devices for three-phase induction motors, and among these, DC braking has long been used in electric motors for hoisting cranes and the like.

[Problem to be solved by the invention]

Although this DC braking has some drawbacks because it uses DC, it has the feature that the braking time can be adjusted by adjusting the magnitude of DC excitation.

By the way, a general induction motor configured with a single stator and a single rotor requires a device for adjusting the DC excitation described above.

In other words, this DC excitation has not been used in a wide variety of devices because it is necessary to set the DC excitation in advance according to each device.

[Means to solve the problem]

In the present invention, while taking advantage of the characteristics of DC braking, the braking force of DC braking is diversified by the action of the voltage phase shifting device of the multi-stator induction motor according to the present invention, and the braking force of DC braking is diversified. The present invention aims to provide a multi-stator induction motor having various braking functions, such as braking at high speeds.

According to the present invention, in a multi-stator induction motor comprising a single rotor, a plurality of stators, and a voltage phase shifter, the power supply circuit of the motor includes a power switchgear, a DC generation circuit, and the DC generation circuit. This is a means for solving the above problem by providing a switching device.

Furthermore, the switching device of the DC generation circuit is provided in parallel with the power supply switching device, and a bypass circuit with a polarity opposite to that of the DC generation circuit is provided, and the DC generation circuit and the bypass circuit are mainly composed of diodes. This is a means to solve the above problem.

In addition, in the induction motor of the present invention, whether the voltage phase shifting device is by rotating the stator, switching the connection of the stator windings, or by other induction, each voltage can be changed. The phase difference created by the phase shifting device provides the means of the invention.

[For production]

The operation of the present invention is as follows.As is well known, the multi-stator induction motor according to the present invention changes the torque characteristic curve by rotating the stator, thereby increasing the torque over a wide range of rotational speeds. The aim is to diversify the induction motor and expand its applications.When braking the induction motor by DC excitation, the change in the phase difference of the rotor conductors caused by the voltage phase shifter causes the DC excitation to change. The braking torque changes according to each phase difference (electrical angle), making it possible to measure diversification.

Further, if 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 compared to the case where the switching device is provided in series. In other words, when installed in series with the power switchgear, the electrical capacity required for the switchgear is the same as that of the power switchgear, but when installed in parallel, only the DC excitation current flowing through the DC generation circuit needs to be considered. Bye.

Furthermore, if a bypass circuit with a polarity opposite to that of the DC generation circuit is provided on the stator winding on which the DC generation circuit operates, the large current generated when the power switchgear is opened and the DC generation circuit is closed can be passed through the bypass circuit. The problem is solved by looping the winding wire.

If the above DC generating circuit and bypass circuit are constructed using diodes, the cost will be much lower than when constructed using other elements.

〔Example〕

Although the invention will mainly be described in detail with reference to a two-stator induction motor with a squirrel-cage rotor, it goes without saying that the invention is not limited thereto. In addition, as mentioned above, there are cases of multi-stator induction motors with a wound rotor, and there are also cases where the stator windings are switched between star connection and delta connection to further diversify the torque characteristics. . The structure between the rotor cores may also use spaces, non-magnetic materials, magnetic materials, etc.

The present applicant has already given a detailed explanation of the structure and operation of a multi-stator induction motor which is a part of the structure of the present invention in Japanese Patent Application No. 128314/1982. This will be explained based on FIGS.

An embodiment of an electric motor forming a part of the structure of the present invention will be explained with reference to FIG. Reference numeral 1 denotes a multi-stator induction motor according to the present invention, and the multi-stator induction motor 1 has the following configuration. Rotor cores 2.3 made of magnetic material are mounted on the rotor shaft 4 at arbitrary intervals. Rotor core 2
A non-magnetic core 5 is interposed between .degree. 3 or a space is provided. A plurality of conductors 6 installed in the rotor cores 2 and 3...
are connected in communication with the rotor core 2.3 to form an integral rotor 7, and both ends of the plurality of conductors 6 connected in series are short-circuited by a short-circuit ring 8.8. Ru. In addition, in this embodiment, the conductor 6 installed on the rotor 7
. . is a non-magnetic core 5 portion between the rotor cores 2 and 3, each of which is connected via a resistive material 9 that conducts current when a current of an arbitrary vector difference flows.

A first stator 12 and a second stator 13, each having a winding l0111 on the outer side facing the rotor cores 2 and 3, are arranged side by side on the machine frame 14, and between the machine frame 14 and the first stator 12. sliding bearing 1
5 is installed, and the second stator 13 is fixed to the machine frame 14. A gear 17 is fitted onto the outer peripheral surface of one side of the first stator 12 . A driving gear 21 is pivotally attached to a rotating electric motor 20 fixed to the outer circumference of the machine frame 14, and the driving gear 21 is engaged with a gear 17 fitted to the first stator 12. With this configuration, the first stator 12 is connected to the rotating electric motor 20.
The rotating stator 16 is rotated concentrically with the rotor 7 by the operation of the rotating stator 16 . Thus, the rotation of the first stator 12 and the second stator 13 constitute a voltage phase shifting device.

In addition, the windings 10.1 of the first stator 12 and the second stator 13
The form of 1 may be either Δ 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 electric motor 1 described above is shown in FIGS. 2 to 4.

First, Figure 2 shows the simplest example. Power source 30 and power source 3
A DC generating circuit 32 consisting of a power switchgear 31 and a diode is connected between the multi-stator induction motor 35 connected to the
A and 32b opening/closing devices 33 are provided. In addition, a bypass circuit 34 is provided on the stator winding on which the DC generating circuit 32 acts.
are connected in parallel.

Although the multi-stator induction motor 35 is shown as being Δ-connected, for convenience of explanation, this is a simplified diagram of a plurality of stator windings and does not show a single stator.

By the way, in this embodiment, the switching device 33 requires the same electrical capacity as the power switching device 31.

In addition, the resistance material r of the DC generator 32a determines the value of the DC excitation current, and the other changes, that is, the change in braking force, are determined by the phase difference in the voltage induced in the rotor 7 due to the rotation of the rotation stator 16. by.

Further, the SW of the bypass circuit 34 operates in conjunction with the opening/closing circuit 33.

Next, second and third embodiments are shown in FIGS. 3 and 4. In this embodiment, explanations of parts that overlap with those in the first embodiment will be omitted. The DC generation circuits 38a and 38b are connected in parallel to the power supply switching device 31, and the switching device 5 of the DC generation circuit 38
W38 is connected in series to the DC generation circuit and in parallel to the power switchgear 31. In this case, the electrical capacity of the switching device 5W38 is determined by the current of the DC generation circuit 28, and is generally much smaller than the electrical capacity of the power switching device 31.

The DC generating circuit 40 shown in FIG. 4 is constructed using a diode bridge, and shows a DC generating circuit using full-wave rectification.

Next, the operations of the first to third embodiments will be described.

In the first embodiment, the switch of the bypass circuit 34 is closed at the same time as the opening/closing device 33 is opened to stop the braking. A half-wave rectified DC current flows through the multi-stator induction motor 35.
The conductors of the rotating rotor generate electric power, but in the case of a squirrel cage rotor, the electric power is dissipated as heat inside the rotor.

When the rotor stops, the power switching device 31 is opened to cut off the power.

The second embodiment and the third embodiment operate almost the same as the first embodiment, but unlike the first embodiment, the switchgear SW3
B, SW4r, SW4゜ as power switchgear 3
Since it is connected in parallel with 1, there is no need to directly cut off the main power supply of the motor, so the electric capacity of the switch may be small. Further, in the third embodiment, an example is shown in which the direct current generating circuit is full-wave rectified by a diode bridge.

Second. The operation of the third embodiment will be briefly described.

To stop braking, open the power switching device 31 and switch the switching device S W a 7. SW 42 is closed, and SW of the bypass circuit 34 is closed. After the motor stops braking, all circuits are opened when the previous S ''VVa+ and SW42.SW are opened.

Now, the operation of the present invention, that is, the operation when a DC generation circuit is provided in a multi-stator induction motor, is shown in FIG.

What is shown in FIG. 5 is the braking torque characteristic with respect to the rotational speed when the rotating stator is rotated to change the phase difference of the voltage induced in the rotor.

As is clear, the braking torque characteristics change depending on each phase difference, and the larger the phase difference, the more the braking torque changes.

In the figure, the braking torque characteristic with the phase difference O0 is the 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 excitation current by the DC circuit, but in the present invention, the excitation current is determined and the braking torque is achieved by rotating the rotary stator. can be selected steplessly and braking torque can be easily adjusted.

As described above, the braking torque can be adjusted and selected steplessly over a wide range of rotational speeds, eliminating the need to change the braking method or device depending on the load.

Further, since the switching device for 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 direct current generating circuit is constructed using diodes, the construction is simple and cost-effective.

Next, a case will be described in which a three-phase power source is used and the phase difference between both stators is determined by switching the connections. This sets the phase difference to 0°, 6
Since it can be set to 0°, 120°, and 180°, four stages of braking are possible.

Specifically, the rotary stator 16 of the induction motor 1 shown in FIG.
The connection of 0 or 11 is switched.

The switching of the connection was previously filed by the applicant in patent application No. 17028/1983.
7, there are at least the following four possible wiring methods. These are so-called series Δ connections, series Y connections, parallel Δ connections, and parallel Y connections. These wiring diagrams and their respective phase differences are shown in FIGS. 6 to 9.

What is shown in FIG. 10 is a braking torque characteristic diagram of DC braking at each phase difference due to connection switching.

Although the method of switching the connection of one stator winding among multiple stators has a limited range of use, it is possible to change the phase difference depending on startup, operation, and intermediate transition, and this method is effective. According to the invention, it is possible to generate braking torque by switching phases depending on when the vehicle is running, when the vehicle is running at low speed, and when the vehicle is coming to a stop.

〔Effect of the invention〕

According to the present invention configured as described above, it is possible to generate a high constant torque according to the load in a multi-stator induction motor from low speed rotation to rated rotation, and also from rated rotation to low speed rotation and stop. It is now possible to generate various braking torques depending on the load. Further, their configuration is also simple and inexpensive according to the present invention.

Therefore, we have created a multi-stator induction motor that can generate high torque from low speeds to the rated rotation range by creating a phase shift in the voltage induced in the rotor conductor by two stators to diversify the torque. It is now possible to make an even greater contribution to all fields that require expanded applications and high-torque electric motors.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of a multi-stator induction motor, Fig. 2 is a circuit diagram showing the first embodiment, Fig. 3 is a circuit diagram showing the second embodiment, and Fig. 4 is a circuit diagram showing the third embodiment. A circuit diagram showing an example, Fig. 5 is a braking torque characteristic diagram using the rotary stator of the present invention, Fig. 6 is connection switching in series Δ connection, Fig. 7 is connection switching in series Y connection, and Fig. 8 is parallel connection switching. △Connection switching in connection,
FIG. 9 is a diagram showing braking torque characteristics when switching connections in a parallel Y connection, and FIG. 10 is a diagram showing braking torque characteristics when switching connections of stator windings according to the present invention. DESCRIPTION OF SYMBOLS 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, 1
4... Machine frame, 15... Bearing, 16... Rotating stator, 17... Gear, 20... Rotating electric motor, 21...
... Drive gear, 30... Power supply, 31... Power switchgear, 32... DC generation circuit, 33... Switchgear,
34... Bypass, 35... Multiple stator induction motor (stator), 38... DC generation circuit, 40... DC generation circuit, SW, 3°S W2B, SW41.
SW42...Switching circuit contact, SW...Switching circuit contact of bypass circuit, r...Current control resistance of DC generation circuit.

Claims (6)

[Claims] (1) A rotor in which a plurality of conductors installed in a plurality of rotor cores provided at arbitrary intervals on the same rotating shaft are connected in a continuous manner, and each of the rotor cores is opposed to the rotor core. a plurality of stators circumferentially provided, a voltage phase shifter;
1. A multiple stator induction motor comprising a plurality of stators, characterized in that a power supply circuit of the motor is provided with a power switching device, a DC generation circuit, and a switching device for the DC generation circuit. (2) The multi-stator induction motor according to claim (1), wherein the voltage phase shifting device of the induction motor rotates at least one stator among the plurality of stators concentrically with the rotor. A multi-stator induction motor consists of a rotating stator. (3) The multi-stator induction motor according to claim (1), wherein the voltage phase shifter for the induction motor connects the windings wound around at least one stator among the plurality of stators. A multi-stator induction motor that is switched. (4) A multi-stator induction motor according to any one of claims (1) to (3), in which a switching device for a DC generation circuit is provided in parallel with a power switching device. induction motor. (5) The multi-stator induction motor according to any one of claims (1) to (4), wherein a bypass having a polarity opposite to that of the DC generation circuit is provided in the winding of the stator on which the DC generation circuit acts. A multiple stator induction motor that is equipped with a circuit. (6) The multi-stator induction motor according to any one of claims (1) to (5), wherein the DC generation circuit and the bypass circuit are mainly composed of diodes.