JPH06217418A - Linear motor for cableway and control method therefor - Google Patents

Abstract

PURPOSE:To allow starting of operation by locking the rotation for a predetermined time when the primary stator and the reaction plate of a linear motor for cableway are freezed during winter season and generating eddy current in the secondary reaction plate thereby unfreezing the primary stator and the reaction plate. CONSTITUTION:A ring type secondary reaction plate 4 is fixed concentrically with a pulley 1 to the peripheral side face of the pulley 1 for driving a wirerope 3 fixed to a rotary shaft 2. Primary stators 5a-5d of a linear induction motor are disposed while resisting against the secondary reaction plate 4. AC power is fed from an inverter to generate a moving field which imparts magnetic thrust to the secondary reaction plate 4 thus rotating a drive pulley 3. When the pulley can not rotate due to freezing during winter season, the linear induction motor is locked for a predetermined time to generate eddy current in the secondary reaction plate 4 thus unfreezing the pulley. This method allows smooth starting of drive pulley.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor for a cableway in a cableway system such as a lift or ropeway driven by a linear induction motor, and a control method thereof.

[0002]

2. Description of the Related Art Conventionally, as a cableway driving device in a cableway system such as a lift or a ropeway, one using a linear induction motor to drive a wire rope driving pulley has been proposed. FIG. 8 and FIG. 9 show an example of a cableway driving device using such a linear induction motor. A wire rope driving pulley 1 is rotatably supported by a rotation support shaft 2 and is attached to the wire rope driving pulley 1. The wire rope 3 is wound around, and the wire rope 3 is driven by the rotational driving force of the drive pulley 1. This wire rope drive pulley 1 is usually designed to reduce the metal fatigue of the wire rope 3 wound around it by 40%.
It is made to have a large diameter of about 00 mm (= 4 m).

In order to rotationally drive the wire rope drive pulley 1, a ring-shaped secondary side reaction plate 4 of a non-magnetic good conductor such as aluminum or copper is concentrically welded to both side surfaces of the circumferential portion of the drive pulley 1. Or fixed by bolting. Then, on the secondary side reaction plate 4, a plurality of sets (four sets in the figure) of linear linear induction motors LIM primary side stators 5a, 5b,
5c and 5d (hereinafter, these may be collectively referred to as primary side stators 5) are circumferentially dispersed so as to face each other with a certain gap therebetween, and one pair is arranged to face the front and back sides. ing. Incidentally, these primary side stators 5 are fixedly supported separately from the drive pulley 1 and thus on another fixing frame member via appropriate supporting means so as not to move even if the drive pulley 1 rotates. Further, a braking disc brake 6 is provided so as to sandwich both side surfaces of the drive pulley 1 in order to stop the drive pulley 1.

In the cableway driving device having such a structure, a moving magnetic field is generated in the primary side stator 5 by exciting the primary side stator 5 of the linear induction motor with a three-phase alternating current. Eddy current is generated in the secondary side reaction plate 4 of the linear induction motor, and thrust is generated in the reaction plate 4 on the side of the drive pulley 1 which is rotatably supported by the interaction between the moving magnetic field and the eddy current.
It is rotationally driven, and as a result, the wire rope 3 is towed.

By the way, in such a cableway driving device, a main circuit configuration as shown in FIGS. 6 and 7 is generally adopted. That is, the AC power supplied from the commercial power source 7 is the inverter circuits 10a, 10b, 10c, 10d (hereinafter,
These may be collectively referred to as an inverter circuit 10) to be converted into AC power of variable voltage variable frequency (VVVF) and supplied to each primary side stator 5 of the linear induction motors LIM1 to LIM8. As a result, each of the primary side stators 5 is excited, and the drive pulley 1 is rotationally driven as described above.

[0006]

SUMMARY OF THE INVENTION In a conventional linear induction motor control device for such a cableway drive device,
When the linear induction motor is started, the inverter circuit 10 generally increases the voltage and the frequency while keeping the ratio of the output voltage and the output frequency constant, that is, V / f constant. This is for the following reason. The relationship between the inverter output voltage V, the inverter frequency f, the slip frequency fs of the linear induction motor, and the thrust F generated by the linear induction motor is expressed by F to (V / f) ² × fs. Therefore, in order to smoothly accelerate at the time of startup, that is, to accelerate with uniform acceleration, V / f and fs may be controlled to be constant.

On the other hand, the cableway drive device usually has the following problems because most of its applications are applied to ski lifts in winter.

That is, in the state where the linear induction motor is stopped at night, snow enters the gap between the primary side stator 5 and the reaction plate 4 of the linear induction motor shown in FIG. Melt water or fog may freeze and the primary side stator 5 and the reaction plate 4 may adhere to each other. Moreover, since this gap needs to be as narrow as possible in view of the characteristics of the linear induction motor, it is more likely to occur. Therefore, when it is attempted to start by the conventional V / f constant control in such a fixed state, the reaction force of the starting thrust of the linear induction motor is generated between the reaction plate 4 and the primary stator 5 of the linear induction motor. However, there is a problem that the coil insulation of the primary side stator 5 may be destroyed.

The present invention has been made in view of the above conventional problems, and is a state in which the primary side stator and the reaction plate are fixed to each other due to freezing or freezing such as in the early morning of winter. To provide a linear motor for a cableway and a control method for the same so that when the vehicle is started in operation, the snow and ice are automatically melted to release the fixed state before starting. With the goal.

[0010]

According to a first aspect of the present invention, a ring-shaped secondary side reaction plate is fixed to a side surface of a circumferential portion of a wire rope drive pulley attached to a rotary support shaft in a concentric manner with the pulley. The primary side stator of the linear induction motor is arranged so as to face the secondary side reaction plate, and the secondary side reaction plate is generated by the moving magnetic field generated by supplying AC power to the primary side stator of the linear induction motor. A method of controlling a linear motor for a cableway, which applies a magnetic thrust to the wire rope driving pulley to drive the wire rope drive pulley, wherein the linear induction motor is maintained in a restrained state for a required time at the start of operation of the cableway linear motor. Characterized by causing the secondary side reaction plate to perform electromagnetic induction heating action by eddy current and melting after freezing or freezing etc. A.

According to a second aspect of the present invention, a ring-shaped secondary side reaction plate is fixed to the circumferential side surface of the wire rope drive pulley attached to the rotary support shaft, concentrically with the pulley,
The primary side stator of the linear induction motor is arranged so as to face the secondary side reaction plate, and the primary side stator of the linear induction motor is magnetized by the AC power of the variable voltage and variable frequency so that the secondary side reaction plate is magnetized. A linear motor for a cableway that applies thrust and rotates a wire rope drive pulley.The primary side stators are electrically divided into two groups, and the primary side stators of each group are controlled to normalize the reaction plate. It is provided with a control device for reversing or restraining.

[0012]

According to the method of controlling a linear motor for a cableway of the first aspect of the present invention, when the gap between the primary side stator of the linear induction motor and the reaction plate is fixed due to freezing or icing of snow or ice, the cableway is fixed. At the start of the operation of the linear motor for use, the linear induction motor is maintained in a restrained state by an external electric or mechanical force for a required time, and the secondary side reaction plate is caused to perform an electromagnetic induction heating action by an eddy current. It melts the freezing and freezing to release the stuck state and allows the drive pulley to be started smoothly.

According to another aspect of the invention, there is provided a linear motor for a cableway in which the gap between the primary stator and the reaction plate of the linear induction motor is fixed due to freezing or icing of snow or ice. At the start of operation, the control device controls each of the primary side stators, which are divided into two groups, to forward, reverse, or restrain the reaction plate so that the linear induction motor is electrically restrained for a required time. This causes the secondary side reaction plate to perform electromagnetic induction heating action by eddy current, automatically melts freezing or freezing to release the stuck state, and makes it possible to smoothly start the drive pulley. To do.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings.

The mechanical structure of the linear induction motor for cableway is the same as that shown in FIGS. 8 and 9 described in the conventional example. The main circuit configuration of an embodiment of the linear motor invention of claim 2 is shown in FIG.
This linear motor embodiment is also a device that uses an embodiment of the control method according to claim 1.

As shown in FIG. 1, in the linear induction motor of this embodiment, the AC power supplied from the commercial power supply 7 is controlled by the first control section 9A in the operation panel 8 and the inverter circuits 10a and 10b are controlled. And the inverter circuit 1 controlled by the second control section 9B in the operation panel 8.
It is designed to be given to 0c and 10d. And
The AC power converted into the AC power of the variable voltage variable frequency (VVVF) through the inverter circuits 10a to 10d is separately supplied to the primary side stators 5a to 5d of the linear induction motor.

The first control unit 9A and the second control unit 9B work independently for one AC power source 7, and are respectively inverter circuits 10a and 10b and inverter circuits 10c and 10b.
Power is supplied to d, and a timer 12 is provided for time management at the start of operation. Note that the restraint state generation means in claim 2 is configured by the control mode at the time of starting the operation, which will be described later, by these control units 9A and 9B.

The speed sensor 11 is for feeding back the rotation speed signal of the drive pulley 1 to both the first control section 9A and the second control section 9B, and controlling the speed by comparison with the speed reference.

Next, the operation of the above-configured linear motor for cableway will be described (this operation description is given in claim 1).
It also serves as an explanation of the control method of the linear motor for cableway according to the invention.

If snow or ice freezes in the gap between the primary side stator 5 and the reaction plate 4 as in winter, or if both are frozen and are stuck, the timer 12 manages them at the start of operation. During the fixed time, the restraint state is generated according to the control pattern shown in FIG.

That is, the two groups of inverter circuits 10a,
10b and inverter circuits 10c and 10d
The control unit 9A and the second control unit 9B give control signals that output electric powers that are in opposite phases to each other and generate the same thrust, whereby the primary side stator 5a excited by the inverter circuits 10a and 10b. , 5b generate a thrust A in the counterclockwise direction indicated by the white arrow in FIG. 3A, and a thrust in the clockwise direction indicated by the black arrow in the primary side stators 5c, 5d excited by the inverter circuits 10c, 10d. B is generated.

As a result, the thrusts A and B cancel each other out, and the reaction plate 4 of the linear motor is constrained in which the rotational thrust is not substantially working. Then, if this restrained state is maintained for a certain period of time, eddy currents are generated in the reaction plate 4 by the respective primary side stators 5a to 5d, whereby electromagnetic induction heating is performed on the reaction plate 4,
The frozen or frozen snow or ice is melted, the fixed state between the primary side stator 5 and the reaction plate 4 is released, and rotation start becomes possible.

Therefore, after the fixed time managed by the timer 12 elapses and the fixed state is released, the control mode is switched to the normal start control. That is,
The first control unit 9A and the second control unit 9B respectively control the inverter circuits 10a to 10d so as to generate thrusts A and B'in the same direction as shown in FIG. The primary side stators 5a, 5b and the primary side stators 5c, 5d of the linear induction motor are excited in the same direction by the electric power, and the output power is gradually increased by the V / f constant control, and the drive pulley 1 is uniformly accelerated. To increase the rotation speed.

The above control method will be described with reference to the graph of FIG. 2. This figure shows the control pattern of the inverter output voltage and the inverter frequency, and the starting point is the first control section 9A and the second control section. Both of the control units 9B are at the point O, and then the first control unit 9A increases the voltage frequency at a constant V / f and the point X corresponding to the set time of the timer 12.
(Voltage Vo, frequency fo) is reached. On the other hand, after the second control unit 9B simultaneously makes a star from the point O, the voltage is equal to that of the first control unit 9A, and the frequency reaches the point X'while maintaining the opposite sign, that is, the antiphase relationship. After that, both the control units 9A and 9B return to the point O, and the initial state of activation is reached.

Until now, two groups of linear induction motors, that is, a group of linear induction motors LIM1 to LIM4 having primary side stators 5a and 5b, and a linear induction motor having primary side stators 5c and 5d are used. Motor LIM5-LIM
Since the same thrust is generated in the opposite phase to the group of 8, the drive pulley 1
The driving pulley 1 is offset, an eddy current flows through the reaction plate 4 while the driving pulley 1 is restrained, and heat is generated by the electromagnetic induction heating action, and the frozen snow or ice in the gap is melted and the fixed state is eliminated. Primary side stator 5
A predetermined gap is secured between the secondary reaction plate 4 and the secondary reaction plate 4.

After that, the first control section 9A and the second control section 9
With respect to the control pattern with B, a constant V / f control is performed from point O, and finally point Y (voltage Vmax, frequency fm
ax) is reached and the drive pulley 1 is rotationally driven at a predetermined rope speed.

As described above, in the control method and the control device for the cableway linear motor of this embodiment, the two groups of linear induction motors LIM1 to LIM for rotationally driving the drive pulley 1 are used.
4. The drive pulley 1 as a whole is electrically restrained by controlling each inverter circuit so that the linear induction motors LIM5 to LIM8 generate rotational force of opposite phases, and the secondary side is excited by exciting the primary side stator. Electromagnetic induction heating is performed by the eddy current generated in the reaction plate, and the snow or ice in the frozen or frozen gap portion is melted to release the fixed state and enable normal activation.

The invention described in claims 1 and 2 is not limited to the above embodiment, and a control method as shown in FIG. 4 can be adopted. That is, the control is not performed at a constant V / f at the start of starting, and the state in which the voltage is reduced to a low value Vlow shown in the drawing is maintained for a certain period of time so that the sum of the thrust generated by the linear induction motor becomes equal to or less than the load torque. With this configuration, as in the above-described embodiment, eddy current is generated in the reaction plate 4 when the drive pulley 1 is stopped and electromagnetic induction heating can be performed, and snow or ice due to freezing or freezing is melted and fixed in the gap. The state can be released, and it becomes possible to start up smoothly.

Further, as another embodiment of the linear motor of the present invention, as shown in FIG. 5, a temperature sensor 13 is installed on the reaction plate 4 in place of the timer 12 so that the reaction plate 4 has a predetermined temperature or higher. When it is decided that the frozen state or frozen ice has melted and the fixed state has been released, the restraint state of the drive pulley 1 is released,
Ordinary activation control may be performed. In this embodiment, the same components as those in the embodiment shown in FIG. 1 are designated by the same reference numerals and the description thereof is omitted.

That is, the temperature sensor 13 is embedded in the reaction plate 4, and after the start of the operation, the temperature change of the reaction plate 4 is monitored by electrically restraining the reaction plate for a required time. Since the temperature of 4 is 0 ° C. or lower, if the temperature becomes 4 ° C. or higher, it may be determined that the melting is completed and the normal start control may be performed.

The invention of claim 1 is not limited to the above-mentioned embodiment, and the mechanical lock mechanism holds the rotational force of the drive pulley for a certain period of time before the start of activation, and each linear induction motor is locked. Power is supplied to the reaction plate to generate an eddy current on the reaction plate side to melt snow or ice in the gap by the electromagnetic induction heating action, and when the melting of the gap is completed,
It may be a method of unlocking.

[0032]

As described above, according to the invention of claim 1,
When the gap between the primary side stator of the linear induction motor and the reaction plate is stuck due to freezing or freezing of snow or ice, the linear induction motor is restrained for the required time when the linear motor for cableway is started. Since the state is maintained and the secondary side reaction plate is made to perform the electromagnetic induction heating action by the eddy current,
Freezing or freezing is melted by the electromagnetic induction heating action by the eddy current to release the fixed state of the linear induction motor,
The drive pulley can be started smoothly.

According to the second aspect of the present invention, when the gap between the primary side stator of the linear induction motor and the reaction plate is stuck due to freezing or freezing of snow or ice, the operation of the linear motor for cableway is started. Occasionally, the restraint state generating means causes the linear induction motor to generate an electrical restraint state for the required time, so that the secondary reaction plate automatically freezes or freezes due to the electromagnetic induction heating action by the eddy current. The linear induction motor is released from the fixed state by melting it, and the drive pulley can be started smoothly.

[Brief description of drawings]

FIG. 1 is a circuit block diagram of an embodiment of the invention of claim 2;

FIG. 2 is a graph showing a control method according to an embodiment of the invention of claim 1.

FIG. 3 is an explanatory diagram showing an operation of an embodiment of the invention of claim 2;

FIG. 4 is a graph showing another embodiment of the invention of claim 1;

FIG. 5 is a circuit block diagram of another embodiment of the invention of claim 2;

FIG. 6 is a circuit block diagram of a conventional example of a cableway linear motor.

FIG. 7 is an operation explanatory diagram of the conventional example.

FIG. 8 is a plan view of a general cableway linear motor.

FIG. 9 is a partially cutaway front view of a general cableway linear motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drive pulley 2 Rotating spindle 3 Wire rope 4 Reaction plate 5, 5a, 5b, ... Primary side stator 6 Disc brake 7 AC power supply 8 Operation panel 9A 1st control part 9B 2nd control part 10, 10a, 10b, ... Inverter circuit 11 Speed sensor 12 Timer 13 Temperature sensor

Claims (2)

[Claims] 1. A ring-shaped secondary side reaction plate is fixed to a side surface of a circumferential portion of a wire rope driving pulley mounted on a rotary support shaft so as to be concentric with the pulley so as to face the secondary side reaction plate. A primary side stator of the linear induction motor is arranged, and a magnetic thrust is applied to the secondary side reaction plate by a moving magnetic field generated by supplying AC power to the primary side stator of the linear induction motor, and the wire A method for controlling a ropeway pulley linear motor for rotationally driving a ropeway pulley, wherein the linear induction motor is maintained in a restrained state for a required time at the start of operation of the ropeway linear motor, and the secondary side reaction plate is provided. Electromagnetic induction heating action by eddy current to thaw ice, freezing, etc. before starting Control method of chromatography data. 2. A ring-shaped secondary side reaction plate is fixed to a circumferential side surface of a wire rope drive pulley attached to a rotary support shaft, concentrically with the pulley, so as to face the secondary side reaction plate. The primary side stator of the linear induction motor is arranged, and the primary side stator of the linear induction motor is excited by AC power having a variable voltage and a variable frequency to give a magnetic thrust to the secondary side reaction plate to drive the wire rope. A linear motor for a cableway that rotationally drives a pulley, wherein the primary side stators are electrically divided into two groups, and the primary side stators of each of these groups are controlled so that the reaction plate is positive.
A linear motor for cableway, which is provided with a control device for reversing or restraining.