JPH09182215A - Method of controlling linear carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the magnetic attraction working between an armature and a secondary conductor so as to lessen the resistance in running, by supplying a linear induction motor with voltage being preset lower than the value led from V/f ratio and power of frequency based on the V/f ratio, while a truck is running at a constant speed after acceleration. SOLUTION: When a truck 1 is accelerated, the output of an acceleration computing element 23 is made the inverter voltage command value and the inverter frequency command value of an inverter 30, and the power based on the V/f ratio obtained by the rated voltage (V) and the rated frequency (f) of a linear induction motor (LIM) is supplied to an armature 2. After completion of acceleration, a changeover circuit 41 detects the slip value of the LIM being the output of the acceleration computing element 22 becoming small, and it changes only the voltage command value of the inverter 30 over to the output value of a voltage setter 42, Here, by setting the set value of the voltage setter 42 lower than the value based on the V/f ratio in advance, the magnetic attraction between an armature 2 and a secondary conductor can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for a so-called on-vehicle primary type linear conveyance device using a linear induction motor.

[0002]

2. Description of the Related Art FIG. 3 is a schematic diagram showing a conventional example of a linear transport device of this type. In FIG. 3, the trolley 1
An armature 2 of a linear induction motor (hereinafter, also referred to as LIM) attached to the LIM, a secondary conductor 3 of the LIM arranged to face the armature 2, and a carriage 1 along the secondary conductor 3. It is a structure which is supported by the wheels 4 and travels on a traveling road (not shown).

In the control circuit 20, the speed command value (v ^* ) commanded to the carriage 1 is converted into a speed set value (v ₀ ) adjusted to a desired acceleration / deceleration time by the acceleration / deceleration calculator 21 and this speed is converted. The output of the speed detector 5 for detecting the traveling speed of the trolley 1 installed on the trolley 1 is added from the set value (v ₀ ) by the addition calculator 22.
The slip obtained by subtraction with and the value obtained by adding the slip and the speed setting value (v ₀ ) by the addition calculator 23 are input to the inverter 10 as the inverter command value, and the inverter 10 calculates the LIM rating based on the inverter command value. A variable voltage / frequency power having a V / f ratio obtained from the voltage (V) and the rated frequency (f) is output.

The power for driving the trolley 1 is supplied to the LIM by an inverter 10 which outputs electric power of a variable voltage and frequency based on the V / f ratio obtained by the rated voltage (V) and the rated frequency (f) of the LIM. It is obtained by exciting the armature 2.

[0005]

In FIG. 3, a trolley 1
The generated thrust force F _{TA of the} LIM required to accelerate the vehicle to a predetermined traveling speed is represented by equation (1).

[0006]

[Equation 1] F _TA = Mα + μ (M ・ G + F _N ) [N] (1) M: Total mass of movable body (including bogie mass) [kg] G: Gravity acceleration [m / s ² ] α: Bogie Acceleration [m / s ² ] μ: Running resistance coefficient of the truck F _N : Magnetic attraction force acting between the armature of the LIM and the secondary conductor [N] In the formula (1), when the truck 1 is accelerated, In addition, a force for accelerating the total mass M of the movable body to a predetermined traveling speed, that is, Mα of the first term on the right side of the equation (1) accounts for most of the thrust force F _TA of the LIM.

When the carriage 1 reaches a predetermined traveling speed, the LI
Since the thrust generated by M is in equilibrium with the running resistance of the bogie 1, the thrust F _TR generated by LIM at this time is expressed by equation (2).

[0008]

F _TR = μ (M · G + F _N ) [N] (2) FIG. 4 and FIG. 5 are operation explanatory diagrams of the linear transport device of this type during traveling. 4, 4 (a) shows the time of the linear transport device - a relational diagram of the traveling speed, while the time t ₀ ~t ₁ shows the acceleration region of the carriage, the time t ₁ later shows the constant speed running region ing. Further, FIG. 4B is a time-thrust relationship diagram of the linear transport device, and similarly to FIG. 4A, the acceleration region of the truck is shown during the time t ₀ t _{1 and} the LIM at this time is shown.
The generated thrust force F _TA of the _LIM is a value obtained by the formula (1), and after the time t ₁ shows the constant speed traveling region, and the generated thrust force F _TR of the LIM at this time is a value obtained by the formula (2). Is.

FIG. 5 is a characteristic diagram of the LIM of the conventional linear carrier shown in FIG. 3, in which the horizontal axis represents the traveling speed of the carriage 1 and the vertical axis represents the thrust (relative value) of the LIM and the LIM. The magnetic attraction force (relative value) between the armature 2 and the secondary conductor 3 is set to LI.
The voltage of the M armature 2 is shown as a parameter. In FIG. 5, when the trolley 1 is accelerating, the traveling speed is set from the voltage V ₁ of the armature 2 having a value that the thrust generated by the LIM is obtained by the above equation (1) when the trolley 1 is traveling at zero speed. Value v
The output of the inverter 10 is changed substantially linearly based on the V / f ratio so that the voltage V _{3 of the} armature 2 that can obtain the thrust at ₀ is obtained, and acceleration is performed.

When the trolley 1 reaches the traveling speed of the speed setting value v ₀ , the output of the inverter 10 is adjusted so that the voltage V _{2 of the} armature 2 becomes the thrust of LIM which is balanced with the traveling resistance of the trolley 1. The change control is performed based on the V / f ratio. According to the above-described control method for the conventional linear carrier, as shown in FIG. 5, for example, the traveling resistance required between the armature 2 and the secondary conductor 3 of the LIM in the constant speed traveling region of the carriage 1 is reduced. There was a problem that a magnetic attraction force F _{N that} was 13 times as large was generated, resulting in an increase in actual running resistance and the LIM outputting an extra thrust.

An object of the present invention is to provide a control method for a linear transfer device that solves the above problems.

[0012]

SUMMARY OF THE INVENTION The present invention is directed to an armature of a linear induction motor mounted on a carriage, a secondary conductor of the linear induction motor arranged facing the armature, and a secondary conductor along the secondary conductor. In a method of controlling a linear carrier device in which the carriage travels on a traveling road, the voltage and frequency obtained by the rated voltage (V) and the rated frequency (f) of the linear induction motor during acceleration or deceleration of the carriage. Ratio of (V / f
Ratio) to the armature of the linear induction motor with variable voltage and frequency power, and after accelerating the carriage, it is derived from the V / f ratio while the carriage is traveling at a constant speed. Electric power based on a preset voltage lower than the voltage and a frequency derived from the V / f ratio is supplied to the armature of the linear induction motor.

According to the present invention, by lowering the voltage of the LIM below the value based on the V / f ratio while the truck is traveling at a constant speed, the magnetic field acting between the armature of the LIM and the secondary conductor is reduced. Since the actual traveling resistance can be reduced by reducing the suction force, the LIM-generated thrust can be reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic configuration diagram of a linear conveyance device showing an embodiment of the present invention, and those having the same functions as those of the conventional example shown in FIG. There is. In FIG. 1, an inverter 30 has a function of separately setting an output voltage and a frequency, and a control circuit 40 is switched between an acceleration / deceleration calculator 21 and addition calculators 22 and 23 having the same function as the conventional control circuit 20. A circuit 41 and a voltage setting device 42 are provided.

While the carriage 1 is accelerating, the output of the addition calculator 23 is input as the inverter voltage command value and the inverter frequency command value of the inverter 30 via the contact 41a of the switch 41, and at this time, the rated voltage of the LIM ( V) and the rated frequency (f) to obtain a voltage / frequency variable voltage / frequency power, which is supplied to the LIM armature 2 for acceleration, and when the trolley 1 is completely accelerated, the addition calculator 22 Since the slip value of the output LIM becomes small, the switching circuit 41 detects this and switches only the inverter voltage command value of the inverter 30 to the output of the voltage setter 42 via the contact 41a of the switching circuit 41. To work.

The output of the voltage setting unit 42 is lower than the voltage value derived from the V / f ratio, and the excitation voltage V ₄ of the LIM armature 2 corresponding to the running resistance at a constant speed v ₀ is output. Is set to. FIG. 2 is a characteristic diagram of the LIM of the linear carrier of the present invention shown in FIG.
The running speed of LIM is the thrust (relative value) of LIM on the vertical axis,
The magnetic attraction force (relative value) between the LIM armature 2 and the secondary conductor 3 is shown using the voltage of the LIM armature 2 as a parameter.

In FIG. 2, when the carriage 1 is accelerated, the voltage of the armature 2 is changed from V ₁ to V ₁ as in the conventional control method described above.
The output of the inverter 20 is changed under the constant V / f ratio so as to be ₃ and accelerated. When the trolley 1 reaches a predetermined traveling speed v ₀ , the output voltage of the inverter 30 is controlled to become V ₄ (V ₄ << V ₃ ), and as a result, the slip of the LIM increases, so that the inverter is increased. The frequency of the output of 30 is almost the same as that at the voltage V ₃ .

According to the above-described control method for the linear carrier of the present invention, for example, as shown in FIG. 2, when the carriage 1 is in the above-mentioned constant speed traveling region, the magnetic attraction force between the armature 2 and the secondary conductor 3 of the LIM is increased. Is reduced to 1/5 or less as compared with the above-mentioned conventional example.

[0019]

According to the present invention, by setting the voltage of the LIM lower than the value based on the V / f ratio while the trolley is traveling at a constant speed, the LIM generated thrust can be made small. The heat generation of the armature can also be suppressed, and as a result, the armature can be made smaller and lighter, so that the running resistance can be further reduced and the power consumption during running at a constant speed can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a linear transfer device showing an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of FIG. 1;

FIG. 3 is a schematic configuration diagram of a linear transport device showing a conventional example.

FIG. 4 is an operation explanatory diagram of FIG. 3;

FIG. 5 is a diagram illustrating the operation of FIG. 3;

[Explanation of symbols]

1 ... Bogie, 2 ... LIM armature, 3 ... LIM secondary conductor, 4 ... Wheel, 5 ... Speed detector, 10, 30 ... Inverter, 20, 40 ... Control circuit, 21 ... Acceleration / deceleration calculator, 2
2, 23 ... Addition calculator, 41 ... Switching circuit, 42 ... Voltage setting device

Claims (1)

[Claims] 1. An armature of a linear induction motor attached to a bogie, a secondary conductor of the linear induction motor arranged so as to face the armature, and the bogie traveling on a traveling path along the secondary conductor. In the method for controlling a linear carrier, the ratio of voltage and frequency (V / f ratio) obtained by the rated voltage (V) and the rated frequency (f) of the linear induction motor during acceleration or deceleration of the carriage. Is supplied to the armature of the linear induction motor by accelerating the trolley, and then while the trolley is traveling at a constant speed, the voltage derived from the V / f ratio is A control method for a linear carrier, comprising supplying electric power based on a low preset voltage and a frequency derived from the V / f ratio to an armature of the linear induction motor.