JP2003199400A - Method for controlling reel drive motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the new controlling method of a reel drive motor for pulling out and winding a cable. <P>SOLUTION: Power is supplied to an induction motor 1 driving a reel 3 via a reducer 2 from an inverter-controlling vector. The inverter is constituted of a PWM inverter 6, a controller 10 and the like. A drive torque value or a braking torque value which the induction motor 1 outputs is controlled by a torque current command value in vector control. Thus, controllability is improved, and a motor part can be made compact in size. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a cable used for supplying electric power or the like to a movable part of a crane so that the cable does not become loose as the movable part moves. The present invention relates to a method for controlling an electric motor as a drive source of a reel for performing the above.

[0002]

2. Description of the Related Art As described above, as a reel driving electric motor for pulling out and winding a cable, a torque motor composed of a DC electric motor, a DC electric generator, etc. has been used conventionally.

[0003]

However, the above-mentioned conventional torque motor drive system is difficult to apply to a reel that requires high-speed, high-tension, and high-frequency operation, and the electric motor portion becomes large. There was also the problem of doing.

An object of the present invention is to provide a method of controlling a reel driving electric motor which solves the above problems.

[0005]

According to a first aspect of the present invention, a reel driving electric motor in which a reel for pulling out and winding a cable is driven by an induction motor fed from an inverter for vector control through a speed reducer. In the control method of
A winding diameter detecting means for detecting a winding diameter of the cable and a limit value calculating means for switching a torque limit value based on an output signal of the winding diameter detecting means are provided, and the winding diameter becomes large when the cable is wound. The driving torque value is increased stepwise according to the above, and the braking torque value is decreased stepwise as the winding diameter becomes smaller when the cable is pulled out, and
The braking torque value is a value obtained by subtracting a correction value based on mechanical efficiency from the driving torque value.

According to a second aspect of the present invention, in the method of controlling the reel driving electric motor of the first aspect, the electric motor outputs when the winding diameter of the cable is less than a predetermined value A at the time of winding the cable. The drive torque value to be output is τ _11, and the drive torque value output by the electric motor when the winding diameter of the cable is A or more when the cable is wound is τ _12, and when the cable is pulled out, the drive torque value of the cable is The braking torque value output by the electric motor when the winding diameter is less than A is τ _21, and the braking torque value output by the electric motor when the winding diameter of the cable is A or more when the cable is pulled out is τ _{21. 22} and there is a relationship of τ ₁₁ <τ ₁₂ between the driving torque values τ ₁₁ and τ _12, and a relationship of τ ₂₁ <τ ₂₂ between the braking torque values τ ₂₁ and τ _22. It is characterized by having.

A third aspect of the invention is the reel drive motor control method of the first or second aspect, wherein the drive torque value or the braking torque value is changed, or the drive torque value and the braking torque value are switched. , Through a filter.

According to the present invention, by applying an induction motor fed from an inverter for performing vector control as a reel driving electric motor, it is possible to operate the reel at high speed, high tension and high frequency. The rotation speed of the induction motor can be made high, and as a result, the output of the motor can be used more effectively, so that the motor part can be downsized.

[0009]

1 is a circuit configuration diagram of a reel drive motor controller according to an embodiment of the present invention, in which 1 is an induction motor and 2 is an output shaft of an induction motor 1. The speed reducer 3 is a reel connected to the output shaft of the speed reducer 2, 4 is a rotation detector connected to the other output shaft of the induction motor 1, and 5 is the winding diameter of the cable wound around the reel 3. A winding diameter detector for detecting the voltage, 6 is a voltage type PWM inverter for supplying desired electric power to the induction motor 1, and 7 is a PWM
A current detector 10 that detects a current flowing from the inverter 6 to the primary winding of the induction motor 1 is a control device that performs vector control of the induction motor 1 via the PWM inverter 6.

The controller 10 includes a speed controller 11 and
Torque limiter 12, current regulator 13, vector rotator 14, speed calculator 15, slip frequency calculator 16
, An integrator 17, a vector rotator 18, and a limit value calculator 19 are provided, and these control elements can be configured by a known technique.

Vector control by the current regulator 13, vector rotator 14, speed calculator 15, slip frequency calculator 16, integrator 17, and vector rotator 18 in the circuit configuration shown in FIG. 1 is performed by rotating the induction motor 1. Standing on the magnetic field,
When the primary current of the induction motor 1 is decomposed into a component parallel to the magnetic field and a component orthogonal thereto, the former is a quantity related only to magnetic flux generation (magnetizing current i _M ), and the latter is a quantity related only to torque generation (torque current i _T). ), These are DC amounts in the steady state, and therefore, like the control method of the DC motor, this is a control method that can independently control the magnetizing current component and the torque current component.

That is, when the cable is wound by the reel 3, the speed command value ω _R ^* is set to a value corresponding to the maximum allowable winding speed of the reel 3, and the speed command value ω _R ^* and the speed calculator 15 are set. The speed controller 11 is made to perform an adjustment calculation for making the deviation from the actual speed value ω _R obtained by the above-mentioned method zero, but when winding the cable normally, ω _R ^* > ω _R , and therefore, the speed controller 11 The adjustment calculation result which is the output is the maximum driving torque value (maximum torque current command value i _T ^* during driving)
The value corresponds to. Therefore, the torque limiter 12
Then, the output value of the speed adjuster 11 is limited by the drive torque limit value (drive torque value τ ₁₁ or τ ₁₂ described later) output by the limit calculator 19, and this drive torque limit value is a new torque current command value. It is input to the current regulator 13 as i _T ^* . As a result, the drive torque value output from the induction motor 1 becomes τ ₁₁ or τ _12, which will be described later.

At this time, when the winding diameter of the cable is less than a predetermined value A (specifically, about the intermediate value of the winding diameter), the winding diameter detector 5 for detecting this state and the limit value calculator 19 , The torque limiter 12 sets the drive torque value output from the induction motor 1 to τ _11, and when the cable winding diameter is A or more, the winding diameter detector 5 that detects this state and the limit value calculator 19 When the drive torque value output from the induction motor 1 by the torque limiter 12 is τ ₁₂ , the drive torque value τ ₁₁
And τ ₁₂ are related by τ ₁₁ <τ ₁₂ .

Here, the winding diameter detector 5 may be of any type as long as it can detect whether the winding diameter is less than A or more, and in the present invention, A is detected by a limit switch.

Next, when pulling out the cable from the reel 3, the speed command value ω _R ^* is set to almost “0”, and the speed command value ω _R ^* and the actual speed value ω obtained by the speed calculator 15 are set.
_The speed controller 11 is made to perform an adjustment operation for making the deviation from _R zero, but when the cable is normally pulled out, ω _R ^* > ω _R , and therefore the result of the adjustment operation, which is the output of the speed controller 11, is The value corresponds to the maximum braking torque value (maximum torque current command value i _T ^* during braking). Therefore, the torque limiter 12 limits the output value of the speed controller 11 by the braking torque limit value (braking torque value τ ₂₁ or τ ₂₂ described later) output from the limit calculator 19, and this braking torque limit value is The new torque current command value i _T ^* is input to the current controller 13. As a result, the braking torque value output from the induction motor 1 becomes τ ₂₁ or τ ₂₂ described later.

At this time, when the winding diameter of the cable is less than A, the braking torque output from the induction motor 1 by the winding diameter detector 5 for detecting this state, the limit value calculator 19 and the torque limiter 12. If the value is τ ₂₁ and the winding diameter of the cable is A or more, the winding diameter detector 5 for detecting this state,
Limit value calculator 19, when the induction motor 1 has a braking torque value to be output tau ₂₂ by the torque limiter 12, have a relationship of τ ₂₁ <τ ₂₂ between the braking torque value tau ₂₁ and tau ₂₂ I am making it.

In order to make the tensions applied to the cables almost equal during winding and pulling out as described above, a value corresponding to the mechanical efficiency of the speed reducer 2 is added to the drive torque of the induction motor 1. Similarly, it is necessary to subtract a value corresponding to the mechanical efficiency of the speed reducer 2 or the like from the braking torque of the induction motor 1. Therefore, the braking torque value τ ₂₁ becomes a value obtained by subtracting the value corresponding to the mechanical efficiency from the driving torque value τ ₁₁ , and similarly, the braking torque value τ ₂₂ is the driving torque value τ _{22.
It is} a value obtained by subtracting the value corresponding to the mechanical efficiency from ₁₂ .
Further, τ ₁₁ and τ ₁₂ are set as the driving torque values, and τ ₂₁ and τ ₂₂ are set as the braking torque values because the reel 3
This is because the value of the mechanical efficiency changes depending on the amount of the cable wound around the cable.For example, in the application where the cable is not loosened due to the movement of the movable part of the crane, the winding diameter of the cable is It is sufficient to have different values with A as the boundary.

Further, the winding operation and the drawing operation can be switched.
As described above, the speed command value ω_{R *}When you change
In addition, the speed actual value output by the speed calculator 15 is changed in accordance with this change.
Market value ω_RConfirm that the polarity of has changed and calculate the limit value
Drive torque limit value (τ₁₁Or τ₁₂)
And braking torque limit value (τ_{twenty one}Or τ_{twenty two}) And switch
You can do it. The value output by the limit value calculator 19
τ₁₁, Τ₁₂, Τ_{twenty one}, Τ _{twenty two}When changing the
In the arithmetic unit 19, the output is made through the first-order lag filter.
Is desirable.

In the above embodiment, the case where the winding diameter detector 5 switches the torque limit value by detecting only one predetermined winding diameter of the cable (for example, approximately the intermediate value of the winding diameter). However, the winding diameter of the cable should be detected at two or more locations.
The winding diameter of the cable may be detected stepwise, and the torque limit value may be switched stepwise each time.

As is apparent from the circuit configuration of FIG. 1, manual operation can be performed by manually setting the speed command value ω _R ^* while monitoring the state of the cable and the reel 3.

[0021]

According to the present invention, by applying an induction motor using a vector control inverter as a reel driving electric motor, the reel winding operation and the drawing operation can be improved, and the electric motor portion can be improved. Can be miniaturized. Further, in the conventional torque motor drive system, while the brushes are regularly replaced, the induction motor is not required and maintenance-free.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention.

[Explanation of symbols]

1 ... Induction motor, 2 ... Reducer, 3 ... Reel, 4 ... Speed detector, 5 ... Winding diameter detector, 6 ... PWM inverter, 7 ... Current detector, 10 ... Control device.

Claims (3)

[Claims] 1. A method of controlling a reel driving electric motor in which a reel for drawing and winding a cable is driven through a speed reducer by an induction motor fed from an inverter for vector control, wherein a winding diameter of the cable is It has a winding diameter detecting means for detecting and a limit value calculating means for switching the torque limit value based on the output signal of the winding diameter detecting means, and when winding the cable, the driving torque value is increased as the winding diameter increases. The braking torque value is gradually increased as the winding diameter is reduced when the cable is pulled out, and the braking torque value is a value obtained by subtracting a correction value based on mechanical efficiency from the driving torque value. A method for controlling a reel driving electric motor, comprising: 2. The reel driving electric motor control method according to claim 1, wherein when the cable is wound, the driving torque value output by the electric motor when the winding diameter of the cable is less than a predetermined value A. Is τ _11, and when the winding diameter of the cable is A or more, the drive torque value output by the electric motor is τ _12, and when the cable is pulled out, the winding diameter of the cable is When the braking torque value output by the electric motor is less than A, τ ₂₁ is set, and when the winding diameter of the cable is A or more when the winding diameter of the cable is A or more, the braking torque value output by the electric motor is τ _22. , Τ ₁₁ <τ ₁₂ between the driving torque values τ ₁₁ and τ _12, and τ ₂₁ <τ ₂₂ between the braking torque values τ ₂₁ and τ _22. A method for controlling a reel driving electric motor, comprising: 3. The reel driving electric motor control method according to claim 1, wherein the driving torque value or the braking torque value is changed, or the driving torque value and the braking torque value are switched by a filter. A method for controlling a reel driving electric motor, characterized in that