Toshiba VF-AS1 instruction manual Precautions on automatic torque boost mode or vector control

E6581301

8)Performing speed control/torque control with high accuracy using the motor speed sensor

Setting for V/f control mode selection ￿￿=￿ (PG feedback vector control)

The torque produced by the motor is controlled by means of specified torque command signals. The rotational speed of the motor depends on the relation between the load torque and the torque produced by the motor.

A PG feedback device (optional) is needed. In addition, a motor with a speed sensor (encoder) should be used. Set ￿￿ to ￿ (PG feedback vector control) to perform speed/torque control with high accuracy.

"Motor constant must be set.

The motor constant can be set in any of the following two ways:

1) Automatic setting

Enter the following information that is indicated on the motor nameplate, and then execute the auto-tuning 1 command (Set ￿￿￿￿ to ￿, and then reset ￿￿￿￿ to ￿.).

<Information indicated on motor nameplate>

￿￿(Base frequency), ￿￿￿ (Base frequency voltage), ￿￿￿￿ (Motor rated capacity), ￿￿￿￿ (Motor rated current), ￿￿￿￿(Motor rated rotational speed)

￿Refer to 6.22 selection 2.

2)Manual setting

Set each motor constant manually.

￿Refer to 6.22 selection 3.

9)Precautions on automatic torque boost mode or vector control

1) When operating a motor in automatic torque boost mode or vector control mode (￿￿￿= ￿, ￿, ￿, ￿ or ￿), enter	5
each motor constant indicated on the nameplate (￿￿ (base frequency), ￿￿￿ (base-frequency voltage), ￿￿￿￿

(rated capacity of motor), ￿￿￿￿ (rated current of motor) and ￿￿￿￿ (rated number of revolutions of motor) ), read the precautions on auto-tuning 1 on section 6.22 (1), and then set ￿￿￿￿ to ￿ (auto-tuning). If the cable length is in excess of 30m, be sure to perform the auto-tuning (￿￿￿￿=￿) mentioned above, even when using a standard motor recommended by Toshiba.

2)The sensorless vector control exerts its characteristics effectively in frequency areas below the base frequency (￿￿). The same characteristics will not be obtained in areas above the base frequency.

3)When setting ￿￿ to ￿ or ￿, use the inverter along with a general-purpose motor with an equal or one notch lower rating.

4)Use a motor that has 2 to 16P.

5)Always operate the motor in single operation (one inverter to one motor). (Except for; ￿￿=￿) Sensorless vector control cannot be used when one inverter is operated with more than one motor.

6)The torque produced by the motor decreases more or less around the rated frequency because of a voltage drop cause motor-generated torque in the vicinity of rated frequency to be somewhat lower.

7)Connecting a reactor or surge voltage suppression filter between the inverter and the motor may reduce motor-generated torque. Setting auto-tuning 1 may also cause a trip (￿￿￿, ￿￿￿￿~￿)rendering sensorless vector control unusable. In the event of a trip, perform auto-tuning with the inverter connected directly to the motor, or enter the motor constant calculated from the motor test results.

8)Connect speed sensor for vector control with sensor to the motor. Connecting via gear, etc. causes motor's oscillating or inverter's trip by lack of rigidity.

9)If running under not connect the motor, please set to ￿￿=￿ temporarily. There is a possibility not to operate normally when running at setting Pt=2,3,4,7,8 under not connect the motor.

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