Toshiba VF-AS1 8) Performing speed control/torque control with high accuracy using the motor speed sensor, 9) Precautions on automatic torque boost mode or vector control

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

RVRV

The torque produced by the motor is controlled by means of specified torq ue command signals. The rotational

speed of the motor depends on the relation between the load torque and the t orque produced by the motor.

A PG feedback device (optional) is needed. In addition, a motor with a speed sensor (encoder) should be used.

Set RV to  (PG feedback vector control) to perform speed/torque control with hi gh accuracy.

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 namepla te, and then execute the auto-tuning 1

command (Set H to , and then reset H to .).

XN (Base frequency), XNX (Base frequency voltage), H (Motor rated capacity), H (Motor rated

current), H(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 (RV = , , ,  or ), enter

each motor constant indicated on the nameplate (XN (base frequency), XNX (base -frequency voltage), H

(rated capacity of motor), H (rated current of motor) and H (rated numb er of revolutions of motor) ),

read the precautions on auto-tuning 1 on section 6.22 (1), and then set H to  (auto-tuning). If the cable

length is in excess of 30m, be sure to perform the auto-tuning (H=) mentioned above, even when using a

standard motor recommended by Toshiba.

2) The sensorless vector control exerts its characteristics effectively in frequency area s below the base frequency

(XN). The same characteristics will not be obtained in areas above the base freque ncy.

3) When setting RV 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). (Excep t for; RV=) 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 freque ncy because of a voltage drop

cause motor-generated torque in the vicinity of rated frequency to be some what lower.

7) Connecting a reactor or surge voltage suppression filter between the inverter a nd the motor may reduce

motor-generated torque. Setting auto-tuning 1 may also cause a trip (GVP , GVP~)rendering sensorless

vector control unusable. In the event of a trip, perform auto-tuni ng with the inverter connected directly to th e 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. cause s motor's

oscillating or inverter's trip by lack of rigidity.

9) If running under not connect the motor, please set to RV= temporarily. There is a possibi lity not to operate

normally when running at setting Pt=2,3,4,7,8 under not connect the motor.