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The transition time between accelerating and decelerating ramps is expressed by discrete numbers in
SBT-L450U. Eight S-curve settings are available, and are expressed as below:
0: No S Curve
1: Very low
2: Low
3: Intermediate 1
4: Intermediate 2
5: Intermediate 3
6: High
7: Very high
Adjusting low numbers leads to shock while high numbers slow the operation. The optimum
operation can be obtained by setting these parameters to 3 or 4.
C4: Torque Compensation
The torque compensation function compensates for insufficient torque production at start-up or when
a load is applied.
Note:
Set the motor parameters (E2-
**
) and V/f pattern properly before setting torque compensation
parameters.
C4-01: Torque Compensation Gain
Sets the gain for the torque compensation function.
No.
Parameter Name
Setting Range
Default
C4-01
Torque Compensation Gain
0.00 to 5.00
1.5
Adjustment
Although this parameter rarely needs to be changed, it may be necessary to adjust the torque
compensation gain in small steps of 0.05 in the following situations:
• Increase this setting when using a long motor cable, or when the starting torque is not high enough
to accelerate the motor.
• Decrease this setting when motor oscillation occurs.
Adjust C4-01 so that the output current does not exceed the drive rated current.
■
C4-02: Torque Compensation Primary Delay Time
It Sets the delay time used for applying torque compensation.
No.
Parameter Name
Setting Range
Default
C4-02
Torque Compensation Primary Delay Time
0.0 to 2000.0 ms
600.0 ms
Adjustment
Although C4-02 rarely needs to be changed, adjustments may be necessary in the following situations:
• Increase this setting if the motor vibrates.
• Decrease this setting if the motor responds too slowly to changes in the load.
C5: Speed Control Loop
These parameters are accessible only in the closed-loop control mode (A1-02=3).
The Speed control Loop Controls the motor speed in CLV and CLV/PM control modes. It adjusts
torque reference in order to minimize the difference between speed reference and actual motor speed.
The speed control block diagram has been shown in fig2.2.
