5.3 C: Tuning
♦ C4: Torque Compensation
The torque compensation function compensates for insufficient torque production at start-up or when a load is applied.
Note: Set the m otor parameters and V /f pattern properly before setting torque com pensation 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 2.50
1.00
Torque Compensation in V/f:
The drive calculates the motor primary voltage loss using the output current and the line to line resistance (E2-05) and
then adjusts the output voltage to compensate insufficient torque at start or when load is applied. The effects of this
voltage compensation can be increased or decreased using parameter C4-01.
Torque Compensation in OLV:
The drive controls the motor excitation current (d-Axis current) and torque producing current (q-Axis current) separately.
Torque compensation affects the torque producing current only. C4-01 works as a factor o f the torque reference value that
builds the torque producing current reference.
Adjustm ent
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.
• Decrease this setting when motor oscillation occurs.
Adjust C4-01 so that the output current does not exceed the drive rated current.
Note: Refrain from adjusting torque com pensation in Open Loop Vector Control, as it can have a negative effect on torque accuracy.
■ C4-02: Torque Compensation Primary Delay Time
Sets the delay time used for applying torque compensation.
No.
Parameter Name
Setting Range
Default
C4-02
Torque Compensation Primary D elay Time
0 to 60000 ms
Determined by A 1-02
Adjustm ent
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.
■ C4-03: Torque Compensation at Forward Start
Sets the amount o f torque at start in the forward direction to improve motor performance during start with a heavy load.
Compensation is applied using the time constant set in parameter C4-05. Enable this function when the load pulls the
motor in reverse when starting with a Forward Up/Down command. Setting of 0.0% disables this feature.
No.
Parameter Name
Setting Range
Default
C4-03
Torque Compensation at Forward Start
0.0 to 200.0%
0.0%
■ C4-04: Torque Compensation at Reverse Start
Sets the amount of torque reference at start in the reverse direction to improve motor performance during start with heavy
load. Compensation is applied using the time constant set in parameter C4-05. Enable this function if the load pulls the
motor in the forward direction when starting with a Reverse Up/Down command. Setting 0.0% disables this feature.
No.
Parameter Name
Setting Range
Default
C4-04
Torque Compensation at Reverse Start
-200.0 to 0.0%
0.0%
■ C4-05: Torque Compensation Time Constant
Sets the time constant for applying the torque compensation at start that is set to C4-03 and C4-04.
No.
Parameter Name
Setting Range
Default
C4-05
Torque Compensation Time Constant
0 to 200 ms
10 ms
YASKAWA ELECTRIC SIEP C710616 33D YASKAWA AC Drive L1000A Technical Manual
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