YASKAWA A1000 Technical Manual page 189

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 of the torque reference value that
builds the torque producing current reference.
Adjustment
Although this parameter rarely needs to be adjusted, changing the torque compensation gain in small steps of 0.05 may
help 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: 1. Refrain from adjusting torque compensation in Open Loop Vector Control, as it can have a negative effect on torque accuracy.
2. Refrain from adjusting this parameter in OLV/PM. Too high a value can cause overcompensation, resulting in motor oscillation.

C4-02: Torque Compensation Primary Delay Time
Sets the delay time used for applying torque compensation.
No.
C4-02
Adjustment
Although C4-02 rarely needs to be changed, adjustments may help in the following situations:
• If the motor vibrates, increase C4-02.
• If the motor responds too slowly to changes in the load, decrease C4-02.

C4-03: Torque Compensation at Forward Start (OLV)
Sets the amount of torque at start in the forward direction in order 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 run command. Setting of 0.0% disables this feature.
No.
C4-03

C4-04: Torque Compensation at Reverse Start (OLV)
Sets the amount of torque reference at start in the reverse direction in order to improve motor performance during start
with heavy load. Compensation is applied using the Torque Compensation Time set in parameter C4-05. Enable this
function if the load pulls the motor in the forward direction when starting with a Reverse run command. Setting 0.0%
disables this feature.
No.
C4-04

C4-05: Torque Compensation Time Constant (OLV)
This parameter is the time constant for applying the torque compensation at start that is set to C4-03 and C4-04.
No.
C4-05

C4-06: Torque Compensation Primary Delay Time 2 (OLV)
This time constant is used during Speed Search or during regenerative operation. Adjust the value if an overvoltage fault
occurs with sudden changes in the load or at the end of acceleration with high inertia load.
No.
C4-06
Note: If C4-06 is set to a relatively large value, be sure to also increase the setting in n2-03 (AFR Time Constant 2) proportionally.
YASKAWA ELECTRIC SIEP C710616 27G YASKAWA AC Drive A1000 Technical Manual
Parameter Name
Torque Compensation Primary Delay Time
Parameter Name
Torque Compensation at Forward Start
Parameter Name
Torque Compensation at Reverse Start
Parameter Name
Torque Compensation Time Constant
Parameter Name
Torque Compensation Primary Delay Time 2
5.3 C: Tuning
Setting Range Default
0 to 60000 ms Determined by A1-02
Setting Range Default
0.0 to 200.0%
Setting Range Default
-200.0 to 0.0%
Setting Range Default
0 to 200 ms
Setting Range Default
0 to 10000 ms 150 ms
0.0%
0.0%
5
10 ms
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