5.9 n: Special Adjustments
YASKAWA ELECTRIC
SIEP C710616 30B YASKAWA AC Drive T1000A Technical Manual
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n8-49: d-Axis Current for High Efficiency Control
Sets the d-axis current reference when running with high load at constant speed. When using an IPM motor, setting this
parameter will increase the efficiency by using the motors reluctance torque and thereby reduce the energy consumption.
This parameter should be set to 0 when using an SPM motor.
Although this setting seldom needs to be changed, please note the following:
• If motor operation is unstable when driving heavy loads, try lowering this setting.
• If motor parameters (E5-
) have been changed, this value will be reset to 0 and will need to be readjusted.
Note:
This parameter is available only when using OLV/PM control mode.
n
n8-51: Acceleration/Deceleration Pull-In Current
Sets the pull-in current during acceleration and deceleration as a percentage of the motor rated current (E5-03).
Adjustments to this setting may help in the following situations:
• Increase this setting when a large amount of starting torque is required.
• Lower this setting if there is excessive current during acceleration.
Note:
This parameter is available only when using OLV/PM control mode.
n
n8-54: Voltage Error Compensation Time Constant
Sets the time constant for voltage error compensation. Make changes to this parameter under the following conditions:
• Adjust the value when hunting occurs at low speed.
• Increase the value in steps of 0.1 when hunting occurs with sudden load changes. Try to disable the compensation by
setting n8-51 = 0 if increasing n8-54 does not help.
• Increase the value when oscillations occur at start.
Note:
This parameter is available only when using OLV/PM control mode.
n
n8-55: Load Inertia
Sets the ratio between motor inertia and the inertia of the connected machinery. If this value is set too low, the motor may
not start very smoothly, and the STo fault (Motor Step-Out) may occur.
For large inertia loads or to improve speed control response, increase this setting from 0. Oscillations may occur if this
value is set too high with low inertia load.
Note:
This parameter is available only when using OLV/PM control mode.
Setting 0: Below 1:10
The inertia ratio between the motor and the load is just less than 1:10.
Setting 1: Between 1:10 and 1:30
The inertia ratio between the motor and the load is between 1:10 and 1:30. Set n8-55 to 1 if an STo fault occurs as a result
of impact load or sudden acceleration/deceleration when n8-55 = 0.
Setting 2: Between 1:30 and 1:50
The inertia ratio between the motor and the load is between 1:30 and 1:50. Set n8-55 to 2 if an STo fault occurs as a result
of impact load or sudden acceleration/deceleration when n8-55 = 1.
No.
Name
Setting Range
Default
n8-49
d Axis Current for High Efficiency Control
-200.0 to 0.0%
Determined by E5-01
No.
Name
Setting Range
Default
n8-51
Acceleration/Deceleration Pull-In Current
0 to 200%
50%
No.
Name
Setting Range
Default
n8-54
Voltage Error Compensation Time Constant
0.00 to 10.00
1.00
No.
Name
Setting Range
Default
n8-55
Load Inertia
0 to 3
0
