6. Control Functions and Parameter Settings
6-79
6-7-7 Load torque observer (IM)
The disturbance load applied on the motor is calculated and the torque command is compensated.
To increase the response toward disturbance, use the load torque observer.
By setting the speed regulator (ASR) to P and using the load torque observer, overshooting can be
suppressed.
Parameter
No.
Parameter
Function
B30-0
Load torque observer gain
Set the observer gain for the load torque observer.
To increase the responsiveness of the external disturbance
response characteristics, set a large gain.
Note that if the gain is set too high, the output torque could
hunt.
When set to zero, the load torque observer will not function.
B30-1
Model machine time
constant
Set the model machine time constant used by the load
torque observer.
6-7-8 Various low path filters (IM)
The time constants of the low path filters used for speed detection, speed commands or torque current
commands, etc., are set.
By adjusting these time constants, vibration caused by noise and overshooting can be suppressed.
Note that if an excessively high value is set, the control performance could drop.
Parameter
No.
Parameter
Function
B30-3
Speed setting LPF time
constant
Overshooting can be suppressed by setting this to the filter
time constant equivalent to the speed response.
B30-4
Speed detection LPF time
constant
The speed detection noise is cut.
B30-5
Speed detection LPF time
constant for ASR
Set the low path filter time constant used for the speed
detection value input into the speed regulator.
B30-6
Speed detection LPF time
constant for compensation
Set the low path filter time constant used for the speed
detection value for constant output range compensation or
iron loss compensation, etc.
B30-7
Torque current command
setting LPF time constant
Set the low path filter time constant used for the torque
current command.
