CSDP Plus Servo Drive User Manual

In tuning, the inertia ratio should be
considered first for the optimum
performance of the servo drive system.
The inertia ratio is the ratio of the inertia
of the load to the that of the motor’s
rotor. If the rotor’s inertia is 3 gf.cm.s 2
and the load’s inertia is 30 gf.cm.s 2 , the
inertia ratio is 10.
Inertia Ratio = Inertia of the Load/Inertia of the Motor’s Rotor
Please set inertia ratio at SEt-66. Setting range
is 0 to 600 (0.1 times) and the default value is 30.
The default value 30 indicates that the inertia ratio
is 3.
ATTENTION
Once the inertia ratio is set, the servo drive adjusts basic
gains according to the inertia ratio. Therefore, adjustment of
the inertia ratio should be done carefully.
Set the system bandwidth.
If auto tuning or user changes the inertia ratio
(SEt-66), it automatically set the system gain
(SEt-42) and the basic gain based on this value.
The servo drive uses position command of the controller device to
generate speed command, and the speed command generate torque
command and transmit them to the servo motor. Thus all of the basic
gains should be set properly in case of using position control mode.
Even if the gains related to position control are appropriate, the best
tuning cannot be carried out if the gains related to torque or speed are
not properly set.
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