YASKAWA SGDV series User Manual page 326

Problem Probable Cause
Unbalanced servo gains
Speed loop gain value (Pn100) too
high.
Servomotor
Vibrates at
Position loop gain value (Pn102)
Frequency of too high.
Approx. 200 to
400 Hz.
Incorrect speed loop integral time
constant (Pn101)
Incorrect moment of inertia ratio
(Pn103)
Unbalanced servo gains
Speed loop gain value (Pn100) too
high
Position loop gain value (Pn102)
High Motor Speed
too high
Overshoot on
Starting and
Incorrect speed loop integral time
Stopping
constant (Pn101)
Incorrect moment of inertia ratio
data (Pn103)
The torque reference is saturated.
9.3 Troubleshooting Malfunction Based on Operation and Conditions of the Servomotor
Investigative Actions
Check to see if the servo gains have
been correctly adjusted.
Check the speed loop gain (Pn100).
Factory setting: Kv = 40.0 Hz
Check the position loop gain
(Pn102).
Factory setting: Kp = 40.0/s
Check the speed loop integral time
constant (Pn101).
Factory setting: Ti = 20.0 ms
Check the moment of inertia ratio
(Pn103).
Check to see if the servo gains have
been correctly adjusted.
Check the speed loop gain (Pn100).
Factory setting: Kv = 40.0 Hz
Check the position loop gain
(Pn102).
Factory setting: Kp = 40.0/s
Check the speed loop integral time
constant (Pn101).
Factory setting: Ti = 20.0 ms
Check the moment of inertia ratio
(Pn103).
Check the torque reference wave-
form.
(cont'd)
Corrective Actions
Execute the advanced autotuning.
Reduce the speed loop gain
(Pn100).
Reduce the position loop gain
(Pn102).
Correct the speed loop integral time
constant (Pn101).
Correct the moment of inertia ratio
(Pn103).
Execute the advanced autotuning.
Reduce the speed loop gain
(Pn100).
Reduce the position loop gain
(Pn102).
Correct the speed loop integral time
constant (Pn101).
Correct the moment of inertia ratio
(Pn103).
Use a mode switch.
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