Mitsubishi Electric FR-E800 Series Instruction Manual page 124

• Adjustment method:
No. Movement / condition
Motor rotation speed in the low-
1
speed range is unstable.
2 Rotation speed trackability is poor. Set Pr.820 Speed control P gain 1 higher. Raise the setting by 10%s and set a
Large fluctuation of the rotation
3
speed relative to load fluctuation.
Torque shortage or motor
backlash occurs when starting or
4
passing a low-speed range under
Real sensorless vector control.
Unusual vibration, noise and
5 overcurrent of the motor or
machine occurs.
Overcurrent or overspeed (E.OS)
6 occurs when starting under Real
sensorless vector control.
5.5 Performing high-accuracy, fast-response control (gain adjustment for Real sensorless vector control, Vector control, and PM sensorless
Adjustment method
Pr.820 Speed control P gain 1 must be set higher according to the motor inertia.
For multi-pole motors, because the inertia of the motor itself tends to be large, first
perform broad adjustment to improve the unstable movements, and then perform
fine adjustment by referring to the response level based on this setting.
value that approximately 80% to 90% of the setting right before vibration/noise
starts occurring. If it cannot be adjusted well, double Pr.821 Speed control integral
time 1 and perform the adjustment of Pr.820 again.
Set the speed control gain higher. (The same as No.1.) If this cannot be prevented
through gain adjustment, raise Pr.13 Starting frequency for a fault that occurs
when starting, or shorten the acceleration time and avoid continuous operation in a
low-speed range.
Set Pr.824 Torque control P gain 1 (current loop proportional gain) lower.
Lower the setting by 10% and set a value that is approximately 80% to 90% of the
setting immediately before the condition improves.
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5. Speed Control
vector control)