Adjusting the speed control gain manually (Pr.819 = "0" No easy gain
• The speed control gain can be adjusted for the conditions such as abnormal machine vibration, acoustic noise, slow
response, and overshoot.
• Setting 60% (initial value) in Pr.820 Speed control P gain 1 is equivalent to 120 rad/s (speed response of a single motor).
(Equivalent to the half the rad/s value during Real sensorless vector control or with the FR-A820-03800(75K) or higher and
the FR-A840-02160(75K) or higher during Vector control.) Setting this parameter higher speeds up the response, but
setting this too high causes vibration and acoustic noise.
• Setting Pr.821 Speed control integral time 1 lower shortens the return time to the original speed during speed fluctuation,
but setting it too low causes overshoot.
(initial value )
The value in parentheses is applicable during Real sensorless vector control or with the FR-A820-03800(75K) or higher and FR-A840-02160(75K)
or higher during Vector control.
Performing PM parameter initialization changes the settings. (Refer to
• Actual speed gain is calculated as follows when load inertia is applied.
Decreasing the integral time shortens the return time taken.
Actual speed gain = Speed gain of a single motor
• Adjustment procedure
Change the Pr.820 setting while checking the conditions.
If it cannot be adjusted well, change Pr.821 setting, and perform step
Since increasing the proportional gain enhances the
response level and decreases the speed fluctuation.
JM: Motor inertia
JL: Load inertia converted as the motor axis inertia
5.3 Speed control under Real sensorless vector control, vector control, PM sensorless vector control