Mitsubishi Electric FR-A800 Series Instruction Manual page 258

 Adjusting the speed control gain manually (Pr.819 = "0" No easy gain
tuning)
• 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.
Proportional gain
*1
200 rad/s
*1
120 rad/s
*1 The following shows the response level to the proportional gain.
60
100
*2 Performing PM parameter initialization changes the settings. (Refer to
• Actual speed gain is calculated as follows when load inertia is applied.
Load
fluctuation
Speed
Actual speed gain = Speed gain of a single motor
 Adjustment procedure
1.
Change the Pr.820 setting while checking the conditions.
2.
If it cannot be adjusted well, change Pr.821 setting, and perform step
Downloaded from ManualsNet.com
Pr.820
Setting
100%
60%
*2
(initial value )
FR-A820-03160(55K) or lower
Pr.820
FR-A840-01800(55K) or lower
setting
Vector control
120
200
Since increasing the proportional gain enhances the
response level and decreases the speed fluctuation.
Decreasing the integral time shortens the return time taken.
5.3 Speed control under Real sensorless vector control, vector control, PM sensorless vector control
search engine
Response level (rad/s)
FR-A820-03800(75K) or higher
FR-A840-02160(75K) or higher
Real sensorless
Vector control
vector control
60 60
100 100
page
JM JM: Motor inertia
JM+JL JL: Load inertia converted as the motor axis inertia
Real sensorless
vector control
30
50
231.)
1
again.
1
2
3
4
5
6
7
8
9
10
257
5. PARAMETERS