Mitsubishi Electric FR-A700 Technical Manual page 252

2.9.3 Gain adjustment [Pr. 818 to 821, 830, 831, 880]
The ratio of the load inertia to the motor inertia (load inertia
moment) is estimated in real time from the torque
command and speed during motor operation by vector
control. As optimum gain of speed control and position
control are automatically set from the load inertia ratio and
response level, time and effort of making gain adjustment
are reduced. (Easy gain tuning)
When the load inertia ratio can not be estimated due to
load fluctuation or Real sensorless vector control is
[Pr. ]
Easy gain tuning response level
818
setting
819 Easy gain tuning selection
820
Speed control P gain 1
821
Speed control integral time 1
830 Speed control P gain 2
831
Speed control integral time 2
880
Load inertia ratio
(1) Block diagram of easy gain tuning function
<Vector control>
Command
Name Initial Value
60%
0.333s
9999
9999
7 times
Automatic setting
Speed control/position loop gain
+
Model speed control gain
-
[Pr. 820, 821, 828, 422]
ON when [Pr. 819 = 1, 2]
Load inertia ratio
Gain table
[Pr. 880]
Response level
setting [Pr. 818]
(A700)
performed, control gain is automatically set by manually
inputting the load inertia ratio.
Make a manual input adjustment when vibration, noise or
any other unfavorable condition occurs due to large load
inertia or gear backlash, for example, or when you want to
have the best performance that matches the machine.
Setting Range
Set the response level.
2 1 to 15
1: Slow response to 15: Fast response
0
Without easy gain tuning
With load inertia ratio estimation, with gain
1
calculation
0
(valid only during vector control)
Load inertia ratio manual input [Pr. 880], with gain
2
calculation
Set the proportional gain for speed control.
(Increasing the value improves trackability in
0 to 1000%
response to a speed command change and reduces
speed variation with disturbance.)
Set the integral time during speed control. (Decrease
the value to shorten the time taken for returning to
0 to 20s
the original speed if speed variation with disturbance
occurs.)
Second function of [Pr. 820] (valid when RT signal is
0 to 1000%
ON)
9999
No function
Second function of [Pr. 821] (valid when RT signal is
0 to 20s
ON)
9999 No function
0 to 200 times
Set the load inertia ratio to the motor.
+
-
ON when
[Pr. 819 = 1]
Load inertia
ratio estimation
section
286
A700
Description
Load
inertia
moment
Current
Motor
control
Torque command
Actual motor speed
Speed/position feedback
PARAMETER
Detector
Encoder