Mitsubishi Electric FR-A700 Series, Technical Manual

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286
PARAMETER
2.9.3 Gain adjustment [Pr. 818 to 821, 830, 831, 880]
(A700)
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
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.
(1) Block diagram of easy gain tuning function
A700
[ Pr. ] Name Initial Value Setting Range Description
818
Easy gain tuning response level
setting
2 1 to 15
Set the response level.
1: Slow response to 15: Fast response
819 Easy gain tuning selection 0
0 Without easy gain tuning
1
With load inertia ratio estimation, with gain
calculation
(valid only during vector control)
2
Load inertia ratio manual input [ Pr. 880 ], with gain
calculation
820
Speed control P gain 1
60% 0 to 1000%
Set the proportional gain for speed control.
(Increasing the value improves trackability in
response to a speed command change and reduces
speed variation with disturbance.)
821
Speed control integral time 1
0.333s 0 to 20s
Set the integral time during speed control. (Decrease
the value to shorten the time taken for returning to
the original speed if speed variation with disturbance
occurs.)
830
Speed control P gain 2
9999
0 to 1000%
Second function of [ Pr. 820 ] (valid when RT signal is
ON)
9999 No function
831 Speed control integral time 2 9999
0 to 20s
Second function of [
Pr. 821
] (valid when RT signal is
ON)
9999
No function
880
Load inertia ratio
7 times 0 to 200 times
Set the load inertia ratio to the motor.
<Vector control>
Automatic setting
Speed control/position loop gain
Model speed control gain
[
Pr. 820, 821, 828, 422 ]
Command
+ +
- -
ON when [ Pr. 819 = 1, 2]
Gain table
Load inertia ratio
[
Pr. 880 ]
Response level
setting [
Pr. 818 ]
ON when
[ Pr. 819 = 1]
Current
control
Load inertia
ratio estimation
section
Speed/position feedback
Actual motor speed
Motor
Detector
Encoder
Load
inertia
moment
Torque command