To Perform High Accuracy / Fast Response Operation (Gain Adjustment Of Real Sensorless Vector Control) (Pr. 818 To Pr. 821, Pr. 880) - Mitsubishi Electric FR-A700 Series Instruction Manual

Before operation
3.3.12 To perform high accuracy / fast response operation (gain adjustment of real
sensorless vector control) (Pr. 818 to Pr. 821, Pr. 880)
Sensorless Sensorless Sensorless Vector Vector Vector
The ratio of the load inertia to the motor inertia (load inertia moment ratio) 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
exercised, control gain is automatically set by manually inputting the load inertia ratio.
Make a manual input adjustment when vibration, noise or any other unfavorable phenomenon occurs due to
large load inertia or gear backlash, for example, or when you want to exhibit the best performance that matches
the machine.
Parameter
Name
Number
Easy gain tuning
818
response level setting
Easy gain tuning
819
selection
820 Speed control P gain 1
Speed control integral
821
time 1
880 Load inertia ratio
(1) Easy gain tuning execution procedure (Pr.819 = "1" load inertia ratio automatic estimation)
Easy gain tuning (load inertia ratio automatic
estimation) is valid only in the speed control or
position control mode under vector control.
It is invalid under torque control, V/F control,
advanced magnetic flux vector control and real
sensorless vector control.
1) Set the response level using Pr.818 Easy gain
tuning response level setting.
Refer to the diagram on the right and set the
response level.
Increasing the value will improve trackability
to the command, but too high value will
generate vibration.
The relationship between the setting and
response level are shown on the right.
68
Initial Value Setting Range
2 1 to 15
0
0 1
2
60% 0 to 1000%
0.333s 0 to 20s
7 times 0 to 200 times
Pr.818 setting
Response level
Guideline of
machine resonance
frequency (Hz)
Description
Set the response level.
1: Slow response to 15: Fast response
Without easy gain tuning
With load estimation, with gain calculation
(only under vector control)
With load (Pr. 880) manual input, gain calculation
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.)
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.)
Set the load intertia ratio to the motor.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Slow Middle
response response
8 10 12 15 18 22 28 34 42 52 64 79 98 122 150
Large conveyor
General machine tool,
Arm robot
Fast
response
conveyor
Precision
machine tool