Mitsubishi Electric FR-A700 Technical Manual page 254

(4) Manual input
adjustment [Pr. 819 = 0, Pr. 820, 821]
Make adjustment when case like unusual machine
vibration/noise, low response level and overshoot
has occurred.
When making manual input gain adjustment, set [Pr.
819 Easy gain tuning selection = 0] (without easy gain
tuning) (initial value).
[Pr. 830 Speed control P gain 2] and [Pr. 831 Speed
control integral time 2] are valid when the RT terminal
is switched ON.
No. Case/Condition
1 Load inertia is large
Vibration/noise generated
2
from mechanical system
3 Slow response
Long return time
4
(response time)
Overshoot or unstable
5
phenomenon occurs.
(5) Switching of P/PI control (X44 signal)
By turning the P/PI control switching signal (X44) ON/
OFF during speed control operation under Real
sensorless vector control and vector control, you can
select whether to add the integral time (I) or not when
performing gain adjustment with P gain and integral
time.
When the X44 signal is OFF.......PI control
When the X44 signal is ON .......P control
For the terminal used for X44 signal input, set 44 in
any of [Pr. 178 to Pr. 189
selection] to assign the function.
Speed
command
Speed
command
speed control gain
Set the [Pr. 820, Pr. 821] value a little higher.
When a speed rise is slow, increase the value by 10% until just before vibration/noise is
[Pr. 802]
produced, and set about 0.8 to 0.9 of that value.
If an overshoot occurs, double the value until an overshoot does not occur, and set about
[Pr. 821]
0.8 to 0.9 of that value.
Set the [Pr. 820] value a little lower and the [Pr. 821] value a little higher.
Decrease the value by 10% until just before vibration/noise is not produced, and set about
[Pr. 820]
0.8 to 0.9 of that value.
If an overshoot occurs, double the value until an overshoot does not occur, and set about
[Pr. 821]
0.8 to 0.9 of that value.
Set the [Pr. 820] value a little higher.
When a speed rise is slow, increase the value by 5% until just before vibration/noise is
[Pr. 820]
produced, and set about 0.8 to 0.9 of that value.
Set the [Pr. 821] value a little lower.
Decrease the [Pr. 821] value by half until just before an overshoot or the unstable behavior does not
occur, and set about 0.8 to 0.9 of that value.
Set the [Pr. 821] value a little higher.
Double the [Pr. 821] value until just before an overshoot or the unstable behavior does not occur, and set
about 0.8 to 0.9 of that value.
Input terminal function
Speed
+
proportional
operation
-
0
Check the conditions referring to the table below and
make adjustment.
1) Adjust speed control P (proportional) gain.
2) Check that no unusual vibration nor noises are
generated, response is enough, the current value
is correct, etc.
3) If you can not make proper adjustment, slightly
change the speed control integral time and repeat
from 1) again.
Adjustment Method
+
+
X44
Speed
integral
operation
Integration
cleared to 0
X44
288
PARAMETER
Torque
Motor
control
Speed estimator