Gain Adjustment Of Position Control (Pr. 422, Pr. 423, Pr. 425) - Mitsubishi Electric FR-A700 Instruction Manual

Parameter
6.5.6

Gain adjustment of position control (Pr. 422, Pr. 423, Pr. 425)

Pr.
Name
No.
422
Position loop gain
Position feed forward
423
gain
Position feed forward
425
command filter
The above parameters can be set when the FR-A7AP (option) is mounted.
Position loop gain (Pr. 422)
● Make adjustment when any of such phenomena as unusual vibration, noise and overcurrent
of the motor/machine occurs.
● Increasing the setting improves trackability for the position command and also improves
servo rigidity at a stop, but oppositely makes an overshoot and vibration more liable to occur.
● Normally set this parameter within the range about 5 to 50.
Phenomenon/Condition
Slow response
Overshoot, stop-time vibration or
other instable phenomenon occurs.
Tab. 6-26: Setting of parameter 422
Position feed forward gain (Pr. 423)
● This function is designed to cancel a delay caused by the droop pulses of the deviation
counter.
● When a tracking delay for command pulses poses a problem, increase the setting gradually
and use this parameter within the range where an overshoot or vibration will not occur.
● This function has no effects on servo rigidity at a stop.
● Normally set this parameter to 0.
FR-A700 EC
Initial
Setting Range Description
Value
−1 −1
Set the gain of the position loop.
25s 0–150s
Function to cancel a delay caused
0% 0–100% by the droop pulses of the deviation
counter.
Enters the primary delay filter in
0s 0–5s response to the feed forward com-
mand.
Adjustment Method
Increase the Pr. 422 value.
Pr. 422
Decrease the Pr. 422 value.
Pr. 422
Position control by vector control
Parameters referred to
−1
Increase the value 3s by 3s
stop-time vibration or other instable phenomenon occurs, and set
about 0.8 to 0.9 of that value.
−1
Decrease the value 3s by 3s
stop-time vibration or other instable phenomenon does not occur,
and set about 0.8 to 0.9 of that value.
Vector Vector Vector
Refer to
Section
7 Acceleration time 6.11.1
8 Deceleration time 6.11.1
72 PWM frequency 6.19.1
selection
800 Control method 6.2.2
selection
802 Pre-excitation 6.13.1
selection
819 Easy gain tuning 6.3.3
selection
820 Speed control P 6.3.3
gain 1
821 Speed control inte- 6.3.3
gral time 1
−1
until just before an overshoot,
−1
until just before an overshoot,
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