Mitsubishi Electric FR-A820-00046 (0.4K), Instruction Manual

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FR-A800 5 - 737
Parameters (G) Control parameters
5.16.16 Speed smoothing control
There are times where the vibration due to mechanical resonance affect the inverter, making the out-
put current (torque) unstable. In such case, vibration can be decreased by reducing the deviation in
the output current (torque) by changing the output frequency.
Control block diagram
Setting method
●
When vibration caused by mechanical resonance occurs, set Pr. 653 "Speed smoothing control"
to 100%, and operate at the operation frequency with largest vibration, and confirm if the
vibration is suppressed after few seconds.
●
If there is no effect, gradually raise the setting value of Pr. 653, perform the operation and
confirmation of the effect repeatedly, and use the value (Pr. 653) with most effect as the final
setting value.
●
If the vibration gets larger by raising Pr. 653, lower the value of Pr. 653 under 100%, and perform
the confirmation of result in a same manner.
●
When the vibration frequency (frequency of torque deviation, speed deviation, or converter
output voltage deviation) by the mechanical resonance with a measurement device, etc., set the
frequency of 1/2 to 1 times the vibration frequency in Pr. 654 "Speed smoothing cutoff frequency".
(Setting vibrational frequency range can suppress the vibration better.)
Pr. Name
Initial
value
Setting
range
Description
653
G410
Speed smoothing control 0% 0 to 200%
Confirm the effect by raising and lowering the value
with 100% as a reference.
654
G411
Speed smoothing cutoff
frequency
20 Hz 0 to 120 Hz
Set the lower limit of the torque deviation cycle
(frequency).
I002760E
Fig. 5-367: Control block diagram
Fig. 5-368:
Setting method
I002761E
NOTE Depending on the equipment, the vibration may not be suppressed sufficiently or the effect is not
obtained.
V/F V/F V/F Magnetic flux Magnetic flux Magnetic flux
+
-
Acceleration/deceleration
processing
Output frequency
V/F control
Speed smoothing control
Cutoff frequency
Pr. 654
Proportional gain
Pr. 653
Current for torque
Speed
command
Frequency output
Voltage output
0
Current for
torque
Torque fluctuation
detection range
Cutoff frequency
Pr. 654 159 Hz (fixed)
Vibrational
frequency