Speed Smoothing Control - Mitsubishi Electric FR-F800 Instruction Manual

5.13.14

Speed smoothing control

There are times where the vibration due to mechanical resonance affect the inverter, making the output current
(torque) unstable. In such case, vibration can be decreased by reducing the deviation in the output current (torque) by
changing the output frequency.
Pr. Name
653
Speed smoothing control
G410
654 Speed smoothing cutoff
G411 frequency
Control block diagram
Acceleration/deceleration
processing
Speed
command
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.)
Cutoff frequency
Current for
torque
Torque fluctuation
detection range
0
Pr.654
NOTE
• Depending on the equipment, the vibration may not be suppressed sufficiently or the effect is not obtained.
Initial Setting
value
0% 0 to 200%
20 Hz 0 to 120 Hz
Output frequency
+
V/F control
-
Speed smoothing control
Cutoff frequency
Pr.654
Proportional gain
Pr.653
159Hz (fixed) Vibrational frequency
V/F V/F V/F Magnetic flux Magnetic flux Magnetic flux
range
Confirm the effect by raising and lowering the value with
100% as a reference.
Set the lower limit of the torque deviation cycle (frequency).
Frequency output
Voltage output
Current for torque
(G) Control parameters
Description
PARAMETERS
5
GROUP
G
519