Mitsubishi Electric 800 Series, Instruction Manual, Page: 625 / 727

(G) Control parameters
624
PARAMETERS
5.16.16
Speed smoothing control

Control block diagram
 Setting method
• When vibration caused by mechanical resonance occurs, set 100% in Pr.653 Speed smoothing control , perform
operation at the frequency with the largest vibration, and check 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.)
NOTE
• Depending on the equipment, the vibration may not be suppressed sufficiently or the effect is not obtained.
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
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).
V/F V/F V/F
V/F control
Current for torque
Frequency output
Voltage output
+
-
Acceleration/deceleration
processing
Output frequency
Speed
command
Proportional gain
Pr.653
Cutoff frequency
Pr.654
Speed smoothing control
0
Vibrational frequency 159Hz (fixed)
Torque fluctuation
detection range
Cutoff frequency
Pr.654
Current for
torque