Mitsubishi Electric FR-F800 Series Instruction Manual page 578

5.13.15 Speed smoothing control
V/F V/F V/F
The output current (torque) of the inverter sometimes becomes unstable due to vibration caused by mechanical resonance.
Such vibration can be suppressed by reducing fluctuation of the output current (torque) by changing the output frequency.
Pr.
653 Speed smoothing
G410 control
654 Speed smoothing
G411 cutoff frequency
 Control block diagram
Speed
command
 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 the setting is not effective, gradually increase the value set in Pr.653 and repeat the operation to check the effect to
determine the most effective value (Pr.653).
• If the vibration increases by increasing the value in Pr.653, decrease the value in Pr.653 from 100% to check the effect.
• When the vibrational frequency at which mechanical resonance occurs (during fluctuation of torque, speed, or converter
output voltage) is measured using an instrument such as a tester, set 1/2 to 1 times of the vibrational frequency in Pr.654
Speed smoothing cutoff frequency. (Setting the resonance frequency range mitigates vibration more effectively.)
Current for
torque
0
NOTE
• Depending on the equipment, the vibration may not be suppressed sufficiently or the setting is not effective.
Downloaded from ManualsNet.com
Name Initial value
0%
20 Hz
Acceleration/deceleration
processing
Output frequency
+
-
Speed smoothing control
Proportional gain
Cutoff frequency
Torque fluctuation
detection range
Pr.654 159Hz (fixed)
search engine
Setting
range
Check the effect by increasing and decreasing the value at around
0% to 200%
100%.
0 to 120 Hz Set the minimum frequency for the torque variation cycle.
V/F control
Cutoff frequency
Pr.654
Pr.653
Vibrational frequency
Description
Frequency output
Voltage output
Current for torque
5.13 (G) Control parameters
1
2
3
4
5
6
7
8
9
10
577
5. PARAMETERS