Motor noise, EMI measures, mechanical resonance Parameter
6 - 174
6.15.2 Speed smoothing control (Pr. 653)
Vibration due to mechanical resonance influences the inverter control, causing the output current
(torque) unstable. In this case, the output current (torque) fluctuation can be reduced to ease vibra-
tion by changing the output frequency.
The above parameter can be set when Pr. 160 "User group read selection" = 0.
Control block diagram
Setting method
If vibration due to mechanical resonance occurs, set 100% in Pr. 653, run the inverter at the frequency
which generates maximum vibration and check if the vibration will be reduced or not after several
seconds.
If effect is not produced, gradually increase the Pr. 653 setting and check the effect repeatedly until
the most effective value is set in Pr. 653.
If vibration becomes large by increasing the Pr. 653 setting, gradually decrease the Pr. 653 setting than
100% to check the effect in a similar manner.
Pr. No. Name Initial Value
Setting
Range
Description Parameters referred to
Refer to
Section
653
Speed smoothing control 0 0ā200%
Increase or decrease the value using 100% as refer-
ence to check an effect.
ā
I001816E
Fig. 6-89: Control block diagram of the speed smoothing control
NOTE
Depending on the machine, vibration may not be reduced enough or an effect may not be pro-
duced.
Output frequency
Speed
command
Torque current
Frequency output
Voltage output
V/F control
Speed smoothing control
Pr. 653
Acceleration/deceleration
processing