Mitsubishi Electronics FR-F740P ユーザーズマニュアル

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 from 100% to
check the effect in a similar manner.
When the vibrational frequency due to the mechanical resonance (fluctuation of torque, speed, and converter
output voltage) is known using a tester and such, set 1/2 to 1 time of the vibrational frequency to Pr.654. (Setting
vibrational frequency range can suppress the vibration better.)

Vibration due to mechanical resonance influences the inverter control, causing the output current (torque) to be
unstable. In this case, the output current (torque) fluctuation can be reduced to ease vibration by changing the
output frequency.

0

0 to 200%

The torque fluctuation is reduced to reduce vibration due to 
mechanical resonance.

20Hz

0 to 120Hz

Set the minimum value for the torque variation cycle 
(frequency).

The above parameters can be set when Pr. 160 User group read selection = "0". (Refer to page 201)

⋅ Depending on the machine, vibration may not be reduced enough or an effect may not be produced.

V/F

V/F

V/F

S

 MFVC

S

 MFVC

S

 MFVC

Acceleration/deceleration  

processing

Speed  
command

V/F control

Current for torque 

Frequency output
Voltage output

+

-

Proportional gain 

Output frequency

Cutoff frequency 

Speed smoothing control

0

Vibrational frequency

159Hz (fixed)

Torque fluctuation  

detection range

Cutoff frequency

Current for 

torque