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

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

· The speed control gain can be adjusted for the conditions such as abnormal machine vibration, acoustic noise, slow

response, and overshoot.

· Actual speed gain is calculated as below when load inertia is applied.

Manual adjustment of gain is useful to exhibit the optimum performance of the machine or to improve
unfavorable conditions such as vibration and acoustic noise during the operation with high load inertia or gear
backlashes. 

820

Speed control P gain 1

25%

0 to 

1000%

The proportional gain during speed control is set.  
(Setting this parameter higher improves the 
trackability for speed command changes. It also 
reduces the speed fluctuation due to a load 
fluctuation.)

821

Speed control integral time 1

0.333s

0 to 20s

The integral time during speed control is set.  
(Setting this parameter lower shortens the return 
time to the original speed when the speed fluctuates 
due to a load fluctuation.)

· Pr.820 Speed control P gain 1 = "25% (initial setting)" is equivalent to

50rad/s (speed response of a single motor). (Half the value for 75K or
higher.) Setting this parameter higher speeds up the response, but
setting this too high causes vibration and acoustic noise. 

· Setting Pr.821 Speed control integral time 1 lower shortens the return time

to the original speed at a speed fluctuation, but setting it too low causes
overshoot. 

Actual speed gain = Speed gain of a single

 

motor 

×

JM

JM: Motor inertia
JL: Load inertia converted as the motor axis inertia

 JM+JL

IPM

IPM

IPM

Pr.820
Setting

100%

25%

(Initial setting)

Proportional gain

200(100)rad/s

50(25)rad/s

* The values for 75K or higher are indicated in 

parenthesis.

Setting the proportional gain higher 
speeds up the response and reduces the speed fluctuation here.

Load fluctuation

Speed

Setting the integral time lower shortens the return time here.