79
Test operation and gain adjustment of the PM sensorless vector control
4.3.5
Adjusting the speed control gain (Pr. 820, Pr. 821)
The above parameters can be set when
Pr. 160 Extended function display selection
= "0".
(1) Adjusting the speed control gain manually
·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.
Parameter
Number
Name
Initial
Value
Setting
Range
Operation
820
Speed control P gain
15%
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
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
= "15% (initial setting)" is equivalent to 30rad/s
(speed response of a single motor). 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
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
Pr. 820
Setting
100%
15%
(Initial setting)
Proportional gain
200rad/s
50rad/s
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.
Summary of Contents for FR-D720-0.2K-G
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