Mitsubishi Electric FR-F800 Series Instruction Manual page 191

5.3.2 Performing high-accuracy, fast-response control
(gain adjustment for PM motor control)
PM PM PM
Manual gain adjustment is useful for achieving optimum machine performance or improving unfavorable conditions, such as
vibration and acoustic noise during operation with high load inertia or gear backlash.
Pr.
820
Speed control P gain 1
G211
821
Speed control integral time 1
G212
824 Torque control P gain 1 (current
G213 loop proportional gain)
825 Torque control integral time 1
G214 (current loop integral time)
830
Speed control P gain 2
G311
831
Speed control integral time 2
G312
834 Torque control P gain 2 (current
G313 loop proportional gain)
835 Torque control integral time 2
G314 (current loop integral time)
 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.
• Setting 25% (initial value) in Pr.820 Speed control P gain 1 is equivalent to 50 rad/s (speed response of a single motor).
(Equivalent to the half the rad/s value with the FR-F820-03160(75K) or higher and FR-F840-01800(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 during speed fluctuation,
but setting it too low causes overshoot.
Proportional gain
∗1
200 (100)rad/s
∗1
50 (25)rad/s
(initial value)
*1 The value in parentheses is applicable with the FR-F820-03160(75K) or higher and FR-F840-01800(75K) or higher.
• Actual speed gain is calculated as follows when load inertia is applied.
Load
fluctuation
Speed
Actual speed gain = Speed gain of a single motor
190
5. PARAMETERS
5.3 Speed control under PM motor control
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Initial
Name
value
25%
0.333 s
50%
40 ms
9999
9999
9999
9999
Pr.820
Setting
25% 100%
Since increasing the proportional gain enhances the
response level and decreases the speed fluctuation.
Decreasing the integral time shortens the return time taken.
JM
JM+JL
search engine
Setting
range
The proportional gain during speed control is set. (Setting this
parameter higher improves the trackability for speed command
0% to 1000%
changes. It also reduces the speed fluctuation caused by external
disturbance.)
The integral time during speed control is set. (Setting this
0 to 20 s parameter lower shortens the return time to the original speed
when the speed fluctuates due to external disturbance.)
0% to 500% The proportional gain of the current controller is set.
0 to 500 ms The integral time of the current controller is set.
0% to 1000% Second function of Pr.820 (enabled when the RT signal is ON)
9999 The Pr.820 setting is applied to the operation.
0 to 20 s Second function of Pr.821 (enabled when the RT signal is ON)
9999 The Pr.821 setting is applied to the operation.
0% to 500% Second function of Pr.824 (enabled when the RT signal is ON)
9999 The Pr.824 setting is applied to the operation.
0 to 500 ms Second function of Pr.825 (enabled when the RT signal is ON)
9999 The Pr.825 setting is applied to the operation.
JM: Motor inertia
JL: Load inertia converted as the motor axis inertia
Description