Performing High-Accuracy, Fast-Response Control - Mitsubishi Electric 800 Series Instruction Manual

5.4

Performing high-accuracy, fast-response control

(gain adjustment for Real sensorless vector
control and PM sensorless vector control)
PM PM PM
Sensorless Sensorless Sensorless
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. Name
820
Speed control P gain 1
G211
821
Speed control integral time 1
G212
830
Speed control P gain 2
G311
831
Speed control integral time 2
G312
 Speed control gain adjustment
• The speed control gain can be adjusted for the conditions such as abnormal machine vibration, acoustic noise, slow
response, and overshoot.
• Setting 60% (initial value) in Pr.820 Speed control P gain 1 is equivalent to 120 rad/s (speed response of a single motor).
(Equivalent to the half the rad/s value during Real sensorless vector control.) 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
200 (100)rad/s
*1
120 (60)rad/s
*1
100%
60%
(initial value )
*2
*1 The value in the parentheses is applicable under Real sensorless vector control.
*2 Performing PM parameter initialization changes the settings. (Refer to
• Actual speed gain is calculated as follows when load inertia is applied.
Load
fluctuation
Speed
Decreasing the integral time shortens the return time taken.
Actual speed gain = Speed gain of a single motor
5.4 Performing high-accuracy, fast-response control (gain adjustment for Real sensorless vector control and PM sensorless vector control)
Initial Setting
value range
60% 0% to 1000%
0.333 s 0 to 20 s
0% to 1000% Second function of Pr.820 (valid when RT signal is ON)
9999
9999
0 to 20 s
9999
9999
Pr.820
Setting
Since increasing the proportional gain enhances the
response level and decreases the speed fluctuation.
JM: Motor inertia
JM
JM+JL JL: Load inertia converted as the motor axis inertia
Description
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 caused by external
disturbance.)
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 external disturbance.)
The Pr.820 setting is applied to the operation.
Second function of Pr.821 (enabled when the RT signal is ON)
The Pr.821 setting is applied to the operation.
page 94.)
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5. Speed Control