Mitsubishi Electric FR-A700 Series, Техническое руководство

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297
2
P
ARAM
ETE
R
PARAMETER
4
Motor speed is
unstable.
(1) The speed command varies. (1)-1
(1)-2
(1)-3
Check that a correct speed command comes from the
command device. (Take measures against noises.)
Decrease [
Pr. 72 PWM frequency selection ] .
Increase [ Pr. 822 Speed setting filter 1 ] .
(Refer to page 323)
(2) Insufficient torque. (2) Increase the torque limit value.
(Refer to torque limit of speed control on page 283)
(3) The speed control gains do not match the
machine. (Machine resonances.)
(3)-1
(3)-2
(3)-3 Perform easy gain tuning.
Adjust [
Pr. 820, 821 ].
Perform speed feed forward/model adaptive speed
control.
5
Motor or machine
hunts (vibration/
noise is
produced).
(1) The speed control gain is high. (1)-1
(1)-2
(1)-3 Perform easy gain tuning.
Decrease [
Pr. 820 ] and increase [ Pr. 821 ] .
Perform speed feed forward control and model
adaptive speed control.
(2) The torque control gain is high. (2) Decrease the [ Pr. 824 ] value.
(3) The motor wiring is wrong (3) Check the wiring
6
Acceleration/
deceleration time
does not match
the setting.
(1) Insufficient torque. (1)-1
(1)-2
Increase the torque limit value.
(Refer to torque limit of speed control on page
283
)
Perform speed feed forward control.
(2) Large load inertia. (2) Set the acceleration/deceleration time that meets the
load.
7
Machine operation
is unstable.
(1) The speed control gains do not match the
machine.
(1)-1
(1)-2
(1)-3 Perform easy gain tuning.
Adjust [
Pr. 820, 821 ] .
Perform speed feed forward control and model
adaptive speed control.
(2) Slow response because of improper
acceleration/deceleration time of the inverter.
(2) Change the acceleration/deceleration time to an
optimum value.
8
Speed fluctuation
at low speed. (1) Adverse effect of high carrier frequency. (1) Decrease [ Pr. 72 PWM frequency selection ].
(2) Low speed control gain. (2) Increase [ Pr. 820 Speed control P gain 1 ].
Case Cause Countermeasures