Torque Control By Real Sensorless Vector Control, Vector Control; Torque Control - Mitsubishi Electric FR-A740-00023 Instruction Manual

4.5 Torque control by real sensorless vector control, vector
control
Purpose
Selection of torque command
source and setting of torque
command value
Prevent the motor overspeed
Improve torque control accuracy
Stabilize the torque detection signal Torque detection filter
4.5.1

Torque control

Torque control is exercised to develop torque as set in the torque command.
The motor speed becomes constant when the motor output torque and load torque are balanced.
For torque control, therefore, the speed is determined by the load.
For torque control, the motor gains speed as the motor output torque becomes greater than the motor load.
To prevent overspeed, set the speed limit value so that the motor speed does not increase too high.
(Torque control is disabled under speed limit since speed control is exercised.)
When speed limit is not set, the speed limit value setting is regarded as 0Hz to disable torque control.
(1) Operation transition
Speed limit value is
increased up to preset value
according to the Pr.7
Acceleration time setting.
Speed
Speed limit
Start signal
Output torque
⋅ When "0" is set in Pr. 7 or Pr. 8 , speed control is exercised upon powering off a start signal and the output torque is
limited at the torque limit value.
Speed
Start signal
Output torque
Item
External operation
Start signal
PU operation
Torque command Select the input method of torque command and input the torque command.
Speed limit Select the input method of speed limit and input the speed limit value.
Parameter that must be Set
Torque command
Speed limit
Gain adjustment for
torque control
Speed limit value
Torque control
Speed control is peformed during speed
limit. (Thus, torque according to the
commanded is not developed.)
Torque control
Limit at the torque limit value
Description
STF, STR signal
and of FR-DU07, FR-PU07 or FR-PU04
Torque control by real sensorless vector
control, vector control
Pr. 803 to Pr. 806
Pr. 807 to Pr. 809
Pr. 824, Pr. 825, Pr. 834, Pr. 835
Pr. 827, Pr. 837
Speed limit value is decreased
down to zero according to the Pr.8
Deceleration time setting.
Speed limit
Output torque is provided
according to the terminal 1
setting.
Speed limit value
Speed control
(speed limit)
Output torque is provided
according to the terminal 1
setting.
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