Mitsubishi Electric FR-A700 Instruction Manual page 306

Torque control by real sensorless vector control, vector control
Phenomenon
When the torque com-
mand is small, the motor
2 rotates in the direction
opposite to the start
signal.
Normal torque control
cannot be exercised dur-
3
ing acceleration/decelera-
tion. The motor vibrates.
Output torque is not lin-
4 ear in response to the
torque command.
Tab. 6-23: Troubleshooting during torque control (2)
6 - 126
Cause
The offset calibration of the torque
command does not match.
The speed limit is activated.
(When Pr. 807 = 0 or 2, the speed
limit may be activated since the
speed limit value changes with the
setting of the acceleration/decel-
eration time in Pr. 7 and Pr. 8. )
Insufficient torque.
Countermeasures
Recalibrate C16 "Terminal 1 bias command
(torque/magnetic flux)" and C17 "Terminal 1
bias (torque/magnetic flux)". (Refer to
section 6.20.6).
Reduce the acceleration/deceleration time.
Or, set the acceleration/deceleration time to
"0". (The speed limit during acceleration/decel-
eration depends on the speed limit during the
constant speed.)
Return the excitation ratio in Pr. 854 to the ini-
tial value.
Parameter