Mitsubishi Electric FR-A820-00046 (0.4K), Instruction Manual

Page: 288 / 1218

Speed control under Real sensorless vector control, vector control, PM sensorless vector control Parameters
5 - 86
NOTES During Real sensorless vector control, offline auto tuning must be performed properly before
starting operations.
The speed command setting range under Real sensorless vector control is 0 to 400 Hz.
The carrier frequency is limited during Real sensorless vector control. (Refer to page 5-227.)
Torque control is not available in a low-speed (about 10 Hz or lower) regenerative range, or with a
low speed and light load (about 5 Hz or lower and rated torque about 20% or lower). The vector
control must be selected.
Performing pre-excitation (LX signal and X13 signal) under torque control may start the motor
running at a low speed even when the start signal (STF or STR) is not input. The motor may run
also at a low speed when the speed limit value = 0 with a start command input. It must be con-
firmed that the motor running will not cause any safety problem before performing pre-excita-
tion.
Switching between the forward rotation command (STF) and reverse rotation command (STR)
must not be performed during operations under torque control. An overcurrent trip (E.OC
첸
) or
opposite rotation deceleration fault (E.11) will occur.
When performing continuous operations under Real sensorless vector control in FR-A820-
00250(3.7K) or lower or FR-A840-00126(3.7K) or lower, the speed fluctuation increases when the
value is 20 Hz or less, and in the low-speed range of less than 1 Hz, there may be torque shortage.
If starting may occur while the motor is coasting under Real sensorless vector control, the fre-
quency search must be set for the automatic restart after instantaneous power failure function
(Pr. 57 ≠ "9999", Pr. 162 = "10"). (Refer to page 5-581.)
When Real sensorless vector control is applied, not enough torque may be provided in the ultra
low-speed range of about 2 Hz or lower.
Generally, the speed control range is as follows.
For power driving:
1:200 (2, 4 or 6 poles) (available at 0.3 Hz or higher when the rating is 60 Hz),
1:30 (8 or 10 poles) (available at 60 Hz or higher when the rating is 60 Hz).
For regenerative driving:
1:12 (2 to 10 poles) (available at 5 Hz or higher when the rating is 60 Hz).