Mitsubishi Electric FR-A700 Instruction Manual page 258

Speed control by real sensorless vector control, vector control
NOTES Make sure to perform offline auto tuning before performing real sensorless vector control.
The carrier frequencies are selectable from among 2k, 6k, 10k, 14kHz for real sensorless
vector control.
Torque control can not be performed in the low speed region and at a low speed with light
load. Choose vector control.
Do not switch between the STF (forward rotation command) and STR (reverse rotation com-
mand) during operation under torque control. Overcurrent shut-off error (E.OC ) or opposite
rotation deceleration error (E.11) occurs.
When the inverter is likely to start during motor coasting under real sensorless vector con-
trol, set to make frequency search of automatic restart after instantaneous power failure
valid (Pr. 57 ≠ 9999, Pr. 162 = 10).
b
CAUTION:
● Performing pre-excitation (LX signal and X13 signal) under torque control may start
the motor running at a low speed even when the start command (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. Perform pre-excitation after making sure that there will
be no problem in safety if the motor runs.
● For the 00023 to 00126, the speed deviation may become large at 20Hz or less and
torque may become insufficient in the low speed region under 1Hz during contin-
uous operation under real sensorless vector control. In such case, stop operation
once and reaccelerate to improve the problems.
● Enough torque may not be generated in the ultra-low speed range less than approx.
2Hz when performing real sensorless vector control. The guideline of speed control
range is as shown below.
Driving:
Regeneration: 1 : 12 (2 bis 10 poles)
6 - 78
1 : 200 (2, 4, 6 poles)
1 : 30 (8, 10 poles)
Can be used at 0.3Hz or more at rated 60Hz
Can be used at 2Hz or more at rated 60Hz
Can be used at 5 Hz or more at rated 60 Hz
Parameter