Auto-Tuning Function; Auto-Tuning With Motor Stop; Auto-Tuning With Motor Rotation - Omron 3G3MX2 User Manual

"H" Group: Motor Constants Functions
3-8-3

Auto-tuning Function

The MX2 inverter has auto-tuning function to get suitable motor control perfor-
mance by measuring the motor constants automatically. Auto-tuning is effec-
tive only for sensorless vector control.
Auto-tuning with motor stop (=)
Motor does not rotate while auto-tuning. If rotating motor could give harm to
your application, use this mode. But the motor constant I0 (no-load current)
and J (inertia) are not measured and remain unchanged. (I0 can be monitored
in 50Hz of V/f operation.)
Auto-tuning with motor rotation (=)
Motor rotates according to a special operation pattern while auto-tuning. How-
ever, the torque during auto-tuning is not sufficient, which may cause a prob-
lem in the load (for example, a lift may slide down). See below instruction 8.-
d).
When using auto-tuning function, follow the instructions below.
1. When using a motor which constants are unknown, execute offline auto-
tuning to obtain the constants.
2. When the motor constant selection (H002/H202) is standard motor (01),
the initial values in / to / are standard motor's values.
3. The motor constant data is corresponding to one-phase of Y (star) connec-
tion for 50 Hz.
4. Set base frequency () and AVR voltage () according to the motor
specifications. If the motor voltage is other than the alternatives, set V/f
gain () according to below formula.
"motor voltage ()"x"output voltage gain ()"="motor rated voltage"
5. Proper motor constants are obtained only when the same size or one size
lower motor is used. If other size of motor is connected, proper values may
not be obtained or auto-tuning operation may not be completed. In this
case, press STOP/RESET key, then error code will be displayed.
6. Be sure to disable DC braking setting (=) and simple positioning se-
lection (=), otherwise motor constants are not measured properly.
7. Be sure to deactivate ATR terminal (: Enable torque cmd. input), other-
wise motor constants are not measured properly.
8. If auto-tuning with motor rotation (=) is used, check the followings
points.
a) The motor rotates up to 80% of base frequency. Check if it is no prob-
lem for the application.
b) The motor should not be driven by any other external force.
c) All the brakes should be released.
d) During auto-tuning, insufficient torque may cause a problem in the
load (for example, a lift may slide down). In this case, remove the motor
from the machine or other load, and perform auto-tuning with the mo-
tor alone. The measured inertia J is based on the motor alone. To ap-
ply the data, add the moment of inertia of the load machine to the
measured J data after converting the moment of inertia to the motor
shaft data.
e) If the application is with limitation (e.g. lift or boring machine), the al-
lowable rotation limit may be exceeded in auto-tuning, and the ma-
chine may be damaged.
9. Even when " (auto-tuning without motor rotation)" is selected, the motor
could rotate slightly during auto-tuning.
Section 3-8
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