Flux Braking - ABB ACS880 Firmware Manual

and forward (±360/polepairs)° in order to determine the rotor position. In case 3
(open-loop control), the shaft is turned only in one direction and the angle is smaller.
The standstill modes can be used if the motor cannot be turned (for example, when
the load is connected). As the characteristics of motors and loads differ, testing must
be done to find out the most suitable standstill mode.
The drive is capable of determining the rotor position when started into a running
motor in open-loop or closed-loop modes. In this situation, the setting of
Autophasing mode
The autophasing routine can fail and therefore it is recommended to perform the
routine several times and check the value of parameter
An autophasing fault
estimated angle of the motor differs too much from the measured angle. This could
be caused by, for example, the following:
• The encoder is slipping on the motor shaft
• An incorrect value has been entered into
• The motor is already turning before the autophasing routine is started
• Turning mode is selected in
locked
• The wrong motor type is selected in
• Motor ID run has failed.
Settings
Parameters 21.13 Autophasing mode
302) and 99.13 ID run requested


Flux braking

The drive can provide greater deceleration by raising the level of magnetization in the
motor. By increasing the motor flux, the energy generated by the motor during
braking can be converted to motor thermal energy.
Motor
speed
Flux braking
has no effect.
(3385 Autophasing) can occur with a running motor if the
21.13 Autophasing mode
(page 305).
No flux braking
t (s)
98.15 Position offset
98.15 Position offset user
99.03 Motor type
(page 155), 98.15 Position offset user
T
Br
(%)
T
N
60
40
Flux braking
20
No flux braking
Program features 47
21.13
but the motor shaft is
T = Braking torque
Br
T = 100 Nm
N
user.
(page
f (Hz)