Flux Braking - ABB ACS280 Firmware Manual

50 Program features


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
The drive monitors the motor status continuously, also during flux braking.
Therefore, flux braking can be used both for stopping the motor and for
changing the speed. The other benefits of flux braking are:
• The braking starts immediately after a stop command is given. The function
does not need to wait for the flux reduction before it can start the braking.
• The cooling of the induction motor is efficient. The stator current of the
motor increases during flux braking, not the rotor current. The stator cools
much more efficiently than the rotor.
• Flux braking can be used with induction motors and permanent magnet
motors.
Two braking power levels are available:
• Moderate braking provides faster deceleration compared to a situation
where flux braking is disabled. The flux level of the motor is limited to
prevent excessive heating of the motor.
• Full braking exploits almost all available current to convert the mechanical
braking energy to motor thermal energy. Braking time is shorter compared
to moderate braking. In cyclic use, motor heating may be significant.
WARNING! The motor needs to be rated to absorb the thermal energy
generated by flux braking.
Settings and diagnostics
97.05 Flux braking
Parameter
Events: -
No flux braking
t
(s)
281
(page
T
Br
T
(%)
60
40
Flux braking
20
No flux braking
).
= Braking torque
Br
= 100 Nm
f
(Hz)