Dc Magnetization - ABB ACQ580 Firmware Manual

76 Program features
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
synchronous 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
• Menu - Primary settings - Motor - Flux braking
• Parameter 97.05 Flux braking


DC magnetization

The drive has different magnetization functions for different phases of motor
start/rotation/stop: pre-magnetization, DC hold, post-magnetization and pre-heating
(motor heating).
Pre-magnetization
Pre-magnetization refers to DC magnetization of the motor before start. Depending
on the selected start mode
magnetization can be applied to guarantee the highest possible breakaway torque,
up to 200% of the nominal torque of the motor. By adjusting the pre-magnetization
time (21.02 Magnetization
example, the release of a mechanical brake.
Settings
Parameters 21.01 Start
(page 288).
(21.01 Start mode
time), it is possible to synchronize the motor start and, for
mode, 21.19 Scalar start
or 21.19 Scalar start
mode, 21.02 Magnetization
mode), pre-
time.