Power Loss Ride-Through - ABB ACS355 series User Manual

138 Program features

Power loss ride-through

If the incoming supply voltage is cut off, the drive will continue to operate by utilizing
the kinetic energy of the rotating motor. The drive will be fully operational as long as
the motor rotates and generates energy to the drive. The drive can continue the
operation after the break if the main contactor remained closed.
T f U
M out DC
(N·m) (Hz) (Vdc)
160 80 520
120 60 390
80 40 260
40 20 130
0 0 0
U = Intermediate circuit voltage of the drive, f
DC
T = Motor torque
M
Loss of supply voltage at nominal load (f
drops to the minimum limit. The controller keeps the voltage steady as long as the input
power is switched off. The drive runs the motor in generator mode. The motor speed falls but
the drive is operational as long as the motor has enough kinetic energy.

Settings
Parameter 2006 UNDERVOLT CTRL
DC magnetizing
When DC magnetizing is activated, the drive automatically magnetizes the motor
before starting. This feature guarantees the highest possible break-away torque, up
to 180% of the motor nominal torque. By adjusting the premagnetizing time, it is
possible to synchronize the motor start and, eg, a mechanical brake release. The
Automatic start feature and DC magnetizing cannot be activated at the same time.

Settings
Parameters 2101 START FUNCTION
1.6 4.8
= 40 Hz). The intermediate circuit DC voltage
out
and
8 11.2
= Output frequency of the drive,
out
2103 DC MAGN TIME
U
input power
U
DC
f
out
T
M
t (s)
14.4