Dc Voltage Control; Overvoltage Control; Undervoltage Control - ABB ACS850 Manual

A "boost" function is also available for the activation of the timers: a signal source can
be selected to extend the activation time for a parameter-adjustable time period.
Timer active
Timer enable signal
Boost signal
Settings
Parameter group 36 Timed functions

DC voltage control

Overvoltage control

Overvoltage control of the intermediate DC link is needed with two-quadrant line-side
converters when the motor operates within the generating quadrant. To prevent the
DC voltage from exceeding the overvoltage control limit, the overvoltage controller
automatically decreases the generating torque when the limit is reached.

Undervoltage control

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.
Boost time
(page 212).
Program features 77