REG 316*4 1MRB520049-Uen / Rev. F ABB Switzerland Ltd
3-71
3.5.5. Voltage-controlled overcurrent (Imax-Umin)
A. Application
Phase fault protection of generators with rapidly decaying fault
current such that a normal time overcurrent function could reset
before its delay had expired.
B. Features
· stores the maximum current value after pick-up
· resets either after recovery of the system voltage or after
tripping
· processes the positive-sequence component of the voltage
· insensitive to DC component and harmonics
· single or three-phase measurement with detection of the
highest phase value in the three-phase mode.
C. Inputs and outputs
I. Analogue inputs:
· current
· voltage
II. Binary inputs:
· blocking
III. Binary outputs:
· pick-up
· tripping
IV. Measurements:
· current amplitude
· positive-sequence voltage.