Micom P634 - 1 Application and Scope; Overview - P634

1 Application and Scope
1.1 Overview - P634
The P634 differential protection device is intended for the fast and selective
short-circuit protection of transformers, motors, generators and other
installations with 4 windings.
Fig. 1-1: P634 in 84 TE case.
The P634 provides high-speed three-system differential protection using a triple-
slope characteristic and two high-set differential elements in combination with
transformer inrush restraint, overfluxing restraint and through-stabilization.
Amplitude and vector group matching is done just by entering the nominal values
of transformer windings and associated current transformers. An (optional)
overreaching current measuring circuit monitoring function will prevent
unwanted tripping by differential protection for faults in the CT's secondary
circuit.
For ring bus and breaker-and-a-half applications a virtual winding can be defined
for which the current measuring inputs are based on the vector sum of currents
from two or three freely selectable windings.
Phase swapping allows motor / generator protection applications with enlarged
protection zones.
In addition many supplementary protective functions are incorporated in the
devices. These can be individually configured and cancelled.
The relevant protection parameters can be stored in four independent parameter
subsets in order to adapt the protection device to different operating and power
system management conditions.
The powerful programmable logic provided by the protection device also makes
it possible to accommodate special applications.
For a list of all available function groups see the Appendix.
P634
P634/EN M/R-42-A // P634‑311‑653 1-1