Feature
2
Protection and monitoring IED with
extensive functional library, user
configuration possibility and expandable
hardware design to meet with user’s
special requirements
Redundant A/D sampling channels
guarantee the high security and
reliability of the IED
Three tripping/reclosing
Highly sensitive startup elements, which
enhance the IED sensitivity in all
disturbance conditions and avoid
maloperation
Current sudden-change startup
element
Zero sequence current startup
element
Over current startup element
Undervoltage startup element for
weak-infeed end of line
Three kinds of faulty phase selectors are
combined to guarantee the correction of
phase selection:
Current sudden-change phase
selector
Zero sequence and negative
sequence phase selector
Under voltage phase selector
Four kinds of directional elements
cooperate each other so as to determine
the fault direction correctly and promptly:
Memory voltage directional element
Zero sequence component
directional element
Negative sequence component
directional element
Impedance directional element
Full scheme phase-to-phase and
phase-to-earth distance protection with
five quadrilateral protection zones and
additional extension zone characteristic
(21, 21N)
Power swing function (68)
Proven and reliable principle of
power swing logic
Unblock elements during power
swing
All useful types of tele-protection
scheme (85)
Permissive Underreach Transfer
Trip (PUTT) scheme
Permissive Overreach Transfer Trip
(POTT) scheme
Blocking scheme
Inter-tripping scheme
Particular logic for tele-protection
scheme
Current reversal
Weak-infeed end
Evolving fault logic
Sequence tripping logic
A complete protection functions library,
include:
Distance protection with
quadrilateral characteristic
(21,21N)
Power swing function (68)
Tele-protection scheme based on
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