1MRK 511 358-UEN A
Section 15
15.1
Tripping logic SMPPTRC
15.1.1
Identification
Function description
Tripping logic
15.1.2
Application
All trip signals from the different protection functions shall be routed through the trip logic. In
its simplest alternative the logic will only link the TRIP signal and make sure that it is long
enough.
Tripping logic SMPPTRC offers three different operating modes:
•
Three-phase tripping for all fault types (3ph operating mode)
•
Single-phase tripping for single-phase faults and three-phase tripping for multi-phase and
evolving faults (1ph/3ph operating mode). The logic also issues a three-phase tripping
command when phase selection within the operating protection functions is not possible,
or when external conditions request three-phase tripping.
•
Two-phase tripping for two-phase faults.
The three-phase trip for all faults offers a simple solution and is often sufficient in well meshed
transmission systems and in sub-transmission systems. Since most faults, especially at the
highest voltage levels, are single phase-to-earth faults, single-phase tripping can be of great
value. If only the faulty phase is tripped, power can still be transferred on the line during the
dead time that arises before reclosing. Single-phase tripping during single-phase faults must
be combined with single pole reclosing.
To meet the different double, 1½ breaker and other multiple circuit breaker arrangements, two
identical SMPPTRC function blocks may be provided within the IED.
One SMPPTRC function block should be used for each breaker, if the line is connected to the
substation via more than one breaker. Assume that single-phase tripping and autoreclosing is
used on the line. Both breakers are then normally set up for 1/3-phase tripping and 1/3-phase
autoreclosing. As an alternative, the breaker chosen as master can have single-phase tripping,
while the slave breaker could have three-phase tripping and autoreclosing. In the case of a
permanent fault, only one of the breakers has to be operated when the fault is energized a
second time. In the event of a transient fault the slave breaker performs a three-phase
reclosing onto the non-faulted line.
The same philosophy can be used for two-phase tripping and autoreclosing.
Application manual
Logic
IEC 61850
identification
SMPPTRC
IEC 60617
ANSI/IEEE C37.2
identification
device number
94
I->O
SYMBOL-K V1 EN-US
Section 15
Logic
IP14576-1 v4
SEMOD56226-2 v6
M12252-3 v8
357