ABB RELION REF610, Technical Reference Manual

Page: 158 / 176

To avoid such a pumping effect, a cutout time is used. The cutout time, like the
reclaim time, will pickup when the set dead time elapses and the AR function issues
a reclosing command to the circuit breaker. By setting the cutout time to be shorter
than the reclaim time (e.g. half of the reclaim time), the blocking of element 50P-1
(in this case) will be reset before the AR function. Element 50P-1 will now be able
to continue the AR sequence and the pumping effect will thus be avoided.
6.1.2. Fast tripping and initiation of shot 1 using pickup signals
An alternative way to achieve fast tripping and shot initiation (typical for certain
countries, such as Finland), is to use pickup signals from protection elements for
shot initiation. The AR function of REF610 can be initiated by the pickup signals
from elements 51P and 51N.
The pickup time of elements 51P and 51N is very short but can be extended with the
settings
AR 51P pickup Delay
and
AR 51N pickup Delay
of the AR
function. When the set pickup delay elapses, the shot will be initiated and the AR
function will trip the circuit breaker by issuing the
Open CB Command
.
51P
79
t
Trip
Close CB
CB closed
CB open
Shot 1
Shot 2 Shot 3 Definite Trip
51P
Pickup
51P
Trip
Open CB
51P Pickup
delay Open CB
Open CB Command
Close CB Command
Close CB
Command
Open CB
Command
Close CB
Command
Close CB
Command
51P TDLY
Open CB
Command
Shots 1, 2 and 3
initiation
Shot 1 initiation
Pickup
0
51P
Trip
51P Pickup
51P TDLY 51P TDLY
51P TDLY
A070041
Fig. 6.1.2.-1 Fast initiation of shot 1 using start signals
Shot initiation by a pickup signal applies only to shot 1, and to definite tripping, i.e.
when no more shots are allowed but the network fault has not been cleared. In this
case, the AR function will trip the circuit breaker on expiration of
AR 51P pickup
Delay
and
AR 51N pickup Delay
.
The signal
Open CB Command
must be routed to the output contact
used for tripping the circuit breaker.
158
REF610 REF610 Feeder Protection Relay
Technical Reference Manual - ANSI Version
1MRS755535