ABB RET670 Applications Manual page 613

1MRK504116-UUS C
Application manual
• Supervision timer that the primary device starts moving after a command
• Supervision of allowed time for intermediate position
• Definition of pulse duration for open/close command respectively
The realization of this function is performed with SXCBR representing a circuit
breaker and with SXSWI representing a circuit switch that is, a disconnector or an
grounding switch.
The Circuit breaker (SXCBR) can be realized either as three one-phase switches or as
one three-phase switch.
The content of this function is represented by the IEC 61850 definitions for the logical
nodes Circuit breaker (SXCBR) and Circuit switch (SXSWI) with mandatory
functionality.
Reservation function (QCRSV/RESIN)
The purpose of the reservation function is primarily to transfer interlocking
information between IEDs in a safe way and to prevent double operation in a bay,
switchyard part, or complete substation.
For interlocking evaluation in a substation, the position information from switching
devices, such as circuit breakers, disconnectors and grounding switches can be required
from the same bay or from several other bays. When information is needed from other
bays, it is exchanged over the serial station bus between the distributed IEDs. The
problem that arises, even at a high speed of communication, is a space of time during
which the information about the position of the switching devices are uncertain. The
interlocking function uses this information for evaluation, which means that also the
interlocking conditions will be uncertain.
To ensure that the interlocking information is correct at the time of operation, a unique
reservation method is available in the IEDs. With this reservation method the operation
will temporarily be blocked for all switching devices in other bays, which switching
states are used for evaluation of permission to operate. Actual position indications from
these bays are then transferred over the serial bus for evaluation in the IED. After the
evaluation the operation can be executed with high security.
This functionality is realized over the station bus by means of the function blocks
QCRSV and RESIN. The application principle appears from figure 234.
The function block QCRSV handles the reservation. It sends out either the reservation
request to other bays or the acknowledgement if the bay has received a request from
another bay.
The other function block RESIN receives the reservation information from other bays.
The number of instances is the same as the number of involved bays (up to 60
instances are available). The received signals are either the request for reservation from
Section 3
IED application
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