Reservation Function (Qcrsv And Resin) - ABB REB670 Applications Manual

Section 12
Control
12.3.1.4
330
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 and 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 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 are 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 bay that
wants the reservation sends a reservation request to other bays and then waits for a
reservation granted signal from the other bays. Actual position indications from these bays
are then transferred over the station 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 is shown in Figure 124.
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 another bay
or the acknowledgment from each bay respectively, which have received a request from
this bay. Also the information of valid transmission over the station bus must be received.
1MRK 505 337-UUS -
Application manual