Switches (Sxcbr/Sxswi); Reservation Function (Qcrsv And Resin) - ABB Relion REC670 Applications Manual

1MRK 511 358-UEN A
In the case when there are three one-phase switches (SXCBR) connected to the switch
controller function, the switch controller will "merge" the position of the three switches to the
resulting three-phase position. In case of a pole discordance situation, that is, the positions of
the one-phase switches are not equal for a time longer than a settable time; an error signal will
be given.
The switch controller is not dependent on the type of switching device SXCBR or SXSWI. The
switch controller represents the content of the SCSWI logical node (according to IEC 61850)
with mandatory functionality.
13.3.1.3

Switches (SXCBR/SXSWI)

Switches are functions used to close and interrupt an ac power circuit under normal
conditions, or to interrupt the circuit under fault, or emergency conditions. The intention with
these functions is to represent the lowest level of a power-switching device with or without
short circuit breaking capability, for example, circuit breakers, disconnectors, earthing
switches etc.
The purpose of these functions is to provide the actual status of positions and to perform the
control operations, that is, pass all the commands to the primary apparatus via output boards
and to supervise the switching operation and position.
Switches have the following functionalities:
• Local/Remote switch intended for the switchyard
• Block/deblock for open/close command respectively
• Update block/deblock of position indication
• Substitution of position indication
• 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 realizations of these function are done with SXCBR representing a circuit breaker and with
SXSWI representing a circuit switch that is, a disconnector or an earthing switch.
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.
13.3.1.4

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 earthing 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
Application manual
Section 13
Control
M16602-3 v5
M16609-3 v4
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