ABB Relion 670 Series Technical Reference Manual page 668

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Switch controller SCSWI

Introduction

The Switch controller (SCSWI) initializes and supervises all functions to properly

select and operate switching primary apparatuses. The Switch controller may handle

and operate on one three-phase device.

Principle of operation

The Switch controller (SCSWI) is provided with verification checks for the select -

execute sequence, that is, checks the conditions prior each step of the operation. The

involved functions for these condition verifications are interlocking, reservation,

blockings and synchronism-check.

Control handling

Two types of control models can be used. The two control models are "direct with

normal security" and "SBO (Select-Before-Operate) with enhanced security". The

parameter CtlModel defines which one of the two control models is used. The control

model "direct with normal security" does not require a select whereas, the "SBO with

enhanced security" command model requires a select before execution.

Normal security means that only the command is evaluated and the resulting position is

not supervised. Enhanced security means that the command sequence is supervised in

three steps, the selection, command evaluation and the supervision of position. Each

step ends up with a pulsed signal to indicate that the respective step in the command

sequence is finished. If an error occurs in one of the steps in the command sequence,

the sequence is terminated and the error is mapped into the enumerated variable

"cause" attribute belonging to the pulsed response signal for the IEC 61850

communication. The last cause L_CAUSE can be read from the function block and

used for example at commissioning.

There is no relation between the command direction and the actual

position. For example, if the switch is in close position it is possible to

execute a close command.

Before an execution command, an evaluation of the position is done. If the parameter

PosDependent is true and the position is in intermediate state or in bad state no

execution command is sent. If the parameter is false the execution command is sent

independent of the position value.

1MRK505222-UUS C

Technical reference manual

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