Siemens 6MD85, Manual

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Command Execution
As described in section Starting and Canceling a Switching Sequence, Page 426 , the display page or the
Control menu can be used to start the switching sequence. The
Start Trigger
signal for indication
Execution
is used to recognize the start and initiates the switching sequence by pickup of TRIG in the DPC-
DEF building block of circuit breaker QA1. Building blocks DPC-DEF and DPC-EXE are always used in pairs. The
DEF building block controls the type and nature of the command
•
VAL = Switching direction (0 = Off, 1 = On)
•
SELECT = Select switching device (2 = Select with a value suitable for the preset control model
SBO w.
enh. security
)
•
OPERATE = Switch switching device (1 = Switching device is switched on or off)
Using the connected DPC-EXE building block, the command checks can be deactivated (REL_...). In the appli-
cation example, all inputs are set to 0 and therefore, all checks are activated.
After the open command of circuit breaker QA1 is acknowledged via the auxiliary contacts, the OK output of
the CFC block DPC_EXE becomes active and triggers the next switching object. With the input PT the signal for
the OK output is time-delayed (in the example by 10 ms) and creates a dead time between individual
switching commands and the switching sequence. This dead time is important for the updating of the inter-
locking conditions.
If QB1 is closed, QB1 will be opened. If QB2 is closed, QB2 will be opened. In order to implement this logic, the
OK output signal of QA1 is linked with the respective positions of circuit breakers QB1 and QB2 via the logical
AND function. This signal serves as a trigger for the trip command of QB1 or QB2.
Because in this example the time-out monitoring is activated, the feedback about the successful or unsuc-
cessful execution of the switching sequence must be parameterized. The Switching sequence function block
provides the inputs
>Successful
and
>Failed
. In order to acknowledge the entire switching sequence
positively, the OR operation of the OK outputs for the disconnectors QB1 and QB2 is sufficient. The feedback
of all failed executions takes place via the OR operation of all ERR outputs of the switching devices. The
benefit of such assessment is the fact that, in case of a failure, waiting for the time-out is not necessary, but
the active switching sequence can be ended immediately.
In this example, the use of the EN_I input of building block DPC-DEF fulfills 2 tasks:
•
Cancelation of the entire switching sequence
•
Resetting of the outputs OK and ERR on building block DPC-EXE
By linking all EN_I inputs and EN_O outputs of building blocks DPC-DEF and DPC-EXE, the execution of the
switching sequence can be controlled centrally since the value is transmitted between the building blocks.
Only if input EN_I on the DPC-EXE is set to 1, a switching command is issued. If the input drops back to 0 while
a command is being processed, this command will be canceled. With this behavior, cancelation of an entire
switching sequence can be achieved. As recognition of a cancelation, the
canceled
signal of the indication
Execution
is used in the CFC chart and connected with the input EN_I of the first switching device, in this
example, with the DPC-DEF building block of circuit breaker QA1.
Since the OK and ERR outputs of the DPC-EXE building block maintain their value until execution of the next
command, it is necessary to reset the continuous output after each execution of the switching sequence for
correct execution of the entire CFC switching sequence multiple times. In this case, the use of the EN_I input
is also helpful. In the input drops back to 0, the OK and ERR outputs are also reset to 0. The triggers for ending
the switching sequence are the events
failed
and
successful
. For this reason, in the above example, the
signals
failed
and
successful
of the indication
Execution
were connected with EN_I of the DPC-DEF
building block.
Settings
Addr. Parameter C Setting Options Default Setting
Swi. seq. #
_:101 Swi. seq. #:Check
switching authority
•
no
•
yes
•
advanced
yes
6.5.4
Control Functions
6.5 Switching Sequences
430 SIPROTEC 5, High-Voltage Bay Controller, Manual
C53000-G5040-C015-9, Edition 11.2017