Functions
2.6 Flexible Protection Functions
SIPROTEC, 7RW80, Manual
C53000-G1140-C233-1, Release date 10.2010
82
The parameters can be set to monitor either exceeding or dropping below of the threshold. The configurable
pickup delay time will be started once the threshold (>-element) has been exceeded. When the delay time has
elapsed and the threshold is still violated, the pickup of the phase (e.g. no. 235.2122
„$00 pickup A“
)and
of the function (no. 235.2121
„$00 picked up“
) is reported. If the pickup delay is set to zero, the pickup will
occur simultaneously with the detection of the threshold violation. If the function is enabled, the pickup will start
the trip delay time and the fault log. This is not the case if set to "Alarm only". If the threshold violation persists
after the trip delay time has elapsed, the trip will be initiated upon its expiration (no. 235.2126
„$00 TRIP“
).
The timeout is reported via (no. 235.2125
„$00 Time Out“
). Expiry of the trip delay time can be blocked via
binary input (no. 235.2113
„>$00 BLK.TDly“
). The delay time will not be started as long as the binary input
is active; a trip can thus be initiated. The delay time is started after the binary input has dropped out and the
pickup is still present. It is also possible to bypass the expiration of the delay time by activating binary input (no.
235.2111
„>$00 instant.“
). The trip will be launched immediately when the pickup is present and the binary
input has been activated. The trip command can be blocked via binary inputs (no. 235.2115
„>$00
BL.TripA“
) and (no. 235.2114
„>$00 BLK.TRIP“
). The phase-selective blocking of the trip command is
required for interaction with the inrush restraint (see „Interaction with other functions“). The function's dropout
ratio can be set. If the threshold (>-element) is undershot after the pickup, the dropout delay time will be started.
The pickup is maintained during that time, a started trip delay time continues to count down. If the trip delay
time has elapsed while the dropout delay time is still during, the trip command will only be given if the current
threshold is exceeded. The element will only drop out when the dropout delay time has elapsed. If the time is
set to zero, the dropout will be initiated immediately once the threshold is undershot.
External Trip Commands
The logic diagram does not explicitly depict the external trip commands since their functionality is analogous.
If the binary input is activated for external trip commands (no. 235.2112
„>$00 Dir.TRIP“
), it will be logically
treated as threshold overshooting, i.e. once it has been activated, the pickup delay time is started. If the pickup
delay time is set to zero, the pickup condition will be reported immediately starting the trip delay time. Other-
wise, the logic is the same as depicted in Figure 2-20.
Interaction with Other Functions
The pickup message of the flexible function is included in the general fault detection, and tripping in the general
trip (see Chapter 2.11). All functionalities linked to the general fault detection and general trip therefore also
apply to the flexible function.
The trip commands by the flexible protection function are maintained after reset of the pickup for at least the
configured minimum trip-command duration 210 T TRIPCOM MIN.
