ABB RER615 - Page 452

Operation mode Description
ate Tm df/dt is dominant regarding the OPERATE output.
The time characteristic is according to DT. The characteristic
that activates the OPERATE output can be seen from the
OPR_UFRQ or OPR_FRG output. If the frequency gradient
restores before the module operates, the reset timer is acti-
vated. If the timer reaches the value set by the Reset delay
Tm df/dt setting, the operate timer resets and the STR_FRG
output is deactivated. If the frequency restores before the
module operates, the reset timer is activated. If the timer
reaches the value set by the Reset delay Tm Freq setting, the
operate timer resets and the STR_UFRQ output is deactiva-
ted.
Freq> OR df/dt A parallel operation between the protection methods is en-
abled. The START output is activated when either of the
measured values of the protection module exceeds its set
value. A detailed information from the active module is avail-
able at the STR_OFRQ and STR_FRG outputs. The shortest
operate delay time from the set Operate Tm Freq or Oper-
ate Tm df/dt is dominant regarding the OPERATE output.
The time characteristic is according to DT. The characteristic
that activates the OPERATE output can be seen from the
OPR_OFRQ or OPR_FRG output. If the frequency gradient
restores before the module operates, the reset timer is acti-
vated. If the timer reaches the value set by the Reset delay
Tm df/dt setting, the operate timer resets and the STR_FRG
output is deactivated. If the frequency restores before the
module operates, the reset timer is activated. If the timer
reaches the value set by the Reset delay Tm Freq setting, the
operate timer resets and the STR_UFRQ output is deactiva-
ted.
The module calculates the start duration value which indicates the percentage ratio
of the start situation and set operate time (DT). The start duration is available
according to the selected value of the Operation mode setting.
Table 477: Start duration value
Operation mode in use Available start duration value
Freq<
ST_DUR_UFRQ
Freq>
ST_DUR_OFRQ
df/dt
ST_DUR_FRG
The combined start duration START_DUR indicates the maximum percentage ratio
of the active protection modes. The values are available via the Monitored data view.
Blocking logic
There are three operation modes in the blocking function. The operation modes
are controlled by the BLOCK input and the global setting in Configuration>
System> Blocking mode which selects the blocking mode. The BLOCK input can
be controlled by a binary input, a horizontal communication input or an internal
Protection functions
1MRS758755 C
452 REC615 & RER615
Technical Manual