ABB RELION Series, Technical Manual

Page: 444 / 804

Operation mode Description
Freq< + df/dt A consecutive operation is enabled between the protection
methods. When the measured frequency is below the set value of
the
Start value Freq< setting, the frequency gradient protection is
enabled. After the frequency has dropped below the set value, the
frequency gradient is compared to the set value of the Start value df/
dt setting. When the frequency gradient exceeds the set value, the
module activates the
START
and
STR_FRG
outputs. The time
characteristic is according to DT. When the operation timer has
reached the value set by the
Operate Tm df/dt setting, the
OPERATE
and
OPR_FRG
outputs are activated. If the frequency gradient
restores before the module operates, the reset timer is activated. If
the timer reaches the value set by the
Reset delay Tm df/dt setting,
the operate timer resets and the
START
and
STR_FRG
outputs are
deactivated. The
OPR_UFRQ
output is not active when this operation
mode is used.
Freq> + df/dt A consecutive operation is enabled between the protection
methods. When the measured frequency exceeds the set value of
the
Start value Freq> setting, the frequency gradient protection is
enabled. After the frequency exceeds the set value, the frequency
gradient is compared to the set value of the Start value df/dt setting.
When the frequency gradient exceeds the set value, the module
activates the
START
and
STR_FRG
outputs. The time characteristic
is according to DT. When the operation timer has reached the value
set by the
Operate Tm df/dt setting, the
OPERATE
and
OPR_FRG
outputs are activated. If the frequency gradient restores before the
module operates, the reset timer is activated. If the timer reaches the
value set by the Reset delay Tm df/dt setting, the operate timer
resets and the
START
and
STR_FRG
outputs are deactivated. The
OPR_OFRQ
output is not active when this operation mode is used.
Freq< OR df/dt A parallel operation between the protection methods is enabled. The
START
output is activated when either of the measured values of the
protection module exceeds its set value. Detailed information about
the active module is available at the
STR_UFRQ
and
STR_FRG
outputs. The shortest operate delay time from the set
Operate Tm
Freq or Operate 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 activated. 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 deactivated.
Freq> OR df/dt A parallel operation between the protection methods is enabled. 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 available at the
STR_OFRQ
and
STR_FRG
outputs. The shortest operate delay time from the set
Operate Tm
Freq or Operate 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 activated. 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 deactivated.
Section 4
1MRS758755 A
Protection functions
438 REC615 and RER615
Technical Manual