ABB RELION Series Technical Manual page 444

Section 4
Protection functions
438
Operation mode
Freq< + df/dt
Freq> + df/dt
Freq< OR df/dt
Freq> OR df/dt
Description
A consecutive operation is enabled between the protection
methods. When the measured frequency is below the set value of
Start value Freq< setting, the frequency gradient protection is
the
enabled. After the frequency has dropped below the set value, the
frequency gradient is compared to the set value of the
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
Operate Tm df/dt setting, the OPERATE
reached the value set by the
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
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.
A consecutive operation is enabled between the protection
methods. When the measured frequency exceeds the set value of
Start value Freq> setting, the frequency gradient protection is
the
enabled. After the frequency exceeds the set value, the frequency
gradient is compared to the set value of the
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
Reset delay Tm df/dt setting, the operate timer
value set by the
resets and the START and STR_FRG outputs are deactivated. The
OPR_OFRQ output is not active when this operation mode is used.
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
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
Reset delay Tm df/dt setting, the operate timer
value set by the
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
the operate timer resets and the STR_UFRQ output is deactivated.
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
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
Reset delay Tm df/dt setting, the operate timer
value set by the
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
the operate timer resets and the STR_UFRQ output is deactivated.
1MRS758755 A
Start value df/
Reset delay Tm df/dt setting,
Start value df/dt setting.
Operate Tm
Reset delay Tm Freq setting,
Operate Tm
Reset delay Tm Freq setting,
REC615 and RER615
Technical Manual