Restoring mode
Description
Disabled
Load restoration is disabled.
Auto
In the “Auto” mode, input frequency is continuously compared to the
Restore
pickup Val setting. The restore detection module includes a timer with the DT
characteristics. Upon detection of restoring, the operation timer activates the
ST_REST
output. When the timer has reached the value of the
Restore delay time
setting, the
RESTORE
output is activated if the restoring condition still persists. If the
frequency drops below the
Restore pickup Val before the
RESTORE
output is
activated, the reset timer is activated. If the reset timer reaches the value of the
Reset delay time setting, the timer resets and the
ST_REST
start output is
deactivated.
Manual
In the “Manual” mode, a manual restoration is possible through the
MAN_RESTORE
input or via communication. The
ST_REST
output is activated if the
MAN_RESTORE
command is available and the frequency has exceeded the
Restore pickup Val
setting. The manual restoration includes a timer with the DT characteristics. When
the timer has reached the set value of the
Restore delay time setting, the
RESTORE
output is activated if the restoring condition still persists. If the frequency drops
below the
Restore pickup Val setting before the
RESTORE
output is activated, the
reset timer is activated. If the reset timer reaches the value of the
Reset delay time
setting, the timer resets and the
ST_REST
start output is deactivated.
A condition can arise where the restoring operation needs to be canceled. Activating the
BLK_REST
input for the "Auto" or "Manual" modes cancels the restoring operation. In
the "Manual" restoring mode, the cancellation happens even if
MAN_RESTORE
is present.
Once the
RESTORE
output command is cancelled, the reactivation of
RESTORE
is
possible only after the reactivation of the
TRIP
output, that is, when the next load-
shedding operation is detected.
If there is a sharp frequency change in the waveform it can result in a
prolonged operate time. The reason is that the frequency algorithm does
not see it as a change in frequency, but as a loss of mains situation. In this
case frequency protection is delayed with 160 ms to give room for vector
shift protection to operate.
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
that selects the blocking mode. The
BLOCK
input can be controlled with a binary
input, a horizontal communication input or an internal signal of the protection relay's
program. The influence of the
BLOCK
input signal activation is preselected with the
Blocking mode
global setting.
The
Blocking mode
setting has three blocking methods. In the "Freeze timers" mode, the
trip timer is frozen to the prevailing value, but the
TRIP
output is not deactivated when
Section 4
1MRS240050-IB C
Protection functions
276
REF615R
Technical Manual
Summary of Contents for RELION REF615R
Page 1: ... RELION PROTECTION AND CONTROL REF615R Technical Manual ...
Page 2: ......
Page 27: ...Section 18 Glossary 653 Table of contents REF615R 21 Technical Manual ...
Page 28: ...22 ...
Page 36: ...30 ...
Page 46: ...40 ...
Page 115: ...3 15 4 Settings 1MRS240050 IB C Section 3 Basic functions REF615R 109 Technical Manual ...
Page 118: ...112 ...
Page 318: ...312 ...
Page 388: ...382 ...
Page 456: ...450 ...
Page 520: ...514 ...
Page 652: ...646 ...
Page 656: ...650 ...
Page 658: ...652 ...
Page 663: ...657 ...