ABB RELION REX640 Technical Manual page 1408

Section 9
Control functions
1402
Energizing check
The Energizing check module checks the energizing direction. Energizing is the
situation where a dead network part is connected to an energized section of the
network. The conditions of the network sections to be controlled by the circuit
breaker, that is, which side has to be live and which side dead, are determined by the
setting Live dead mode.
Live dead mode can be set in two ways: either through settings or through the
command control.
If the Live dead mode parameter under the Setting menu is set as
"Command", then Live dead mode Ctl parameter under the Control
menu can be used to select the values in
Live dead mode parameter under the Setting menu is used to select the
values in
Table 1355: Live dead mode of operation when switching can be carried out
Live dead mode
Off
Both Dead
Live G, Dead B
Dead B, G Any
The actual value for defining the dead bus or generator is given with the Dead voltage
value setting. Similarly, the actual values of live bus or generator are defined with the
Live voltage value setting.
When the energizing direction corresponds to the settings, the situation has to be
constant for a time set with the Energizing time setting before the circuit breaker
closing is permitted. This time delay ensures that the dead side remains de-energized
and that the situation is not caused by a temporary interference. If the conditions do not
persist for a specified operate time, the timer is reset and the procedure is restarted
when the conditions allow it. The circuit breaker does not close if the measured
voltage on the live side is greater than the set value of Maximum voltage.
The measured energized state is available as a monitored data value ENERG_STATE
and as four function outputs LBLG ("Both Live"), LBDG ("Live B, Dead G"), DBLG
("Dead B, Live G") and DBDG ("Both Dead"), of which only one can be active at a
time. The measured energized state indicates "Unknown" if at least one of the
measured voltages is between the limits set with the dead and live setting parameters.
Synchronization check and control
The operation of Synchronization check and control can be described with a module
diagram. All the modules in the diagram are explained in the next sections.
Table 1355.
Description
Live dead mode setting is in off status
Both bus and generator de-energized
Bus de-energized and generator energized
Bus de-energized and generator energized or de-
energized
1MRS759142 C
Table 1355. Otherwise, the
REX640
Technical Manual