ABB REG670 Applications Manual

power swing in the net and the phase angle difference may begin to oscillate.
Generally, the frequency difference is the time derivative of the phase angle difference
and will, typically oscillate between positive and negative values. When the circuit
breaker needs to be closed by auto-reclosing after fault-clearance some frequency
difference should be tolerated, to a greater extent than in the steady condition
mentioned in the case above. But if a big phase angle difference is allowed at the same
time, there is some risk that auto-reclosing will take place when the phase angle
difference is big and increasing. In this case it should be safer to close when the phase
angle difference is smaller.
To fulfill the above requirements the synchrocheck function is provided with
duplicate settings, one for steady (Manual) conditions and one for operation under
disturbed conditions (Auto).
SynchroCheck
UHighBusSC > 50 - 120 % of GblBaseSelBus
UHighLineSC > 50 - 120 % of GblBaseSelLine
UDiffSC < 0.02 – 0.50 p.u.
PhaseDiffM < 5 - 90 degrees
PhaseDiffA < 5 - 90 degrees
FreqDiffM < 3 - 1000 mHz
FreqDiffA < 3 - 1000 mHz
Fuse fail
Fuse fail
Line voltage
Line
reference
voltage
Bus voltage
IEC10000079-2-en.vsd
IEC10000079 V2 EN
Figure 224: Principle for the synchrocheck function
15.1.2.3 Energizing check
The main purpose of the energizing check function is to facilitate the controlled re-
connection of disconnected lines and buses to energized buses and lines.
The energizing check function measures the bus and line voltages and compares them
to both high and low threshold values. The output is given only when the actual
measured conditions match the set conditions. Figure 225 shows two substations,
where one (1) is energized and the other (2) is not energized. The line between CB A
and CB B is energized (DLLB) from substation 1 via the circuit breaker A and
energization of station 2 is done by CB B energization check device for that breaker
DBLL. (or Both).
Section 15 1MRK 502 071-UEN -
Control
482 Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Application manual

ABB REG670 Specifications

General

Brand	ABB
Model	REG670
Category	Protection Device
Language	English