EDR-5000 IM02602007E
Synchronization Modes
The sync-check module is able to check the synchronization of two electrical systems (system-to-system) or between a
generator and an electrical system (generator-to-system). For paralleling two electrical systems, the station frequency,
voltage, and phase angle should be exactly the same as the utility grid. Whereas the synchronization of a generator to
a system can be done with a certain slip-frequency, depending on the size of the generator used. Therefore the
maximum breaker closing time has to be taken into consideration. With the set breaker closing time, the sync-check
module is able to calculate the moment of synchronization and gives the paralleling release.
When paralleling two systems, it has to be verified that the system-to-
system mode is selected. Paralleling two systems in generator-to-system
mode can cause severe damage!
Working Principle Sync-check (Generator-to-System)
(Please refer to the block diagram on next page.)
The sync-check element measures the three phase-to-neutral voltages »
VA«
, »
VB«,
and »
VC«
or the three phase-to-
phase voltages »
VAB«
, »
VBC«,
and »
VCA«
of the generator busbar. The line voltage Vx is measured by the fourth
voltage input. If all synchronous conditions are fulfilled (i. e.: ΔV [VoltageDiff], ΔF [SlipFrequency], and
Δφ [AngleDiff]) are within the limits, a signal will be issued that both systems are synchronous. An advanced Close
Angle Evaluator function takes the breaker closing time into consideration.
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