7.3.1 Phase controller
When the static synchronisation is used and the synchronising is activated, the frequency controller will bring
the genset frequency towards the busbar frequency. When the genset frequency is within 50 mHz of the bus-
bar frequency, the phase controller takes over. This controller uses the angle difference between the genera-
tor system and the busbar system as the controlling parameter.
This is illustrated in the example above where the phase controller brings the phase angle from 30 deg. to 0
deg.
Close signal
The close signal will be issued when phase L1 of the synchronising generator is close to the 12 o’clock posi-
tion, compared to the busbar which is also in 12 o’clock position. It is not relevant to use the response time of
the circuit breaker when using static synchronisation, because the slip frequency is either very small or non-
existing.
To get a faster synchronisation, a “close window” can be adjusted. The close signal can be issued when the
phase angle UGENL1-UBBL1 is within the adjusted set point. The range is +/-0.1 to 20.0 deg. This is illustra-
ted in the drawing below.
± close window
Max. dU difference
Max. dU difference
U
BB
U
GEN
Direction of
rotation
The synchronisation pulse is sent according to the settings in menu 2030 Sync.
Load picture after synchronisation
The synchronised genset will not be exposed to an immediate load after the breaker closure if the maximum
df setting is adjusted to a low value. Since the fuel rack position almost exactly equals what is required to run
at the busbar frequency, no load jump will occur.
If the maximum df setting is adjusted to a high value, the observations in the section “Dynamic synchronisa-
tion” must be observed.
Static synchronisation is recommended where a slip frequency is not accepted, for example if
several gensets synchronise to a busbar with no load groups connected.
GPC-3 DRH 4189340587 UK
Synchronisation
DEIF A/S
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