INFO
To avoid trips caused by reverse power, configure the synchronisation parameters for a positive slip frequency.
Close breaker signal
The controller always calculates when to send the close breaker signal to get the best possible synchronisation of the power
sources. The close breaker signal is sent just before the power sources are synchronised. The close breaker signal is timed so that
the breaker is closed when the difference in the phase angle of the L1 vectors is zero.
The timing of the close breaker signal depends on the
Breaker closing time
and the slip frequency.
For example, if the response time of the circuit breaker (t
CB
) is 250 ms, and the slip frequency (f
slip
) is 0.1 Hz:
degrees
CLOSE
= 360 degrees × t
CB
× f
slip
= 360 degrees × 0.25 s × 0.1 Hz = 9 degrees
In this example, the controller will start the close breaker signal when the difference between the phase angles of the sources is 9
degrees.
5.4.2 Static synchronisation
During static synchronisation, the synchronising genset runs very close to the same speed as the generator on the busbar. The aim
is to let the gensets run at exactly the same speed, with the phase angles of the source and the busbar matching exactly. Static
synchronisation is most suited to systems with a very stable busbar frequency.
Static synchronisation is recommended where a slip frequency is not acceptable.
Static synchronisation should only be used with an analogue output (that is, not relay outputs).
Static synchronisation application example
Use static synchronisation during commissioning, to synchronise the genset to the busbar while the breaker closing is
disabled. The commissioning engineer can then measure the voltages across the breaker, as a safety check.
Inputs and outputs
This function uses the controller AC measurements, regulators, and breaker configuration.
Parameters
Configure the synchronisation parameters under
Configure > Parameters > Breakers > [Breaker] configuration >
Synchronisation setting
.
Table 5.23
Static synchronisation parameters
Name
Range
Default
Notes
Sync. type
•
Dynamic
•
Static
Dynamic
Static
must be selected. To see the static synchronisation parameters,
write the change to the controller, and refresh.
Delta frequency
min.
-0.5 to 0.3 Hz
-0.1 Hz
For synchronisation: Add
Delta frequency min.
to the busbar frequency,
for the
minimum
frequency of the synchronising generator.
This value must be negative for static synchronisation.
Delta frequency
max.
0.0 to 2.0 Hz
0.3 Hz
For synchronisation: Add
Delta frequency max.
to the busbar frequency,
for the
maximum
frequency of the synchronising generator.
Delta frequency max.
must always be higher than
Delta frequency min
.
DESIGNER'S HANDBOOK 4189340911K UK
Page 156 of 521