72/78 SUREWAVE SFC USER MANUAL
Step
Description
1
With the output CB open, start the SureWave SFC
2
Enable V/F droops to allow the SFC to parallel with the generator
3
Command the SureWave SFC to synchronize to the reference as measured on the exter-
nal voltage sense board.
5
Once the SFC is synchronized, the output CB can now be closed connecting the SFC to
the AC bus.
6
Remove the synchronize command
The SFC is now in parallel with the generator.
7
Once the generator is offline, disable the V/F droops. The AC bus is now being supplied
from the SFC.
Table 11-1: Generator to SFC transfer procedure
11.6.1.3
Parallel operation with generator
If a long-term parallel operation and load sharing with a generator is required, ensure the gener-
ator has the identical voltage and frequency setpoints, as well as equal droop characteristic set-
tings for both voltage and frequency. Follow the steps above until step 6. The SFC and generator
will now be sharing the load.
The load may be transferred from either machine by setting the unload command on the SFC or
unloading the Generator.
11.6.2 Transfer SFC to generator
Typically, generators will have their own synchronizer, which will perform the synchronization to
the SFC supplied AC bus. If a generator is unstable when connected to the AC bus supplied by
the SFC, enabling V/F droops on the SureWave SFC might help with stability.
11.6.2.1
SFC to generator installation SLD
The installation and connection of the SureWave SFC to allow seamless transfer from the SFC to
generator is shown in Figure 11-3: Seamless transfer from the SFC to generator. In this scenario
the external voltage sensing must be moved to sense the generator output voltage that is to be
brought online. This could be done with a change-over relay to allow both connections to the ex-
ternal voltage sensing board.
Note, for proper operation the phase and voltage relationship between the voltages measured
by the external voltage sense and the inverter terminals must be known. A neutral is not re-
quired for the synchronizing function and if present, does not need to be connected to the ex-
ternal voltage sense board.
