Winco DGC-2020 - Manual (Page 125)

that is required to compensate for the breaker closure time by monitoring the frequency difference
between the generator and the bus.
BESTCOMSPlus automatic synchronizer settings (DGC-2020, Breaker Management, Synchronizer) are
illustrated in Figure 4-51.
Frequency Correction
Generator frequency correction is defined by the slip frequency setting and further refined by the breaker
closing angle setting. The slip frequency setting
B establishes the maximum allowable deviation of the
generator speed (frequency) from the bus frequency. To minimize the impact on the bus during
synchronization, the Fgen>Fbus setting
C can be enabled to force the generator frequency to exceed the
bus frequency at the moment of breaker closure. If this is the case, the DGC-2020 will drive the generator
frequency higher than the bus frequency before closing the breaker. The breaker closing angle setting
D
defines the maximum allowable phase angle difference between the generator and the bus. For breaker
closure to be considered, the slip angle must remain below this setting for the duration of the sync
activation delay setting
E .
Voltage Correction
Generator voltage correction is defined by the regulation offset setting
F . This setting, expressed as a
percentage of the bus voltage, determines the band of generator voltage surrounding the bus voltage
when breaker closure will be considered. If the Vgen>Vbus setting
G is enabled, the DGC-2020 will drive
the generator voltage to be greater than the bus voltage by an amount equal to the regulation offset
setting divided by two.
Synchronization Failure
The maximum desired duration for synchronizing to take place is established by the sync fail activation
delay setting
H . If synchronization (breaker closure) fails to occur within this time setting, generator
synchronization will be aborted and a failure will be annunciated. Note that if either bus goes unstable, the
synchronizer timers are reset.
NOTE
If the generator frequency is 400 Hz, the settings on the Synchronizer screen do
NOT apply. In this case, BESTCOMSPlus will not allow these settings to be
changed.
Figure 4-51. Synchronizer Settings
A Sync Type: Phase Lock Loop or Anticipatory.
B Slip Frequency: Adjustable from 0.05 to 0.5 Hz in 0.05 Hz increments. If Anticipatory synchronization is
selected, this specifies the maximum acceptable slip under which a close command can occur. If Phase
Lock Loop synchronization is selected and the slip angle is within the Breaker Closing Angle criterion for
a period long enough to indicate the slip frequency criterion has been met, a breaker close command can
be issued.
C Fgen>Fbus: Enable or Disable.
9400200990 Rev K DGC-2020 BESTCOMSPlus Software 4-55