Winco DGC-2020 - Manual (Page 80)

4-30 DGC-2020 BESTCOMSPlus Software 9400200990 Rev B
Figure 4-28. BESTCOMSPlus Bus Condition Detection Settings
A
Dead Bus Threshold: Adjustable from 0 to 4,800 Vac in 1 Vac increments.
B
Dead Bus Time Delay: Adjustable from 0.1 to 600 s in 0.1 s increments.
C
Gen and Bus Stable Overvoltage Pickup and Dropout: Adjustable from 10 to 1,200 Vac in 1 Vac
increments.
D Gen and Bus Stable Undervoltage Pickup and Dropout: Adjustable from 10 to 12,000 Vac in 1 Vac
increments.
E
Gen and Bus Stable Overfrequency Pickup and Dropout: Adjustable from 46 to 64 Hz in 0.05 Hz
increments for 50/60 Hz generator frequency (style number x1xxxxxxx).
F
Gen and Bus Stable Underfrequency Pickup and Dropout: Adjustable from 46 to 64 Hz in 0.05 Hz
increments for 50/60 Hz generator frequency (style number x1xxxxxxx).
Automatic Synchronizer (Optional)
Two methods of generator synchronization are offered: phase lock loop and anticipatory
A
. In both
methods, the DGC-2020 adjusts the frequency and voltage of the generator to match that of the bus
(mains) and then connects the generator to the bus by closing the breaker. Anticipatory mode has the
added capability of compensating for the breaker closing time (the delay between when a breaker close
command is issued and the breaker blades close). The DGC-2020 calculates the advance phase angle
that is required to compensate for the breaker closure time by monitoring the frequency difference
between the generator and the bus.
Correction Signals
The DGC-2020 adjusts the generator voltage and frequency by issuing voltage correction signals to the
generator AVR (automatic voltage regulator) and speed correction signals to the generator governor.
Correction signals are issued in the form of DGC-2020 output contact closures. These correction signals
can be either continuous or proportional
B
. Proportional correction uses control pulses of varying widths
C
and intervals
D
. Initially, long pulses are issued when the voltage and frequency differences are large. As
the correction pulses take effect and the voltage and frequency differences become smaller, the
correction pulse widths are proportionally decreased. Proportional correction pulses are beneficial in
applications where fixed correction pulses can result in overshooting the slip frequency and regulation
offset targets.
NOTE
If the generator frequency is 400 Hz, the settings on the Bus Condition Detection
screen do NOT apply. In this case, BESTCOMSPlus will not allow these settings
to be changed.