Deif Multi-line 2 User Manual

AGC Designer’s Reference Handbook
DEIF A/S Page 137 of 168
After the synchronising the unit will change the controller setpoint according to the requirements of
the selected gen-set mode.
Settings
The following settings must be adjusted, if the static synchroniser is selected:
Setting Description Comment
Maximum df The maximum allowed frequency difference
between the busbar/mains and the generator.
+/- value.
Maximum dU The maximum allowed voltage difference
between the busbar/mains and the generator.
+/- value, related to the
nominal generator voltage.
Close window The size of the window where the syn-
chronisation pulse can be released.
+/- value.
Phase K
P
Adjustment of the proportional factor of the PI
phase controller.
Phase K
I
Adjustment of the integral factor of the PI phase
controller.
Only used during static syn-
chronisation.
GB closing before excitation
It is possible to adjust the AGC to start up the gen-set with the excitation switched off. When the
gen-sets are started up, then the breakers will be closed and the excitation started. It is also
possible to close the breaker before the engine is started. This function is called ‘close before
excitation’.
The purpose of the ‘close before excitation’ is that the gen-sets are able to be ready for the load
very quickly. All of the gen-sets will be connected to the busbar as soon as they are started, and
as soon as the excitation is switched on the gen-sets are ready for operation. This is faster than
the normal synchronising, because in that case the breakers will not be closed until the
generator voltage is in the synchronised position, and it takes some time to achieve that position.
The ‘close before start’ function can also be used, if the load requires a ‘soft’ start. This can be
the case when the gen-sets connect to a transformer.
As soon as the excitation is activated, the generators will equalize the voltage and frequency and
will eventually run in a synchronised system. When the excitation is activated, then the
regulators of the AGC will be switched on after an adjustable delay.
The function can be used in the single AGC but also the AGC with option G5. The only
exception is that when option G3 is selected, then the ‘close before excitation’ function is not
available.
The principle is described in the flowcharts below.
Static synchronisation is recommended where a slip frequency is not accepted,
for instance if several gen-sets synchronise to a busbar with no load groups
connected.
The excitation must be increased slowly when this function is used.
This function can only be used when a magnetic pick-up is used.

Deif Multi-line 2 Specifications

General

Brand	Deif
Model	Multi-line 2
Category	Controller
Language	English