•
If there is no other busbar, or if the bus tie breaker cannot be closed automatically, or if the bus tie breaker fails to close, the
controller attempts to use genset start to resolve the blackout.
3. The power management system checks whether there are any GENSET controllers under PMS control, with gensets ready to
start.
a. The power management system changes all GENSET controllers in SEMI mode to AUTO mode.
b. The power management system sends a start signal to the number of gensets specified, according to their position in the
genset priority order. Gensets that are not ready to start are not sent a start signal.
c. The power management system sends the first genset that has running feedback and its voltage and frequency within range
an acknowledge signal. The first genset closes its breaker immediately. If the breaker does not close within the
Closing
failure
time, the breaker close signal is sent to the next genset to start.
d. Any other gensets that start are synchronised to the busbar, and their breakers are closed.
e. The blackout is resolved when a genset has successfully connected to the busbar. The power management controller
switches back to normal operation. All the gensets that were sent a start signal are allowed to start and connect to the
busbar. After the load-dependent stop timer expires, the power management controller will stop the lowest priority gensets if
they are not required to power the load.
4. If the genset starts do not resolve the blackout, the power management system checks whether a shaft generator with auto close
ON is present and OK to supply power.
•
Yes: The power management system sends a breaker close signal to the controller. If the breaker closes, the blackout is
resolved.
5. The power management system checks whether a shore connection with auto close ON is present and OK to supply power.
•
Yes: The power management system sends a breaker close signal to the controller. If the breaker closes, the blackout is
resolved.
More information
See
SHAFT generator controller
,
Shaft generator breaker
,
Shaft generator breaker blackout close flowchart
for
more information.
More information
See
SHORE connection controller
,
Shore connection breaker
,
Shore connection breaker blackout close flowchart
for more information.
7.6 Load sharing
7.6.1 Introduction
When gensets operate in parallel, supplying power to the same busbar, the operation cannot be stable unless the loading on the
gensets is controlled. To efficiently control the gensets' operation, the power management system must perform
load sharing
for the
gensets.
The
load sharing
is achieved by using the
DEIF network load sharing
(for DEIF controllers connected together via Ethernet
cabling).
Table 7.11
Load sharing possibilities
Load sharing connection
Asymmetric
Equal
DEIF network
●
●
INFO
The voltage and frequency for paralleled gensets on the same busbar are forced to exactly the same values. As a result,
the busbar voltage and genset speed alone do not provide the information needed for load sharing calculations.
7.6.2 DEIF network load sharing
The controllers can share the load (both active power (P) and reactive power (Q)) over the DEIF network.
DESIGNER'S HANDBOOK 4189340911K UK
Page 246 of 521
