215Section 12 Paralleling System InformationTP-6953 7/19
12.4.9 Start Modes
The generator controller supports a system start
(Auto-Run, remote start contacts, CAN gauge start
signal, SiteTecht start signal) and local start (pressing
the run button). The paralleling system behaves
diff erently depending on which start command is
received.
A system start command to any generator in the system
will start all generators that are in auto. If a generator is
placed in auto after the start signal is applied to any
generator, that generator will start. A generator does not
have to be in auto to accept a start signal, but it does
have to be in auto to start. The synchronizer uses the
Sync Mode in Auto parameter to determine the
synchronizing settings during a system start event.
Generator Management and load management are only
active during a system start.
A local start command to a generator will result in only
that generator starting. The synchronizer uses the Sync
Mode in Run parameter to determine the synchronizing
settings during a local start event. Generator
Management will not consider a generator that is
operating in local start mode as available, even if it is
running.
12.4.10 Control Inputs
The Paralleling logic accepts the following Control
Inputs, configurable for a digital input:
D Disable Synchronization. This function will prevent
the controller from synchronizing or closing the
breaker to a dead bus, but will not cause the breaker
to trip if it is closed. This input is commonly u sed to
coordinate Decision-Makerr 3500 controller
generators with the first -on logic of older, existing
generators.
D Load Enable. This function allows the generator to
take load. If disabled, the generator speed will drop if
load is present on the paralleling bus and no other
nodes are connected to support the load. If other
nodes exist, the generator will control its output power
to no load.
D Baseload Mode. This function puts the generator into
baseload mode. If a start signal is received in baseload
mode, the controller will start, synchronize, connect to
the paralleling bus, and ramp the power control target
to the baseload setpoint.
Note: The baseload input takes priority over the System
control and System Sync input. Baseload mode
will not ramp to the target if load enable is off.
Baseload can be used to exercise generators
against the utility with a fixed load, it should not be
used in an islanded paralleling system except for
troubleshooting purposes.
D System Control Mode. This function puts the
generator in a power control mode where the power
level for all generators on the paralleling bus is
controlled by an external device using the speed and
voltage bias (speed bias controls real power, voltage
bias controls reactive power or power factor,
depending on the VAR control mode). This mode takes
priority over the System Sync Mode and requires load
enable to be active in order to ramp output powe r to the
system control target. Once the load ramp reaches the
target, the generator will try to match the power target
with the output power. This mode is not to be used in an
islanded system, but will allow external switchgear to
control the entire generator bus to soft load and unload
against the utility. The speed and voltage bias can be
applied to any number of generators in the system, as
only one will have control of the bus. System Control
Mode must be enabled on generators receiving the
speed and voltage bias.
D System Sync Mode. This function causes all the
running generators in a paralleling system to adjust
their target speed and voltage to match the speed and
voltage bias applied to the external bias inputs on the
controller set to system sync mode. This bias can be
applied to multiple units, but only one will have control
of the paralleling bus. System sync mode is intended
to allow external s witchgear to synchronize the
generator paralleling bus to the utility.
12.4.11 Generator Management
See Section 13.
12.4.12 Load Management
See Section 14.
To Next Page
Loading...
