InteliMains 210 Global Guide
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The bus frequency is regulated to match the mains fre
. The frequency
regulation loop is active (setpoints
and
). Once the frequency
is matched, the regulation loop gets frozen immediately and the command for breaker closing is unblocked after
the delay given by setpoint
. However the closing breaker command is issued later in
advance before the expected phase match. The proper "angle of advance" is calculated from setpoints
or
Whenever the bus frequency leaves off the
Slip Frequency Window (page 206)
, the command for breaker closing
gets blocked and regulation of frequency is activated again. The same procedure starts again.
5.4.3 Power management
The Power management function decides how many gen-sets should run and selects particular gen-sets to run.
The power management is applicable in cases multiple gen-sets run in parallel to mains or in the island
operation. The function is based on the load evaluation in order to provide enough of available running power.
Since it allows the system to start and stop gen-sets based on the load demand, it can vastly improve the
system fuel efficiency. In other words, an additional gen-set starts when the load of the system raises above
certain level. The additional gen-set stops, when the load of the system drops down below a certain level. The
process of determining gen-set start and stop is done in each controller; there is no "master slave" system.
Therefore, the system is very robust and resistant to failures of any unit in the system. Each of the controllers
can be switched off without influencing the whole system. Except the situation the respective gen-set is not
available for the power management.
The power management evaluates so called load reserve. The load reserve is calculated as difference between
actual load and nominal power of running gen-sets. The reserve is calculated as absolute value (in kW / kVA) or
relatively to the nominal power of gen-set(s) (in %). The setpoint
#Power Management Mode (page 192)
is used
to select the absolute or relative mode.
The automatic priority swapping function focuses on efficient run of gen-set in regards to running hours and gen-
set size.
IMPORTANT: The function of the controller is designed to handle the maximum sum of nominal
power at 32000 kW (or 3200,0 with decimal number).
Example:
There are 20 gen-sets each with 1000 kW of nominal power. The sum of the nominal power is
20000 kW. Therefore the decimal power format in 0.1 kW cannot be used because the sum exceeds 32000.
Therefore power format in kW needs to be chosen.
Basic power management
The Logical binary inputs
requests the system to start or stop. If the input is
not active, the system stops with delay
after the input has been deactivated and
will not start again if in AUTO mode. If the input is activated again, the delay
#System Start Delay (page 193)
starts to count down. Once the delay elapsed, the system is activated and can be started by the power
management. In other words, the power management is activated only if the Logical binary inputs
is activated.
Note:
The gen-set performs load and VAR sharing whenever it is connected to the bus bar i.e. it is independent
on whether the controller is in AUTO or MAN mode or whether the power management is active or not.
Principle of power management
Internal conditions based on remaining load reserves and priorities are evaluated once a delay is elapsed. If the
load reserve is insufficient the gen-set is started after delay given by the setpoint
