The
Minimum ON time
sets the minimum amount of time a relay is allowed to be closed. This should be similar to the minimum time
required for the system to respond to the output signal.
The
Maximum ON time
sets the maximum amount of time a relay is allowed to be closed when the regulation is in the constant
range. The parameter is a percentage of the Period time.
The pulse length is never shorter than the
Minimum ON time
. Once the pulse length is equal to or greater than the period time, the
controller shifts from the variable range to the constant range, if the
Maximum ON time
is set to 100 %. The deviation where this shift
occurs depends on
Kp
and the period time. As
Kp
increases, the variable range decreases. As
Kp
decreases, the variable range
increases.
6.1.4 Regulation mode overview
The genset regulation system consists of a number of basic control modes for the governor, and for the AVR. Each controller
processes the input information and calculates what action the genset should take to reach the required operating value. The
calculated value is then modified according to the governor or AVR interface, and sent to the governor or AVR.
The table below shows under which conditions the modes are active.
Table 6.2
Active modes for different system conditions
Condition
Governor mode
AVR mode
G
The generator breaker is open and
the genset is running.
This can be a stand alone genset, or
a genset in a system.
•
Frequency
regulation
•
Voltage
regulation
G
G
The generator breaker is open and
the controller receives a close
breaker command.
The controller sends commands to
synchronise the genset to the busbar
frequency, voltage and phase (static
synchronisation).
•
Frequency
synchronisation
•
Phase
synchronisation
(only for static
synchronisation)
•
Voltage
regulation
G
G
The genset is connected to the
busbar and is producing power.
The genset can be a stand alone
genset, or a genset running in
parallel to another power producing
component on the busbar.
•
Power regulation
•
Power load share
•
Reactive
power
regulation
•
Power
factor
regulation
•
Reactive
power load
share
DESIGNER'S HANDBOOK 4189340911K UK
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