DSEGenset DSE8610, Operator'S Manual

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Dead Bus Synchronising (Auto Mode)
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7 DEAD BUS SYNCHRONISING (AUTO MODE)
Generator set specifications often contain the requirement for the set to be on load within 15 seconds
of a mains supply failure. This is easily achievable in single set applications. However in the current
era of fuel conservation, multiple sets are often used to provide the backup power solution for many
applications. This gives challenges in starting and synchronising the required sets before they can be
used to power the load.
The solution to this is a longstanding one, having being used for many decades. However modern
digital communications such as the DSE MSC link has vastly improved the control and hence safety of
the system operation. The solution is called “Dead Bus Synchronising”
7.1 OPERATION
Before the generator sets are started, the load switches are closed. This requires DC controlled
breakers. Next, the alternator excitation field is disconnected from the AVRs and the engines are
started.
Once running satisfactorily, the AVR is reconnected to the excitation field and load sharing begins.
The MSC link is used to ensure all sets excite the alternator at exactly the same time. Any sets not up
to speed before the end of the “Excitation Delay” timer are instructed to open their breakers. A short
time later, these sets synchronise to the bus in the traditional manner.