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power disturbances experienced by
data center power systems.
With online double-conversion,
incoming AC power is rectified to
DC power to supply the internal
DC bus of the UPS. The output
inverter takes the DC power and
produces regulated AC power to
support the critical load. Batteries
attached to the DC bus are float
charged during normal operation.
When the input power is out of
limits, the batteries provide power
to support the inverter and critical
load. The critical load is always
being supplied by the output
inverter, which is always being
supplied from the internal DC bus.
When input power fails, there is no
transitional sag in the output
voltage because the inverter is
already operating on DC input.
Online double-conversion UPS
topologies (Figure 4) deliver better
protection than other types of UPS
systems because they completely
isolate sensitive electronics from the
incoming power source, remove a
wider range of disturbances and
provide a seamless transition to
backup power sources. With the
combination of improved operating
efficiencies and the use of new
technologies, these robust power
systems can achieve efficiencies
greater than 96 percent without any
impact on availability.
AvAIlABIlITy,
eFFICIenCy And
SCAlABIlITy
The mission-critical data center is
one of the most dynamic and
critical operations in any business.
Complexity and criticality have only
increased in recent years as data
centers experienced steady growth
in capacity and density, straining
resources and increasing the
consequences of poor performance.
As the data center continues to
evolve and become more complex
and heterogeneous, it is important
that organizations now select those
power systems that optimize the
“trifecta” of availability, efficiency
and scalability.
AvAIlABIlITy
It is easy to understand how
availability became the dominant
metric on which data centers and
power systems were evaluated. One
significant outage can be so costly
that it wipes out years of savings
achieved through incremental
efficiency improvements, and can
severely impact an organization’s
bottom line.
The actual costs associated with an
unplanned outage can be alarming.
A 2013 Ponemom Institute study,
sponsored by Emerson Network
Power, revealed that the cost of a
data center outage has increased
since 2010. The cost per square
foot of data center outages now
ranges from $45 to $95. Or, a
minimum cost of $74,223 to a
maximum of $1,734,433 per
organization in the study. The
overall average cost is $627,418 per
incident. In some applications, a
power outage may result in the
complete loss of the business
enterprise.
One of the primary reasons power
vulnerabilities are so costly for data
Figure 3. Online double-conversion UPS topology.
Figure 4. Select your topology based on your local power profile and required availability.
