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COMMERCIAL FEATURE
Active cooling
for maximum yields
A s beneficial as intense solar
irradiation is for the photovoltaic
(PV) industry, rising heat places
heavier demands on central inverters
used to produce clean current for millions
of people in the hotter areas of the globe.
They are not only required to work at
the highest efficiency possible but are
also expected to function reliably and
faultlessly for the duration of operation.
Here, cooling systems play an important
role. There is a high risk, due to
overheating, that sensitive
components within the inverter
will begin to behave
differently, leading to their
eventual breakdown.
Anything from short-term
failures to a complete
system standstill bringing
about high losses in yield
are only some of the
consequences faced by PV
power plant operators and
investors in photovoltaic
projects. An intelligent and
reliable cooling system is
a decisive factor when it
comes to investments in
central inverters, especially
in regions characterised
by extreme ambient
conditions. For example, in
the varying climate regions
of South Africa fine dust
particles stirred up by sand
storms place an additional
burden, apart from the
effects of the extremely
high temperatures, on the
central inverters in PV
power plants. Millions of
people in South Africa, for example,
benefit from the PV energy source. A
total of 3,000 hours of sun per year
and PV yields of up to 2,100 kilowatts
per kilowatt of nominal plant power are
achieved. Active cooling
“An intelligent cooling concept is the key
to optimal central inverter operation,”
94 Hilton Hunkin, technical sales support
engineer at SMA South Africa, explains.
“This requires, apart from the optimal
spatial organisation of all components,
an efficient and properly dimensioned
cooling system. Our Sunny Central
inverters function at temperatures of
up to 50 O C at nominal power – and full
energy yield – based on the innovative
cooling concept OptiCool and clever
spatial design.
“Even at temperatures of between
50 O C and 62 O C Sunny Central inverters
continue to feed in but at the same time
reduce the feed-in capacity according to
temperature for self-protection. At 55 O C a
Sunny Central continues to feed in 50%
of its nominal power.”
In addition, Hunkin points out that
SMA central inverters operating with
optimal cooling can even yield a nominal
power of 110% at temperatures of up to
25 O C during continuous operation.
Fresh air is drawn in through the ventilation grids on the top front of the Sunny Central. The air
passes the cooling-fan and the heat producing stacks and the sine wave filter choke stuck out in the
air duct. The warm air leaves the inverter through a low-maintenance grid filter.
ESI AFRICA ISSUE 1 2014