Newsletter_12-2022_EN

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NEWSLETTER
www.cleanroom-online.com Edition EN 12-2022 | Page 16/42
Optimising wind energy sustainably
weisstechnik supplies high-performance climate simulation systems for load tests
on wind turbine electronics
Wind power makes an important contribution to combating climate change. However, breakdowns as well as maintenance and repair
of wind turbines are usually time-consuming and costly. This often affects the power electronics, which are exposed to extremely high
loads. This is why the University of Bremen is researching how to extend their service life and optimise maintenance as part of the joint
project HiPE-WiND, funded by the BMWi. As part of this project, weisstechnik has planned and implemented a climatic test chamber for
multidimensional load tests.
Partner for wind energy research
The joint project HiPE-WiND (High Power Electronics in Wind Energy
Plants) is being led by the Institute for Electrical Drives, Power Electronics
and Devices at the University of Bremen in cooperation with the
Fraunhofer Institute for Wind Energy Systems in Bremerhaven. In order
to find out which components of the power electronics fail under
which conditions, long-term load tests are carried out on complete
wind turbine converter systems up to the ten megawatt class. This
simulates the high loads caused by changing wind conditions and
the power grid under different climatic conditions - from the Arctic to
the Sahara. All this is taking place in the customised climate chamber
developed by weisstechnik. As the climatological heart of the „HiPE-
LAB“ in Bremen, the climate chmber helps to realistically and quickly
recreate how the converter systems age under the multimodal loads
during 20 years of use.
300 kW large-scale facility with heavy duty floor
As an experienced specialist in environmental technology, weisstechnik
was able to successfully win the tender for the facility and
plan and realise the project from a single source. The size and performance
of the walk-in and drive-in chamber was a demanding task
in itself, needing a usable test space volume of approx. 190 m3 and
an electrical connected load of just under 300 kW. The surface load
of the heavy-duty floor in the test space is more than 10,000 N/m2.
The large test specimens - switch cabinets with converters - weighing
up to 5,000 kg are moved into the test chamber on rollers via
a double-wing door. The inner chamber walls are made of stainless
steel (welded vapour-tight) and have a 200 mm thick 2-layer insulation
consisting of special foam and mineral wool. A side door serves
as access for the staff.
Environmentally friendly CO2 refrigeration system
The required temperature range for the tests is (-)40 °C to (+)120 °C. In
order to realise this as efficiently and environmentally friendly as possible,
a CO2 cascade refrigeration system was used. This means that
temperatures down to (-)45 °C can be achieved with ease while at
the same time enabling a high level of thermal compensation. This is
important for the load tests because the test specimens tested under
load generate a high thermal load. This is around 70 kW at 100 °C and
a humidity range of up to 95% RH and 50 kW at 85 °C/85% RH. The
use of CO2 as a refrigerant necessitates additional safety devices. It
was therefore necessary to integrate a standstill cooling system with
a separate power supply in order to prevent the CO2 from expanding
and to avoid excessive system pressure during system standstill. In addition,
a gas warning system is integrated in the test chamber and
in the equipment compartment, which triggers visual and acoustic
alarms and activates the emergency purge if CO2 escapes. Furthermore,
the oxygen content is continuously monitored with redundant
measuring technology.
(Source: Weiss Technik GmbH)