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THE TECH
Siemens is set to sell its eAircraft unit to Rolls-Royce –
the companies expect the move to take place in late 2019.
Siemens eAircraft develops electric and hybrid-elec-
tric propulsion systems for the aerospace industry. At
locations in Munich and Erlangen in Germany as well
as Budapest, Hungary, it cooperates with partners such
as Airbus to create prototypes for propulsion systems
like Airbus’s CityAirbus, with power ratings ranging
from less than 100 kW to several thousand kW. eAircraft
entered a development partnership with Airbus in 2016,
but Siemens has been researching and developing elec-
tric aircraft propulsion systems for about ten years.
“Our eAircraft team is a pioneer in electric and hy-
brid-electric systems for aircraft,” said Siemens CTO and
COO Roland Busch. “With Rolls-Royce, we’ve found a
perfect home for this business and have placed its exper-
tise in the hands of one of Airbus’s close partners. We
will continue to cooperate with Rolls-Royce, in partic-
ular by making our digital solutions portfolio available
in order to facilitate this major step toward sustainable,
lower-emission aviation.”
Siemens sells electric aircraft
propulsion business to Rolls-
Royce
The Fraunhofer
Institute and Hitachi
Metals say they’ve
produced an on-board
charger (OBC) proto-
type that delivers both
high power output and
compactness. Hitachi says the technology enables the
OBC prototype to generate a power density of 3.8 kW/l.
Hitachi explains that there is typically a trade-off be-
tween the high output EVs need to charge their batteries
and the compactness designers need to keep interior
spaces as large as possible, and achieving a good balance
between the two has been a challenge.
The companies say their OBC prototype delivers both
high power output and a compact body by combining
soft magnetic materials developed by Hitachi Metals
with Fraunhofer’s circuit technology. The designers uti-
lized a nanocrystalline alloy called FINEMET FT-3K50T
for the common-mode choke coils in the input/output
noise filter and another choke coil made with an amor-
phous powder core HLM50 for rectification and power
factor correction. In the DC/DC converter, designers
used an isolation transformer with resonance inductors
made of the low-loss soft ferrite core ML29D.
Three of the OBCs connected in parallel can produce
an 11 kW output and three-phase input. The parallel
connection can cover both single- and three-phase AC
input to produce a maximum output of 22 kW through
six parallel connections. The researchers say this flexibili-
ty can significantly reduce OBC design time and costs.
Bernd Eckardt, Head of Automotive Electronics at
Fraunhofer, said, “By using the advanced magnetic
materials of GRIT we were able to realize an ultra-com-
pact and modular OBC with high efficiency. The highly
integrated mechatronic design allows an easy scale up in
power from 3.6 kW up to 22 kW.”Fraunhofer and Hitachi Metals
create on-board charger with
3.8 kW/l power density
Image courtesy of SiemensImage courtesy of Hitachi Metals