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NTB University of Applied Sciences Buchs, Switzerland
The Power Electronics Laboratory
The Power Electronics Laboratory at the
NTB University of Applied Sciences Buchs
focuses on modern Power Electronics
research with a team of about ten spe-
cialists and graduate students. The vast
majority of the projects are carried out in
close collaboration with local or interna-
tional partners in industry. The primary
focus is on applications in the lower power
range where typically switched mode
techniques are employed.
Research Fields and Competence
Areas
The R&D activities in the area of circuits
range from classical PWM converters to
resonant topologies for a large variety
of applications. These include adapters,
battery chargers, power factor corrector
frontends, inverters, motor drives, high
voltage sources to name but a few. Typical
fields of application are industrial and
consumer electronics, renewable energy
systems, drives and chargers ranging
from IT equipment to electric vehicles.
The scope of projects varies from feasibil-
ity studies and comparative investigations
to simulations and analyses, the realiza-
tion of prototypes all the way to indus-
trialization and certification of complete
designs.
Emphasis is also placed on advanced
magnetic components. For example, op-
timized coupled inductors in multi-phase
PWM converters or integrated magnet-
ics placed in LLC-resonant converters
are utilized to achieve high power den-
sity designs. The tools used include FEA
simulations as well as lumped reluctance
models.
A further research field is wireless charg-
ing for electric vehicles. Recent and cur-
rent work includes prototypes for 3.5 kW,
7 kW and 22 kW charger systems. The key
to success is to optimize the coupler ge-
ometry and the electronic circuit simulta-
neously and not as separate systems. DC-
to-DC efficiencies of well above 95% have
been reached over an air gap of 16 cm.
Finally, small signal analysis and model-
ling are integral parts of Power Electron-
ics circuit design. Analytical derivation
of the transfer functions of new topolo-
gies as well as loop gain measurements
on existing circuits are tools to optimize
analog or digital control circuits.
Equipment
The laboratory is equipped with state-
of-the-art hardware and software tools.
These include a climate chamber, an EMC
test setup, a spectrum analyzer, a net-
work analyzer, frequency response ana-
lyzers, power analyzers, a range of DC
and AC power sources and sinks, as well
as high-end oscilloscopes.
