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Research Topics
Focus
Research is focused on new power semi-
conductor devices in power electronic cir-
cuits and systems: To make circuit and
system design appropriately profit from
the rapid development of devices com-
ing rather close to ideal switches, a basic
physical understanding of their operation
is required. On the other hand, device de-
velopment taking into account major cir-
cuit or application-related requirements
can facilitate usage of the components op-
timised this way. To achieve viable results
in this respect, theoretical calculations and
simulations need to be complemented by
experimental work in laboratory.
The interaction between component, cir-
cuit and system is influenced on such dif-
ferent levels as circuit elements including
parasitics, drivers, control methods and
operational conditions of the system. To
a large extent, power supplies or electric
drives are investigated, aiming at applica-
tions such as in the fields of electric grid
with HVDC, renewable energy, automo-
tive electronics, welding sources or ap-
pliances.
Topic EMC
The switching slopes of the power semi-
conductors cause conducted and radi-
ated emissions of the system which need
to be limited according to standards to
avoid disturbances of the power elec-
tronic or other equipment. The propa-
gation of these disturbances is strongly
influenced by capacitive and inductive
parasitic elements, thus a detailed inves-
tigation of power section – comprising
mechanical construction, semiconductor
devices and their control – is required to
achieve an optimisation.
Topic Reliability
Power semiconductor devices typically
consist of a chip which is packaged in a
structure of several conductive and iso-
lating layers. Several known mechanisms
limit lifetime. Those can be triggered by
operational conditions, e. g. load cycles
leading to thermo-mechanical stress and
subsequent fatigue. Again, the require-
ments defined by increasingly demanding
applications – e.g. cycles in traction, elec-
tromobility or wind generators – need to
be determined and appropriately applied
to the devices’ capabilities as qualified in
standardised tests.
Research Environment
With a mixed team of experienced and
young scientists and a state-of-the-art in-
frastructure of power electronic labora-
tories and computer equipment with rel-
evant simulation software, a variety of
research projects in the aforementioned
fields have successfully been carried out.
Students are involved, providing them an
education to become the next generation
of experts in the field of power electron-
ics with its increasing importance as key
technology for energy efficiency and us-
age of electrical energy generated from
renewable sources.
Otto-von-Guericke-Universität Magdeburg
Measured conducted emissionsof a converter over
frequency under different conditions
Power section with driver and filter circuits of an
experimental converter
Equipment for reliability tests
