TY  - CHAP
A1  - Finger, Felix
A1  - Khalsa, R.
A1  - Kreyer, Jörg
A1  - Mayntz, Joscha
A1  - Braun, Carsten
A1  - Dahmann, Peter
A1  - Esch, Thomas
A1  - Kemper, Hans
A1  - Schmitz, O.
A1  - Bragard, Michael
T1  - An approach to propulsion system modelling for the conceptual design of hybrid-electric general aviation aircraft
T2  - Deutscher Luft- und Raumfahrtkongress 2019, 30.9.-2.10.2019, Darmstadt
N2  - In this paper, an approach to propulsion system modelling for hybrid-electric general aviation aircraft is presented. Because the focus is on general aviation aircraft, only combinations of electric motors and reciprocating combustion engines are explored. Gas turbine hybrids will not be considered. The level of the component's models is appropriate for the conceptual design stage. They are simple and adaptable, so that a wide range of designs with morphologically different propulsive system architectures can be quickly compared. Modelling strategies for both mass and efficiency of each part of the propulsion system (engine, motor, battery and propeller) will be presented.
Y1  - 2019
ER  - 
TY  - JOUR
A1  - Kowalewski, Paul
A1  - Bragard, Michael
A1  - Hüning, Felix
A1  - De Doncker, Rik W.
T1  - An inexpensive Wiegand-sensor-based rotary encoder without rotating magnets for use in electrical drives
JF  - IEEE Transactions on Instrumentation and Measurement
N2  - This paper introduces an inexpensive Wiegand-sensor-based rotary encoder that avoids rotating magnets and is suitable for electrical-drive applications. So far, Wiegand-sensor-based encoders usually include a magnetic pole wheel with rotating permanent magnets. These encoders combine the disadvantages of an increased magnet demand and a limited maximal speed due to the centripetal force acting on the rotating magnets. The proposed approach reduces the total demand of permanent magnets drastically. Moreover, the rotating part is manufacturable from a single piece of steel, which makes it very robust and cheap. This work presents the theoretical operating principle of the proposed approach and validates its benefits on a hardware prototype. The presented proof-of-concept prototype achieves a mechanical resolution of 4.5 ° by using only 4 permanent magnets, 2Wiegand sensors and a rotating steel gear wheel with 20 teeth.
KW  - Rotary encoder
KW  - Wiegand sensor
Y1  - 2023
U6  - http://dx.doi.org/10.1109/TIM.2023.3326166
SN  - 0018-9456 (Print)
SN  - 1557-9662 (Online)
N1  - Early Access
SP  - 10 Seiten
PB  - IEEE
ER  - 
TY  - JOUR
A1  - Bragard, Michael
A1  - Soltau, N.
A1  - Thomas, S.
A1  - De Doncker, R. W.
T1  - The balance of renewable sources and user demands in grids : power electronics for modular battery energy storage systems
JF  - IEEE transactions on power electronics
N2  - The continuously growing amount of renewable sources starts compromising the stability of electrical grids. Contradictory to fossil fuel power plants, energy production of wind and photovoltaic (PV) energy is fluctuating. Although predictions have significantly improved, an outage of multi-MW offshore wind farms poses a challenging problem. One solution could be the integration of storage systems in the grid. After a short overview, this paper focuses on two exemplary battery storage systems, including the required power electronics. The grid integration, as well as the optimal usage of volatile energy reserves, is presented for a 5- kW PV system for home application, as well as for a 100- MW medium-voltage system, intended for wind farm usage. The efficiency and cost of topologies are investigated as a key parameter for large-scale integration of renewable power at medium- and low-voltage.
Y1  - 2010
U6  - http://dx.doi.org/10.1109/TPEL.2010.2085455
SN  - 0885-8993
VL  - 25
IS  - 12
SP  - 3049
EP  - 3056
PB  - IEEE
CY  - New York
ER  -