@inproceedings{KastenHofmann, author = {Kasten, Henning and Hofmann, Wilfried}, title = {Optimal number of strands in electrical medium-frequency machines}, series = {The XIX International Conference on Electrical Machines - ICEM 2010, Rome, Italy}, booktitle = {The XIX International Conference on Electrical Machines - ICEM 2010, Rome, Italy}, publisher = {IEEE}, isbn = {978-1-4244-4174-7}, doi = {10.1109/ICELMACH.2010.5608252}, pages = {1 -- 6}, abstract = {The conductors of rotating electrical machines run through slots. The conductor will often be divided into many strands in order to reduce the current displacement losses. However, a high number of strands also results in a higher volume for the wire enamel so that the slot space factor and the conductor cross-sectional area will be reduced. A smaller conductor cross-sectional area is the reason for higher ohmic winding resistance and copper losses. Therefore the copper losses are minimal at a certain number of strands. Additionally, higher numbers of strands reduce the thermal conductivity, so that thermal aspects should also be considered. This paper provides a theoretical foundation for the dimensioning of the strands.}, language = {en} } @inproceedings{KastenHofmann, author = {Kasten, Henning and Hofmann, Wilfried}, title = {Electrical machines with higher efficiency through combined star-delta windings}, series = {2011 IEEE International Electric Machines \& Drives Conference (IEMDC), Niagara Falls, ON, Canada}, booktitle = {2011 IEEE International Electric Machines \& Drives Conference (IEMDC), Niagara Falls, ON, Canada}, publisher = {IEEE}, isbn = {978-1-4577-0061-3}, doi = {10.1109/IEMDC.2011.5994806}, pages = {1374 -- 1379}, abstract = {Combined windings have higher fundamental winding factors and produce smaller harmonic contents. Therefore, the efficiency can be increased without any additional active mass. This paper presents specifics of the combined windings. Special topics are the higher efficiency in comparison to machines with the same size and classical windings, design and calculation of combined windings, winding technique and experimental results of a 30 kW standard asynchronous motor.}, language = {en} } @inproceedings{KastenBeinekeBachmann, author = {Kasten, Henning and Beineke, Stephan and Bachmann, Matthias}, title = {Double inverter concept for high-speed drives without motor filters}, series = {2022 24th European Conference on Power Electronics and Applications (EPE'22 ECCE Europe), Hannover, Germany}, booktitle = {2022 24th European Conference on Power Electronics and Applications (EPE'22 ECCE Europe), Hannover, Germany}, publisher = {IEEE}, isbn = {978-9-0758-1539-9}, pages = {1 -- 10}, abstract = {It is known that high-speed machines have high power and loss densities [1]. The additional losses in the rotor caused by harmonics are particularly critical, as they act in the center of the machine. This paper shows an approach to reach small additional losses without a filter between inverter and machine.}, language = {en} } @inproceedings{MessagerCheKastenetal., author = {Messager, Gael and Che, Guoyi and Kasten, Henning and Redemann, Christian}, title = {Optimization of axial magnetic bearing for application of vibration assisted drilling}, series = {IKMT 2022; 13. GMM/ETG-Symposium, Linz, Austria}, booktitle = {IKMT 2022; 13. GMM/ETG-Symposium, Linz, Austria}, publisher = {VDE}, isbn = {978-3-8007-5938-5}, pages = {1 -- 6}, abstract = {Thrust magnetic bearing characteristics are frequency dependent due to the eddy-currents inducted inside magnetic parts that oppose any change of magnetic flux in the inner parts. When used as linear actuator for vibration assisted drilling in industrial production, eddy-currents limit the maximum achievable stroke and vibration frequency with active thrust bearing. This reduces tool-feed rate or shortens tool average useful life. After introducing the problem, material properties and shape optimization are evaluated and compared in the frequency range of interest for vibration assisted drilling. While material properties are determinant, mechanical constraints often limit the selection to materials with significant electrical conductivity. Eddy-current effect can only be partially mitigated with shape optimization.}, language = {en} } @inproceedings{KastenHofmann, author = {Kasten, Henning and Hofmann, Wilfried}, title = {Combined stator windings in electric machines with same coils}, series = {2012 XXth International Conference on Electrical Machines, Marseille, France}, booktitle = {2012 XXth International Conference on Electrical Machines, Marseille, France}, publisher = {IEEE}, isbn = {978-1-4673-0142-8}, doi = {10.1109/ICElMach.2012.6349848}, pages = {103 -- 108}, abstract = {The idea of combined windings is very old, but only a few motor windings have been built with them until today. Recently some releases were cast out about this topic, because the combined winding reduces the copper losses. The international claim IEC 60034 for more efficiency to reduce greenhouse gases pushes the factories to look for new ways of reducing the losses in electrical machines. A way to save energy is to build up asynchronous machines with copper cast rotors. Combined windings are a further possibility and avoid the higher costs caused by the copper rotor. A further application of combined windings is the high speed drives. Combined windings can be built up to generate a very small harmonic content so that the losses of permanent magnet rotors and its temperatures decrease. A problem of combined windings is that two kinds of coils will be needed. This paper shows a way to create one layer combined windings with only one sort of coils. By using this windings the higher costs will be narrowed. Examples of combined windings will be compared with conventional windings about copper losses and harmonic content.}, language = {en} } @inproceedings{KastenRedemann, author = {Kasten, Henning and Redemann, Christian}, title = {Influence on unbalanced magnetic pull}, series = {Proceedings of the 14th International Symposium on Magnetic Bearings (ISMB14)}, booktitle = {Proceedings of the 14th International Symposium on Magnetic Bearings (ISMB14)}, pages = {758 -- 761}, abstract = {This article describes the effects of the unbalanced magnetic pull and the opportunities to suppress asymmetries of the air gap field.}, language = {en} } @inproceedings{MinkPeterKastenetal., author = {Mink, Fabian and Peter, Klaus and Kasten, Henning and Beineke, Stephan}, title = {Feedback control of high-speed PMSM with synchronous optimal PWM}, series = {2016 18th European Conference on Power Electronics and Applications (EPE'16 ECCE Europe), Karlsruhe, Germany}, booktitle = {2016 18th European Conference on Power Electronics and Applications (EPE'16 ECCE Europe), Karlsruhe, Germany}, publisher = {IEEE}, doi = {10.1109/EPE.2016.7695470}, pages = {1 -- 10}, abstract = {A new field oriented control structure is presented which makes it possible to use synchronous optimal PWM (SOPWM) for high-speed PMSM drives. Due to the simplicity of modulator and control, parametrization is straightforward. The algorithms are implemented on an industrial drive controller. Measurement results show the advantages compared to standard PWM schemes using asynchronous space vector modulation (SVPWM).}, language = {en} } @inproceedings{KastenCheBeineke, author = {Kasten, Henning and Che, Guoyi and Beineke, Stephan}, title = {PM-machines with an additional shielding sleeve to reduce the rotor losses}, series = {Electromechanical Drive Systems 2021; ETG Symposium}, booktitle = {Electromechanical Drive Systems 2021; ETG Symposium}, publisher = {VDE}, isbn = {978-3-8007-5685-8}, pages = {1 -- 6}, abstract = {Rotor losses have a major impact on the performance of high-speed permanent magnet synchronous machines. Therefore a way to reduce rotor losses by using shielding cylinders is proposed and the effects of these measure are discussed according to the main causes of the rotor losses, which are current harmonics and winding harmonics. The loss minimisation will be demonstrated a for a specific high-speed motor design.}, language = {en} } @inproceedings{RaabHofmannKastenetal., author = {Raab, Sebastian and Hofmann, Martin and Kasten, Henning and Ackva, Ansgar}, title = {High Bandwidth PWM-based Amplifier for Non-Linear Hybrid Filter in Electric Vehicle DC Grids}, series = {25th European Conference on Power Electronics and Applications (EPE'23 ECCE Europe)}, booktitle = {25th European Conference on Power Electronics and Applications (EPE'23 ECCE Europe)}, publisher = {IEEE}, isbn = {978-9-0758-1541-2}, doi = {10.23919/EPE23ECCEEurope58414.2023.10264683}, pages = {1 -- 9}, abstract = {The paper presents design and modulation strategy for a high bandwidth PWM-based amplifier. It consists of multiple H-bridges connected in parallel and switched sequentially. As the effective switching frequency is a multiple of the switching frequency of each single switch, the bandwidth is scaled by the number of H-bridges in parallel. The prototype presented supports a maximum number of eight H-bridges in parallel.}, language = {en} }