Andreas Looser

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Airborne wind turbines (AWTs) represent a radically new and fascinating concept for future harnessing of wind power. This concept consists of realizing only the blades of a conventional wind turbine (CWT) in the form of a power kite flying at high speed perpendicular to the wind. On the kite are mounted a turbine, an electrical generator, and a power(More)
This paper proposes a method for the efficiency optimization of ultrahigh-speed permanent-magnet machines. Analytical methods are applied for the modeling of the machine that is equipped with a diametrically magnetized rotor and a slotless stator. The outer dimensions of the machine are design constraints, and the internal dimensioning is optimized for(More)
Slotless windings, both skewed and rhombic, are widely used in industry. In addition to the drive torque, possibly undesirable transverse torques and forces are generated. An analytical derivation of the torque and force components in all three directions is detailed in this paper for the skewed and the rhombic windings. It is shown that, for some winding(More)
Successful application of ultra high-speed electrical drive systems in industrial products is currently limited by lacking high-speed bearing technologies permitting high reliability and long lifetime. Promising bearing technologies for high rotational speeds are contact-less bearing concepts such as active magnetic bearings or gas bearings. While magnetic(More)
Active magnetic bearings are a preferred choice for supporting rotors spinning at high-speed due to low friction losses and no wear. However, the rotational speed in previous bearing topologies has been limited by complex rotor constructions, high rotor losses, or position control instabilities at high speed. This paper presents a novel Lorentz-type,(More)
Slotless windings, skewed and rhombic, are widely used in industry. Beside the drive torque, possibly undesired transverse torques and forces are generated, which have not been analyzed previously. An analytical derivation of the torque and force components in all three directions is detailed in this paper for the skewed winding. It is shown that for some(More)
For various drilling applications where the space in the tool head is limited, two motor topologies with the stator outsourced from the head are proposed, allowing for compact design and direct drive. In order to meet the high torque requirements at low speed and operate at high speed up to 200 000 rpm a finite element analysis (FEA) is carried out and the(More)
In many applications electrical energy has to be transferred to rotating parts. Usually a cylindrical transformer with a rotating and a stationary part is used, which are separated by a small air gap. In order to achieve a high magnetic coupling, on both parts a highly permeable core material is employed. In high-speed applications the diameter of the(More)
In a previous study, lateral stator electrical machines have been proposed for micro-machining applications where the space in the tool head is limited. In this paper, the construction of a lateral stator machine merged into a test bench is described. The test bench is used for measuring the standstill torque of the machine in a configuration without(More)
This paper proposes a method for the efficiency optimization of ultra-high-speed permanent-magnet machines. Analytical methods are applied for the modeling of the machine that is equipped with a diametrically magnetized rotor and a slotless stator. The outer dimensions of the machine are design constraints, and the internal dimensioning is optimized for(More)