Frode Magnussen

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In order to increase the fault tolerance of a motor drive, multiphase systems are adopted. Since custom solutions are expensive, machines with dual three-phase windings supplied by two parallel converters seem to be more convenient. In the event of a fault, one of the two three-phase windings (the faulty winding) is disconnected, and the motor is operated(More)
Permanent-magnet machines using concentrated windings are gaining popularity at the expense of distributed windings in various applications, mainly due to cost savings. The result is often an increased amount of parasitic effects like ripple torque, alternating magnetic fields in the rotor, unbalanced radial forces, and magnetic noise. This paper describes(More)
Measures to improve the modeling of steel-sheet laminations in electrical machine design tools are studied. Only the magnetic properties, namely, the permeability (BH curves) and the iron losses are addressed. The sensitivity of these properties upon dimensional, directional (anisotropy) and excitation variations, as well as upon the electrical machines(More)
The interior permanent-magnet (IPM) synchronous motor is characterized by a high rotor anisotropy. Such an anisotropy is the cause of a high harmonic content of the air-gap flux density distribution, almost independent of the main flux. As a consequence, there are fluctuations of the flux density in the stator iron and, consequently, eddy-current iron(More)
The growing interest in fault-tolerant drives requires new solutions avoiding the adoption of custom and expensive configurations. The machine with a dual three-phase winding is an interesting candidate. It is provided with two windings, each of them fed by one converter of half power. With a proper mechanical and electrical arrangement, the machine can be(More)
Permanent magnet machines for electric vehicles are often designed with a magnetic saliency to improve the torque generation as a result of the reluctance torque at field-weakening operation. The armature reaction is pronounced in such operation, leading to extensive magnetic field harmonics in the teeth and consequently iron losses. This paper analyses the(More)
Properties of mixed gels made from two different thermo-setting biopolymers at associative phase separated conditions are presented as function of temperature. Special emphasis is put on the relative importance of the two polymers in relation to network formation and apparent equilibrium modulus. The mechanical properties are linked to differences in(More)
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