Different buried permanent magnet arrangements in rotors are compared based on electrical machines found in literature regarding high-speed capability. An analytical approach is presented to analytically calculate mechanical stresses in the bilateral and central bridge of V arrangements in order to determine the achievable circumferential velocity of a rotor geometry. The mechanical model is coupled to an analytical model which can determine the flux density in the main air gap under consideration of flux leakage within the rotor. The multi-domain model enables the analytical design of high-speed rotors with buried permanent magnets in V-arrangement.

Rare-earth permanent magnets are coated in order to avoid corrosion. When considering the rated geometrical properties of a sample, the coating thickness has to be known precisely as it wrongly enlarges the magnetically active volume which in turn affects the accuracy of the measured magnetic properties. In this work, the sensitivity of hard magnetic material property measurements regarding the consideration of different coating thicknesses is evaluated. Moreover, the impact of eddy current effects on the magnetic properties is studied when measuring in an open circuit. Additionally, an outlook for a measurement-based determination of the electric conductivity of permanent magnet samples is given.

Due to speed-dependent centrifugal forces, the support of the torque, static mechanical stress introduced by manufacturing processes the laminated core of rotating electrical machines is exposed to considerable mechanical stress. The resulting stress distribution changes the magnetic properties of the electrical steel. To take this into account, a magnetization model is constituted on the basis of vector magneto-mechanical measurements that include the magnetic permeability as a function of the mechanical stress and the angle between magnetization - and the maximum principal stress direction. Subsequently, the model is integrated into the finite element simulation of a permanent magnet excited synchronous machine at different rotational speeds.