Matthias Gregor

A comparison of the transverse, axial and radial flux PM synchronous motors for electric vehicle

This paper presents the performance comparison among three different topologies of the permanent magnet synchronous machine, namely a transverse flux permanent magnet machine with flux concentration and claw pole structure, an axial flux machine with segmented armature torus structure and a conventional radial flux machine with embedded permanent magnets in the rotor. With the help of Finite Element Method, three electrical machines have been designed considering the required dimensions and permanent magnets mass. The complete results evaluation and comparisons are described in this paper. From the obtained results it can be concluded, the axial flux machine with segmented armature torus structure can be a competitive alternative compared with the conventional radial flux machine for applications with limited axial length, while the transverse flux machine is an attractive alternative for the high torque and low-speed applications due to its high pole number.

Mechanical construction and analysis of an axial flux segmented armature torus machine

This paper deals with the mechanical construction and static strength analysis of an axial flux permanent magnet machine with segmented armature torus topology, which consists of two external rotors and an inner stator. In order to conduct the three dimensional magnetic flux, the soft magnetic composites is used to manufacture the stator segments and the rotor yoke. On the basis of the detailed electromagnetic analysis, the main geometric dimensions of the machine are determined, which is also the precondition of the mechanical construction. Through the application of epoxy with high thermal conductivity and high mechanical strength, the independent segments of the stator are bounded together with the liquid-cooling system, which makes a high electrical load possible. Due to the unavoidable errors in the manufacturing and montage, there might be large force between the rotors and the stator. Thus, the rotor is held with a rotor carrier made from aluminum alloy with high elastic modulus and the form of the rotor carrier is optimized, in order to reduce the axial deformation. In addition, the shell and the shaft are designed and the choice of bearings is discussed. Finally, the strain and deformation of different parts are analyzed with the help of finite element method to validate the mechanical construction.