A Novel Interior Permanent Magnet Machine with Magnet Axis Shifted Effect for Electric Vehicle Applications

This paper proposes a novel interior permanent magnet (IPM) machine with asymmetrical PM configuration. Different from the traditional IPM counterparts, the proposed machine can perform a magnet axis shifted (MAS) effect. The magnet axis is shifted towards the reluctance axis so that a higher resultant torque capability can be obtained. Firstly, the configuration and the basic principle of the proposed machine are described. The design parameters are optimized to improve the torque capability, and the effect of the PM asymmetry ratio on the torque performance is then evaluated in detail. In addition, the major electromagnetic characteristics of the optimized machine are investigated and compared with those of the Prius 2010 IPM machine by finite element method (FEM). The results demonstrate that the proposed asymmetrical PM configuration can achieve the torque improvement due to the MAS effect.

Transient Attitude Motion of TNS-0#2 Nanosatellite during Atmosphere Re-Entry

Attitude motion reconstruction of the Technological NanoSatellite TNS-0 #2 during the last month of its mission is presented in the paper. The satellite was designed to test the performance of the data transmission via the Globalstar communication system. This system successfully provided telemetry (even during its atmosphere re-entry) up to an altitude of 156 km. Satellite attitude data for this phase is analyzed in the paper. The nominal satellite attitude represents its passive stabilization along a geomagnetic field induction vector. The satellite was equipped with a permanent magnet and hysteresis dampers. The permanent magnet axis tracked the local geomagnetic field direction with an accuracy of about 15 degrees for almost two years of the mission. Rapid altitude decay during the last month of operation resulted in the transition from the magnetic stabilization to the aerodynamic stabilization of the satellite. The details of the initial tumbling motion after the launch, magnetic stabilization, transition phase prior to the aerodynamic stabilization, and subsequent satellite motion in the aerodynamic stabilization mode are presented.

Evaluation of shimmed DECY-13 MeV Cyclotron Magnet Using H- Beam Tracking Simulation

–Using OPERA3DTM, the magnet poles’ shimming that provide an isochronous magnetic field in DECY-13 cyclotron was designed and calculated. The shimmed magnet poles as designed were placed in the magnet and the distribution of the magnetic field in the magnet axis direction (Bz) was measured in radial ( x and y) directions using 2 probes covering x=0 to 480 mm for one probe and 481 to 960 mm for the other, and y=0 to 960 mm, all were done at z=0 in 9 hours of scanning at 5 mm steps. This paper describes the interpolation and extrapolation to obtain data for magnetic field components (Bx, By,Bz) at 1 mm resolution and at z≠0 as required for beam tracking simulations. The tracking results are used to evaluate the distribution of the shimmed magnetic fields of DECY-13. The program for the interpolation and extrapolation was written and run using a free software Scilab 5.4.1, and tested against OPERA3DTM design data. The beam can reach final energy of 13 MeV when both data was applying in the beam tracking simulation.. However when the measured data was used, the final energy of the beam reached only 3 MeV, meaning that at the place where that energy was reached the magnetic field is no longer is of isochronous and the shimming of the magnetic poles’ must be improved or redesigned to reach the final beam energy of 13 MeV.Key words: isochronous, DECY-13 cyclotron, Scilab 5.4.1, interpolation and extrapolation, beam tracking simulation

A Novel Magnet-Axis-Shifted Hybrid Permanent Magnet Machine for Electric Vehicle Applications

This paper proposes a novel magnet-axis-shifted hybrid permanent magnet (MAS-HPM) machine, which features an asymmetrical magnet arrangement, i.e., low-cost ferrite and high-performance NdFeB magnets, are placed in the two sides of a “▽”-shaped rotor pole. The proposed magnet-axis-shift (MAS) effect can effectively reduce the difference between the optimum current angles for maximizing permanent magnet (PM) and reluctance torques, and hence the torque capability of the machine can be further improved. The topology and operating principle of the proposed MAS-HPM machine are introduced and are compared with the BMW i3 interior permanent magnet (IPM) machine as a benchmark. The electromagnetic characteristics of the two machines are investigated and compared by finite element analysis (FEA), which confirms the effectiveness of the proposed MAS design concept for torque improvement.

Calculating Extrusion Textures of the Alloy Mn-Al-C

The alloy Mn-Al-C (magnetic τ-phase) has a face-centered tetragonal lattice with the superstructure L10 (Shangurov, Gornostyrev, Teitel et al., 1990). The tetragonal crystal axes c (the directions of the easy magnetization) of the grain lattices of the polycrystal permanent magnet must be preferably oriented along the magnet axis. In the present paper the forming of the axial extrusion textures in the alloy Mn-Al-C is investigated theoretically. The texture inhomogeneity is taken into account by solving the boundary value problem of plasticity.