Presentations

Magnetic clutches are used in applications where the minimum torque must be transmitted independently from the slip. Unlike the synchronous and eddy current clutches, the hysteresis clutches can operate with synchronous - and asynchronous speed and transfer the minimum torque safety. In this work new functionalities of different magnetic clutches will be introduced, especially the properties of permanently excited hysteresis clutches, the most important influencing factors for dimensioning, as well as the special advantages of using it in hoists.

Comparison of Halbach array against surface mounted permanent magnet arrangement for in-wheel traction motor. It will be consider demagnetisation, physical-airgap and torque capability at continuous and overload operation. It will cover one and three transition Halbach arrays as well as introducing a novel trapezoidal Halbach array to reduce demagnetisation.

This presentation will describe the use of JMAG to assess the demagnetisation risk of a 10 pole permanent magnet motor. JMAG was used with a new post processing analysis to predict the performance of rare earth magnets at a range of currents and to characterise different designs in terms of their risk of demagnetisation.  The 10 pole motor design did not offer sufficient operating margin against demagnetisation. Using the new analysis, a new design with a different pole number was selected that has a much lower demagnetisation risk, and its performance was compared with the original design.  Additional demagnetisation analysis was performed using 3D analysis in JMAG to ensure there is a low risk at the ends of the machine. Test results from a prototype of the new design are compared with simulation.

The automotive sector demands high performance, low cost motors for fulfilling a number of applications. Höganäs AB helps its customers develop solutions utilising a powder metallurgy process, where grains of iron can be compacted and heat treated to provide a net shape product. This approach has a number of benefits but must be carefully considered in order to provide a successful product in a highly competitive market. Single sided permanent magnet axial flux machines can benefit greatly from the use of soft magnetic composites (SMC), where traditional design methods prove difficult in mechanical aspects of their construction. Höganäs AB takes a modular approach to the design, yielding a high performance, low cost, and small volumetric product. Design aspects and considerations in the design are discussed along with Höganäs AB materials readily available in JMAG’s material database.

The vibration due to EM force is the one of the critical issues for NVH of the EV powertrain. The electromagnetic force acting on the motor resonates with the eigenmode of the motor, causing vibration and noise. In order to accurately evaluate this phenomenon, it is necessary to ascertain each frequency and spatial mode in detail regarding the electromagnetic force and eigenmode of the motor. In this presentation, the approach using the correlation analysis with the measured eigen modes is introduced to identify the system stiffness accurately. Also, accurate EM forces can be obtained by detailed EM FEA and 1D control/circuit simulation with the fidelity plant models. Finally, a comparison with the measured acoustic noise proved the simulation captures the vibration due to EM force.