Optimisation and Design Performance of a Small-Scale DC Vernier Reluctance Machine for Direct-Drive Wind Generator Drives

The study begins with a proposal to design a small-scale DC Vernier reluctance machine (DC-VRM) for direct-drive wind generator drives. The motivation centres on the increasing need for renewable energy technologies, as well as the quest for non-PM and gearless wind generator drives upon which the DC-VRM is uniquely compatible. A global optimisation is first undertaken based on solutions from 2D finite element modelling (FEM) to produce optimal benchmark designs (OBDs). The OBDs are further evaluated for independent performance improvement of the torque ripple using the simple rotor tooth-pairing technique. The findings show that the torque ripple can be drastically reduced when absolved from the integrated optimisation process. On the average, at 0.8 tooth-paring ratio, the torque ripple reduces by at least by 50 %, with observation of special quid pro quo effects in torque ripple and average torque generation of this machine. Already, 3D FEM simulations have been issued to draw out the end-effect discrepancies, while laboratory validation is still pending.