Flux modulation principles of DC-biased sinusoidal current vernier reluctance machines

摘要

DC-biased sinusoidal current vernier reluctance machines (DC-biased-VRMs) are with a doubly salient structure, and their phase currents contain an alternating current (AC) component and a direct current (DC) component. Hence, their main features are one set of concentrated windings compared with variable flux reluctance machines (VFRMs), low vibration and noise due to smooth current, compared with switched reluctance machines (SRMs), and robust rotor structure. Besides, its achievable high slot fill factor can improve the torque density further. However, the existing DC-biased VRMs, whose stator/rotor slots of 6/4 and 6/8 have high torque ripple. In this paper, based on the flux modulation principles, the torque production mechanism of DC-biased VRMs are analyzed and two slot combinations of 12/8 and 12/10 are proposed. Firstly, the machine topology and inverter main circuit is illustrated. Secondly, the stator armature pole pairs/rotor pole relationship and pole ratio is given. Furthermore, the inductance, optimal current configuration for maximum torque and lowest torque ripple are theoretically analyzed and by the finite element analysis (FEA). Finally, one prototype has been designed and under built, and the experimental results will be then given.