This paper proposes a novel multi-phase double-winding vernier permanent magnet (DW-VPM) wind power generator applied for hybrid ac/dc microgrid. The key is to employ two sets of windings, namely, ac windings and dc windings in the machine, which serve to produce ac power and dc power for microgrid, respectively. The permanent magnets (PMs) are surface mounted on the rotor, and the stator is designed with open slots. The stator teeth can act as flux modulator for the permeance difference between the stator teeth and the air. Therefore, the field excited by PMs can be effectively modulated. Besides the original harmonic used to induce sinusoidal back electromotive force (EMF) in the ac windings and generate ac power, another low-order harmonic can be generated, which is used to induce square wave EMF in the dc windings and generate dc power through diode-bridge rectifier. Since multi-phase windings can get the square wave EMF more easier, the dc windings are designed with six phases. By using time-stepping finite-element method, the electromagnetic performances of the proposed DW-VPM wind generator are comprehensively investigated and verified.
- AC/DC microgrid
- double winding (DW)
- time-stepping finite-element method (TS-FEM)
- vernier machine