Analysis three- and five-phase permanent magnet machines supplying diode bridge rectifiers for small-scale wind generators

In this paper, performance of three- and five-phase permanent magnet generators (PMG) feeding a rectifier system are compared for small-scale wind generator systems. The volume and rated speeds of the two generators are kept equal and determined using FEM 2D. No-load induced voltage, self and mutual inductances and resistance are calculated and used to simulate the performance of the 3-phase and 5-phase generators coupled to a dc link through a diode bridge rectifier. Generator mathematical models are developed and simulated. The simulations show that five-phase system has torque ripple that is a factor of 7 lower than the three-phase system with an almost identical efficiency figure.