Influence of rotor containment sleeve on high-speed PM generator performance based on multi-physics field analysis

The rotor containment sleeve brings serious deficiencies in heat dissipations of a high-speed machine with surface-mounted magnets while preventing the centrifugal force generated by the high-speed rotation of the rotor from fracturing the permanent magnet (PM). To address the aforementioned issues, this paper explores the influence of rotor containment sleeves on the comprehensive performance of a high-speed PM generator. In this respect, the electromagnetic losses, temperature distribution and rotor strength considering pole fillers under different material fabricated sleeves are compared and analyzed by electromagnetic field, coupled three-dimensional fluid-thermal field and stress field analysis. The numerical results show that the PM with a copper-embedded composite sleeve has a higher margin factor under a high-speed rotation at a high temperature, while the rotor with a carbon fiber sleeve performs better in view of eddy current losses and temperature rises.