Maximising the flux-weakening capability of permanent magnet brushless AC machines and drives

Abstract

The behaviour of permanent magnet brushless AC machines, having alternative rotor topologies, viz. surface mounted, inset, interior radial and circumferential magnets, is investigated, when they are designed and operated under the 'infinite' flux-weakening capability condition. The corresponding torque/power-speed characteristics, the demagnetisation withstand capability, the variation of iron losses, and the fault management of the drive and/or machine etc. are analysed.