High-Torque-Density High-Efficiency Flux-Switching PM Machine for Aerospace Applications

Recently, flux-switching permanent magnet (FSPM) machines have been increasingly investigated due to its torque density and fault tolerance. Because of this, they are attractive for aerospace applications where weight, installation spaces, and safety play a critical role. Recent research has investigated a variation of the conventional FSPM machine called the C-core FSPM machine, which offers 40% greater electromagnetic torque, while using half of the magnet mass. This paper proposes a new topology called Halbach-FSPM capable of achieving an electromagnetic torque 20% higher than the C-core FSPM machine, while maintaining machine volume and phase current constant and using no more magnet material than a conventional FSPM machine. First, a physical explanation of the advantages are developed for use in all FSPM machines using Halbach arrays. An analysis and comparison of torque, power and efficiency are made. Further, magnet losses and segmentation applicable to all FSPM topologies are discussed, plus an analysis on magnet usage is given.