Multiphase machine theory and its applications

Compared with their three-phase counterparts, multiphase machines with phase number n ges 5 have many advantages like lower torque pulsation, higher power density, better fault tolerance, etc. Due to these advantages and the increasing demands on high performance and high power adjustable speed drives, the research on multiphase drives has experienced a significant growth since the end of last century. In this paper, after a brief analysis to the MMF and a brief description to the mathematical model, it is revealed the design specialty, the new design freedom and multi-control freedom of multiphase machine. And finally, typical applications of the new design- and control-freedoms are surveyed.