Traditionally, electrical machines are classi?ed into d. c. commutator (brushed) machines, induction (asynchronous) machines and synchronous machines. These three types of electrical machines are still regarded in many academic curricula as fundamental types, despite that d. c. brushed machines (except small machines) have been gradually abandoned and PM brushless machines (PMBM) and switched reluctance machines (SRM) have been in mass p- duction and use for at least two decades. Recently, new topologies of high torque density motors, high speed motors, integrated motor drives and special...