Fault-Tolerant Electrical Machines for Transport Applications

This paper provides an overview of-fault-tolerant electric machine for transport applications. A number of motor failure cases and methods to prevent or minimize their impact on the drive system are considered. The fault tolerance of bearings, stator and rotor windings are both analysed in detail. In addition, finite element simulations of an outer rotor permanent magnet machine with a power of 4.5 kW and rated speed of 12000 rpm have been carried out. To verify the simulation results, an experimental prototype of a 6-phase permanent magnet motor for aircraft fuel pump application was developed. It is shown that the use of 6-phase (and more phases) electrical machines with permanent magnets is more effective than machines with duplex three phase system in terms of fault tolerance and efficiency. In addition, it is shown that the use of bearingless machines with permanent magnets is one of the most promising technologies for providing of fault-tolerance.