Fault tolerant design of fractional slot concentrated winding PM motor for electric traction

This paper deals with the fault tolerant design of an in-wheel 300 W, 350 rpm Surface Mounted Permanent Magnet Synchronous Motor (PMSM) with Fractional-Slot Concentrated Windings (FSCW) for actuator applications. Initially, a preliminary design is conducted with the use of analytical equations taking into account the configuration fault tolerance capability. In a second step, sensitivity analysis is conducted for a wide range of dimension variables and selection of the most advantageous design is accomplished through a composite cost function involving performance and fault tolerance criteria. The proposed geometry is constructed and a good agreement is observed between the simulation and experimental results. To enable fault tolerant operation, a double inverter driving scheme is proposed. The motor characteristics under healthy and faulty operation are also examined and compared.