Design Process of Traction Motor having Concentrated Non-overlapping Windings

This study deals with the demands of traction motor design process in where not only the application set some design limits but also the control method set its own boundaries. It is a demanding task to design a traction application in where the driving speed varies from low speed up to field weakening area. Permanent Magnet (PM) synchronous reluctance motors are often used in traction applications because of their ability to control the stator flux in the field weakening operation. Reluctance torque is produced due to the inductance difference between the direct and quadrature axes' inductances and the stator current linkage. Power density can be increased by adding interior permanent magnets to the machine. In general, car manufacturers seem to be oriented to use synchronous reluctance torque assisted permanent magnet motors with interior permanent magnets. Rotors with permanent magnets in V-shape have been used in hybrid electric vehicles and traction applications. The efficiency should be reasonable over the wide speed range, although the torque demand can be very challenging. In the low speed area a high torque is needed and therefore the current may achieve high values. At high speed the frequency rises and the voltage will be restricting the power or torque available.