Design of outer rotor type induction motor having high power density for in-wheel system

In this paper, the optimal design of outer rotor type induction motor having high power density was carried out for electric vehicle traction systems. Because of lower magnetic flux density of induction motor compare to permanent magnet synchronous motor, it is difficult to achieve the high power density. Therefore the Controlled filling (CF) die casting method was proposed and adapted for high density rotor bar. because the CF die casting increase the filling ratio of rotor bar, the secondary resistance of motor is decreased. Hence we can achieve the high output power density. Moreover, the high power density design of induction motor carried out varying with stack height, stator / rotor slot combination, slot shape, lamination, winding pattern, turns and material property of rotor bar. The design and performance of a new type of induction motor capable of extremely high power was described this paper with result of 0.53kw/kg.