An improved induction machine design procedure for electric vehicle traction

Electric vehicles (EVs) represent one of the most promising technologies for increasing the global energy security and reducing emissions. As one of the most potential candidates for EV traction motor, induction machines (IMs) should be designed to satisfy the traction characteristics rather than the fixed voltage and fixed frequency (FVFF) operation point. In this paper, a new IM modelling method is applied to analyse the machine torque and power characteristics over the whole speed range. Based on the analysis of a conventionally designed FVFF IM, an improved IM design procedure for EV traction is proposed. The design procedure leads to improvements in machine performance with regards to torque and power density and efficiency, especially in field weakening region. Finite-element analysis solutions of the traditional and proposed IM designs are compared.