Design and optimization of fractional slot concentrated winding permanent magnet machines for class IV electric vehicles

The design, optimization and application of a number of surface mounted fractional slot concentrated winding (FSCW) electric machines for application to Class IV electric vehicles have been considered. Four FSCW motors with nominal power ratings of 50, 65, 75 and 100 kW have been designed. The motors were optimized using a novel multi-objective optimization strategy which allows a large numbers of objectives to be considered while ensuring computational efficiency and Pareto optimality. Vehicle simulations were carried out using the optimized motors for some typical drive cycles. The gear ratio of the drive train was optimized for each motor with respect to the drive cycle and the vehicle performances were calculated. The methodology and results presented provide a novel and improved framework for considering the trade-offs between the motor size, gear ratio and vehicle performance for Class IV and other vehicle classes.