Page - 139 - in Hybrid Electric Vehicles

did not meet the specific requirement has been excluded from the next step of the proposed methodology. The optimization procedure was terminated when for an investigated con- figuration the target was achieved for all the examined driving cycles. The relative results are presented in Table 7. From Tables 5–7, it is initially clear that the proposed approach succeeded in finding optimum and feasible design solutions satisfying all the existing con- straints. Analytically the following can be observed: Quantity Symbol Motor A Motor B Motor C Motor D Motor efficiency (%) η 94.41 94.31 94.97 95.41 Phase current (A) Iph 62.49 69.16 92.41 70.44 Current density (A/mm2) Jc 9.42 9.68 8.76 8.41 Copper losses(W) Pcu 839.81 864.75 722.06 604.61 Core losses (W) Pcore 66.93 69.16 87.75 132.44 Motor total mass (kg) Mtot 14.82 14.36 12.49 14.77 Magnets mass (gr) Mm 713.16 545.09 593.45 628.85 Cogging torque (mNm) Tcog 41.07 50.96 31.05 23.15 Torque ripple (%) Trip 2.1 2.4 3.3 2.4 Torque angle (°) Tang 44.79 45.38 26.62 37.61 Nominal frequency (Hz) f 198.3 240.8 340 425 Power density (kW/kg) Pd 1.03 1.06 1.22 1.03 Table 6. Electromechanical quantities results (at rated condition). Figure 6. The four driving cycles used during the proposed optimization procedure. Design, Optimization and Modelling of High Power Density Direct-Drive Wheel Motor for Light Hybrid Electric Vehicles http://dx.doi.org/10.5772/intechopen.68455 139