This paper presents design feasibility study and development of a new hybrid excitation flux switching motor (HEFSM) as a contender for traction drives in hybrid electric vehicles (HEVs). Initially, the motor general construction, the basic working principle and the design concept of the proposed HEFSM are outlined. Then, the initial drive performances of the proposed HEFSM are evaluated based on 2D-FEA, in which the design restrictions, specifications and target performances are similar with conventional interior permanent magnet synchronous motor (IPMSM) used in HEV. Since the initial results fail to achieve the target performances, deterministic design optimization approach is used to treat several design parameters. After several cycles of optimization, the proposed motor makes it possible to obtain the target torque and power of 333 Nm and 123 kW, respectively. In addition, due to definite advantage of robust rotor structure of HEFSM, rotor mechanical stress prediction at maximum speed of 12,400 r/min is much lower than the mechanical stress in conventional IPMSM. Finally, the maximum torque and power density of the final design HEFSM are approximately 11.41 Nm/kg and 5.55 kW/kg, respectively, which is 19.98% and 58.12% more than the torque and power density in existing IPMSM for Lexus RX400h.
 N. Naoe and T. Fukami, “Trial Production of a Hybrid Excitation Type Synchronous Machine,” Proceedings of IEEE International Electric Machines and Drives Con ference, Cambridge, 17-20 June 2001, pp. 545-547. doi:10.1109/IEMDC.2001.939362
 D. Fodorean, A. Djerdir, I. A. Viorel and A. Miraoui, “A Double Excited Synchronous Machine for Direct Drive Application-Design and Prototype Tests,” IEEE Transactions on Energy Conversion, Vol. 22, No. 3, 2007, pp. 656-665. doi:10.1109/TEC.2007.896279
 J. A. Tapia, F. Leonardi and T. A. Lipo, “Consequent Pole Permanent-Magnet Machine with Extended Field Weakening Capability,” IEEE Transactions on Industry Applications, Vol. 39, No. 6, 2003, pp. 1704-1709. doi:10.1109/TIA.2003.818993
 T. Kosaka and N. Matsui, “Hybrid Excitation Machines with Powdered Iron Core for Electrical Traction Drive Applications,” Proceedings of International Conference on Electrical Machines and Systems, Wuhan, China, 17-20 October 2008, pp. 2974-979.
 T. Kosaka, M. Sridharbabu, M. Yamamoto and N. Matsui, “Design Studies of Hybrid Excitation Motor for Main Spindle Drive in Machine Tools,” IEEE Transactions on Industrial Electronics, Vol. 57, No. 11, 2010, pp. 3807-3813. doi:10.1109/TIE.2010.2040560
 Z. Chen, Y. Sun and Y. Yan, “Static Characteristics of A Novel Hybrid Excitation Doubly Salient Machine,” Pro ceedings of the Eight International Conference on Elec trical Machines and Systems, Nanjing, 27-29 September 2005, pp. 718-721.
 K. T. Chau, J. Z. Jiang and W. Yong, “A Novel Stator Doubly Fed Doubly Salient Permanent Magnet Brushless Machine,” IEEE Transactions on Magnetics, Vol. 39, No. 5, 2003, pp. 3001-3003. doi:10.1109/TMAG.2003.816722
 Y. Amara, L. Vido, M. Gabsi, E. Hoang, A. H. Ben Ah med and M. Lecrivain, “Hybrid Excitation Synchronous Machines: Energy-Efficient Solution for Vehicles Pro pulsion,” IEEE Transactions on Vehicular Technology, Vol. 58, No. 5, 2009, pp. 2137-2149. doi:10.1109/TVT.2008.2009306
 D. Fodorean, A. Djerdir, I. A. Viorel and A. Miraoui, “A Double Excited Synchronous Machine for Direct Drive Application-Design and Prototype Tests,” IEEE Transac tions on Energy Conversion, Vol. 22, No. 3, 2007, pp. 656-665. doi:10.1109/TEC.2007.896279
 E. Sulaiman, T. Kosaka and N. Matsui, “Design Improvement and Performance Analysis of 12S-10P Permanent Magnet Flux Switching Machine with Field Excitation Coil,” Journal of Electrical System, Vol. 8, No. 4, 2012, pp. 425-432. doi:10.1109/TIA.2003.818993
 H. Wei, M. Cheng and G. Zhang, “A Novel Hybrid Exci tation Flux-Switching Motor for Hybrid Vehicles,” IEEE Transactions on Magnetics, Vol. 45, No. 10, 2009, pp. 4728-4731. doi:10.1109/TMAG.2009.2022497
 E. Hoang, M. Lecrivain and M. Gabsi, “A New Structure of a Switching Flux Synchronous Polyphased Machine with Hybrid Excitation,” Proceedings of European Con ference on Power Electronics and Applications, Aalborg, 2-5 September 2007, pp. 1-8. doi:10.1109/EPE.2007.4417204
 E. Sulaiman, T. Kosaka and N. Matsui, “Design Optimi zation and Performance of A Novel 6-Slot 5-Pole PMFSM with Hybrid Excitation for Hybrid Electric Ve hicle,” IEEJ Transactions on Industry Applications, Vol. 132, No. 2, 2011, pp. 211-218.
 A. Zulu, B. C. Mecrow and M. Armstrong, “A Wound-Field Three-Phase Flux-Switching Synchronous Motor with All Excitation Sources on The Stator,” IEEE Transactions on Industry Applications, Vol. 46, No. 6, 2010, pp. 2363-2371. doi:10.1109/TIA.2010.2072972
 E. Sulaiman, T. Kosaka and N. Matsui, “High Power Density Design of 6Slot-8Pole Hybrid Excitation Flux Switching Machine for Hybrid Electric Vehicle,” IEEE Transactions on Magnetics, Vol. 47, No. 10, 2011 pp. 4453-4456. doi:10.1109/TMAG.2011.2140315