This paper proposes a design of 90 kW concentrated flux synchronous motor (CFSM). A ferrite magnet is used
because of low price compared to rare-earth materials and this spoke type structure of motor can be an alternative
to the interior permanent magnet synchronous motor (IPMSM) using NdFeB. However, a greater size of
ferrite magnet is required to achieve the same torque as NdFeB is used, because the residual induction of ferrite
is approximately one third of NdFeB. Consequently, the spoke type structure is applied to improve the
torque density. In the design process, methods of deciding the stack length, stator diameter, rotor diameter, and
the number of poles and slots are suggested. Series turns per phase are determined by applying back-electromotive
force-inductance map (EL map) in the initial design. A response surface method is applied for the optimization.
Furthermore, a structural analysis is also conducted to confirm the safety at high speed. Finally, test
of CFSM is conducted for the verification.