To empower safe, economical and eco-friendly sustainable solution for enhancing oil and gas productivity from deep water reservoirs, new downhole technologies are recommended. Since electric machine plays leading role in the downhole application, it is a squeezing requirement for researchers to design and develop advanced electric machine. The Recent improvement in technology and uses of high-temperature magnets, permanent
magnet flux switching machine (PMFSM) has become one of the appropriate contenders for offshore drilling but fewer designed for downhole due to ambient temperature. Therefore this comprehensive study deals with
the design optimization and performance analysis of outer rotor PMFSM for the downhole application. Preliminary, the basic design parameters needed for machine design are calculated mathematically. Then the
design refinement technique is implemented through deterministic method. Finally, initial and optimized performance of the machine is compared and as a result the output torque is increase from 16.39 Nm to
33.57 Nm while diminishing the cogging torque and PM weight up to 1.77 Nm and 0.79 kg, respectively. Therefore, it is concluded that purposed optimized design is suitable for the downhole application.