[Objective] Fractional slot concentrated winding (FSCW) has the advantages of high torque density and low copper consumption

but its rich harmonic magnetic field and high proportion of low-order harmonics can cause torque ripple

affecting motor stability. This study focuses on FSCW induction motors. [Methods] Based on the initial rotor position

the expressions for each harmonic magnetic density in the air gap were deduced; the influence of each harmonic magnetic density on the total torque was qualitatively analyzed; and Maxwell variant was applied to calculate the electromagnetic torque of the motor. Secondly

through mathematical analysis and finite element simulation

the effects of the initial rotor position on the harmonic magnetic flux density in the air gap and the electromagnetic torque of the motor were analyzed. Finally

the prototype locked-rotor test was carried out. [Results] The correctness of the theoretical analysis of the magnetic flux density in the air gap and electromagnetic torque of the FSCW induction motor was verified based on theory

simulation

and experiment. [Conclusion] Starting the motor with different rotor initial positions can result in varying electromagnetic torque.