A large number of non-dominant pole-pair harmonics are present in fractional slot concentrated winding (FSCW) induction motors, resulting in high torque ripple and core losses. To address this problem, a FSCW doubly-fed induction motor with a 15-slot stator and 18-slot rotor was used to study the torque characteristics and core loss characteristics of this type of motor. Firstly, the structure and working principle of FSCW doubly-fed induction motor were introduced, and the stator current equation under doubly-fed operation was derived. Secondly, the sum of self-inductance and mutual inductance of the first n harmonics of the stator and rotor under a specific pole-slot fit was calculated using the winding function method and turns function method. Then, the electromagnetic torque was theoretically calculated based on the virtual displacement method, and the results were compared and analyzed with the finite element simulation results as well as the experimental measurement results. Finally, the torque characteristics and core loss characteristics under different operating conditions were analyzed, revealing the variation patterns of electromagnetic torque ripple frequency and core losses at different slip rates. Specifically, the torque ripple frequency increased as the slip rate decreased, while core losses decreased with the reduction in slip rate.