The Effect of Slit Skew Angle on the Performance of Axially-Slitted Solid Rotor Induction Motors

Axial slits in solid rotor induction motors (SRIMs) enhance torque production, yet the impact of skewing these slits remains insufficiently explored. This paper presents a finite element analysis (FEA) of an Axially-Slitted SRIM (AS-SRIM) with skew angles from 0° to 60°, evaluated under constant-speed operation. Key performance metrics—including torque, torque-to-current ratio, efficiency, and input current—were assessed alongside the air-gap flux density spectrum, overall flux distribution, and flux-line trajectories. The results indicate that an optimum skew angle not only mitigates space harmonics in the air-gap flux but also improves efficiency and torque-to-current performance. In this study, a 4 kW, 400 V/400 Hz AS-SRIM was analyzed, and the findings provide practical insights for skew angle selection in high-performance solid rotor induction machines.